Sample records for active volcano mt

  1. New geophysical views of Mt.Melbourne Volcano (East Antarctica)

    NASA Astrophysics Data System (ADS)

    Armadillo, E.; Gambetta, M.; Ferraccioli, F.; Corr, H.; Bozzo, E.

    2009-05-01

    Mt. Melbourne volcano is located along the transition between the Transantarctic Mountains and the West Antarctic Rift System. Recent volcanic activity is suggested by the occurrence of blankets of pyroclastic pumice and scoria fall around the eastern and southern flanks of Mt Melbourne and by pyroclastic layers interbedded with the summit snows. Geothermal activity in the crater area of Mount Melbourne may be linked to the intrusion of dykes within the last 200 years. Geophysical networks suggest that Mount Melbourne is a quiescent volcano, possibly characterised by slow internal dynamics. During the 2002-2003 Italian Antarctic campaign a high-resolution aeromagnetic survey was performed within the TIMM (Tectonics and Interior of Mt. Melbourne area) project. This helicopter-borne survey was flown at low-altitude and in drape-mode configuration (305 m above terrain) with a line separation less than 500 m. Our new high-resolution magnetic maps reveal the largely ice-covered magmatic and tectonic patters in the Mt. Melbourne volcano area. Additionally, in the frame of the UK-Italian ISODYN-WISE project (2005-06), an airborne ice-sounding radar survey was flown. We combine the sub-ice topography with images and models of the interior of Mt. Melbourne volcano, as derived from the high resolution aeromagnetic data and land gravity data. Our new geophysical maps and models also provide a new tool to study the regional setting of the volcano. In particular we re-assess whether there is geophysical evidence for coupling between strike-slip faulting, the Terror Rift, and Mount Melbourne volcano.

  2. ASTER Images Mt. Usu Volcano

    NASA Image and Video Library

    2000-04-26

    On April 3, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra Satellite captured this image of the erupting Mt. Usu volcano in Hokkaido, Japan. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet. This false color infrared image of Mt Usu volcano is dominated by Lake Toya, an ancient volcanic caldera. On the south shore is the active Usu volcano. On Friday, March 31, more than 11,000 people were evacuated by helicopter, truck and boat from the foot of Usu, that began erupting from the northwest flank, shooting debris and plumes of smoke streaked with blue lightning thousands of feet in the air. Although no lava gushed from the mountain, rocks and ash continued to fall after the eruption. The region was shaken by thousands of tremors before the eruption. People said they could taste grit from the ash that was spewed as high as 2,700 meters (8,850 ft) into the sky and fell to coat surrounding towns with ash. "Mount Usu has had seven significant eruptions that we know of, and at no time has it ended quickly with only a small scale eruption," said Yoshio Katsui, a professor at Hokkaido University. This was the seventh major eruption of Mount Usu in the past 300 years. Fifty people died when the volcano erupted in 1822, its worst known eruption. In the image, most of the land is covered by snow. Vegetation, appearing red in the false color composite, can be seen in the agricultural fields, and forests in the mountains. Mt. Usu is crossed by three dark streaks. These are the paths of ash deposits that rained out from eruption plumes two days earlier. The prevailing wind was from the northwest, carrying the ash away from the main city of Date. Ash deposited can be traced on the image as far away as 10 kilometers (16 miles

  3. ASTER Images Mt. Usu Volcano

    NASA Technical Reports Server (NTRS)

    2000-01-01

    On April 3, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra Satellite captured this image of the erupting Mt. Usu volcano in Hokkaido, Japan. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet.

    This false color infrared image of Mt Usu volcano is dominated by Lake Toya, an ancient volcanic caldera. On the south shore is the active Usu volcano. On Friday, March 31, more than 11,000 people were evacuated by helicopter, truck and boat from the foot of Usu, that began erupting from the northwest flank, shooting debris and plumes of smoke streaked with blue lightning thousands of feet in the air. Although no lava gushed from the mountain, rocks and ash continued to fall after the eruption. The region was shaken by thousands of tremors before the eruption. People said they could taste grit from the ash that was spewed as high as 2,700 meters (8,850 ft) into the sky and fell to coat surrounding towns with ash. 'Mount Usu has had seven significant eruptions that we know of, and at no time has it ended quickly with only a small scale eruption,' said Yoshio Katsui, a professor at Hokkaido University. This was the seventh major eruption of Mount Usu in the past 300 years. Fifty people died when the volcano erupted in 1822, its worst known eruption.

    In the image, most of the land is covered by snow. Vegetation, appearing red in the false color composite, can be seen in the agricultural fields, and forests in the mountains. Mt. Usu is crossed by three dark streaks. These are the paths of ash deposits that rained out from eruption plumes two days earlier. The prevailing wind was from the northwest, carrying the ash away from the main city of Date. Ash deposited can be traced on the image as far away as 10 kilometers (16

  4. Full-wave Ambient Noise Tomography of Mt Rainier volcano, USA

    NASA Astrophysics Data System (ADS)

    Flinders, Ashton; Shen, Yang

    2015-04-01

    Mount Rainier towers over the landscape of western Washington (USA), ranking with Fuji-yama in Japan, Mt Pinatubo in the Philippines, and Mt Vesuvius in Italy, as one of the great stratovolcanoes of the world. Notwithstanding its picturesque stature, Mt Rainier is potentially the most devastating stratovolcano in North America, with more than 3.5 million people living beneath is shadow in the Seattle-Tacoma area. The primary hazard posed by the volcano is in the form of highly destructive debris flows (lahars). These lahars form when water and/or melted ice erode away and entrain preexisting volcanic sediment. At Mt Rainier these flows are often initiated by sector collapse of the volcano's hydrothermally rotten flanks and compounded by Mt Rainier's extensive snow and glacial ice coverage. It is therefore imperative to ascertain the extent of the volcano's summit hydrothermal alteration, and determine areas prone to collapse. Despite being one of the sixteen volcanoes globally designated by the International Association of Volcanology and Chemistry of the Earth's Interior as warranting detailed and focused study, Mt Rainier remains enigmatic both in terms of the shallow internal structure and the degree of summit hydrothermal alteration. We image this shallow internal structure and areas of possible summit alteration using ambient noise tomography. Our full waveform forward modeling includes high-resolution topography allowing us to accuratly account for the effects of topography on the propagation of short-period Rayleigh waves. Empirical Green's functions were extracted from 80 stations within 200 km of Mt Rainier, and compared with synthetic greens functions over multiple frequency bands from 2-28 seconds.

  5. Activity at Europe Most Active Volcano Eyed by NASA Spacecraft

    NASA Image and Video Library

    2016-05-27

    Mt. Etna, Sicily, Italy, is Europe most active volcano. In mid-May 2016, Mt. Etna put on a display of lava fountaining, ash clouds and lava flows. Three of the four summit craters were active. NASA Terra spacecraft acquired this image on May 26, 2016.

  6. Stereo Image of Mt. Usu Volcano

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On April 3, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra Satellite captured this image of the erupting Mt. Usu volcano in Hokkaido, Japan. This anaglyph stereo image is of Mt Usu volcano. On Friday, March 31, more than 15,000 people were evacuated by helicopter, truck and boat from the foot of Usu, that began erupting from the northwest flank, shooting debris and plumes of smoke streaked with blue lightning thousands of feet in the air. Although no lava gushed from the mountain, rocks and ash continued to fall after the eruption. The region was shaken by thousands of tremors before the eruption. People said they could taste grit from the ash that was spewed as high as 2,700 meters (8,850 ft) into the sky and fell to coat surrounding towns with ash. A 3-D view can be obtained by looking through stereo glasses, with the blue film through your left eye and red film with your right eye at the same time. North is on your right hand side. For more information, see When Rivers of Rock Flow ASTER web page Image courtesy of MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team

  7. A New Statistical Model for Eruption Forecasting at Open Conduit Volcanoes: an Application to Mt Etna and Kilauea Volcanoes

    NASA Astrophysics Data System (ADS)

    Passarelli, Luigi; Sanso, Bruno; Laura, Sandri; Marzocchi, Warner

    2010-05-01

    eruptions given by our model for Mt Etna volcano flank eruption are published on a internet website and are updated after any change in the eruptive activity.

  8. Snow cover correlation between Mt. Villarrica and Mt. Lliama in Chile

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Cheol; Park, Sung-Hwan; Jung, Hyung-Sup

    2014-11-01

    The Southern Volcanic Zone (SVZ) of Chile consists of many volcanoes, and all of the volcanoes are covered with snow at the top of mountain. Monitoring snow cover variations in these regions can give us a key parameter in order to understand the mechanisms of volcanic activity. In this study, we investigate on the volcanic activity and snow cover interaction from snow cover area mapping, snow-line extraction. The study areas cover Mt. Villarrica and Mt. Llaima, Chile. Both of them are most active volcanos in SVZ. Sixty Landsat TM and Landsat ETM+ images are used for observing snow cover variations of Mt. Villarrica and Mt. Llaima, spanning the 25 years from September 1986 to February 2011. Results show that snow cover area between volcanic activity and non-activity are largely changed from 42.84 km2 to 13.41 km2, temporarily decreased 79% at the Mt. Villarrica and from 28.98 km2 to 3.82 km2, temporarily decreased 87% at the Mt. Villarrica. The snow line elevation of snow cover retreated by approximately 260 m from 1,606m to 1,871 m at the Mt. Villarrica, approximately 266m from 1,741m to 2,007m at the Mt. Llaima. The results show that there are definitely correlations between snow cover and volcanic activity.

  9. Interpretation of Historical Eruptions of Mt. Baekdu Volcano, Korea

    NASA Astrophysics Data System (ADS)

    Yun, S. H.; Cho, E.; Yang, I. S.

    2014-12-01

    This study is performed to find out the eruptive events of the historical period recorded in literature, which have been recognized and regarded as ones from Mt. Baekdusan, and to make volcanological interpretations of the eruptive events. Since the Millennium eruption, more than 31 eruptive events have been discovered, most of which are Plinian eruptions with volcanic ash that dispersed into the regions in the vicinity of the volcano. The minimum volume of erupted materials in 1702 is estimated to be 1.2 km3when calculated with an empirical formula using an isopach line obtained from two points 140 km away from the vent. The 1702 eruption was a paroxysmal one with VEI of 5. The historical record described a deposition of wind-modified fallout ash by movement of hot ash cloud. The 1903 record includes the event of the phreatomagmatic or vulcanian eruption that occurred within the Cheonji caldera lake. Based on the eruption records of the historical period and the 2002 precursor unrest to volcanic eruptions, Mt. Baekdusan has been evaluated and regarded as an active volcano that has the potential to erupt in the future. This research was supported by a grant [NEMA-BAEKDUSAN-2012-1-2] from the Volcanic Disaster Preparedness Research Center sponsored by National Emergency Management Agency of Korea. T

  10. Subsurface Structure Interpretation Beneath of Mt. Pandan Based on Gravity Data

    NASA Astrophysics Data System (ADS)

    Santoso, D.; Wahyudi, E. J.; Alawiyah, S.; Nugraha, A. D.; Widiyantoro, S.; Kadir, W. G. A.; Supendi, P.; Wiyono, S.; Zulkafriza

    2017-04-01

    Mt. Pandan is one of the volcano that state as dormant volcano. On the other hand, Smyth et al. (2008) defined that Mt. Pandan is an active volcano. This volcano is apart a volcanic chain in Java island which is trending east-west along the island. This volcanic chain known as present day volcanic arc. Mt. Wilis is located in the south and it relatively much bigger compare to Mt. Pandan. There were earthquakes activity experienced in the surrounding Mt. Pandan area in the past several years. This event is interesting, because Mt. Pandan is not classify as the active volcano according to the list of volcanoes in Indonesia. On the otherhand Smyth et. al. (2008) mentioned that G. Pandan as modern volcanic which is located in Kendeng Zone of East Java. Gravity measurement around Mt. Pandan area was done in order to understand subsurface structure of Mt. Pandan. Gravity interpretation results shows that there is a low density structure beneath Mt. Pandan. It could be interpreted as existing of magma body below the surface. Some indication of submagmatic activities were found as hot spring and warm ground. Therefore it could be concluded that there is a possibility of magmatic activity below the Mt. Pandan.

  11. Patterns in Seismicity at Mt St Helens and Mt Unzen

    NASA Astrophysics Data System (ADS)

    Lamb, Oliver; De Angelis, Silvio; Lavallee, Yan

    2014-05-01

    Cyclic behaviour on a range of timescales is a well-documented feature of many dome-forming volcanoes. Previous work on Soufrière Hills volcano (Montserrat) and Volcán de Colima (Mexico) revealed broad-scale similarities in behaviour implying the potential to develop general physical models of sub-surface processes [1]. Using volcano-seismic data from Mt St Helens (USA) and Mt Unzen (Japan) this study explores parallels in long-term behaviour of seismicity at two dome-forming systems. Within the last twenty years both systems underwent extended dome-forming episodes accompanied by large Vulcanian explosions or dome collapses. This study uses a suite of quantitative and analytical techniques which can highlight differences or similarities in volcano seismic behaviour, and compare the behaviour to changes in activity during the eruptive episodes. Seismic events were automatically detected and characterized on a single short-period seismometer station located 1.5km from the 2004-2008 vent at Mt St Helens. A total of 714 826 individual events were identified from continuous recording of seismic data from 22 October 2004 to 28 February 2006 (average 60.2 events per hour) using a short-term/long-term average algorithm. An equivalent count will be produced from seismometer recordings over the later stages of the 1991-1995 eruption at MT Unzen. The event count time-series from Mt St Helens is then analysed using Multi-taper Method and the Short-Term Fourier Transform to explore temporal variations in activity. Preliminary analysis of seismicity from Mt St Helens suggests cyclic behaviour of subannual timescale, similar to that described at Volcán de Colima and Soufrière Hills volcano [1]. Frequency Index and waveform correlation tools will be implemented to analyse changes in the frequency content of the seismicity and to explore their relations to different phases of activity at the volcano. A single station approach is used to gain a fine-scale view of variations in

  12. Volcanogenic fluorine in rainwater around active degassing volcanoes: Mt. Etna and Stromboli Island, Italy.

    PubMed

    Bellomo, S; D'Alessandro, W; Longo, M

    2003-01-01

    Many studies have assessed the strong influence of volcanic activity on the surrounding environment. This is particularly true for strong gas emitters such as Mt. Etna and Stromboli volcanoes. Among volcanic gases, fluorine compounds are potentially very harmful. Fluorine cycling through rainwater in the above volcanic areas was studied analysing more than 400 monthly bulk samples. Data indicate that only approximately 1% of fluorine emission through the plume is deposited on the two volcanic areas by meteoric precipitations. Although measured bulk rainwater fluorine fluxes are comparable to and sometimes higher than in heavily polluted areas, their influence on the surrounding vegetation is limited. Only annual crops, in fact, show some damage that could be an effect of fluorine deposition, indicating that long-living endemic plant species or varieties have developed some kind of resistance. Copyright 2002 Elsevier Science B.V.

  13. Erupting Volcano Mount Etna

    NASA Technical Reports Server (NTRS)

    2001-01-01

    An Expedition Two crewmember aboard the International Space Station (ISS) captured this overhead look at the smoke and ash regurgitated from the erupting volcano Mt. Etna on the island of Sicily, Italy. At an elevation of 10,990 feet (3,350 m), the summit of the Mt. Etna volcano, one of the most active and most studied volcanoes in the world, has been active for a half-million years and has erupted hundreds of times in recorded history.

  14. Mt. St. Helens Memories.

    ERIC Educational Resources Information Center

    Sharp, Len

    1992-01-01

    Provides a personal account of one science teacher's participation in a teacher workshop in which teachers learned about volcanic development, types of eruption, geomorphology, plate tectonics, volcano monitoring, and hazards created by volcanoes by examining Mt. St. Helens. Provides a graphic identifying volcanoes active since 1975. (MDH)

  15. Vulnerability of settlements around Mt. Cameroon volcano, Cameroon

    NASA Astrophysics Data System (ADS)

    Zogning, Appolinaire; Spinetti, Claudia; Ngouanet, Chretien; Tchoudam, David; Kouokam, Emmanuel; Thierry, Pierre; Bignami, Christian; Fabrizia Buongiorno, Maria; Ilaria Pannaccione Apa, Maria

    2010-05-01

    Located at the bottom of the Gulf of Guinea, Cameroon is exposed to a large variety of natural hazards, including volcanism. Most of the hazard are concentrated around the active volcano Mt. Cameroon which combines effusive and explosive types of activity. The threatened stakes are numerous and different exposed: people, settlements, industrial plantations, petrol refinery and many other factories and infrastructures. Until 2005, no risk management plans has been available. In 2006, the French Embassy in Cameroon, within the framework of a financial convention between Cameroon and France, put in place the GRINP (Management of Natural Risks and Civil Protection) project whose objective was to reinforce the capacity of Cameroon's civil protection department and thus, contribute to the improvement of the security of the population faced with catastrophes. The objective was to realize a Risk Prevention Plan at a local council scale, and taking into consideration the specific natural risks of each zone. The general objective of the RPP was to clearly draw land use maps for risks zones, showing the overlay of stakes with risk of different intensities. In 2008 European Commission funded the Mia-Vita project (Mitigating and Assessing Volcanic Impacts on Terrain and human Activities). The aim of the project is to improve the crisis management capabilities based on monitoring and early warning systems and secure communications; reduction of people's vulnerability and development of recovering capabilities after an event occurs for both local communities and ecological systems. Keyword: natural hazards, Mt. Cameroon, vulnerability, risk prevention plan

  16. Detecting hidden volcanic explosions from Mt. Cleveland Volcano, Alaska with infrasound and ground-couples airwaves

    USGS Publications Warehouse

    De Angelis, Slivio; Fee, David; Haney, Matthew; Schneider, David

    2012-01-01

    In Alaska, where many active volcanoes exist without ground-based instrumentation, the use of techniques suitable for distant monitoring is pivotal. In this study we report regional-scale seismic and infrasound observations of volcanic activity at Mt. Cleveland between December 2011 and August 2012. During this period, twenty explosions were detected by infrasound sensors as far away as 1827 km from the active vent, and ground-coupled acoustic waves were recorded at seismic stations across the Aleutian Arc. Several events resulting from the explosive disruption of small lava domes within the summit crater were confirmed by analysis of satellite remote sensing data. However, many explosions eluded initial, automated, analyses of satellite data due to poor weather conditions. Infrasound and seismic monitoring provided effective means for detecting these hidden events. We present results from the implementation of automatic infrasound and seismo-acoustic eruption detection algorithms, and review the challenges of real-time volcano monitoring operations in remote regions. We also model acoustic propagation in the Northern Pacific, showing how tropospheric ducting effects allow infrasound to travel long distances across the Aleutian Arc. The successful results of our investigation provide motivation for expanded efforts in infrasound monitoring across the Aleutians and contributes to our knowledge of the number and style of vulcanian eruptions at Mt. Cleveland.

  17. Seismic Activity Related to the 2002-2003 Mt. Etna Volcano Eruption (Italy): Fault Plane Solutions and Stress Tensor Computation

    NASA Astrophysics Data System (ADS)

    Barberi, G.; Cammarata, L.; Cocina, O.; Maiolino, V.; Musumeci, C.; Privitera, E.

    2003-04-01

    Late on the night of October 26, 2002, a bi-lateral eruption started on both the eastern and the southeastern flanks of Mt. Etna. The opening of the eruptive fracture system on the NE sector and the reactivation of the 2001 fracture system, on the S sector, were accompanied by a strong seismic swarm recorded between October 26 and 28 and by sharp increase of volcanic tremor amplitude. After this initial phase, on October 29 another seismogenetic zone became active in the SE sector of the volcano. At present (January 2003) the eruption is still in evolution. During the whole period a total of 862 earthquakes (Md≫1) was recorded by the local permanent seismic network run by INGV - Sezione di Catania. The maximum magnitude observed was Md=4.4. We focus our attention on 55 earthquakes with magnitude Md≫ 3.0. The dataset consists of accurate digital pickings of P- and S-phases including first-motion polarities. Firstly earthquakes were located using a 1D velocity model (Hirn et alii, 1991), then events were relocated by using two different 3D velocity models (Aloisi et alii, 2002; Patane et alii, 2002). Results indicate that most of earthquakes are located to the east of the Summit Craters and to northeast of them. Fault plane solutions (FPS) obtained show prevalent strike-slip rupture mechanisms. The suitable FPSs were considered for the application of Gephart and Forsyth`s algorithm in order to evaluate seismic stress field characteristics. Taking into account the preliminary results we propose a kinematic model of the eastern flank eastward movement in response of the intrusion processes in the central part of the volcano. References Aloisi M., Cocina O., Neri G., Orecchio B., Privitera E. (2002). Seismic tomography of the crust underneath the Etna volcano, Sicily. Physics of the Earth and Planetary Interiors 4154, pp. 1-17 Hirn A., Nercessian A., Sapin M., Ferrucci F., Wittlinger G. (1991). Seismic heterogeneity of Mt. Etna: structure and activity. Geophys. J

  18. Probabilistic Reasoning Over Seismic Time Series: Volcano Monitoring by Hidden Markov Models at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Cassisi, Carmelo; Prestifilippo, Michele; Cannata, Andrea; Montalto, Placido; Patanè, Domenico; Privitera, Eugenio

    2016-07-01

    From January 2011 to December 2015, Mt. Etna was mainly characterized by a cyclic eruptive behavior with more than 40 lava fountains from New South-East Crater. Using the RMS (Root Mean Square) of the seismic signal recorded by stations close to the summit area, an automatic recognition of the different states of volcanic activity (QUIET, PRE-FOUNTAIN, FOUNTAIN, POST-FOUNTAIN) has been applied for monitoring purposes. Since values of the RMS time series calculated on the seismic signal are generated from a stochastic process, we can try to model the system generating its sampled values, assumed to be a Markov process, using Hidden Markov Models (HMMs). HMMs analysis seeks to recover the sequence of hidden states from the observations. In our framework, observations are characters generated by the Symbolic Aggregate approXimation (SAX) technique, which maps RMS time series values with symbols of a pre-defined alphabet. The main advantages of the proposed framework, based on HMMs and SAX, with respect to other automatic systems applied on seismic signals at Mt. Etna, are the use of multiple stations and static thresholds to well characterize the volcano states. Its application on a wide seismic dataset of Etna volcano shows the possibility to guess the volcano states. The experimental results show that, in most of the cases, we detected lava fountains in advance.

  19. Monitoring Seismo-volcanic and Infrasonic Signals at Volcanoes: Mt. Etna Case Study

    NASA Astrophysics Data System (ADS)

    Cannata, Andrea; Di Grazia, Giuseppe; Aliotta, Marco; Cassisi, Carmelo; Montalto, Placido; Patanè, Domenico

    2013-11-01

    Volcanoes generate a broad range of seismo-volcanic and infrasonic signals, whose features and variations are often closely related to volcanic activity. The study of these signals is hence very useful in the monitoring and investigation of volcano dynamics. The analysis of seismo-volcanic and infrasonic signals requires specifically developed techniques due to their unique characteristics, which are generally quite distinct compared with tectonic and volcano-tectonic earthquakes. In this work, we describe analysis methods used to detect and locate seismo-volcanic and infrasonic signals at Mt. Etna. Volcanic tremor sources are located using a method based on spatial seismic amplitude distribution, assuming propagation in a homogeneous medium. The tremor source is found by calculating the goodness of the linear regression fit ( R 2) of the log-linearized equation of the seismic amplitude decay with distance. The location method for long-period events is based on the joint computation of semblance and R 2 values, and the location method of very long-period events is based on the application of radial semblance. Infrasonic events and tremor are located by semblance-brightness- and semblance-based methods, respectively. The techniques described here can also be applied to other volcanoes and do not require particular network geometries (such as arrays) but rather simple sparse networks. Using the source locations of all the considered signals, we were able to reconstruct the shallow plumbing system (above sea level) during 2011.

  20. The tephrostratigraphy of Mt. Berlin volcano, Antarctica: Integrating blue ice tephra and ice core tephra records

    NASA Astrophysics Data System (ADS)

    Iverson, N. A.; Dunbar, N. W.; McIntosh, W. C.; Kurbatov, A.

    2016-12-01

    Reconstructing volcanic activity in Antarctica is difficult because of the limited outcrop exposure. However, ice is an excellent medium for sampling tephra, allowing for a more complete eruptive record than can be found in other depositional environments. Furthermore, because of low ambient temperature, glass shards trapped in ice remain unaltered and unhydrated. Mt. Berlin is an ice covered volcano in Marie Byrd Land, Antarctica, and, because of heavy glaciation, eruptive records on the volcano itself are sparse. Here, we present the integration of two different records of Mt. Berlin volcanism: the blue ice record found at Mt. Moulton (Dunbar et al., 2008) and the ice core record from the WAIS Divide ice core. Tephra from Mt. Berlin are also found in other ice and marine core records, and these have been correlated and integrated into the combined volcanic record. The Mt. Moulton blue ice area is located 30 km from Mt. Berlin and hosts a fabulous tephra record spanning the last 500 ka. A total of 36 tephra from Mt. Berlin were sampled in stratigraphic order and nine were directly dated by 40Ar/39Ar dating method. Twenty five tephra from WAIS Divide have been analyzed and are geochemically similar to Mt. Berlin with ice core ages dating back to 70 ka. The two tephra records were integrated using their respective timescales. In locations where the Mt. Moulton record does not have precise chronology, the δ18O records from Mt. Moulton (Popp, 2008) and WAIS (WAIS, 2015) were used to integrate the stratigraphy. In total 61 tephra from both ice sections provide an excellent record of the magmatic evolution of Mt. Berlin over the past 500 ka. EMP analyses on glass shards show a gradual change in Fe and S over time. Most of the other major elements remain relatively unchanged. The trend in Fe and S could be produced by progressive tapping of a single, stratified magma chamber, but the long duration of volcanism makes this unlikely. We instead favor small batches of

  1. GlobVolcano pre-operational services for global monitoring active volcanoes

    NASA Astrophysics Data System (ADS)

    Tampellini, Lucia; Ratti, Raffaella; Borgström, Sven; Seifert, Frank Martin; Peltier, Aline; Kaminski, Edouard; Bianchi, Marco; Branson, Wendy; Ferrucci, Fabrizio; Hirn, Barbara; van der Voet, Paul; van Geffen, J.

    2010-05-01

    ), Stromboli and Volcano (Italy), Hilo (Hawai), Mt. St. Helens (United States), CTM (Coherent Target Monitoring): Cumbre Vieja (La Palma) To generate products either Envisat ASAR, Radarsat 1or ALOS PALSAR data have been used. Surface Thermal Anomalies Volcanic hot-spots detection, radiant flux and effusion rate (where applicable) calculation of high temperature surface thermal anomalies such as active lava flow, strombolian activity, lava dome, pyroclastic flow and lava lake can be performed through MODIS (Terra / Aqua) MIR and TIR channels, or ASTER (Terra), HRVIR/HRGT (SPOT4/5) and Landsat family SWIR channels analysis. ASTER and Landsat TIR channels allow relative radiant flux calculation of low temperature anomalies such as lava and pyroclastic flow cooling, crater lake and low temperature fumarolic fields. MODIS, ASTER and SPOT data are processed to detect and measure the following volcanic surface phenomena: Effusive activity Piton de la Fournaise (Reunion Island); Mt Etna (Italy). Lava dome growths, collapses and related pyroclastic flows Soufrière Hills (Montserrat); Arenal - (Costa Rica). Permanent crater lake and ephemeral lava lake Karthala (Comores Islands). Strombolian activity Stromboli (Italy). Low temperature fumarolic fields Nisyros (Greece), Vulcano (Italy), Mauna Loa (Hawaii). Volcanic Emission The Volcanic Emission Service is provided to the users by a link to GSE-PROMOTE - Support to Aviation Control Service (SACS). The aim of the service is to deliver in near-real-time data derived from satellite measurements regarding SO2 emissions (SO2 vertical column density - Dobson Unit [DU]) possibly related to volcanic eruptions and to track the ash injected into the atmosphere during a volcanic eruption. SO2 measurements are derived from different satellite instruments, such as SCIAMACHY, OMI and GOME-2. The tracking of volcanic ash is accomplished by using SEVIRI-MSG data and, in particular, the following channels VIS 0.6 and IR 3.9, and along with IR8.7, IR 10

  2. Pattern Matching for Volcano Status Assessment: what monitoring data alone can say about Mt. Etna activity

    NASA Astrophysics Data System (ADS)

    Cannavo, F.; Cannata, A.; Cassisi, C.

    2017-12-01

    The importance of assessing the ongoing status of active volcanoes is crucial not only for exposures to the local population but due to possible presence of tephra also for airline traffic. Adequately monitoring of active volcanoes, hence, plays a key role for civil protection purposes. In last decades, in order to properly monitor possible threats, continuous measuring networks have been designed and deployed on most of potentially hazardous volcanos. Nevertheless, at the present, volcano real-time surveillance is basically delegated to one or more human experts in volcanology, who interpret data coming from different kind of monitoring networks using their experience and non-measurable information (e.g. information from the field) to infer the volcano status. In some cases, raw data are used in some models to obtain more clues on the ongoing activity. In the last decades, with the development of volcano monitoring networks, huge amount of data of different geophysical, geochemical and volcanological types have been collected and stored in large databases. Having such big data sets with many examples of volcanic activity allows us to study volcano monitoring from a machine learning perspective. Thus, exploiting opportunities offered by the abundance of volcano monitoring time-series data we can try to address the following questions: Are the monitored parameters sufficient to discriminate the volcano status? Is it possible to infer/distinguish the volcano status only from the multivariate patterns of measurements? Are all the kind of measurements in the pattern equally useful for status assessment? How accurate would be an automatic system of status inference based only on pattern recognition of data? Here we present preliminary results of the data analysis we performed on a set of data and activity covering the period 2011-2017 at Mount Etna (Italy). In the considered period, we had 52 events of lava fountaining and long periods of Strombolian activity. We

  3. Special issue “The phreatic eruption of Mt. Ontake volcano in 2014”

    USGS Publications Warehouse

    Yamaoka, Koshun; Geshi, Nobuo; Hashimoto, Tasheki; Ingebritsen, Steven E.; Oikawa, Teruki

    2016-01-01

    Mt. Ontake volcano erupted at 11:52 on September 27, 2014, claiming the lives of at least 58 hikers. This eruption was the worst volcanic disaster in Japan since the 1926 phreatic eruption of Mt. Tokachidake claimed 144 lives (Table 1). The timing of the eruption contributed greatly to the heavy death toll: near midday, when many hikers were near the summit, and during a weekend of clear weather conditions following several rainy weekends. The importance of this timing is reflected by the fact that a somewhat larger eruption of Mt. Ontake in 1979 resulted in injuries but no deaths. In 2014, immediate precursors were detected with seismometers and tiltmeters about 10 min before the eruption, but the eruption started before a warning was issued.

  4. Geophysical and geochemical methods applied to investigate fissure-related hydrothermal systems on the summit area of Mt. Etna volcano (Italy)

    NASA Astrophysics Data System (ADS)

    Maucourant, Samuel; Giammanco, Salvatore; Greco, Filippo; Dorizon, Sophie; Del Negro, Ciro

    2014-06-01

    A multidisciplinary approach integrating self-potential, soil temperature, heat flux, CO2 efflux and gravity gradiometry signals was used to investigate a relatively small fissure-related hydrothermal system near the summit of Mt. Etna volcano (Italy). Measurements were performed through two different surveys carried out at the beginning and at the end of July 2009, right after the end of the long-lived 2008-2009 flank eruption and in coincidence with an increase in diffuse flank degassing related to a reactivation of the volcano, leading to the opening of a new summit vent (NSEC). The main goal was to use a multidisciplinary approach to the detection of hidden fractures in an area of evident near-surface hydrothermal activity. Despite the different methodologies used and the different geometry of the sampling grid between the surveys, all parameters concurred in confirming that the study area is crossed by faults related with the main fracture systems of the south flank of the volcano, where a continuous hydrothermal circulation is established. Results also highlighted that hydrothermal activity in this area changed both in space and in time. These changes were a clear response to variations in the magmatic system, notably to migration of magma at various depth within the main feeder system of the volcano. The results suggest that this specific area, initially chosen as the optimal test-site for the proposed approach, can be useful in order to get information on the potential reactivation of the summit craters of Mt. Etna.

  5. Monitoring eruption activity using temporal stress changes at Mount Ontake volcano.

    PubMed

    Terakawa, Toshiko; Kato, Aitaro; Yamanaka, Yoshiko; Maeda, Yuta; Horikawa, Shinichiro; Matsuhiro, Kenjiro; Okuda, Takashi

    2016-02-19

    Volcanic activity is often accompanied by many small earthquakes. Earthquake focal mechanisms represent the fault orientation and slip direction, which are influenced by the stress field. Focal mechanisms of volcano-tectonic earthquakes provide information on the state of volcanoes via stresses. Here we demonstrate that quantitative evaluation of temporal stress changes beneath Mt. Ontake, Japan, using the misfit angles of focal mechanism solutions to the regional stress field, is effective for eruption monitoring. The moving average of misfit angles indicates that during the precursory period the local stress field beneath Mt. Ontake was deviated from the regional stress field, presumably by stress perturbations caused by the inflation of magmatic/hydrothermal fluids, which was removed immediately after the expulsion of volcanic ejecta. The deviation of the local stress field can be an indicator of increases in volcanic activity. The proposed method may contribute to the mitigation of volcanic hazards.

  6. Monitoring eruption activity using temporal stress changes at Mount Ontake volcano

    PubMed Central

    Terakawa, Toshiko; Kato, Aitaro; Yamanaka, Yoshiko; Maeda, Yuta; Horikawa, Shinichiro; Matsuhiro, Kenjiro; Okuda, Takashi

    2016-01-01

    Volcanic activity is often accompanied by many small earthquakes. Earthquake focal mechanisms represent the fault orientation and slip direction, which are influenced by the stress field. Focal mechanisms of volcano-tectonic earthquakes provide information on the state of volcanoes via stresses. Here we demonstrate that quantitative evaluation of temporal stress changes beneath Mt. Ontake, Japan, using the misfit angles of focal mechanism solutions to the regional stress field, is effective for eruption monitoring. The moving average of misfit angles indicates that during the precursory period the local stress field beneath Mt. Ontake was deviated from the regional stress field, presumably by stress perturbations caused by the inflation of magmatic/hydrothermal fluids, which was removed immediately after the expulsion of volcanic ejecta. The deviation of the local stress field can be an indicator of increases in volcanic activity. The proposed method may contribute to the mitigation of volcanic hazards. PMID:26892716

  7. Erupting Volcano Mount Etna

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Expedition Five crew members aboard the International Space Station (ISS) captured this overhead look at the smoke and ash regurgitated from the erupting volcano Mt. Etna on the island of Sicily, Italy in October 2002. Triggered by a series of earthquakes on October 27, 2002, this eruption was one of Etna's most vigorous in years. This image shows the ash plume curving out toward the horizon. The lighter-colored plumes down slope and north of the summit seen in this frame are produced by forest fires set by flowing lava. At an elevation of 10,990 feet (3,350 m), the summit of the Mt. Etna volcano, one of the most active and most studied volcanoes in the world, has been active for a half-million years and has erupted hundreds of times in recorded history.

  8. Nitrogen multitemporal monitoring through mosses in urban areas affected by mud volcanoes around Mt. Etna, Italy.

    PubMed

    Bonanno, Giuseppe

    2013-10-01

    Nitrogen emissions were assessed by using mosses as bioindicators in a densely inhabited area affected by mud volcanoes. Such volcanoes, locally called Salinelle, are phenomena that occur around Mt. Etna (Sicily, Italy), and are interpreted as the surface outflow of a hydrothermal system located below Mt. Etna, which releases sedimentary fluids (hydrocarbons and Na-Cl brines) along with magmatic gases (mainly CO2 and He). To date, N emissions from such mud volcanoes have been only quantitatively assessed, and no biomonitoring campaigns are reported about the cumulative effects of these emissions. This study analyzed N concentrations in moss, water and soil samples, collected in a 4-year monitoring campaign. The bryophyte Bryum argenteum, a species widely adopted in surveys of atmospheric pollution, was used as a biological indicator. N concentrations in biomonitors showed relatively low values in the study sites. However, the results of this study suggest that N emissions from Salinelle may have an impact on surrounding ecosystems because N values in moss and water showed a significant correlation. N oxides, in particular, contribute to acidification of ecosystems, thus multitemporal biomonitoring is recommended, especially in those areas where N emitting sources are anthropogenic and natural.

  9. Mt. Etna: rationale and implementation of a Supersite

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe

    2017-04-01

    Mt. Etna is one of the most active volcanoes on Earth and, in the past few decades, has erupted virtually every year. The volcanism of Mt. Etna results from the interaction between magma ascent in the rather complex plumbing feeding system and the local tectonic regime controlled by the volcano edifice's eastern flank instability, whose driving conditions (e.g., structural setting, tectonic forces) and cause-effect relationships are not yet completely understood. At the surface, the combination of the two factors produces eruptions that might consist of either strongly explosive (e.g., 2002; 2011) and produce volcanic ash plumes likely to disrupt air traffic for hours to weeks (e.g., 5 January 2012), including powerful summit paroxysms in the 2012-2013 time span or lava flows capable of invading the populated sectors, that can threat human property and vital infrastructures. Mt. Etna presents many characteristics that make it prone to be a Geohazard Supersite. The volcano consists of an open-vent system characterised by continuous degassing from the volcano summit craters and frequent eruptive summit and flank eruptions. Eruptions can be of different kinds passing from violent short-lasting explosive events to long-lasting lava output, thus producing different kinds of impacts on the surrounding environment, and especially on the large number of people living around the volcano foot. Over time, the frequency and variety of Mt. Etna's eruptive activity have made the volcano one of the most well-studied and monitored worldwide. At Mt. Etna volcanic activity produces a wide spectrum of signals, spanning from seismic and geodetic to geochemical and radiometric signals, which are tracked in continuous and in real-and quasi-real time by the automatic multi-disciplinary monitoring systems deployed by INGV. The huge amount of ground-based collected data sets enforces the vision of Mt. Etna supersite as a Geohazard Supersite where applying the overarching criteria of the

  10. Assessment of pre-crisis and syn-crisis seismic hazard at Campi Flegrei and Mt. Vesuvius volcanoes, Campania, southern Italy

    NASA Astrophysics Data System (ADS)

    Convertito, Vincenzo; Zollo, Aldo

    2011-08-01

    In this study, we address the issue of short-term to medium-term probabilistic seismic hazard analysis for two volcanic areas, Campi Flegrei caldera and Mt. Vesuvius in the Campania region of southern Italy. Two different phases of the volcanic activity are considered. The first, which we term the pre-crisis phase, concerns the present quiescent state of the volcanoes that is characterized by low-to-moderate seismicity. The second phase, syn-crisis, concerns the unrest phase that can potentially lead to eruption. For the Campi Flegrei case study, we analyzed the pattern of seismicity during the 1982-1984 ground uplift episode (bradyseism). For Mt. Vesuvius, two different time-evolutionary models for seismicity were adopted, corresponding to different ways in which the volcano might erupt. We performed a site-specific analysis, linked with the hazard map, to investigate the effects of input parameters, in terms of source geometry, mean activity rate, periods of data collection, and return periods, for the syn-crisis phase. The analysis in the present study of the pre-crisis phase allowed a comparison of the results of probabilistic seismic hazard analysis for the two study areas with those provided in the Italian national hazard map. For the Mt. Vesuvius area in particular, the results show that the hazard can be greater than that reported in the national hazard map when information at a local scale is used. For the syn-crisis phase, the main result is that the data recorded during the early months of the unrest phase are substantially representative of the seismic hazard during the whole duration of the crisis.

  11. Mt, St. Helens, Mt. Adams, and Mt. Rainier, WA, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This view of Mt. St. Helens (46.5N, 122.0W), taken 12 years after the volcanic eruption on 18 May 1980, in which the top 1300 ft. of the 9,677 ft. mountain was blown away, shows the rapid vegetation recovery within the blast area. Many fir trees have grown to heights of 20 ft. within the 150 square mile devastated area. Mt. Adams, an extinct volcano is just to the west and Mt. Rainier is to the north. Checkerboard logging can be seen throughout.

  12. Mt. Etna, Italy

    NASA Image and Video Library

    2002-11-07

    On Sunday, November 3, 2002, Mt. Etna's ash-laden plume was imaged by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. The plume is seen blowing toward the south-southeast, over the city and airport of Catania, Sicily. The previous day, the plume was blowing toward the northwest, and posed no hazard to Catania. The current eruption of Mt. Etna, Europe's most active volcano, began on October 27. These sorts of observations from space may help civil defense authorities mitigate hazards from active eruptions. Space data may also help scientists evaluate the behavior and effects volcanic eruptions have on our global climate system. http://photojournal.jpl.nasa.gov/catalog/PIA03881

  13. Mt. St. Helens

    NASA Image and Video Library

    2001-10-22

    This 3-D anaglyph image of Mt. St. Helens volcano combines the nadir-looking and back-looking band 3 images of ASTER. To view the image in stereo, you will need blue-red glasses. Make sure to look through the red lens with your left eye. This ASTER image of Mt. St. Helens volcano in Washington was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The image is centered at 46.2 degrees north latitude, 122.2 degrees west longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11160

  14. The recent pumice eruptions of Mt. Pelée volcano, Martinique. Part I: Depositional sequences, description of pumiceous deposits

    NASA Astrophysics Data System (ADS)

    Traineau, Hervé; Westercamp, Denis; Bardintzeff, Jacques-Marie; Miskovsky, Jean-Claude

    1989-08-01

    Mount Pelée is one of the most active volcanoes of the Lesser Antilles arc, with more than twenty eruptions over the last 5000 years. Both nuée ardente-type eruptions, which are well known, and pumice eruptions, although little known, are very common in the stratigraphic record. The four younger pumice eruptions, P4 (2440 y.B.P.), P3 (2010 y.B.P.), P2 (1670 y.B.P.) and P1 (650 y.B.P.) can be used to reconstruct the eruption sequences. The various pumiceous deposits can be described as fine lithic ash layer, Plinian fall deposits, pumice and ash flow deposits with associated ash cloud fall deposits, and pumice surge deposits. Three kinds of depositional sequences have been defined. The distinctions between them are based on the occurrence of an initial Plinian phase and the generation of intraflow pyroclastic surges. The pumice eruptions of Mt. Pelée are small in intensity and magnitude, as expressed by the dispersal of their products and by the total mass of erupted material which is estimated to be less than 1 km 3 in each case. The pumice fall deposits have dispersal characteristics of small Plinian eruptions, close to the sub-Plinian type. Nevertheless, the probability of an occurrence of a new pumice eruption at Mt. Pelée is high, and the widespread distribution of pumice deposits around the volcano suggests that such an eruption is a major volcanic risk during the present stage of activity.

  15. Application of photogrammetry to the study of volcano-glacier interactions on Mount Wrangell, Alaska

    NASA Technical Reports Server (NTRS)

    Benson, C. S.; Follett, A. B.

    1986-01-01

    Most Alaskan volcanoes are glacier covered and provide excellent opportunities to study interactions between glaciers and volcanoes. The present paper is concerned with such a study, taking into account the Mt. Wrangell (4317 m) which is the northernmost active volcano (solfatara activity) on the Pacific Rim (62 deg N; 144 deg W). While the first photographs on the summit of Mt. Wrangell were published more than 75 years ago, research there began in 1953 and 1954. Satellite images reveal activity at the summit of Mt. Wrangell. However, the resolution is not sufficient for conducting important measurements regarding ice volume losses. For this reason, vertical aerial photographs of the summit were obtained, and a field trip to the summit was conducted. Aspects of photogrammetry are discussed, taking into account questions of ground control, aerial photography, topographic mapping, digital cross sections, and orthophotos.

  16. Attaining high-resolution eruptive histories for active arc volcanoes with argon geochronology

    NASA Astrophysics Data System (ADS)

    Calvert, A. T.

    2012-04-01

    Geochronology of active arc volcanoes commonly illuminates eruptive behavior over tens to hundreds of thousands of years, lengthy periods of repose punctuated by short eruptive episodes, and spatial and compositional changes with time. Despite the >1 Gyr half-life of 40K, argon geochronology is an exceptional tool for characterizing Pleistocene to Holocene eruptive histories and for placing constraints on models of eruptive behavior. Reliable 40Ar/39Ar ages of calc-alkaline arc rocks with rigorously derived errors small enough (± 500 to 3,000 years) to constrain eruptive histories are attainable using careful procedures. Sample selection and analytical work in concert with geologic mapping and stratigraphic studies are essential for determining reliable eruptive histories. Preparation, irradiation and spectrometric techniques have all been optimized to produce reliable, high-precision results. Examples of Cascade and Alaska/Aleutian eruptive histories illustrating duration of activity from single centers, eruptive episodicity, and spatial and compositional changes with time will be presented: (1) Mt. Shasta, the largest Cascade stratovolcano, has a 700,000-year history (Calvert and Christiansen, 2011 Fall AGU). A similar sized and composition volcano (Rainbow Mountain) on the Cascade axis was active 1200-950 ka. The eruptive center then jumped west 15 km to the south flank of the present Mt. Shasta and produced a stratovolcano from 700-450 ka likely rivaling today's Mt. Shasta. The NW portion of that edifice failed in an enormous (>30 km3) debris avalanche. Vents near today's active summit erupted 300-135 ka, then 60-15 ka. A voluminous, but short-lived eruptive sequence occurred at 11 ka, including a summit explosion producing a subplinian plume, followed by >60 km3 andesite-dacite Shastina domes and flows, then by the flank dacite Black Butte dome. Holocene domes and flows subsequently rebuilt the summit and flowed to the north and east. (2) Mt. Veniaminof on

  17. Locating the depth of magma supply for volcanic eruptions, insights from Mt. Cameroon.

    PubMed

    Geiger, Harri; Barker, Abigail K; Troll, Valentin R

    2016-10-07

    Mt. Cameroon is one of the most active volcanoes in Africa and poses a possible threat to about half a million people in the area, yet knowledge of the volcano's underlying magma supply system is sparse. To characterize Mt. Cameroon's magma plumbing system, we employed mineral-melt equilibrium thermobarometry on the products of the volcano's two most recent eruptions of 1999 and 2000. Our results suggest pre-eruptive magma storage between 20 and 39 km beneath Mt. Cameroon, which corresponds to the Moho level and below. Additionally, the 1999 eruption products reveal several shallow magma pockets between 3 and 12 km depth, which are not detected in the 2000 lavas. This implies that small-volume magma batches actively migrate through the plumbing system during repose intervals. Evolving and migrating magma parcels potentially cause temporary unrest and short-lived explosive outbursts, and may be remobilized during major eruptions that are fed from sub-Moho magma reservoirs.

  18. TOMO-ETNA MED-SUV.ISES an active seismic and passive seismic experiment at Mt. Etna volcano. An integrated marine and onland geophysical survey.

    NASA Astrophysics Data System (ADS)

    Ibáñez, Jesus. M.; Patane, Domenico; Puglisi, Guisseppe; Zuccarello, Lucciano; Bianco, Francesca; Luehr, Birger; Diaz-Moreno, Alejandro; Prudencio, Janire; Koulakov, Ivan; Del Pezzo, Edoardo; Cocina, Ornella; Coltelli, Mauro; Scarfi, Lucciano; De Gori, Pascuale; Carrion, Francisco

    2014-05-01

    An active seismic experiment to study the internal structure of Etna Volcano is going to carried out on Sicily and Aeolian islands. The main objective of the TOMO-ETNA MED-SUV.ISES experiment, beginning in summer 2014, is to perform a high resolution seismic tomography, in velocity and attenuation, in Southern Italy, by using active and passive seismic data, in an area encompassing outstanding volcanoes as Mt. Etna, and Aeolian volcanoes. The achievement of this objective is based on the integration and sharing of the in-situ marine and land experiments and observations and on the implementation of new instruments and monitoring systems. For the purpose, onshore and offshore seismic stations and passive and active seismic data generated both in marine and terrestrial environment will be used. Additionally, other geophysical data, mainly magnetic and gravimetric data will be considered to obtain a joint Upper Mantle-Crust structure that could permit to make progress in the understanding of the dynamic of the region. This multinational experiment which involves institutions from Spain, Italy, Germany, United Kingdom, Ireland, France, Malta, Portugal, Russia, USA and Mexico. During the experiment more than 6.600 air gun shots performed by the Spanish Oceanographic vessel "Sarmiento de Gamboa" will be recorder on a dense local seismic network consisting of 100 on land non-permanent stations, 70 on land permanent stations and 20-25 OBSs. Contemporaneously other marine geophysical measures will be performed using a marine Gravimeter LaCoste&Romberg Air-Sea Gravity System II and a Marine Magnetometer SeaSPY. The experiments will provide a unique data set in terms of data quantity and quality, and it will provide a detailed velocity and attenuation structural image of volcano edifice. The results will be essential in the development and interpretation of future volcanic models. It is noteworthy that this project is fully transversal, multidisciplinary and crosses several

  19. Trace element biomonitoring using mosses in urban areas affected by mud volcanoes around Mt. Etna. The case of the Salinelle, Italy.

    PubMed

    Bonanno, Giuseppe; Lo Giudice, Rosa; Pavone, Pietro

    2012-08-01

    Trace element impact was assessed using mosses in a densely inhabited area affected by mud volcanoes. Such volcanoes, locally called Salinelle, are phenomena that occur around Mt. Etna (Sicily, Italy) and are interpreted as the surface outflow of a hydrothermal system located below Mt. Etna, releasing sedimentary fluids (hydrocarbons and NaCl brines) along with magmatic gases (mainly CO(2) and He). To date, scarce data are available about the presence of trace elements, and no biomonitoring campaigns are reported about the cumulative effects of such emissions. In this study, concentrations of Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn were detected in the moss Bryum argenteum, in soil and water. Results showed that the trace element contribution of the Salinelle to the general pollution was significant for Al, Mn, Ni, and Zn. The comparison of trace concentrations in mosses from Salinelle and Etna showed that the mud volcanoes release a greater amount of Al and Mn, whereas similar values of Ni were found. Natural emissions of trace elements could be hazardous in human settlements, in particular, the Salinelle seem to play an important role in environmental pollution.

  20. Thermal surveillance of active volcanoes. [infrared scanner recordings of thermal anomalies of Mt. Baker volcano

    NASA Technical Reports Server (NTRS)

    Friedman, J. D. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. By the end of 1973, aerial infrared scanner traverses for thermal anomaly recordings of all Cascade Range volcanoes were essentially completed. Amplitude level slices of the Mount Baker anomalies were completed and compiled at a scale of 1:24,000, thus producing, for the first time, an accurate map of the distribution and intensity of thermal activity on Mount Baker. The major thermal activity is concentrated within the crater south of the main summit and although it is characterized by intensive solfataric activity and warm ground, it is largely subglacial, causing the development of sizable glacier perforation features. The outgoing radiative flux from the east breach anomalies is sufficient to account for the volume of ice melted to form the glacier perforations. DCP station 6251 has been monitoring a thermally anomalous area on the north slope of Mount Baker. The present thermal activity of Mount Baker accounts for continuing hydrothermal alteration in the crater south of the main summit and recurrent debris avalanches from Sherman Peak on its south rim. The infrared anomalies mapped as part of the experiment SR 251 are considered the basic evidence of the subglacial heating which was the probable triggering mechanism of an avalanche down Boulder Glacier on August 20-21, 1973.

  1. Degassing behavior of Mt. Etna volcano (Italy) before and during the 2008-2009 eruption, inferred from crater plume and soil gas measurements

    NASA Astrophysics Data System (ADS)

    Salerno, Giuseppe; La Spina, Alessandro; Giammanco, Salvatore; Burton, Michael; Caltabiano, Tommaso; Murè, Filippo; Randazzo, Daniele; Lopez, Manuela; Bruno, Nicola; Longo, Vincenza

    2010-05-01

    The evolution of magmatic degassing that preceded and accompanied the 2008-2009 Mt. Etna eruption was monitored by using a combination of: i) near-daily SO2 flux measurements; ii) calculated HCl and HF fluxes, obtained combining the daily SO2 flux values with discrete FTIR measurements of SO2/HCl and SO2/HF molar ratios; iii) periodic soil CO2 flux measurements. Thanks to the differential release of magmatic gas species from an ascending magma body we were able to track the magma transfer process in the volcano plumbing system from depth (< 5 km) to the surface. Our data suggest that the intermittent paroxysmal activity that mainly affected the South-East Crater (SEC) during 2007, displayed the efficient but complex nature of Mt. Etna's plumbing system, with gas-rich magma ascending and degassing via the central conduit system prior to eruption at the peripheral SEC. Conversely, the 15 month long 2008-09 eruption event was characterized by quasi steady state magma supply. The calculated volume of magma required to produce the observed SO2 flux during the 2008-2009 eruption closely matches the volume of erupted magma. This "eruptive" steady-state would indicate an almost perfect process of magma migration and eruption at the surface, without substantial storage within the volcano plumbing system.

  2. Resistivity variations related to the large March 9, 1998 eruption at La Fournaise volcano inferred by continuous MT monitoring

    NASA Astrophysics Data System (ADS)

    Wawrzyniak, Pierre; Zlotnicki, Jacques; Sailhac, Pascal; Marquis, Guy

    2017-11-01

    The 2645 m-high La Fournaise volcano, located in the Southwest of Réunion Island (Indian Ocean), is a shield basaltic volcano where effusive eruptions generally occur along long fissures starting from the summit, alongside major fractures that characterize the eruptions' dynamism and effusivity. Between 1992 and 1998, the volcano underwent a quiet period during which few earthquakes were recorded. Minor seismic activity returned after 1997 and picked up in March 1998 during the 35 h preceding the March 9 eruption. From 1996, two autonomous stations (CSV and BAV) were installed on the volcano. CSV was located inside the Enclos Fouqué caldera while BAV was positioned 8.2 km NW of the volcano summit. Horizontal components of the electric and magnetic fields were sampled every 20 s. Continuous time-series were available from 1996 to 1999 at CSV, and from 1997 to March 1998 at BAV. Data have been processed using both single-station and remote-reference processing. Both results show apparent resistivity variations synchronous to the eruption. Time-lapse impedance estimates are computed on overlapping time windows of about two days at both stations. The only major decrease of the observed impedance coincides with the March 1998 eruption. At CSV, the resistivity started to drop about five days before the eruption, reached several local minima until April, and then slowly increased as the volcanic crisis reduced in activity. After the end of the crisis in September 1998, the apparent resistivity recovered its pre-crisis value. The time-lapse results also show variability in directionality: sharp and elongated phase tensor ellipse residuals appear during the eruption with a N105° orientation, suggesting the emergence of an almost NS-striking dyke. A 1D background model built from MT soundings performed during the quiet period (1996 to February 1998) on which a 3D NS-striking dyke was added shows a good agreement with phase tensor residuals and spatial distribution of the

  3. Mt. Etna, Sicily as seen from STS-64

    NASA Image and Video Library

    1994-09-19

    STS064-71-037 (9-20 Sept. 1994) --- Mt. Etna on Sicily displays a steam plume from its summit. Geologists attribute the volcano's existence to the collision of tectonic plates. Unlike the sudden, explosive eruption at Rabaul, Mt. Etna's activity is ongoing and is generally not explosive - Etna's slopes have been settled with villages and cultivated land for centuries. Other Mediterranean volcanoes (like Santorini) have experienced large catastrophic eruptions. Etna recently finished a two-year eruption (ending in 1993), marked by relatively gentle lava flows down the eastern flank. It has been continually degassing since then, according to the geologists, producing an omnipresent steam plume, as seen here. The 1993 flow is difficult to identify in this image because it lies within shadows on the eastern flank, but small cinder cones on the western flank mark earlier episodes of volcanic activity. Photo credit: NASA or National Aeronautics and Space Administration

  4. A metallogenic survey of alkalic rocks of Mt. Somma-Vesuvius volcano

    USGS Publications Warehouse

    Paone, A.; Ayuso, R.A.; de Vivo, B.

    2001-01-01

    Somma-Vesuvius is an alkaline volcano whose products (pumice, scoria and lava) have alkaline (Na2O+K2O) contents between 6 and 16 wt%, Mg number <50, SiO2 59-47 wt% and MgO 0-7.8 wt% (more than 50% of the samples have a content <2 wt%). Immobile-element ratios (Th/Yb, Ta/Yb, Ce/Yb) indicate a shoshonitic character, while the K2O content (4-10 wt%) is characteristic of ultrapotassic rocks. The behavior of selected metals is discussed by grouping them on the basis of the stratigraphic sequence and differentiating the volcanic activity between plinian and interplinian (Rolandi et al., 1998; Ayuso et al., 1998). This allows observation of the variation within each formation from 25.000y. BP to the last historic eruptive cycle (1631-1944 AD). The main processes to explain the wide distribution of the data presented are fractional crystallization of a mantle-derived magma, magma mixing, and contamination with heterogeneous lower and/or upper crust. Variation diagrams distinguish different behavior for groups of metals: Ag (0.01-0.2 ppm), Mo (1-8.8 ppm), W (1.3-13 ppm), Pb (16-250 ppm), Sb (0.2-2.6 ppm), Sc (0.2-61 ppm), Li (15-140 ppm) and Be (1-31 ppm) increase with increasing differentiation and tend to correlate with the incompatible trace elements (Th, Hf, etc). Cu (10-380 ppm), Au (2-143 ppb), Co (0.7-35.1 ppm) and Fe (1.3-6.2 wt%) decrease towards advanced stage of differentiation. Iron also identifies three magmatic groups. The ratio Fe3+/Fe2+ ranges between 0.2 and 1.8, and Fe2O3/ (Fe2O3+FeO) ranges between 0.2 and 0.8, giving rise to an oxidized environment; exceptions are in the samples belonging to the interplinian formations: I, II, medieval and 1631-1994 AD. Fluorine ranges between 0.1 and 0.4 wt% for the complete Mt. Somma-Vesuvius activity, except for the Ottaviano and Avellino plinian (0.8 wt%) events. Chlorine has a wider range, from 0.1 wt% to 1.6 wt%. Mt Somma-Vesuvius has some features similar to those of mineralized alkaline magmatic systems which

  5. Time-dependent brittle deformation (creep) at Mt. Etna volcano

    NASA Astrophysics Data System (ADS)

    Heap, M. J.; Baud, P.; Meredith, P. G.; Vinciguerra, S.; Bell, A. F.; Main, I. G.

    2009-04-01

    Mt. Etna is the largest and most active volcano in Europe. Time-dependent weakening mechanisms, leading to slow fracturing, have been shown to act during pre-eruptive patterns of flank eruptions at Mt. Etna volcano. Due to the high permeability of its volcanic rocks, the volcanic edifice hosts one of the biggest hydrogeologic reservoirs of Sicily (Ogniben, 1966). The presence of a fluid phase in cracks within rock has been shown to dramatically affect both mechanical and chemical interactions. Chemically, it promotes time-dependent brittle deformation through such mechanisms as stress corrosion cracking that allows rocks to deform at stresses far below their short-term failure strength. Such crack growth is highly non-linear and accelerates towards dynamic failure over extended periods of time, even under constant applied stress; a phenomenon known as ‘brittle creep'. Here we report results from a study of time-dependent brittle creep in water-saturated samples of Etna basalt (EB) under triaxial stress conditions (confining pressure of 50 MPa and pore fluid pressure of 20 MPa). Samples of EB were loaded at a constant strain rate of 10-5 s-1 to a pre-determined percentage of the short-term strength and left to deform under constant stress until failure. Crack damage evolution was monitored throughout each experiment by measuring the independent damage proxies of axial strain, pore volume change and output of acoustic emission (AE) energy, during brittle creep of creep strain rates ranging over four orders of magnitude. Our data not only demonstrates that basalt creeps in the brittle regime but also that the applied differential stress exerts a crucial influence on both time-to-failure and creep strain rate in EB. Furthermore, stress corrosion is considered to be responsible for the acceleratory cracking and seismicity prior to volcanic eruptions and is invoked as an important mechanism in forecasting models. Stress-stepping creep experiments were then performed to

  6. Degassing Processes at Persistently Active Explosive Volcanoes

    NASA Astrophysics Data System (ADS)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with < 20 % error. Using the same protocol, I establish a record of the degassing patterns at Semeru volcano (Indonesia), a volcano that has been producing cycles of repeated explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range

  7. Volcanoes: Coming Up from Under.

    ERIC Educational Resources Information Center

    Science and Children, 1980

    1980-01-01

    Provides specific information about the eruption of Mt. St. Helens in March 1980. Also discusses how volcanoes are formed and how they are monitored. Words associated with volcanoes are listed and defined. (CS)

  8. Identifying Water on Mt. Baker and Mt. St. Helens, WA with Geophysics: Implications for Volcanic Landslide Hazards

    NASA Astrophysics Data System (ADS)

    Finn, C.; Bedrosian, P.; Wisniewski, M.; Deszcz-Pan, M.

    2015-12-01

    Groundwater position, abundance, and flow rates within a volcano affect the transmission of fluid pressure, transport of mass and heat and formation of mechanically weak hydrothermal alteration influencing the stability of volcanoes. In addition, eruptions can shatter volcanic rocks, weakening the edifice. Helicopter magnetic and electromagnetic (HEM) data collected over Mt. Baker and Mt. St. Helens volcanoes reveal the distribution of water, shattered volcanic rocks and hydrothermal alteration essential to evaluating volcanic landslide hazards. These data, combined with geological mapping and rock property measurements, indicate the presence of localized <100 m thick zones of water-saturated hydrothermally altered rock beneath Sherman Crater and the Dorr Fumarole Fields at Mt. Baker. Nuclear magnetic resonance data indicate that the hydrothermal clays contain ~50% bound water with no evidence for free water ponded beneath the ice. The HEM data suggest water-saturated fresh volcanic rocks from the surface to the detection limit (~100 m) over the entire summit of Mt. Baker (below the ice). A 50-100 m thick high resistivity layer (>1500 ohm-m) corresponding to domes, debris avalanche, volcanic rocks and glaciers mantles the crater at Mt. St. Helens. Shallow low resistivity layers corresponding to fresh, cold water and hot brines are observed below the high resistivity surface in EM data. Shallow ground water mainly concentrates in shattered dome material in the crater of Mt. St. Helens. Aeromagnetic data indicate the location of basalts sandwiched between debris avalanche deposits and shattered dome material. The combination of the EM and magnetic data help map the location of the shattered dome material that is considered to be the failure surface for the 1980 debris avalanche. The EM data image the regional groundwater table near the base of the volcano. The geophysical identification of groundwater and weak layers constrain landslide hazards assessments.

  9. Nonconscious memory for motion activates MT+.

    PubMed

    Thakral, Preston P; Slotnick, Scott D

    2014-11-12

    Extrastriate region MT+ is widely thought to reflect conscious motion processing. The primary aim of the present functional MRI study was to assess whether MT+ is activated during nonconscious memory for motion. During the encoding phase, moving and stationary abstract shapes were presented to the left or right of fixation. During the retrieval phase, the same shapes were presented at fixation and participants classified each shape as 'moving-left', 'moving-right', 'stationary-left', or 'stationary-right'. The contrast of moving>stationary shapes at encoding was used to identify the location of MT+. Event-related activity was then extracted from MT+ within each hemisphere. MT+ activity was significantly greater for moving-misses than for stationary-misses, which indicates that nonconscious memory for motion activates MT+. Furthermore, nonconscious memory activity (moving-misses) had an earlier temporal onset than conscious memory activity (moving-hits). The present results are the first, to our knowledge, to demonstrate that MT+ is associated with nonconscious motion processing. Therefore, activity in this region or in other visual-sensory regions should not be assumed to reflect conscious processing.

  10. An extended monitoring network for the volcanoes of St. Eustatius and Saba, the Caribbean Netherlands.

    NASA Astrophysics Data System (ADS)

    de Zeeuw-van Dalfsen, Elske; Sleeman, Reinoud; Evers, Läslo G.

    2017-04-01

    The volcanoes of the Quill (St. Eustatius) and Mt. Scenery (Saba) are part of the Lesser Antilles volcanic island arc in the West Indies, which hosts seventeen active volcanoes. The last eruptive activity at the Quill occurred 1600-1800 years ago but Mt. Scenery erupted as recent as in 1640. The existence of heated groundwater at St. Eustatius and hot springs at Saba indicate that both the Quill and Mt. Scenery are active, but quiet, rather than extinct. Volcanic hazard is therefore present and monitoring of these volcanoes of utmost importance. Especially considering the fact that Soufrière Hills volcano, at the neighbouring island of Montserrat and of comparable nature to Mt. Scenery, started to erupt in 1995 after 450 years of quietness. Currently, a network of four broadband seismometers is operational at each island. Seismic data are transmitted in real-time to the Royal Netherlands Meteorological Institute (KNMI), where they are (automatically) analysed. We plan to extend this monitoring effort by adding integrated geodetic observations (campaign and continuous GPS, InSAR) and temperature measurements of the hot springs. Furthermore we intend to improve our understanding of the terrain and surface geology by thorough analysis of a TanDEM-X DEM. An improved geophysical characterization of the islands is of great importance both for the population and local governments. These combined efforts will greatly improve the chance to observe the onset and follow the evolution of a future volcanic crisis.

  11. Volcanic risk metrics at Mt Ruapehu, New Zealand: some background to a probabilistic eruption forecasting scheme and a cost/benefit analysis at an open conduit volcano

    NASA Astrophysics Data System (ADS)

    Jolly, Gill; Sandri, Laura; Lindsay, Jan; Scott, Brad; Sherburn, Steve; Jolly, Art; Fournier, Nico; Keys, Harry; Marzocchi, Warner

    2010-05-01

    The Bayesian Event Tree for Eruption Forecasting software (BET_EF) is a probabilistic model based on an event tree scheme that was created specifically to compute long- and short-term probabilities of different outcomes (volcanic unrest, magmatic unrest, eruption, vent location and eruption size) at long-time dormant and routinely monitored volcanoes. It is based on the assumption that upward movements of magma in a closed conduit volcano will produce detectable changes in the monitored parameters at the surface. In this perspective, the goal of BET_EF is to compute probabilities by merging information from geology, models, past data and present monitoring measurements, through a Bayesian inferential method. In the present study, we attempt to apply BET_EF to Mt Ruapehu, a very active and well-monitored volcano exhibiting the typical features of open conduit volcanoes. In such conditions, current monitoring at the surface is not necessarily able to detect short term changes at depth that may occur only seconds to minutes before an eruption. This results in so-called "blue sky eruptions" of Mt Ruapehu (for example in September 2007), that are volcanic eruptions apparently not preceded by any presently detectable signal in the current monitoring. A further complication at Mt Ruapehu arises from the well-developed hydrothermal system and the permanent crater lake sitting on top of the magmatic conduit. Both the hydrothermal system and crater lake may act to mask or change monitoring signals (if present) that magma produces deeper in the edifice. Notwithstanding these potential drawbacks, we think that an attempt to apply BET_EF at Ruapehu is worthwhile, for several reasons. First, with the exception of a few "blue sky" events, monitoring data at Mt Ruapehu can be helpful in forecasting major events, especially if a large amount of magma is intruded into the edifice and becomes available for phreatomagmatic or magmatic eruptions, as for example in 1995-96. Secondly, in

  12. A data sequence acquired at Mt. Etna during the 2002 2003 eruption highlights the potential of continuous gravity observations as a tool to monitor and study active volcanoes

    NASA Astrophysics Data System (ADS)

    Carbone, D.; Budetta, G.; Greco, F.; Zuccarello, L.

    2007-03-01

    A 2.5-month long gravity sequence, encompassing the starting period of the 2002-2003 Etna eruption and coming from a summit station only 1 km away from the new fractures, is presented and discussed. The sequence comprises four hours-long anomalies that have a great chance to reflect mass redistributions linked to the ensuing activity. In particular, the start of the eruptive activity on the northeastern flank was marked by a gravity decrease as strong as about 400 μGal, which reverted soon afterwards. This strong decrease/increase anomaly is interpreted as the opening, by tectonic forces, of a fracture system along the Northeastern Rift of Mt. Etna, followed by an intrusion of magma from the central conduit to the new fractures. They were used by the intruding magma as a path to the eruptive vents at lower elevations. Afterwards, on three occasions, in November and December 2002, 6-12 h-lasting gravity decreases, with amplitude ranging between 10 and 30 μGal, were observed simultaneously with increases in the amplitude of the volcanic tremor from four seismic stations. A correlation analysis, between the gravity signal and the overall spectral amplitude of each tremor sequence is performed over the 7 November-9 December period. A marked anti-correlation is found over each contemporaneous gravity decrease/tremor increase, while, over the rest of the investigated period, the correlation is negligible. Accordingly, a joint source is inferred to have acted during the occurrence of the three common anomalies. On the grounds of some volcanological observations spanning the period covered by our analysis, we propose the temporary accumulation of a gas cloud at some level within the plumbing system of the volcano to have acted as a joint source. The present work is a further evidence of the potential of continuous gravity observations as a tool to monitor and study active volcanoes and encourages their employment in spite of the difficulty of running spring gravimeters

  13. Late Pleistocene glaciation of the Mt Giluwe volcano, Papua New Guinea

    USGS Publications Warehouse

    Barrows, T.T.; Hope, G.S.; Prentice, M.L.; Fifield, L.K.; Tims, S.G.

    2011-01-01

    The Mt Giluwe shield volcano was the largest area glaciated in Papua New Guinea during the Pleistocene. Despite minimal cooling of the sea surface during the last glacial maximum, glaciers reached elevations as low as 3200 m. To investigate changes in the extent of ice through time we have re-mapped evidence for glaciation on the southwest flank of Mt Giluwe. We find that an ice cap has formed on the flanks of the mountain on at least three, and probably four, separate occasions. To constrain the ages of these glaciations we present 39 new cosmogenic 36Cl exposure ages complemented by new radiocarbon dates. Direct dating of the moraines identifies that the maximum extent of glaciation on the mountain was not during the last glacial maximum as previously thought. In conjunction with existing potassium/argon and radiocarbon dating, we recognise four distinct glacial periods between 293-306 ka (Gogon Glaciation), 136-158 ka (Mengane Glaciation), centred at 62 ka (Komia Glaciation) and from >20.3-11.5 ka (Tongo Glaciation). The temperature difference relative to the present during the Tongo Glaciation is likely to be of the order of at least 5 ??C which is a minimum difference for the previous glaciations. During the Tongo Glaciation, ice was briefly at its maximum for less than 1000 years, but stayed near maximum levels for nearly 4000 years, until about 15.4 ka. Over the next 4000 years there was more rapid retreat with ice free conditions by the early Holocene. ?? 2011 Elsevier Ltd.

  14. Magmatic history of mt. Vesuvius on the basis of new geochemical and isotopic data

    NASA Astrophysics Data System (ADS)

    Arienzo, I.; Civetta, L.; D'Antonio, M.; di Renzo, V.; di Vito, M. A.; Giordano, F.; Orsi, G.

    2003-04-01

    Mt. Vesuvius is an active volcano famous for the AD 79 eruption that destroyed Pompeii, Herculaneum and Stabiae. Because of the intense urbanization around and on the volcano itself, volcanic risk is very high. Therefore, the knowledge of the structure and behaviour of the magmatic system is fundamental for both interpretation of any change in the dynamics of the volcano and eruption forecasting. We have produced new geochemical and isotopic data on rocks from a 240-m deep core drilled along the southern slope of the volcano. The investigated portion of the core includes lava flows aged between 39 and 20 ka. The obtained results, together with those already available for the younger than 20 ka activity, have allowed us to reconstruct the complex history of the magmatic system. Mt. Vesuvius magmas, originated in a mantle source variably contaminated by slab derived components, stagnate in a deep complex reservoir, located between 10 and 20 km of depth, where they differentiate and contaminate with continental crust. From the deep reservoir magmas discontinuously rise up to shallow reservoirs, where they differentiate, mingle and mix, feeding the volcanic activity. The shallow reservoirs are located at depth of about 3-5 km before Plinian eruptions, and of less than 1 km before strombolian activity.

  15. GlobVolcano: Earth Observation Services for Global Monitroing of Active Volcanoes

    NASA Astrophysics Data System (ADS)

    Borgstrom, S.; Bianchi, M.; Bronson, W.; Tampellini, M. L.; Ratti, R.; Seifert, F. M.; Komorowski, J. C.; Kaminski, E.; Peltier, A.; Van der Voet, P.

    2010-03-01

    The GlobVolcano project (2007-2010) is part of the Data User Element (DUE) programme of the European Space Agency (ESA).The objective of the project is to demonstrate EO-based (Earth Observation) services able to support the Volcano Observatories and other mandate users (Civil Protection, volcano scientific community) in their monitoring activities.The set of offered EO based information products is the following:- Deformation Mapping- Surface Thermal Anomalies- Volcanic Gas Emission- Volcanic Ash TrackingThe Deformation Mapping service is performed exploiting either PSInSARTM or Conventional DInSAR (EarthView® InSAR). The processing approach is selected according to the availability of SAR data and users' requests.The information services are assessed in close cooperation with the user organizations for different types of volcano, from various geographical areas in various climatic zones. Users are directly and actively involved in the validation of the Earth Observation products, by comparing them with ground data available at each site.In a first phase, the GlobVolcano Information System was designed, implemented and validated, involving a limited number of test areas and respective user organizations (Colima in Mexico, Merapi in Indonesia, Soufrière Hills in Montserrat Island, Piton de la Fournaise in La Reunion Island, Karthala in Comore Islands, Stromboli and Volcano in Italy). In particular Deformation Mapping results obtained for Piton de la Fournaise were compared with deformation rates measured by the volcano observatory using GPS stations and tiltmeters. IPGP (Institut de Physique du Globe de Paris) is responsible for the validation activities.The second phase of the project (currently on-going) concerns the service provision on pre-operational basis. Fifteen volcanic sites located in four continents are monitored and as many user organizations are involved and cooperating with the project team.In addition to the proprietary tools mentioned before, in

  16. Mount Rainier active cascade volcano

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  17. Mt. Etna, Sicily as seen from STS-62

    NASA Image and Video Library

    1994-03-05

    STS062-85-195 (4-18 March 1994) --- A thin plume of steam blows southward from the summit of Mt. Etna, the active volcano on the island of Sicily. The summit is capped with snow but the dark lava flow along the eastern flank (the 1991-93 flow) is clearly visible. The coastal city south of Etna is Catania.

  18. A Comparison of Slow Slip Events at Etna and Kilauea Volcanoes

    NASA Astrophysics Data System (ADS)

    Mattia, M.; Montgomery-Brown, E. K.; Bruno, V.; Scandura, D.

    2016-12-01

    Mt. Etna and Kilauea Volcano are both large basaltic volcanoes with unstable flanks, on which slow slip events have been observed by continuous GPS networks. The slow slip events (SSEs) last about two days at both volcanoes, although there are some differences in the depths and frequencies. While recurrence intervals were initially somewhat irregular at Kilauea, the most recent 5 events have become more regular with an inter-event time of about 2.4 years. At Mt. Etna, these events seem to be more frequent (about 2 per year) and are often related to the main recharge phases of the volcano. Ground deformation data have been used on both volcanoes for determining the source of the anomalous displacements and, from this point of view, the two volcanoes seem very different. Although slow slip events at Mt. Etna and Kilauea are much shallower than many subduction zone slow slip events, slip at Kilauea occurs on a discrete decollement at about 8 km deep. At Mt. Etna, a variety of data suggest that the sliding could be much shallower and more diffuse. In this work, we show some preliminary results of a "block-like" model of Mt. Etna's slow slip events that is able to explain the source of the flank displacements with slip on the Giarre Wedge near the coast. This work will allow a possible classification of different types of slip events affecting the flanks of large basaltic volcanoes, often densely populated, with a significant impact on the evaluation of seismic and volcanic hazard.

  19. Italy: Mt. Etna

    Atmospheric Science Data Center

    2013-04-17

    article title:  Eruption of Mt. Etna     View ... repeated caldera collapse, and partially buried by younger volcanic structures. Eruptions are related to a complex tectonic situation, ... available at JPL . July 22, 2001 - Eruption of the volcano in true-color and stereo. project:  ...

  20. Monitoring volcano activity through Hidden Markov Model

    NASA Astrophysics Data System (ADS)

    Cassisi, C.; Montalto, P.; Prestifilippo, M.; Aliotta, M.; Cannata, A.; Patanè, D.

    2013-12-01

    During 2011-2013, Mt. Etna was mainly characterized by cyclic occurrences of lava fountains, totaling to 38 episodes. During this time interval Etna volcano's states (QUIET, PRE-FOUNTAIN, FOUNTAIN, POST-FOUNTAIN), whose automatic recognition is very useful for monitoring purposes, turned out to be strongly related to the trend of RMS (Root Mean Square) of the seismic signal recorded by stations close to the summit area. Since RMS time series behavior is considered to be stochastic, we can try to model the system generating its values, assuming to be a Markov process, by using Hidden Markov models (HMMs). HMMs are a powerful tool in modeling any time-varying series. HMMs analysis seeks to recover the sequence of hidden states from the observed emissions. In our framework, observed emissions are characters generated by the SAX (Symbolic Aggregate approXimation) technique, which maps RMS time series values with discrete literal emissions. The experiments show how it is possible to guess volcano states by means of HMMs and SAX.

  1. Gravitational sliding of the Mt. Etna massif along a sloping basement

    NASA Astrophysics Data System (ADS)

    Murray, John B.; van Wyk de Vries, Benjamin; Pitty, Andy; Sargent, Phil; Wooller, Luke

    2018-04-01

    Geological field evidence and laboratory modelling indicate that volcanoes constructed on slopes slide downhill. If this happens on an active volcano, then the movement will distort deformation data and thus potentially compromise interpretation. Our recent GPS measurements demonstrate that the entire edifice of Mt. Etna is sliding to the ESE, the overall direction of slope of its complex, rough sedimentary basement. We report methods of discriminating the sliding vector from other deformation processes and of measuring its velocity, which averaged 14 mm year-1 during four intervals between 2001 and 2012. Though sliding of one sector of a volcano due to flank instability is widespread and well-known, this is the first time basement sliding of an entire active volcano has been directly observed. This is important because the geological record shows that such sliding volcanoes are prone to devastating sector collapse on the downslope side, and whole volcano migration should be taken into account when assessing future collapse hazard. It is also important in eruption forecasting, as the sliding vector needs to be allowed for when interpreting deformation events that take place above the sliding basement within the superstructure of the active volcano, as might occur with dyke intrusion or inflation/deflation episodes.

  2. Mt. Spurr's 1992 eruptions

    USGS Publications Warehouse

    1993-01-01

    On 27 June, 1992, the Crater Peak vent on the south side of Mt. Spurr awoke from 39 years of dormancy and burst into sub-plinian eruption after 10 months of elevated seismicity. Two more eruptions followed in August and September. The volcano lies 125 km west of Anchorage, Alaska's largest city and an important international hub for air travel. The Alaska Volcano Observatory (AVO) was able to warn communities and the aviation industry well in advance of these eruptions.

  3. Ubinas Volcano Activity in Peruvian Andes

    NASA Image and Video Library

    2014-05-01

    On April 28, 2014, NASA Terra spacecraft spotted signs of activity at Ubinas volcano in the Peruvian Andes. The appearance of a new lava dome in March 2014 and frequent ash emissions are signs of increasing activity at this volcano.

  4. Dark Oligotrophic Volcanic Ecosystems (DOVEs) in Fumarolic Ice Caves of Mt. Erebus Volcano

    NASA Astrophysics Data System (ADS)

    Staudigel, H.; Anitori, R.; Davis, R.; Connell, L.; Tebo, B. M.

    2011-12-01

    Dark Oligotrophic Volcanic Ecosystems (DOVEs) in the earth's crust may host substantial biomass sustained by chemolithoautotrophic metabolic reactions. It may serve as the base of the foodweb at the surface via hydrothermal circulation, venting pore fluids, cold seeps or gases, and offer a means for primary carbon fixation. When compared to other crustal oligotrophic environments, DOVEs are particularly relevant due to their considerable reductive potential, high permeability and the substantial chemical exchange facilitated by their hydrothermal systems. We studied terrestrial DOVEs in fumarolic ice caves on the summit plateau of Mt Erebus, an active volcano on Ross Island, Antarctica (http://erebuscaves.nmt.edu/). Most of the ice caves on Mt Erebus are relatively shallow and illuminated by natural light, but some are deep enough to afford complete darkness. Fumarole gases forming these caves are mostly atmospheric, enriched with water vapor and CO2. The fumaroles were studied in three caves, Warren, Warren West and Harry's Dream; these displayed, respectively, temperatures of 18°C, 2°C and 11°C at our sampling sites. Both Warren caves were completely dark, while Harry's Dream received continuous indirect light during the Austral summer, and offered a control to the two dark caves. The composition of the resident microbial communities was assessed using 16S rRNA and ITS libraries, while metabolic and functional characteristics were analyzed by culturing. The latter results are presented by Anitori et al. (this session). The three cave soils displayed very low (Warren, Warren West) or moderate division-level diversity, with distinct communities in each environment. Acidobacteria was the only phylum detected in all three caves, and was a major component of each library. The phototroph-containing phyla Cyanobacteria, Chloroflexi, and Chlorophyta (latter eukaryotic) were only seen in Harry's Dream. A number of phyla whose members are known to oxidize Mn(II) or Fe

  5. Three active volcanoes in China and their hazards

    NASA Astrophysics Data System (ADS)

    Wei, H.; Sparks, R. S. J.; Liu, R.; Fan, Q.; Wang, Y.; Hong, H.; Zhang, H.; Chen, H.; Jiang, C.; Dong, J.; Zheng, Y.; Pan, Y.

    2003-02-01

    The active volcanoes in China are located in the Changbaishan area, Jingbo Lake, Wudalianchi, Tengchong and Yutian. Several of these volcanoes have historical records of eruption and geochronological evidence of Holocene activity. Tianchi Volcano is a well-preserved Cenozoic polygenetic central volcano, and, due to its recent history of powerful explosive eruptions of felsic magmas, with over 100,000 people living on its flanks is a high-risk volcano. Explosive eruptions at 4000 and 1000 years BP involved plinian and ignimbrite phases. The Millennium eruption (1000 years BP) involved at least 20-30 km 3 of magma and was large enough to have a global impact. There are 14 Cenozoic monogenetic scoria cones and associated lavas with high-K basalt composition in the Wudalianchi volcanic field. The Laoheishan and Huoshaoshan cones and related lavas were formed in 1720-1721 and 1776 AD. There are three Holocene volcanoes, Dayingshan, Maanshan, and Heikongshan, among the 68 Quaternary volcanoes in the Tengchong volcanic province. Three of these volcanoes are identified as active, based on geothermal activity, geophysical evidence for magma, and dating of young volcanic rocks. Future eruptions of these Chinese volcanoes pose a significant threat to hundreds of thousands of people and are likely to cause substantial economic losses.

  6. The changing shapes of active volcanoes: History, evolution, and future challenges for volcano geodesy

    USGS Publications Warehouse

    Poland, Michael P.; Hamburger, Michael W.; Newman, Andrew V.

    2006-01-01

    At the very heart of volcanology lies the search for the 'plumbing systems' that form the inner workings of Earth’s active volcanoes. By their very nature, however, the magmatic reservoirs and conduits that underlie these active volcanic systems are elusive; mostly they are observable only through circumstantial evidence, using indirect, and often ambiguous, surficial measurements. Of course, we can infer much about these systems from geologic investigation of materials brought to the surface by eruptions and of the exposed roots of ancient volcanoes. But how can we study the magmatic processes that are occurring beneath Earth’s active volcanoes? What are the geometry, scale, physical, and chemical characteristics of magma reservoirs? Can we infer the dynamics of magma transport? Can we use this information to better forecast the future behavior of volcanoes? These questions comprise some of the most fundamental, recurring themes of modern research in volcanology. The field of volcano geodesy is uniquely situated to provide critical observational constraints on these problems. For the past decade, armed with a new array of technological innovations, equipped with powerful computers, and prepared with new analytical tools, volcano geodesists have been poised to make significant advances in our fundamental understanding of the behavior of active volcanic systems. The purpose of this volume is to highlight some of these recent advances, particularly in the collection and interpretation of geodetic data from actively deforming volcanoes. The 18 papers that follow report on new geodetic data that offer valuable insights into eruptive activity and magma transport; they present new models and modeling strategies that have the potential to greatly increase understanding of magmatic, hydrothermal, and volcano-tectonic processes; and they describe innovative techniques for collecting geodetic measurements from remote, poorly accessible, or hazardous volcanoes. To provide

  7. Capturing the fingerprint of Etna volcano activity in gravity and satellite radar data

    PubMed Central

    Negro, Ciro Del; Currenti, Gilda; Solaro, Giuseppe; Greco, Filippo; Pepe, Antonio; Napoli, Rosalba; Pepe, Susi; Casu, Francesco; Sansosti, Eugenio

    2013-01-01

    Long-term and high temporal resolution gravity and deformation data move us toward a better understanding of the behavior of Mt Etna during the June 1995 – December 2011 period in which the volcano exhibited magma charging phases, flank eruptions and summit crater activity. Monthly repeated gravity measurements were coupled with deformation time series using the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique on two sequences of interferograms from ERS/ENVISAT and COSMO-SkyMed satellites. Combining spatiotemporal gravity and DInSAR observations provides the signature of three underlying processes at Etna: (i) magma accumulation in intermediate storage zones, (ii) magmatic intrusions at shallow depth in the South Rift area, and (iii) the seaward sliding of the volcano's eastern flank. Here we demonstrate the strength of the complementary gravity and DInSAR analysis in discerning among different processes and, thus, in detecting deep magma uprising in months to years before the onset of a new Etna eruption. PMID:24169569

  8. Spreading and slope instability at the continental margin offshore Mt Etna, imaged by high-resolution 2D seismic data

    NASA Astrophysics Data System (ADS)

    Gross, Felix; Krastel, Sebastian; Behrmann, Jan-Hinrich; Papenberg, Cord; Geersen, Jacob; Ridente, Domenico; Latino Chiocci, Francesco; Urlaub, Morelia; Bialas, Jörg; Micallef, Aaron

    2015-04-01

    Mount Etna is the largest active volcano in Europe. Its volcano edifice is located on top of continental crust close to the Ionian shore in east Sicily. Instability of the eastern flank of the volcano edifice is well documented onshore. The continental margin is supposed to deform as well. Little, however, is known about the offshore extension of the eastern volcano flank and its adjacent continental margin, which is a serious shortcoming in stability models. In order to better constrain the active tectonics of the continental margin offshore the eastern flank of the volcano, we acquired and processed a new marine high-resolution seismic and hydro-acoustic dataset. The data provide new detailed insights into the heterogeneous geology and tectonics of shallow continental margin structures offshore Mt Etna. In a similiar manner as observed onshore, the submarine realm is characterized by different blocks, which are controlled by local- and regional tectonics. We image a compressional regime at the toe of the continental margin, which is bound to an asymmetric basin system confining the eastward movement of the flank. In addition, we constrain the proposed southern boundary of the moving flank, which is identified as a right lateral oblique fault movement north of Catania Canyon. From our findings, we consider a major coupled volcano edifice instability and continental margin gravitational collapse and spreading to be present at Mt Etna, as we see a clear link between on- and offshore tectonic structures across the entire eastern flank. The new findings will help to evaluate hazards and risks accompanied by Mt Etna's slope- and continental margin instability and will be used as a base for future investigations in this region.

  9. Near-real time 3D probabilistic earthquakes locations at Mt. Etna volcano

    NASA Astrophysics Data System (ADS)

    Barberi, G.; D'Agostino, M.; Mostaccio, A.; Patane', D.; Tuve', T.

    2012-04-01

    Automatic procedure for locating earthquake in quasi-real time must provide a good estimation of earthquakes location within a few seconds after the event is first detected and is strongly needed for seismic warning system. The reliability of an automatic location algorithm is influenced by several factors such as errors in picking seismic phases, network geometry, and velocity model uncertainties. On Mt. Etna, the seismic network is managed by INGV and the quasi-real time earthquakes locations are performed by using an automatic-picking algorithm based on short-term-average to long-term-average ratios (STA/LTA) calculated from an approximate squared envelope function of the seismogram, which furnish a list of P-wave arrival times, and the location algorithm Hypoellipse, with a 1D velocity model. The main purpose of this work is to investigate the performances of a different automatic procedure to improve the quasi-real time earthquakes locations. In fact, as the automatic data processing may be affected by outliers (wrong picks), the use of a traditional earthquake location techniques based on a least-square misfit function (L2-norm) often yield unstable and unreliable solutions. Moreover, on Mt. Etna, the 1D model is often unable to represent the complex structure of the volcano (in particular the strong lateral heterogeneities), whereas the increasing accuracy in the 3D velocity models at Mt. Etna during recent years allows their use today in routine earthquake locations. Therefore, we selected, as reference locations, all the events occurred on Mt. Etna in the last year (2011) which was automatically detected and located by means of the Hypoellipse code. By using this dataset (more than 300 events), we applied a nonlinear probabilistic earthquake location algorithm using the Equal Differential Time (EDT) likelihood function, (Font et al., 2004; Lomax, 2005) which is much more robust in the presence of outliers in the data. Successively, by using a probabilistic

  10. Spreading And Collapse Of Big Basaltic Volcanoes

    NASA Astrophysics Data System (ADS)

    Puglisi, G.; Bonforte, A.; Guglielmino, F.; Peltier, A.; Poland, M. P.

    2015-12-01

    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. Our work aims to investigate the relation between basement setting and volcanic activity and stability at Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These volcanoes, due to their similarities and differences, coupled with

  11. Mt. St. Helens

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1 Movie

    This 3-D anaglyph image of Mt. St. Helens volcano combines the nadir-looking and back-looking band 3 images of ASTER. To view the image in stereo, you will need blue-red glasses. Make sure to look through the red lens with your left eye. Figure 1: This ASTER image of Mt. St. Helens volcano in Washington was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The image is centered at 46.2 degrees north latitude, 122.2 degrees west longitude.

    Movie: The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a natural color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  12. Distant Mt. Fuji, Island of Honshu Japan

    NASA Image and Video Library

    1992-11-01

    This distant view of Mt. Fuji, on the main home island of Honshu, Japan (34.0N, 139.0E) was taken from about 450 miles to the south. Evan at that great distance, the majestic and inspiring Mt. Fuji is still plainly visible and easily recognized as a world renowned symbol of Japan. The snow capped extinct volcano lies just a few miles south of Tokyo.

  13. Spreading and collapse of big basaltic volcanoes

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael

    2016-04-01

    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  14. Active Deformation of Etna Volcano Combing IFSAR and GPS data

    NASA Technical Reports Server (NTRS)

    Lundgren, Paul

    1997-01-01

    The surface deformation of an active volcano is an important indicator of its eruptive state and its hazard potential. Mount Etna volcano in Sicily is a very active volcano with well documented eruption episodes.

  15. Mount St. Helens Volcano, WA, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Mount St. Helens Volcano (46.0N, 122.0W) and its blast zone can be seen in this northeast looking infrared view. Mt. Rainier and Mt. Adams can also be seen in the near area. The Columbia River can be seen at the bottom of the view. When Mt. St. Helens erupted on 18 May 80, the top 1300 ft. disappeared within minutes. The blast area covered an area of more than 150 sq. miles and sent thousands of tons of ash into the upper atmosphere.

  16. Glacier-volcano interactions in the north crater of Mt. Wrangell, Alaska

    USGS Publications Warehouse

    Abston, Carl; Motyka, Roman J.; McNutt, Stephen; Luthi, Martin; Truffer, Martin

    2007-01-01

    Glaciological and related observations from 1961 to 2005 at the summit of Mt Wrangell (62.008 N, 144.028W; 4317 m a.s.l.), a massive glacier-covered shield volcano in south-central Alaska, show marked changes that appear to have been initiated by the Great Alaska Earthquake (MW = 9.2) of 27 March 1964. The 4 x 6 km diameter, ice-filled Summit Caldera with several post-caldera craters on its rim, comprises the summit region where annual snow accumulation is 1–2 m of water equivalent and the mean annual temperature, measured 10 m below the snow surface, is –20°C. Precision surveying, aerial photogrammetry and measurements of temperature and snow accumulation were used to measure the loss of glacier ice equivalent to about 0.03 km3 of water from the North Crater in a decade. Glacier calorimetry was used to calculate the associated heat flux, which varied within the range 20–140W m–2; total heat flow was in the range 20–100 MW. Seismicity data from the crater’s rim show two distinct responses to large earthquakes at time scales from minutes to months. Chemistry of water and gas from fumaroles indicates a shallow magma heat source and seismicity data are consistent with this interpretation.

  17. Living on Active Volcanoes - The Island of Hawai'i

    USGS Publications Warehouse

    Heliker, Christina; Stauffer, Peter H.; Hendley, James W.

    1997-01-01

    People on the Island of Hawai'i face many hazards that come with living on or near active volcanoes. These include lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and tsunamis (giant seawaves). As the population of the island grows, the task of reducing the risk from volcano hazards becomes increasingly difficult. To help protect lives and property, U.S. Geological Survey (USGS) scientists at the Hawaiian Volcano Observatory closely monitor and study Hawai'i's volcanoes and issue timely warnings of hazardous activity.

  18. New inferences from spectral seismic energy measurement of a link between regional seismicity and volcanic activity at Mt. Etna, Italy

    NASA Astrophysics Data System (ADS)

    Ortiz, R.; Falsaperla, S.; Marrero, J. M.; Messina, A.

    2009-04-01

    The existence of a relationship between regional seismicity and changes in volcanic activity has been the subject of several studies in the last years. Generally, activity in basaltic volcanoes such as Villarica (Chile) and Tungurahua (Ecuador) shows very little changes after the occurrence of regional earthquakes. In a few cases volcanic activity has changed before the occurrence of regional earthquakes, such as observed at Teide, Tenerife, in 2004 and 2005 (Tárraga et al., 2006). In this paper we explore the possible link between regional seismicity and changes in volcanic activity at Mt. Etna in 2006 and 2007. On 24 November, 2006 at 4:37:40 GMT an earthquake of magnitude 4.7 stroke the eastern coast of Sicily. The epicenter was localized 50 km SE of the south coast of the island, and at about 160 km from the summit craters of Mt. Etna. The SSEM (Spectral Seismic Energy Measurement) of the seismic signal at stations at 1 km and 6 km from the craters highlights that four hours before this earthquake the energy associated with volcanic tremor increased, reached a maximum, and finally became steady when the earthquake occurred. Conversely, neither before nor after the earthquake, the SSEM of stations located between 80 km and 120 km from the epicentre and outside the volcano edifice showed changes. On 5 September, 2007 at 21:24:13 GMT an earthquake of magnitude 3.2 and 7.9 km depth stroke the Lipari Island, at the north of Sicily. About 38 hours before the earthquake occurrence, there was an episode of lava fountain lasting 20 hours at Etna volcano. The SSEM of the seismic signal recorded during the lava fountain at a station located at 6 km from the craters highlights changes heralding this earthquake ten hours before its occurrence using the FFM method (e.g., Voight, 1988; Ortiz et al., 2003). A change in volcanic activity - with the onset of ash emission and Strombolian explosions - was observed a couple of hours before the occurrence of the regional

  19. Geochemical surveillance of magmatic volatiles at Popocatepetl volcano, Mexico

    USGS Publications Warehouse

    Goff, F.; Janik, C.J.; Delgado, H.; Werner, C.; Counce, D.; Stimac, J.A.; Siebe, C.; Love, S.P.; Williams, S.N.; Fischer, T.; Johnson, L.

    1998-01-01

    Surveillance of Popocatepetl volcanic plume geochemistry and SO2 flux began in early 1994 after fumarolic and seismic activity increased significantly during 1993. Volatile traps placed around the summit were collected at near-monthly intervals until the volcano erupted on December 21, 1994. Additional trap samples were obtained in early 1996 before the volcano erupted again, emplacing a small dacite dome in the summit crater. Abundances of volatile constituents (ppm/day of Cl, Stotal, F, CO2, Hg, and As) vaaried, but most constituents were relatively high in earl\\y and late 1994. However, ratios of these constituents to Cl were highest in mid-1994. ??34S-Stotal in trap solutions ranged from 1.5??? to 6.4???; lowest values generally occurred during late 1994. ??13C-CO2 of trap solutions were greatly contaminated with atmospheric CO2 and affected by absorption kinetics. When trap data are combined with SO2 flux measurements made through November 1996, Popocatepetl released about 3.9 Mt SO2, 16 Mt CO2, 0.75 Mt HCl, 0.075 Mt HF, 260 t As, 2.6 t Hg, and roughly 200 Mt H2O. Near-vent gas concentrations in the volcanic plume measured by correlation spectrometer (COSPEC) and Fourier transform infrared (FTIR) commonly exceed human recommended exposure limits and may constitute a potential health hazard. Volatile geochemistry combined with petrologic observations and melt-inclusion studies show that mafic magma injection into a preexisting silicic chamber has accompanied renewed volcanism at Popocatepetl. Minor assimilation of Cretaceous wall rocks probably occurred in mid-1994.

  20. The limits of seaward spreading and slope instability at the continental margin offshore Mt Etna, imaged by high-resolution 2D seismic data

    NASA Astrophysics Data System (ADS)

    Gross, Felix; Krastel, Sebastian; Geersen, Jacob; Behrmann, Jan Hinrich; Ridente, Domenico; Chiocci, Francesco Latino; Bialas, Jörg; Papenberg, Cord; Cukur, Deniz; Urlaub, Morelia; Micallef, Aaron

    2016-01-01

    Mount Etna is the largest active volcano in Europe. Instability of its eastern flank is well documented onshore, and continuously monitored by geodetic and InSAR measurements. Little is known, however, about the offshore extension of the eastern volcano flank, defining a serious shortcoming in stability models. In order to better constrain the active tectonics of the continental margin offshore the eastern flank of the volcano, we acquired a new high-resolution 2D reflection seismic dataset. The data provide new insights into the heterogeneous geology and tectonics at the continental margin offshore Mt Etna. The submarine realm is characterized by different blocks, which are controlled by local- and regional tectonics. A compressional regime is found at the toe of the continental margin, which is bound to a complex basin system. Both, the clear link between on- and offshore tectonic structures as well as the compressional regime at the easternmost flank edge, indicate a continental margin gravitational collapse as well as spreading to be present at Mt Etna. Moreover, we find evidence for the offshore southern boundary of the moving flank, which is identified as a right lateral oblique fault north of Catania Canyon. Our findings suggest a coupled volcano edifice/continental margin instability at Mt Etna, demonstrating first order linkage between on- and offshore tectonic processes.

  1. The Magmatic Structure of Mt. Vesuvius: Isotopic and Thermal Constraints

    NASA Astrophysics Data System (ADS)

    Civetta, L.; D'Antonio, M.; de Lorenzo, S.; Gasparini, P.

    2002-12-01

    Mt. Vesuvius is an active volcano famous for the AD 79 eruption that destroyed Pompeii, Herculaneum and Stabiae. Because of the intense urbanization around and on the volcano, the risk today is very high. Therefore, the knowledge of the structure and behavior of the magmatic system is fundamental both for the interpretation of any change in the dynamics of the volcano and for prediction of eruptions. A review of available and new isotopic data on rocks from Mt. Vesuvius, together with mineralogical and geochemical data and recent geophysical results, allow us to constrain a thermal modeling that describes history and present state of Mt. Vesuvius magmatic system. This system is formed by a "deep", complex magmatic reservoir where mantle-derived magmas arrive, stagnate and differentiate. The reservoir extends discontinuously between 10 and 20 km of depth, is hosted in densely fractured crustal rocks, where magmas and crust can interact, and has been fed more than once since 400 ka. The hypothesis of crustal contamination is favored by the high temperatures reached by crustal rocks as a consequence of repetitive intrusions of magma. From the "deep" reservoir magmas of K-basaltic to K-tephritic to K-phonotephritic composition rise to shallow depths where they stagnate at 3-5 km of depth before plinian eruptions, and through crystallization and mixing processes with the residual portion of the feeding systems, generate isotopically and geochemically layered reservoirs. Alternatively, during "open conduit" conditions deep, volatile-rich magma batches rise from the "deep" reservoir to less than 1 km of depth and mix with the crystal-rich, volatile-poor resident magma, triggering eruptions.

  2. Orographic Flow over an Active Volcano

    NASA Astrophysics Data System (ADS)

    Poulidis, Alexandros-Panagiotis; Renfrew, Ian; Matthews, Adrian

    2014-05-01

    Orographic flows over and around an isolated volcano are studied through a series of numerical model experiments. The volcano top has a heated surface, so can be thought of as "active" but not erupting. A series of simulations with different atmospheric conditions and using both idealised and realistic configurations of the Weather Research and Forecast (WRF) model have been carried out. The study is based on the Soufriere Hills volcano, located on the island of Montserrat in the Caribbean. This is a dome-building volcano, leading to a sharp increase in the surface skin temperature at the top of the volcano - up to tens of degrees higher than ambient values. The majority of the simulations use an idealised topography, in order for the results to have general applicability to similar-sized volcanoes located in the tropics. The model is initialised with idealised atmospheric soundings, representative of qualitatively different atmospheric conditions from the rainy season in the tropics. The simulations reveal significant changes to the orographic flow response, depending upon the size of the temperature anomaly and the atmospheric conditions. The flow regime and characteristic features such as gravity waves, orographic clouds and orographic rainfall patterns can all be qualitatively changed by the surface heating anomaly. Orographic rainfall over the volcano can be significantly enhanced with increased temperature anomaly. The implications for the eruptive behaviour of the volcano and resulting secondary volcanic hazards will also be discussed.

  3. Post Eruption Hazards at Mt. Pinatubo, Philippines

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, Peter J.

    2004-01-01

    Our project focused on the investigation of the post-eruption hazards at Mt. Pinatubo (Philippines) using remote sensing data, and field observations of the 1991 eruption deposits. Through the use of multiple satellite images, field work, and the 1996/2000 PacRim data sets, we conducted studies of the co- and post-eruption hazards of the volcano due to erosion and re-deposition of the extensive pyroclastic flow deposits. A major part of this project was the assembly and analysis of a database of over 50 high resolution (1 - 50 m/pixel) images that will facilitate this study. We collected Ikonos, SPOT, SIR-C/X-SAR, Landsat, ERS, RADARSAT, and ASTER images of the area around Mt. Pinatubo. An example of the changes that could be seen in these data is shown. Our investigation focused on a retrospective analysis of the erosion, redeposition, and re-vegetation of the 1991 pyroclastic flow deposits of Mt. Pinatubo. The primary geologic goal of our work was the analysis of the spatial distribution and volume change of the sources and sinks of materials associated with mudflow ('lahar') events. This included the measurement of river valley gradients and cross-sections using TOPSAR digital elevation data, as we are participating in the PacRim 2000 deployment to the Philippines specifically so that we can collect a second set of TOPSAR data that can then be used to create a topographic difference image of the volcano. The main results from this multi-sensor study have been published as Torres et al.. A discussion of the methodology that we used to assemble an appropriate database was included in Mouginis-Mark and Domergue-Schmidt. As part of an educational outreach effort, we also helped the Philippine Institute of Volcanology and Seismology (PHIVOLCS) in the Philippines to use NASA data to study Mt. Pinatubo and other Filipino volcanoes.

  4. When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy - Part 2: Computational implementation and first results

    NASA Astrophysics Data System (ADS)

    Peruzza, Laura; Azzaro, Raffaele; Gee, Robin; D'Amico, Salvatore; Langer, Horst; Lombardo, Giuseppe; Pace, Bruno; Pagani, Marco; Panzera, Francesco; Ordaz, Mario; Suarez, Miguel Leonardo; Tusa, Giuseppina

    2017-11-01

    This paper describes the model implementation and presents results of a probabilistic seismic hazard assessment (PSHA) for the Mt. Etna volcanic region in Sicily, Italy, considering local volcano-tectonic earthquakes. Working in a volcanic region presents new challenges not typically faced in standard PSHA, which are broadly due to the nature of the local volcano-tectonic earthquakes, the cone shape of the volcano and the attenuation properties of seismic waves in the volcanic region. These have been accounted for through the development of a seismic source model that integrates data from different disciplines (historical and instrumental earthquake datasets, tectonic data, etc.; presented in Part 1, by Azzaro et al., 2017) and through the development and software implementation of original tools for the computation, such as a new ground-motion prediction equation and magnitude-scaling relationship specifically derived for this volcanic area, and the capability to account for the surficial topography in the hazard calculation, which influences source-to-site distances. Hazard calculations have been carried out after updating the most recent releases of two widely used PSHA software packages (CRISIS, as in Ordaz et al., 2013; the OpenQuake engine, as in Pagani et al., 2014). Results are computed for short- to mid-term exposure times (10 % probability of exceedance in 5 and 30 years, Poisson and time dependent) and spectral amplitudes of engineering interest. A preliminary exploration of the impact of site-specific response is also presented for the densely inhabited Etna's eastern flank, and the change in expected ground motion is finally commented on. These results do not account for M > 6 regional seismogenic sources which control the hazard at long return periods. However, by focusing on the impact of M < 6 local volcano-tectonic earthquakes, which dominate the hazard at the short- to mid-term exposure times considered in this study, we present a different

  5. The 2011-2012 paroxysmal eruptions at Mt. Etna volcano: Insights on the vertically zoned plumbing system

    NASA Astrophysics Data System (ADS)

    Giacomoni, P. P.; Coltorti, M.; Mollo, S.; Ferlito, C.; Braiato, M.; Scarlato, P.

    2018-01-01

    The activity of Mt. Etna volcano from January 2011 to April 2012 was characterized by 24 paroxysmal, short-duration (from a few to several hours) eruptions at the New South-East summit crater. Despite the violence of the activity, no appreciable geophysical signals were recorded during this period, except for an increase in seismic tremors just minutes/hours before the occurrence of the paroxysm. This type of activity represents a significant shift from the mainly effusive eruptions of 2004, 2006, and 2008/2009, as well as from the lateral rift-related events of 2001 and 2002/2003. The 2011-2012 paroxysmal activity thus represents an important opportunity to better understand the effects of different magmatic parameters (i.e., P-T-fO2) and magmatic H2O content on the crystallization and fractionation processes. To this aim the petrographic and geochemical features of lava and scoria clasts from 10 paroxysmal events have been investigated. Fractional crystallization modelling indicates that most of the eruptions are related to magmas rising along the vertically-developed feeding system of the volcano, accompanied by one main recharge of a more primitive, deep-seated magma feeding the 4/3/2012 event. Olivine-, clinopyroxene-, and plagioclase-melt equilibria and thermobarometric calculations were performed in order to estimate the crystallization conditions of magmas. These calculations reveal that the erupted products contain different phenocryst populations in equilibrium with a spectrum of primitive to more evolved magma compositions. On the basis of crystal composition, crystal-melt equilibrium conditions and thermobarometric estimations, four main magmatic facies have been recognized: F1, 1600 MPa at 1270 °C (Ol Fo88); F2, 800 MPa to 600 MPa at 1178 °C to 1151 °C (Ol Fo84-78); F3, 450 MPa to 250 MPa at 1139 °C to 1118 °C (Ol Fo79-74); F4, < 250 MPa at < 1120 °C (Ol Fo75-70). The overall geochemistry and thermobarometric data allow us to characterize the

  6. Lahar flow simulation using Laharz_py program: Application for the Mt. Halla volcano, Jeju, Korea

    NASA Astrophysics Data System (ADS)

    Chang, C.; Yun, S. H.; Yi, W.

    2017-12-01

    Lahar, one of catastrophic events, has the potential to cause the loss of life and damage to infrastructure over inhabited areas. This study using Laharz_py, was performed schematic prediction on the impact area of lahar hazards at the Mt. Halla volcano, Jeju island. In order to comprehensively address the impact of lahar for the Mt. Halla, two distinct parameters, H/L ratio and lahar volume, were selected to influence variable for Laharz_py simulation. It was carried out on the basis of numerical simulation by estimating a possible lahar volumes of 30,000, 50,000, 70,000, 100,000, 300,000, 500,000 m3 according to H/L ratios (0.20, 0.22 and 0.25) was applied. Based on the numerical simulations, the area of the proximal hazard zone boundary is gradually decreased with increasing H/L ratio. The number of streams which affected by lahar, tended to decrease with increasing H/L ratio. In the case of H/L ratio 0.20, three streams (Gwangryeong stream, Dogeun stream, Han stream) in the Jeju-si area and six streams (Gungsan stream, Hogeun stream, Seohong stream, Donghong stream, Bomok stream, Yeong stream-Hyodon stream) in the Seogwipo-si area are affected. In the case of H/L ratio 0.22, two streams (Gwangryeong stream and Han stream) in the Jeju-si area and five streams (Gungsan stream, Seohong stream, Donghong stream, Bomok stream, Yeong stream-Hyodon stream) in the Seogwipo-si area are affected. And in the case of H/L ratio 0.25, two streams (Gwangryeong stream and Han stream) in the Jeju-si area and one stream (Yeong stream-Hyodon stream) in the Seogwipo-si area are affected. The results of this study will be used as basic data to create a risk map for the direct damage that can be caused due to volcanic hazards arising from Mt. Halla. This research was supported by a grant [MPSS-NH-2015-81] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  7. Insights into Proximal-Medial Pyroclastic Density Current Deposits at a High-Risk Glaciated Volcano: Mt Ruapehu, New Zealand

    NASA Astrophysics Data System (ADS)

    Cowlyn, J.; Kennedy, B.; Gravley, D. M.; Cronin, S. J.; Pardo, N.; Wilson, T. M.; Leonard, G.; Townsend, D.; Dufek, J.

    2014-12-01

    Pyroclastic density currents (PDCs) are a destructive volcanic hazard. Quantifying the types, frequency and magnitudes of PDC events in the geological record is essential for effective risk management. However small-medium volume valley-confined PDC deposits have low preservation potential, especially when emplaced in active drainages or onto snow or ice. Where PDC deposits are preserved they can be difficult to distinguish from other surficial deposits and are frequently misinterpreted or overlooked. This is the case at Mt. Ruapehu; a much visited, high-risk active volcano in New Zealand with no historical PDCs. Through systematic field observations we identified several young proximal-medial andesitic PDC deposits exposed on Ruapehu's eastern flanks. The oldest deposits (Ohinewairua PDCs, <13.6 ka) are massive pumice-rich deposits that are preserved at least 7km from source (North Crater) and correlate with Ruapehu's largest plinian eruptions. Overlying these, the pumice-rich Pourahu PDC deposit reaches >10km from source (South Crater) and correlates with Ruapehu's last known plinian eruption (~11.6 ka). Several younger locally preserved PDC deposits (Tukino PDCs) with denser juvenile clasts represent proximal PDCs from smaller eruptions at South Crater. Finally, a variably welded, bedded deposit containing clasts of welded spatter is interpreted to represent multiple failures of near-vent (North Ruapehu) accumulations of erupted material. Here, PDC initiation appears to have been controlled by the topographic gradient and deposition rate, without requiring a collapsing eruption column. The Ruapehu deposits highlight the limited preservation of PDC deposits, which appears to be favoured at PDC margins. Lateral and vertical flow stratification means the resulting deposits may not then represent the bulk flow. Additionally, deposit textures, distributions, and associations with moraines indicate that many of Ruapehu's PDCs encountered glacial ice during transport

  8. Integrating ambient noise with GIS for a new perspective on volcano imaging and monitoring: The case study of Mt. Etna

    NASA Astrophysics Data System (ADS)

    Guardo, R.; De Siena, L.

    2017-11-01

    The timely estimation of short- and long-term volcanic hazard relies on the availability of detailed 3D geophysical images of volcanic structures. High-resolution seismic models of the absorbing uppermost conduit systems and highly-heterogeneous shallowest volcanic layers, while particularly challenging to obtain, provide important data to locate feasible eruptive centres and forecast flank collapses and lava ascending paths. Here, we model the volcanic structures of Mt. Etna (Sicily, Italy) and its outskirts using the Horizontal to Vertical Spectral Ratio method, generally applied to industrial and engineering settings. The integration of this technique with Web-based Geographic Information System improves precision during the acquisition phase. It also integrates geological and geophysical visualization of 3D surface and subsurface structures in a queryable environment representing their exact three-dimensional geographic position, enhancing interpretation. The results show high-resolution 3D images of the shallowest volcanic and feeding systems, which complement (1) deeper seismic tomography imaging and (2) the results of recent remote sensing imaging. The study recovers a vertical structure that divides the pre-existing volcanic complexes of Ellittico and Cuvigghiuni. This could be interpreted as a transitional phase between the two systems. A comparison with recent remote sensing and geological results, however, shows that anomalies are generally related to volcano-tectonic structures active during the last 17 years. We infer that seismic noise measurements from miniaturized instruments, when combined with remote sensing techniques, represent an important resource to monitor volcanoes in unrest, reducing the risk of loss of human lives and instrumentation.

  9. Mobility and fluxes of major, minor and trace metals during basalt weathering and groundwater transport at Mt. Etna volcano (Sicily)

    NASA Astrophysics Data System (ADS)

    Aiuppa, Alessandro; Allard, Patrick; D'Alessandro, Walter; Michel, Agnes; Parello, Francesco; Treuil, Michel; Valenza, Mariano

    2000-06-01

    The concentrations and fluxes of major, minor and trace metals were determined in 53 samples of groundwaters from around Mt Etna, in order to evaluate the conditions and extent of alkali basalt weathering by waters enriched in magma-derived CO 2 and the contribution of aqueous transport to the overall metal discharge of the volcano. We show that gaseous input of magmatic volatile metals into the Etnean aquifer is small or negligible, being limited by cooling of the rising fluids. Basalt leaching by weakly acidic, CO 2-charged water is the overwhelming source of metals and appears to be more extensive in two sectors of the S-SW (Paternò) and E (Zafferana) volcano flanks, where out flowing groundwaters are the richest in metals and bicarbonate of magmatic origin. Thermodynamic modeling of the results allows to evaluate the relative mobility and chemical speciation of various elements during their partitioning between solid and liquid phases through the weathering process. The facts that rock-forming minerals and groundmass dissolve at different rates and secondary minerals are formed are taken into account. At Mt. Etna, poorly mobile elements (Al, Th, Fe) are preferentially retained in the solid residue of weathering, while alkalis, alkaline earth and oxo-anion-forming elements (As, Se, Sb, Mo) are more mobile and released to the aqueous system. Transition metals display an intermediate behavior and are strongly dependent on either the redox conditions (Mn, Cr, V) or solid surface-related processes (V, Zn, Cu). The fluxes of metals discharged by the volcanic aquifer of Etna range from 7.0 × 10 -3 t/a (Th) to 7.3 × 10 4 t/a (Na). They are comparable in magnitude to the summit crater plume emissions for a series of elements (Na, K, Ca, Mg, U, V, Li) with lithophile affinity, but are minor for volatile elements. Basalt weathering at Mt Etna also consumes about 2.1 × 10 5 t/a of magma-derived carbon dioxide, equivalent to ca. 7% of contemporaneous crater plume

  10. b-value distribution in and around Mt. Tarumae, Japan

    NASA Astrophysics Data System (ADS)

    Chiba, K.

    2017-12-01

    Mt. Tarumae is an active volcano located in southeastern Shikotsu caldera, Hokkaido, Japan. Recently, crustal expansion occurred in 1999-2000 and 2013 near the summit of Mt. Tarumae, with a M5.6 earthquake recorded west of the summit on 8 July 2014. In this study, I determined hypocenter distributions and then performed b-value analysis for the period between 1 August 2014 and 12 August 2016 to improve our understanding of the magma system geometry beneath the summit of Mt. Tarumae. Hypocenters are mainly distributed in two regions: 3 - 5 km west of Mt. Tarumae, and beneath the volcano. I then determined b-value distributions. Regions with relatively high b-values ( 1.3) are located at depths of -0.5 to 2.0 km beneath the summit and at depths greater than 6.0 km in the northwestern part at about 1.5 - 3.0 km from the summit, while a region with relatively low b-values ( 0.6) is located at depths of 2.0 - 6.0 km beneath the summit. Compared the b-value distributions with other geophysical observations, it was found that the high b-value region from -0.5 to 2.0 km depth corresponds to regions of lower resistivity, positive self-potential anomaly, and an inflation source observed in 1999-2000. It is thus inferred that this region is generated by crustal heterogeneity, a decrease in effective normal stress, and change of a frictional property due to the development of faults and fissures, and the circulation of hydrothermal fluids. On the other hand, the inflation source observed in 2013 was located near the boundary between the low b-value region beneath the summit and the deeper high b-value region in the northwestern part at about 1.5 - 3.0 km from the summit. Studies of other volcanoes suggest that such a high-b-value region likely corresponds to a magma chamber. From the deeper high b-value region estimated in this study, I am able to point out that the magma chamber is located to depths greater than 6.0 km in the northwestern part at about 1.5 - 3.0 km from the

  11. When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy - Part 1: Model components for sources parameterization

    NASA Astrophysics Data System (ADS)

    Azzaro, Raffaele; Barberi, Graziella; D'Amico, Salvatore; Pace, Bruno; Peruzza, Laura; Tuvè, Tiziana

    2017-11-01

    The volcanic region of Mt. Etna (Sicily, Italy) represents a perfect lab for testing innovative approaches to seismic hazard assessment. This is largely due to the long record of historical and recent observations of seismic and tectonic phenomena, the high quality of various geophysical monitoring and particularly the rapid geodynamics clearly demonstrate some seismotectonic processes. We present here the model components and the procedures adopted for defining seismic sources to be used in a new generation of probabilistic seismic hazard assessment (PSHA), the first results and maps of which are presented in a companion paper, Peruzza et al. (2017). The sources include, with increasing complexity, seismic zones, individual faults and gridded point sources that are obtained by integrating geological field data with long and short earthquake datasets (the historical macroseismic catalogue, which covers about 3 centuries, and a high-quality instrumental location database for the last decades). The analysis of the frequency-magnitude distribution identifies two main fault systems within the volcanic complex featuring different seismic rates that are controlled essentially by volcano-tectonic processes. We discuss the variability of the mean occurrence times of major earthquakes along the main Etnean faults by using an historical approach and a purely geologic method. We derive a magnitude-size scaling relationship specifically for this volcanic area, which has been implemented into a recently developed software tool - FiSH (Pace et al., 2016) - that we use to calculate the characteristic magnitudes and the related mean recurrence times expected for each fault. Results suggest that for the Mt. Etna area, the traditional assumptions of uniform and Poissonian seismicity can be relaxed; a time-dependent fault-based modeling, joined with a 3-D imaging of volcano-tectonic sources depicted by the recent instrumental seismicity, can therefore be implemented in PSHA maps

  12. 2013 Mt. Etna Pyroclastic Activity through the ADCP Recordings of NEMO-SN1 Multidisciplinary Seafloor Observatory

    NASA Astrophysics Data System (ADS)

    Lo Bue, N.; Sgroi, T.; Giovinetti, G.; Marinaro, G.; Favali, P.

    2014-12-01

    The Acoustic Doppler Current Profiler (ADCP) is one of the most useful sensor used to measure speed and direction of sea currents in the water column. More often ADCPs are being also used to monitor concentration of suspended matter in rivers or in marine environments by the analysis of the acoustic backscatter intensity. In the framework of the European Research Infrastructure EMSO (European Multidisciplinary Seafloor and water-column Observatory, www.emso-eu.org), its cabled node, the NEMO-SN1 multidisciplinary seafloor observatory, was deployed in the Western Ionian Sea (Southern Italy) at a depth of 2100 m, about 25 km off-shore Eastern Sicily close to the submarine slope of the Mt. Etna volcano. Starting from February 2013, the Mt. Etna was interested by thirteen different parossistic events producing intense eruption followed by pyroclastic fallout that reached distances of tens kilometres from the eruptive centre. Four of these events affected the ESE sector with a consequent fallout in the Western Ionian Sea and they were detected by NEMO-SN1. In fact, its scientific payload also included an ADCP (RDI WorkHorse 600 kHz) with the main aim to monitor the hydrodynamic conditions of about 30 metres of the water column above the station. Surprisingly, this sensor offered spectacular recordings of the Mt. Etna pyroclastic activity occurred on 2013 wich affected the ESE sector. This work aims to present new records of pyroclastic fallout associated to explosive events observed at sea bottom by the analysis of backscatter signal of the ADCP. A multidisciplinary approach taking into account the Mt. Etna eruptive activity as well as the local oceanographic dynamic is necessary to describe marine processes involved in volcanic ash sedimentation.

  13. MEDiterranean Supersite Volcanoes (MED-SUV) project: state of the art and main achievements after the first 18 months

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe; Spampinato, Letizia; Allard, Patrick; Baills, Audrey; Briole, Pierre; D'Auria, Luca; Dingwell, Donald; Martini, Marcello; Kueppers, Ulrich; Marzocchi, Warner; Minet, Christian; Vagner, Amélie

    2015-04-01

    Taking account of the valuable resources and information available for Mt. Etna, Campi Flegrei, and Vesuvius Supersites, MED-SUV aims at exploiting the huge record of geophysical, geochemical and volcanological data available for the three Supersite volcanoes and carry out experiments to fill gaps in the knowledge of the structure of these volcanoes and of the processes driving their activity. The project's activities have focused on (1) gaining new insights into the inner structure of these volcanoes; (2) evaluating the suitability of the current EO and in-situ observations to track the dynamics of the volcano supply system and/or the eruptive phenomena, (3) making the access to observations easy; (4) defining the effects of magma ascent on the stress/strain field (and vice versa); (5) assessing the capability of the Earth science community to forecast the occurrence of eruptions in terms of both location and time of an eruption; (6) optimizing the chain from observations to end-users during an eruptive event; and (7) making the project outcomes "exportable" to other European volcanic areas and elsewhere. Indeed, the overall goal of the project is to apply the rationale of the Geohazard Supersites and Natural Laboratories GEO-GEOSS initiative to the three volcanoes, in order to better assess the volcanic hazards they posed. In the first 18 months, MED-SUV consortium carried out activities relating to coordination, scientific/technological development, and dissemination. Coordination included mainly meetings organised in order to start the project and consortium activity and to strengthen the synergy with EC and international initiatives, such as geohazard activities of GEO-GEOSS, EPOS-PP and the other two FP7 Supersite projects, MARsite and FUTUREVOLC. The main scientific/technological results included the design and development of a prototype (NETVIS) for the optimization and implementation of processing tools for the analysis of Mt. Etna's camera network, design

  14. The Role of Community-Based Organization in Disaster Response at Mt. Sinabung

    NASA Astrophysics Data System (ADS)

    Wulandari, Y.; Sagala, S. A. H.; Sullivan, G. B.

    2018-05-01

    In August 2010, Mt. Sinabung in North Sumatera erupted for the very first time in 400 years; until that moment the volcano had been declared as dormant. In contrast to the communities living around Mt. Merapi in Java, the Mt. Sinabung communities had little to no preparation when faced with the sudden volcanic eruption. The Sinabung eruption caused disturbances as it ruined the farmlands and community’s sources of livelihood, especially since most of the community members are farmers. Most of the time, these farmlands are located not far from their house, so displacing them means moving them away from their main source of income. This makes some of the displaced keep moving back to their old villages to farm even though they are putting themselves in danger by doing so. This condition motivated the community to initiate Beidar, an organization to monitor volcanic activities and give out early warnings to villagers nearby and within the hazard zone to evacuate. This paper will study Beidar’s involvement with the community and the government, how they operate, and how they impact the community members living near the volcano. This data used in this study are primarily from interviews with Beidar members and organizers, volcanic monitoring posts, and the local disaster management. A thematic analysis of the interviews shows the history of Beidar’s development as an organization proudly independent of the government; the “recruitment” of members; the important roles in the community including mediating between government and other local organizations (e.g., volcano monitoring station); specific monitoring; communication and evacuation activities (e.g., including search activities after eruptions and lahars); contacts and sharing of experience with similar groups in Indonesia; and identifying the limits of their influence in preventing local people from returning to the red zone. This research concludes that Beidar was officially acknowledged as an

  15. An investigation of vegetation and other Earth resource/feature parameters using LANDSAT and other remote sensing data. 1: LANDSAT. 2: Remote sensing of volcanic emissions. [New England forest and emissions from Mt. St. Helens and Central American volcanoes

    NASA Technical Reports Server (NTRS)

    Birnie, R. W.; Stoiber, R. E. (Principal Investigator)

    1981-01-01

    A fanning technique based on a simplistic physical model provided a classification algorithm for mixture landscapes. Results of applications to LANDSAT inventory of 1.5 million acres of forest land in Northern Maine are presented. Signatures for potential deer year habitat in New Hampshire were developed. Volcanic activity was monitored in Nicaragua, El Salvador, and Guatemala along with the Mt. St. Helens eruption. Emphasis in the monitoring was placed on the remote sensing of SO2 concentrations in the plumes of the volcanoes.

  16. SmallWorld Behavior of the Worldwide Active Volcanoes Network: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Spata, A.; Bonforte, A.; Nunnari, G.; Puglisi, G.

    2009-12-01

    We propose a preliminary complex networks based approach in order to model and characterize volcanoes activity correlation observed on a planetary scale over the last two thousand years. Worldwide volcanic activity is in fact related to the general plate tectonics that locally drives the faults activity, that in turn controls the magma upraise beneath the volcanoes. To find correlations among different volcanoes could indicate a common underlying mechanism driving their activity and could help us interpreting the deeper common dynamics controlling their unrest. All the first evidences found testing the procedure, suggest the suitability of this analysis to investigate global volcanism related to plate tectonics. The first correlations found, in fact, indicate that an underlying common large-scale dynamics seems to drive volcanic activity at least around the Pacific plate, where it collides and subduces beneath American, Eurasian and Australian plates. From this still preliminary analysis, also more complex relationships among volcanoes lying on different tectonic margins have been found, suggesting some more complex interrelationships between different plates. The understanding of eventually detected correlations could be also used to further implement warning systems, relating the unrest probabilities of a specific volcano also to the ongoing activity to the correlated ones. Our preliminary results suggest that, as for other many physical and biological systems, an underlying organizing principle of planetary volcanoes activity might exist and it could be a small-world principle. In fact we found that, from a topological perspective, volcanoes correlations are characterized by the typical features of small-world network: a high clustering coefficient and a low characteristic path length. These features confirm that global volcanoes activity is characterized by both short and long-range correlations. We stress here the fact that numerical simulation carried out in

  17. Imaging an Active Volcano Edifice at Tenerife Island, Spain

    NASA Astrophysics Data System (ADS)

    Ibáñez, Jesús M.; Rietbrock, Andreas; García-Yeguas, Araceli

    2008-08-01

    An active seismic experiment to study the internal structure of Teide volcano is being carried out on Tenerife, a volcanic island in Spain's Canary Islands archipelago. The main objective of the Tomography at Teide Volcano Spain (TOM-TEIDEVS) experiment, begun in January 2007, is to obtain a three-dimensional (3-D) structural image of Teide volcano using seismic tomography and seismic reflection/refraction imaging techniques. At present, knowledge of the deeper structure of Teide and Tenerife is very limited, with proposed structural models based mainly on sparse geophysical and geological data. The multinational experiment-involving institutes from Spain, the United Kingdom, Italy, Ireland, and Mexico-will generate a unique high-resolution structural image of the active volcano edifice and will further our understanding of volcanic processes.

  18. Cognate xenoliths in Mt. Etna lavas: witnesses of the high-velocity body beneath the volcano

    NASA Astrophysics Data System (ADS)

    Corsaro, Rosa Anna; Rotolo, Silvio Giuseppe; Cocina, Ornella; Tumbarello, Gianvito

    2014-01-01

    Various xenoliths have been found in lavas of the 1763 ("La Montagnola"), 2001, and 2002-03 eruptions at Mt. Etna whose petrographic evidence and mineral chemistry exclude a mantle origin and clearly point to a cognate nature. Consequently, cognate xenoliths might represent a proxy to infer the nature of the high-velocity body (HVB) imaged beneath the volcano by seismic tomography. Petrography allows us to group the cognate xenoliths as follows: i) gabbros with amphibole and amphibole-bearing mela-gabbros, ii) olivine-bearing leuco-gabbros, iii) leuco-gabbros with amphibole, and iv) Plg-rich leuco gabbros. Geobarometry estimates the crystallization pressure of the cognate xenoliths between 1.9 and 4.1 kbar. The bulk density of the cognate xenoliths varies from 2.6 to 3.0 g/cm3. P wave velocities (V P ), calculated in relation to xenolith density, range from 4.9 to 6.1 km/s. The integration of mineralogical, compositional, geobarometric data, and density-dependent V P with recent literature data on 3D V P seismic tomography enabled us to formulate the first hypothesis about the nature of the HVB which, in the depth range of 3-13 km b.s.l., is likely made of intrusive gabbroic rocks. These are believed to have formed at the "solidification front", a marginal zone that encompasses a deep region (>5 km b.s.l.) of Mt. Etna's plumbing system, within which magma crystallization takes place. The intrusive rocks were afterwards fragmented and transported as cognate xenoliths by the volatile-rich and fast-ascending magmas of the 1763 "La Montagnola", 2001 and 2002-03 eruptions.

  19. The Mediterranean Supersite Volcanoes (MED-SUV) Project: an overview

    NASA Astrophysics Data System (ADS)

    Puglisi, G.

    2013-12-01

    The EC FP7 MEDiterranean SUpersite Volcanoes (MED-SUV) EC-FP7 Project, which started on June 2013, aims to improve the capacity of the scientific institutions, end users and SME forming the project consortium to assess the volcanic hazards at Italian Supersites, i.e. Mt. Etna and Campi Flegrei/Vesuvius. The Project activities will focus on the optimisation and integration of ground and space monitoring systems, the breakthrough in understanding of volcanic processes, and on the increase of the effectiveness of the coordination between the scientific and end-user communities in the hazard management. The overall goal of the project is to apply the rationale of the Supersites GEO initiative to Mt. Etna and Campi Flegrei/Vesuvius, considered as cluster of Supersites. For the purpose MED-SUV will integrate long-term observations of ground-based multidisciplinary data available for these volcanoes, i.e. geophysical, geochemical, and volcanological datasets, with Earth Observation (EO) data. Merging of different parameters over a long period will provide better understanding of the volcanic processes. In particular, given the variety of styles and intensities of the volcanic activity observed at these volcanoes, and which make them sort of archetypes for 'closed conduit '; and ';open conduit' volcanic systems, the combination of different data will allow discrimination between peculiar volcano behaviours associated with pre-, syn- and post-eruptive phases. Indeed, recognition of specific volcano patterns will allow broadening of the spectrum of knowledge of geo-hazards, as well as better parameterisation and modelling of the eruptive phenomena and of the processes occurring in the volcano supply system; thus improving the capability of carrying out volcano surveillance activities. Important impacts on the European industrial sector, arising from a partnership integrating the scientific community and SMEs to implement together new observation/monitoring sensors

  20. The Mediterranean Supersite Volcanoes (MED-SUV) Project: an overview

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe

    2014-05-01

    The EC FP7 MEDiterranean SUpersite Volcanoes (MED-SUV) EC-FP7 Project, which started on June 2013, aims to improve the capacity of the scientific institutions, end users and SME forming the project consortium to assess the volcanic hazards at Italian Supersites, i.e. Mt. Etna and Campi Flegrei/Vesuvius. The Project activities will focus on the optimisation and integration of ground and space monitoring systems, the breakthrough in understanding of volcanic processes, and on the increase of the effectiveness of the coordination between the scientific and end-user communities in the hazard management. The overall goal of the project is to apply the rationale of the Supersites GEO initiative to Mt. Etna and Campi Flegrei/Vesuvius, considered as cluster of Supersites. For the purpose MED-SUV will integrate long-term observations of ground-based multidisciplinary data available for these volcanoes, i.e. geophysical, geochemical, and volcanological datasets, with Earth Observation (EO) data. Merging of different parameters over a long period will provide better understanding of the volcanic processes. In particular, given the variety of styles and intensities of the volcanic activity observed at these volcanoes, and which make them sort of archetypes for 'closed conduit ' and 'open conduit' volcanic systems, the combination of different data will allow discrimination between peculiar volcano behaviours associated with pre-, syn- and post-eruptive phases. Indeed, recognition of specific volcano patterns will allow broadening of the spectrum of knowledge of geo-hazards, as well as better parameterisation and modelling of the eruptive phenomena and of the processes occurring in the volcano supply system; thus improving the capability of carrying out volcano surveillance activities. Important impacts on the European industrial sector, arising from a partnership integrating the scientific community and SMEs to implement together new observation/monitoring sensors/systems, are

  1. Locating the depth of magma supply for volcanic eruptions, insights from Mt. Cameroon

    PubMed Central

    Geiger, Harri; Barker, Abigail K.; Troll, Valentin R.

    2016-01-01

    Mt. Cameroon is one of the most active volcanoes in Africa and poses a possible threat to about half a million people in the area, yet knowledge of the volcano’s underlying magma supply system is sparse. To characterize Mt. Cameroon’s magma plumbing system, we employed mineral-melt equilibrium thermobarometry on the products of the volcano’s two most recent eruptions of 1999 and 2000. Our results suggest pre-eruptive magma storage between 20 and 39 km beneath Mt. Cameroon, which corresponds to the Moho level and below. Additionally, the 1999 eruption products reveal several shallow magma pockets between 3 and 12 km depth, which are not detected in the 2000 lavas. This implies that small-volume magma batches actively migrate through the plumbing system during repose intervals. Evolving and migrating magma parcels potentially cause temporary unrest and short-lived explosive outbursts, and may be remobilized during major eruptions that are fed from sub-Moho magma reservoirs. PMID:27713494

  2. Megathrust earthquakes in Japan and Chile triggered multiple volcanoes to subside

    NASA Astrophysics Data System (ADS)

    Takada, Y.; Pritchard, M. E.; Fukushima, Y.; Jay, J.; Aron, F. A.; Henderson, S.; Lara, L. E.

    2012-12-01

    With spaceborne interferometric synthetic aperture radar (InSAR) analysis, we found that two recent megathrust earthquakes, the 2011 Mw 9.0 Tohoku earthquake in Japan (March 11, 2011) and the 2010 Mw 8.8 Maule earthquake in Chile (February 27, 2010), have triggered unprecedented subsidence of multiple volcanoes. There are strong similarities in the characteristics of the surface deformation in Chile and Japan; (1) the maximum amount of subsidence is about 15 cm, (2) the shape of subsidence areas exhibit elliptic shape elongated in the North-South direction -- perpendicular to the principal axis of the extensional stress change, and (3) most of the subsidence was aseismic. These similarities imply that volcanic subsidence from megathrust earthquakes is a ubiquitous phenomenon. In both areas, we found that hydro-thermal reservoirs (including water, gas, and possibly magma) would play key roles in the subsidence. Further continuous monitoring is necessary to determine if the surface subsidence leads to additional volcanic unrest. For the 2011 Tohoku Earthquake, we used SAR data acquired before and after the mainshock by ALOS (PALSAR). By removing long wave-length phase trend from InSAR images, we obtained the localized subsidence signals at five active volcanoes: Mt. Akitakoma, Mt. Kurikoma region, Mt. Zao, Mt. Azuma, and Mt. Nasu. All of them belong to the volcanic front of Northeast Japan and so they are among the closest volcanoes to the earthquake. The maximum amount of subsidence reaches 15 cm at Mt. Azuma. GPS data from two volcanoes also indicate surface subsidence consistent with the satellite radar observations. Furthermore, the GPS data show that the subsidence occurred immediately after the earthquake. According to numerical modelling, the observed subsidence can be explained by the co-seismic response of fluid-filled ellipsoid with horizontal dimensions of 10-40 × 5-15 km beneath each volcano. For the 2010 Maule Earthquake, we extracted the localized

  3. Eruption histories and hypotheses of magma genesis of Mt. Baegdu volcano

    NASA Astrophysics Data System (ADS)

    Lim, C.; Lee, I.

    2017-12-01

    The tephra or cryptotephra are principally composed of alkaline glass shards, and INAA of individual grains offers a way of distinguishing chemical characteristics. That may be used to discriminate different events age and to correlate separate deposits of the same source volcanoes. The identification of tephra or cryptotephra layers presents an opportunity to define time-parallel marker horizons. With using INAA scanning method three newly identified tephras (named B-J, B-Sado and B-Ym) were detected and eruption ages identified between AT (29.24 cal. ka) and Aso-4 (88 ka) in five cores based on microscopic observation and the stratigraphic correlations between cores of the Holocene sediments in the southeastern East Sea/Japan Sea. By the correlation with TL (dark layer) data, the approximate age of B-J, B-Sado and B-Ym tephras were calculated as to be 50.6 ka, 67.6 ka, 86.8 ka, respectively. The intraplate Baegdusan (Changbai) volcanoes located on the border of China and North Korea have been explained by either hotspots by mantle plumes or asthenospheric mantle upwelling (wet plume) caused by stagnation slab of the subducted Pacific plate. To understand the origin of the Baegdusan volcanism, we performed geochemical analyses on the volcanic rocks and tephra deposits erupted from the Baegdusan volcanoes. We propose that the intraplate alkaline volcanism associated with Baekdusan volcanic region is fed by a mantle upwelling originating below the discontinuity subducting slab. The upwelling is a result of a slab neck into the subducting slabs. The Baekdusan volcano relies on a slab neck within subducting slab at depth to allow for a focused upwelling. Therefore, the magmatic progression of back-arc magmatism in Baekdusan volcanoes can be explained by the interaction of this Philippine Sea Plate Slab and upwelling mantle.

  4. July 1973 ground survey of active Central American volcanoes

    NASA Technical Reports Server (NTRS)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.

    1973-01-01

    The author has identified the following significant results. Ground survey has shown that thermal anomalies of various sizes associated with volcanic activity at several Central American volcanoes should be detectable from Skylab. Anomalously hot areas of especially large size (greater than 500 m in diameter) are now found at Santiaguito and Pacaya volcanoes in Guatemala and San Cristobal in Nicaragua. Smaller anomalous areas are to be found at least seven other volcanoes. This report is completed after ground survey of eleven volcanoes and ground-based radiation thermometry mapping at these same points.

  5. Using the Landsat Thematic Mapper to detect and monitor active volcanoes - An example from Lascar volcano, northern Chile

    NASA Technical Reports Server (NTRS)

    Francis, P. W.; Rothery, D. A.

    1987-01-01

    The Landsat Thematic Mapper (TM) offers a means of detecting and monitoring thermal features of active volcanoes. Using the TM, a prominent thermal anomaly has been discovered on Lascar volcano, northern Chile. Data from two short-wavelength infrared channels of the TM show that material within a 300-m-diameter pit crater was at a temperature of at least 380 C on two dates in 1985. The thermal anomaly closely resembles in size and radiant temperature the anomaly over the active lava lake at Erta'ale in Ethiopia. An eruption took place at Lascar on Sept. 16, 1986. TM data acquired on Oct. 27, 1986, revealed significant changes within the crater area. Lascar is in a much more active state than any other volcano in the central Andes, and for this reason it merits further careful monitoring. Studies show that the TM is capable of confidently identifying thermal anomalies less than 100 m in size, at temperatures of above 150 C, and thus it offers a valuable means of monitoring the conditions of active or potentially active volcanoes, particularly those in remote regions.

  6. Petrographic and geochemical investigation of magma chamber processes beneath small Quaternary volcanic centers between Mt. Jefferson and Mt. Hood volcanoes, Cascade Range Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Cunningham, E.; Cribb, J. W.

    2017-12-01

    The northern Oregon Cascade Range has been dominated by andesite to rhyodacite lavas at both Mt. Jefferson (Conrey, 1991) and at Mt. Hood (Cribb and Barton, 1996) during the Quaternary period. Eruptive sequences at both Mt. Hood and Mt. Jefferson have been attributed to open-system mama mixing (Kent et al., 2010) (Ferrell et al., 2015), and the narrow range of lavas erupted at both centers has been derived from repeated cycles of magma mixing-fractionation (Cribb and Barton, 1996). This research examines major and trace element geochemistry as well as the petrographic characteristics of Clear Lake Butte (CLB), Pinhead Butte (PB), and Olallie Butte (OB), all of which are located between Mt. Hood and Mt. Jefferson, and have ben active in the Quaternary period. The research investigates whether the same type of open-system magma mixing known to have occurred at Mt. Hood and Mt. Jefferson has also occurred at CLB, PB, or OB, or whether those systems were closed to mixing and dominated by fractional crystallization. One of the main goals of this project is to highlight the similarities and differences exhibited by neighboring magmatic systems of similar age, but different scale. Disequilibrium textures observed in thin sections from CLB, OB, and PB suggest open-system magma mixing is likely occurring beneath all three buttes. This petrographic evidence includes plagioclase and pyroxene zoning, embayed margins, sieving, and reaction rims. Major element oxide trends at all three buttes are consistent with fractional crystallization, but show narrow concentrations and non-overlapping compositions between PB, CLB, and OB. All three buttes are characterized by narrow ranges of incompatible and compatible trace element concentrations. CLB, PB, and OB all exhibit LREE enrichment and lack significant HFSE depletions, with PB exhibiting greatest enrichment in REE.

  7. Viscosity controlled magma-carbonate interaction: a comparison of Mt. Vesuvius (Italy) and Mt. Merapi (Indonesia).

    NASA Astrophysics Data System (ADS)

    Blythe, L. S.; Misiti, V.; Masotta, M.; Taddeucci, J.; Freda, C.; Troll, V. R.; Deegan, F. M.; Jolis, E. M.

    2012-04-01

    Magma-carbonate interaction is increasingly seen as a viable and extremely important cause of magma contamination, and the generation of a crustally sourced CO2 phase (Goff et al., 2001; Freda et al., 2010). Even though the process is well recognized at certain volcanoes e.g. Popocatépetl, (Mexico); Merapi, (Indonesia); and Colli Albani, (Italy) (Goff et al., 2001; Deegan et al., 2010; Freda et al., 2010), neither the kinetics of carbonate assimilation nor its consequences for controlling the explosivity of eruptions have been constrained. Here we show the results of magma-carbonate interaction experiments conducted at 1200 °C and 0.5 GPa for varying durations (0 s, 60 s, 90 s and 300 s) for the Mt. Merapi (Indonesia) and Mt. Vesuvius (Italy) volcanic systems. We performed experiments using glassy starting materials specific to each volcano (shoshonite for Mt. Vesuvius, basaltic-andesite for Mt. Merapi) with different degrees of hydration (anhydrous vs hydration with ~ 2 wt % water) and using carbonate fragments of local origin; see Deegan et al., (2010) and Jolis et al., (2011). Experimental products include a gas phase (CO2-rich) and two melt phases, one pristine (Ca-normal) and one contaminated (Ca-rich) separated by a 'contamination front' which propagates outwards from the carbonate clast. Vesicles appear to nucleate in the contaminated glass and then migrate into the pristine one. Both contamination front propagation and bubble migration away from the carbonate are slower in anhydrous basaltic-andesite (Merapi anhydrous series) than in hydrated basaltic-andesite and shoshonite (Merapi and Vesuvius hydrated series), suggesting that assimilation speed is strongly controlled by the degree of hydration and the SiO2 content, both of which influence melt viscosity and hence diffusivity. As the carbonate dissolution proceeds in our experiments, initially dissolved and eventually exsolved CO2 builds up in the contaminated Ca-rich melt phase. Once melt volatile

  8. Hydrothermal reservoir beneath Taal Volcano (Philippines): Implications to volcanic activity

    NASA Astrophysics Data System (ADS)

    Nagao, T.; Alanis, P. B.; Yamaya, Y.; Takeuchi, A.; Bornas, M. V.; Cordon, J. M.; Puertollano, J.; Clarito, C. J.; Hashimoto, T.; Mogi, T.; Sasai, Y.

    2012-12-01

    Taal Volcano is one of the most active volcanoes in the Philippines. The first recorded eruption was in 1573. Since then it has erupted 33 times resulting in thousands of casualties and large damages to property. In 1995, it was declared as one of the 15 Decade Volcanoes. Beginning in the early 1990s it has experienced several phases of abnormal activity, including seismic swarms, episodes of ground deformation, ground fissuring and hydrothermal activities, which continues up to the present. However, it has been noted that past historical eruptions of Taal Volcano may be divided into 2 distinct cycles, depending on the location of the eruption center, either at Main Crater or at the flanks. Between 1572-1645, eruptions occurred at the Main Crater, in 1707 to 1731, they occurred at the flanks. In 1749, eruptions moved back to the Main Crater until 1911. During the 1965 and until the end of the 1977 eruptions, eruptive activity once again shifted to the flanks. As part of the PHIVOLCS-JICA-SATREPS Project magnetotelluric and audio-magnetotelluric surveys were conducted on Volcano Island in March 2011 and March 2012. Two-dimensional (2-D) inversion and 3-D forward modeling reveals a prominent and large zone of relatively high resistivity between 1 to 4 kilometers beneath the volcano almost directly beneath the Main Crater, surrounded by zones of relatively low resistivity. This anomalous zone of high resistivity is hypothesized to be a large hydrothermal reservoir filled with volcanic fluids. The presence of this large hydrothermal reservoir could be related to past activities of Taal Volcano. In particular we believe that the catastrophic explosion described during the 1911 eruption was the result of the hydrothermal reservoir collapsing. During the cycle of Main Crater eruptions, this hydrothermal reservoir is depleted, while during a cycle of flank eruptions this reservoir is replenished with hydrothermal fluids.

  9. Mt. Pinatubo Volcano - Post Eruption, Luzon, Philippines

    NASA Image and Video Library

    1992-08-08

    Mt. Pinatubo on the island of Luzon (15.0N, 120.0E) erupted catastrophically in June 1991 after over 600 years of inactivity. In this vertical view, the full extent of the eruption is obvious. Thick layers of ash completely surrounds the crater and the effect of mudflows in this previously heavily forested and agricultural region can be traced as ribbons flowing downhill. Clark AFB, once the crossroads of the SW Pacific can only partially be seen.

  10. Special issue: The changing shapes of active volcanoes: Recent results and advances in volcano geodesy

    USGS Publications Warehouse

    Poland, Michael P.; Newman, Andrew V.

    2006-01-01

    The 18 papers herein report on new geodetic data that offer valuable insights into eruptive activity and magma transport; they present new models and modeling strategies that have the potential to greatly increase understanding of magmatic, hydrothermal, and volcano-tectonic processes; and they describe innovative techniques for collecting geodetic measurements from remote, poorly accessible, or hazardous volcanoes. To provide a proper context for these studies, we offer a short review of the evolution of volcano geodesy, as well as a case study that highlights recent advances in the field by comparing the geodetic response to recent eruptive episodes at Mount St. Helens. Finally, we point out a few areas that continue to challenge the volcano geodesy community, some of which are addressed by the papers that follow and which undoubtedly will be the focus of future research for years to come.

  11. Fiber Bragg grating strain sensors to monitor and study active volcanoes

    NASA Astrophysics Data System (ADS)

    Sorrentino, Fiodor; Beverini, Nicolò; Carbone, Daniele; Carelli, Giorgio; Francesconi, Francesco; Gambino, Salvo; Giacomelli, Umberto; Grassi, Renzo; Maccioni, Enrico; Morganti, Mauro

    2016-04-01

    Stress and strain changes are among the best indicators of impending volcanic activity. In volcano geodesy, borehole volumetric strain-meters are mostly utilized. However, they are not easy to install and involve high implementation costs. Advancements in opto-electronics have allowed the development of low-cost sensors, reliable, rugged and compact, thus particularly suitable for field application. In the framework of the EC FP7 MED-SUV project, we have developed strain sensors based on the fiber Bragg grating (FBG) technology. In comparison with previous implementation of the FBG technology to study rock deformations, we have designed a system that is expected to offer a significantly higher resolution and accuracy in static measurements and a smooth dynamic response up to 100 Hz, implying the possibility to observe seismic waves. The system performances are tailored to suit the requirements of volcano monitoring, with special attention to power consumption and to the trade-off between performance and cost. Preliminary field campaigns were carried out on Mt. Etna (Italy) using a prototypal single-axis FBG strain sensor, to check the system performances in out-of-the-lab conditions and in the harsh volcanic environment (lack of mains electricity for power, strong diurnal temperature changes, strong wind, erosive ash, snow and ice during the winter time). We also designed and built a FBG strain sensor featuring a multi-axial configuration which was tested and calibrated in the laboratory. This instrument is suitable for borehole installation and will be tested on Etna soon.

  12. Volcanoes

    MedlinePlus

    ... Oregon have the most active volcanoes, but other states and territories have active volcanoes, too. A volcanic eruption may involve lava and other debris that can flow up to 100 mph, destroying everything in their ...

  13. Dynamic Deformation of ETNA Volcano Observed by GPS and SAR Interferometry

    NASA Technical Reports Server (NTRS)

    Lundgren, P.; Rosen, P.; Webb, F.; Tesauro, M.; Lanari, R.; Sansosi, E.; Puglisi, G.; Bonforte, A.; Coltelli, M.

    1999-01-01

    Synthetic aperture radar (SAR) interferometry and GPS have shown that during the quiescent period from 1993-1995 Mt. Etna volcano, Italy, inflated. Since the initiation of eruptive activity since late 1995 the deformation has been more contentious. We will explore the detailed deformation during the period from 1995-1996 spanning the late stages of inflation and the beginning of eruptive activity. We use SAR interferometry and GPS data to measure the volcano deformation. We invert the observed deformation for both simple point source. le crack elastic sources or if warranted for a spheroidal pressure So In particular, we will examine the evolution of the inflation and the transition to a lesser deflation observed at the end of 1995. We use ERS-1/2 SAR data from both ascending and descending passes to allow for dense temporal 'sampling of the deformation and to allow us to critically assess atmospheric noise. Preliminary results from interferometry suggest that the inflation rate accelerated prior to resumption of activity in 1995, while GPS data suggest a more steady inflation with some fluctuation following the start of activity. This study will compare and contrast the interferometric SAR and GPS results and will address the strengths and weaknesses of each technique towards volcano deformation studies.

  14. Cyclic Activity of Mud Volcanoes: Evidences from Trinidad (SE Caribbean)

    NASA Astrophysics Data System (ADS)

    Deville, E.

    2007-12-01

    Fluid and solid transfer in mud volcanoes show different phases of activity, including catastrophic events followed by periods of relative quiescence characterized by moderate activity. This can be notably shown by historical data onshore Trinidad. Several authors have evoked a possible link between the frequencies of eruption of some mud volcanoes and seismic activity, but in Trinidad there is no direct correlation between mud eruptions and seisms. It appears that each eruptive mud volcano has its own period of catastrophic activity, and this period is highly variable from one volcano to another. The frequency of activity of mud volcanoes seems essentially controlled by local pressure regime within the sedimentary pile. At the most, a seism can, in some cases, activate an eruption close to its term. The dynamics of expulsion of the mud volcanoes during the quiescence phases has been studied notably from temperature measurements within the mud conduits. The mud temperature is concurrently controlled by, either, the gas flux (endothermic gas depressurizing induces a cooling effect), or by the mud flux (mud is a vector for convective heat transfer). Complex temperature distribution was observed in large conduits and pools. Indeed, especially in the bigger pools, the temperature distribution characterizes convective cells with an upward displacement of mud above the deep outlet, and ring-shaped rolls associated with the burial of the mud on the flanks of the pools. In simple, tube-like shaped, narrow conduits, the temperature is more regular, but we observed different types of profiles, with either downward increasing or decreasing temperatures. If the upward flow of mud would be regular, we should expect increasing temperatures and progressively decreasing gradient with depth within the conduits. However, the variable measured profiles from one place to another, as well as time-variable measured temperatures within the conduits and especially, at the base of the

  15. New Insights on Mt. Etna's Crust and Relationship with the Regional Tectonic Framework from Joint Active and Passive P-Wave Seismic Tomography

    NASA Astrophysics Data System (ADS)

    Díaz-Moreno, A.; Barberi, G.; Cocina, O.; Koulakov, I.; Scarfì, L.; Zuccarello, L.; Prudencio, J.; García-Yeguas, A.; Álvarez, I.; García, L.; Ibáñez, J. M.

    2018-01-01

    In the Central Mediterranean region, the production of chemically diverse volcanic products (e.g., those from Mt. Etna and the Aeolian Islands archipelago) testifies to the complexity of the tectonic and geodynamic setting. Despite the large number of studies that have focused on this area, the relationships among volcanism, tectonics, magma ascent, and geodynamic processes remain poorly understood. We present a tomographic inversion of P-wave velocity using active and passive sources. Seismic signals were recorded using both temporary on-land and ocean bottom seismometers and data from a permanent local seismic network consisting of 267 seismic stations. Active seismic signals were generated using air gun shots mounted on the Spanish Oceanographic Vessel `Sarmiento de Gamboa'. Passive seismic sources were obtained from 452 local earthquakes recorded over a 4-month period. In total, 184,797 active P-phase and 11,802 passive P-phase first arrivals were inverted to provide three different velocity models. Our results include the first crustal seismic active tomography for the northern Sicily area, including the Peloritan-southern Calabria region and both the Mt. Etna and Aeolian volcanic environments. The tomographic images provide a detailed and complete regional seismotectonic framework and highlight a spatially heterogeneous tectonic regime, which is consistent with and extends the findings of previous models. One of our most significant results was a tomographic map extending to 14 km depth showing a discontinuity striking roughly NW-SE, extending from the Gulf of Patti to the Ionian Sea, south-east of Capo Taormina, corresponding to the Aeolian-Tindari-Letojanni fault system, a regional deformation belt. Moreover, for the first time, we observed a high-velocity anomaly located in the south-eastern sector of the Mt. Etna region, offshore of the Timpe area, which is compatible with the plumbing system of an ancient shield volcano located offshore of Mt. Etna.

  16. Volcano hazards at Newberry Volcano, Oregon

    USGS Publications Warehouse

    Sherrod, David R.; Mastin, Larry G.; Scott, William E.; Schilling, Steven P.

    1997-01-01

    Newberry volcano is a broad shield volcano located in central Oregon. It has been built by thousands of eruptions, beginning about 600,000 years ago. At least 25 vents on the flanks and summit have been active during several eruptive episodes of the past 10,000 years. The most recent eruption 1,300 years ago produced the Big Obsidian Flow. Thus, the volcano's long history and recent activity indicate that Newberry will erupt in the future. The most-visited part of the volcano is Newberry Crater, a volcanic depression or caldera at the summit of the volcano. Seven campgrounds, two resorts, six summer homes, and two major lakes (East and Paulina Lakes) are nestled in the caldera. The caldera has been the focus of Newberry's volcanic activity for at least the past 10,000 years. Other eruptions during this time have occurred along a rift zone on the volcano's northwest flank and, to a lesser extent, the south flank. Many striking volcanic features lie in Newberry National Volcanic Monument, which is managed by the U.S. Forest Service. The monument includes the caldera and extends along the northwest rift zone to the Deschutes River. About 30 percent of the area within the monument is covered by volcanic products erupted during the past 10,000 years from Newberry volcano. Newberry volcano is presently quiet. Local earthquake activity (seismicity) has been trifling throughout historic time. Subterranean heat is still present, as indicated by hot springs in the caldera and high temperatures encountered during exploratory drilling for geothermal energy. This report describes the kinds of hazardous geologic events that might occur in the future at Newberry volcano. A hazard-zonation map is included to show the areas that will most likely be affected by renewed eruptions. In terms of our own lifetimes, volcanic events at Newberry are not of day-to-day concern because they occur so infrequently; however, the consequences of some types of eruptions can be severe. When Newberry

  17. 2014-2016 Mt. Etna Ground deformation imaged by SISTEM approach using GPS and SENTINEL-1A/1B TOPSAR data

    NASA Astrophysics Data System (ADS)

    Bonforte, Alessandro; Guglielmino, Francesco; Puglisi, Giuseppe

    2017-04-01

    In the frame of the EC FP7 MED-SUV project (call FP7 ENV.2012.6.4-2), and thanks to the GEO-GSNL initiative, GPS data and SENTINEL 1A/1B TOPSAR acquired on Mt. Etna between October 2014 and November 2016 were analyzed. The SENTINEL data were used in order to combine and integrate them with GPS, and detail the ground deformation recorded by GPS on Mt. Etna, during the last two-year's volcanic activity. The Sentinel data were processed by GAMMA software, using a spectral diversity method and a procedure able to co-register the SENTINEL pairs with extremely high precision (< 0.01 pixel). In order to optimize the time processing, a new software architecture based on the hypervisor virtualization technology for the x64 versions of Windows has been implemented. The DInSAR results are analysed and successively used as input for the time series analysis using the StaMPS package. On December 28, 2014 eruptive activity resumed at Mt. Etna with a fire fountain activity feeding two lava flows spreading on the eastern and south-western upper flanks of the volcano, producing evident deformation at the summit of the volcano. GPS displacements and Sentinel-1A ascending interferogram were calculated in order to image the ground deformation pattern accompanying the eruption. The ground deformation pattern has been perfectly depicted by the GPS network, mainly affecting the uppermost part of the volcano edifice, with a strong decay of the deformation, according to a very shallow and strong dyke intrusion. The Sentinel 1A SAR data, covering the similar time spanning, confirmed that most of displacements are related to the dike intrusion, and evidenced a local gravity-driven motion of the western wall of the Valle del Bove, probably related to the dike intrusion. To monitor the temporal successive evolution of ground deformation, we performed an A-DInSAR SENTINEL analysis using the Small BAseline Subset (SBAS) approach included with the StaMPS processing package. The April 2015

  18. Deep low-frequency earthquake activities during the failed magmatic eruptions of Mts. Iwate and Fuji, Japan

    NASA Astrophysics Data System (ADS)

    Nakamichi, H.; Hamaguchi, H.; Ukawa, M.; Tanaka, S.; Ueki, S.; Nishimura, T.

    2008-12-01

    I review deep low-frequency earthquake (DLF) activities during the failed magmatic eruptions of Mts. Iwate and Fuji, Japan. Volcanic unrests at Mts. Iwate and Fuji were observed in 1998-1999 and 2000-2001, respectively. Several hundred DLFs occurred during the unrest at Mt. Iwate; the number of DLFs in a normal year is less than or equal to 10. The DLF activity at Mt. Fuji increased sharply during the period from September 2000 to May 2001. The frequency of DLFs at Mt. Fuji during the DLF swarm was 20 times higher than that during normal activity. The DLFs of Mts. Iwate and Fuji show non-DC source mechanisms and suggest fluid motion at the focal regions. The DLF hypocenters of Mt. Fuji defined an ellipsoid with a diameter of 5 km; their focal depths are 11-16 km. The ellipsoid was centered 3 km northeast of the summit, and its major axis was directed in the northwest-southeast direction. The center of the ellipsoid gradually migrated upward, and 2-3 km in the northwest direction during 1998-2001. The migration of the DLFs reflects the volcanic fluid migration associated with a northwest-southeast-oriented dike beneath Mt. Fuji. The DLFs of Mt. Iwate were located at intermediate depths (5-12 km) beneath the summit and at deep depths (31-37 km) in the regions located 10 km south and 10 km northeast of the summit. In April 1998, the frequency of DLFs increased five days before an increase in the occurrence of shallow volcanic earthquakes at Mt. Iwate. Hypocenter migration of the DLFs at intermediate depths was observed from April 1998 to September 1998. New fumarole activity in the western region of Mt. Iwate commenced in 1999. These observations indicate that DLFs at Mts. Fuji and Iwate have common features in their activities and source mechanisms. But, shallow volcanic activities at these two volcanoes were much different: strong shallow seismic activity and volcano inflations as well as a new formation of fumarolic area were observed at Mt. Iwate, while such

  19. 4D volcano gravimetry

    USGS Publications Warehouse

    Battaglia, Maurizio; Gottsmann, J.; Carbone, D.; Fernandez, J.

    2008-01-01

    Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful evaluation of the layout of network benchmarks, the gravity environmental signal, and the coupling between gravity changes and crustal deformation. When changes in the system under study are fast (hours to weeks), as in hydrothermal systems and restless volcanoes, continuous gravity observations at selected sites can help to capture many details of the dynamics of the intrusive sources. Despite the instrumental effects, mainly caused by atmospheric temperature, results from monitoring at Mt. Etna volcano show that continuous measurements are a powerful tool for monitoring and studying volcanoes.Several analytical and numerical mathematical models can beused to fit gravity and deformation data. Analytical models offer a closed-form description of the volcanic source. In principle, this allows one to readily infer the relative importance of the source parameters. In active volcanic sites such as Long Valley caldera (California, U.S.A.) and Campi Flegrei (Italy), careful use of analytical models and high-quality data sets has produced good results. However, the simplifications that make analytical models tractable might result in misleading volcanological inter-pretations, particularly when the real crust surrounding the source is far from the homogeneous/ isotropic assumption. Using numerical models allows consideration of more realistic descriptions of the sources and of the crust where they are located (e.g., vertical and lateral mechanical discontinuities, complex source geometries, and topography). Applications at Teide volcano (Tenerife) and Campi Flegrei demonstrate the

  20. Very-low-frequency resistivity, self-potential and ground temperature surveys on Taal volcano (Philippines): Implications for future activity

    NASA Astrophysics Data System (ADS)

    Zlotnicki, J.; Vargemezis, G.; Johnston, M. J. S.; Sasai, Y.; Reniva, P.; Alanis, P.

    2017-06-01

    Taal volcano is one of the most dangerous volcanoes in the Philippines. Thirty-three eruptions have occurred through historical time with several exhibiting cataclysmic phases. Most recent eruptions are confined to Volcano Island located within the prehistoric Taal collapse caldera that is now filled by Taal Lake. The last eruptive activity from 1965 to 1977 took place from Mt. Tabaro, about 2 km to the southwest of the Main Crater center. Since this time, episodes of seismic activity, ground deformation, gas release, surface fissuring, fumarole activity and temperature changes are recorded periodically around the main crater, but no major eruption has occurred. This period of quiescence is the third longest period without eruptive activity since 1572. In March 2010, a campaign based on Very-Low-Frequency (VLF) resistivity surveys together with repeated surveys of self-potential, ground temperature and fissure activity was intensified and the results compared to a large-scale Electrical Resistivity Tomography experiment. This work fortunately occurred before, within and after a new seismovolcanic crisis from late April 2010 to March 2011. The joint analysis of these new data, together with results from previous magnetotelluric soundings, allows a better description of the electrical resistivity and crustal structure beneath the Main Crater down to a depth of several kilometers. No indication of growth of the two geothermal areas located on both sides of the northern crater rim was apparent from 2005 to March 2010. These areas appear controlled by active fissures, opened during the 1992 and 1994 crises, that dip downward towards the core of the hydrothermal system located at about 2.5 km depth beneath the crater. Older mineralized fissures at lower elevations to the North of the geothermal areas also dip downward under the crater. Repeated self-potential and ground temperature surveys completed between 2005 and 2015 show new geothermal and hydrothermal activity in

  1. Long-term eruptive activity at a submarine arc volcano.

    PubMed

    Embley, Robert W; Chadwick, William W; Baker, Edward T; Butterfield, David A; Resing, Joseph A; de Ronde, Cornel E J; Tunnicliffe, Verena; Lupton, John E; Juniper, S Kim; Rubin, Kenneth H; Stern, Robert J; Lebon, Geoffrey T; Nakamura, Ko-ichi; Merle, Susan G; Hein, James R; Wiens, Douglas A; Tamura, Yoshihiko

    2006-05-25

    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes.

  2. Long-term eruptive activity at a submarine arc volcano

    USGS Publications Warehouse

    Embley, R.W.; Chadwick, W.W.; Baker, E.T.; Butterfield, D.A.; Resing, J.A.; de Ronde, Cornel E. J.; Tunnicliffe, V.; Lupton, J.E.; Juniper, S.K.; Rubin, K.H.; Stern, R.J.; Lebon, G.T.; Nakamura, K.-I.; Merle, S.G.; Hein, J.R.; Wiens, D.A.; Tamura, Y.

    2006-01-01

    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. ?? 2006 Nature Publishing Group.

  3. Do Glaciers on Cascade Volcanoes Behave Differently Than Other Glaciers in the Region?

    NASA Astrophysics Data System (ADS)

    Riedel, J. L.; Ryane, C.; Osborn, J.; Davis, T.; Menounos, B.; Clague, J. J.; Koch, J.; Scott, K. M.; Reasoner, M.

    2006-12-01

    It has been suggested that glaciers on two stratovolcanoes in the Cascade Range of Washington state, Mt. Baker and Glacier Peak, achieved their maximum extent of the past 10,000 years during the early Holocene. These findings differ from most evidence in western North America, which indicates that Little Ice Age moraines represent the most extensive glacier advances of the Holocene. Significant early Holocene advances are difficult to reconcile with the documented warm, dry conditions at this time in western North America. Our data indicate that glaciers on these volcanoes responded similarly to Holocene climatic events as glaciers in other areas in Washington and British Columbia. Heavy winter accumulation and favorable hypsometry have been proposed as the explanations for the unusual behavior of glaciers on volcanoes compared to similar-sized glaciers elsewhere in the Cascade Range. However, glacier mass balance on the volcanoes is controlled by not only these factors, but also by glacier geometry, snow erosion and ablation. Accumulation zones of glaciers on isolated Cascade stratovolcanoes are high, but are narrow at the top. For example, the accumulation zone of Deming Glacier on the southwest side of Mt. Baker extends above 3000 m asl, but due to its wedge shape lies largely below 2500 m asl. Furthermore, glaciers on Mt. Baker and other symmetrical volcanoes have high ablation rates because they are not shaded, and south-southwest aspects are subject to erosion of snow by prevailing southwesterly winds. Modern glacier observations in the North Cascades quantify the important influence of aspect and snow erosion on glacier mass balance. For example, average equilibrium line altitude (ELA) of Easton Glacier on the south flank of Mt. Baker is 2160 m, whereas the ELA of a north-facing cirque glacier 25km to the east is 2040m. Our research at Mt. Baker contradicts the claim of extensive early Holocene advances on the south flank of the volcano. Tephra set SC, which

  4. Expert Systems for Real-Time Volcano Monitoring

    NASA Astrophysics Data System (ADS)

    Cassisi, C.; Cannavo, F.; Montalto, P.; Motta, P.; Schembra, G.; Aliotta, M. A.; Cannata, A.; Patanè, D.; Prestifilippo, M.

    2014-12-01

    In the last decade, the capability to monitor and quickly respond to remote detection of volcanic activity has been greatly improved through use of advanced techniques and semi-automatic software applications installed in most of the 24h control rooms devoted to volcanic surveillance. Ability to monitor volcanoes is being advanced by new technology, such as broad-band seismology, microphone networks mainly recording in the infrasonic frequency band, satellite observations of ground deformation, high quality video surveillance systems, also in infrared band, improved sensors for volcanic gas measurements, and advances in computer power and speed, leading to improvements in data transmission, data analysis and modeling techniques. One of the most critical point in the real-time monitoring chain is the evaluation of the volcano state from all the measurements. At the present, most of this task is delegated to one or more human experts in volcanology. Unfortunately, the volcano state assessment becomes harder if we observe that, due to the coupling of highly non-linear and complex volcanic dynamic processes, the measurable effects can show a rich range of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data, precise state assessment is usually not achievable. Hence, the volcano state needs to be expressed in probabilistic terms that take account of uncertainties. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management) work, we have developed an expert system approach to estimate the ongoing volcano state from all the available measurements and with minimal human interaction. The approach is based on hidden markov model and deals with uncertainties and probabilities. We tested the proposed approach on data coming from the Mt. Etna (Italy) continuous monitoring networks for the period 2011-2013. Results show that this approach can be a valuable tool to aid the

  5. Monitoring an EGS injection at Newberry Volcano using Magnetotelluric dimensionality analysis

    NASA Astrophysics Data System (ADS)

    Bowles-martinez, E.; Schultz, A.; Rose, K.; Urquhart, S.

    2016-12-01

    The sensitivity of magnetotelluric (MT) data to the presence of electrically conductive subsurface features makes it applicable for determining the extent of injected fluids in enhanced geothermal systems (EGS). We use MT to monitor fluid injection during tests of a proposed EGS site at Newberry Volcano in Central Oregon, USA. Newberry is a large shield volcano located where fault systems of the northern Basin and Range meet the Cascade Arc and the high lava plains. Its strong potential for geothermal energy has made it a target for energy exploration for over 40 years. MT measurements were made before, during, and after an EGS stimulation in 2014 in an effort to detect subsurface pathways taken by fluids that are attributable to stimulation. We begin by creating a baseline model from inverting over 200 wideband MT stations located in the western half of the volcano. This model is constrained by well logs, as well as by high resolution gravity and seismic velocity modeling. Our model shows conductive regions associated with the caldera's ring fault, likely showing where hydrothermal fluids or their mineral alteration products are present. However, as this is an EGS study, we are interested in detecting fluid intrusion into hot, dry rock. Therefore, our primary target is a resistive zone on the western flank of Newberry volcano that is interpreted as a series of hot intrusive sequences. Well bottom temperatures in this area have been measured in excess of 300 °C. The stimulation's effect on resistivity is subtle, in part because the injected fluid is fresh groundwater, the injected volume is modest, and the target depth is 2,000-3,000 m below ground level. We found that it is advantageous to look at the impedance tensor data directly to detect injected fluids. Because fluids and their associated change in resistivity are expected to be concentrated around the injection well, the injection will exhibit a highly three-dimensional resistivity structure. Therefore, we

  6. The 2001 Mt. Etna eruption: new constraints on the intrusive mechanism from ground deformation data

    NASA Astrophysics Data System (ADS)

    Palano, Mimmo; González, Pablo J.

    2013-04-01

    The occurrence of seismic swarms beneath the SW flank of Mt. Etna, often observed just a few months before an eruption, has been considered as the fragile response to a magma intrusion (Bonanno et al., 2011 and reference therein). These intrusions and/or pressurization of deep magmatic bodies, have been able to significantly affect the seismic pattern within the volcano edifice, leading to a changes in the local stress field. For example, during the months preceding the 1991-1993 Mt. Etna eruption, shallow intense seismic swarms (4-6 km deep) occurring in the SW flank (e.g. Cocina et al., 1998), related to the magma intrusion before the eruption onset, were observed contemporaneously with a rotation of stress field of about 90°. A similar scenario was observed during January 1998, when a magma recharging phases induced a local rotation of stress tensor, forcing a buried fault zone located beneath the SW flank of Mt. Etna to slip as a right-lateral strike-slip fault (Bonanno et al., 2011). This fault system was forced to slip again, during late April 2001 (more than 200 events in less than 5 days; maximum Magnitude = 3.6) by the pressurization of the magmatic bodies feeding the July-August 2001 Mt. Etna eruption. Here we analyzed in detail the July-August 2001 Mt. Etna eruption as well as the dynamics preceding this event, by using a large dataset of geodetic data (GPS and synthetic aperture radar interferometry) collected between July 2000 and August 2001. References Cocina, O., Neri, G., Privitera, E. and Spampinato S., 1998. Seismogenic stress field beneath Mt. Etna South Italy and possible relationships with volcano-tectonic features. J. Volcanol. Geotherm. Res., 83, 335-348. Bonanno A., Palano M., Privitera E., Gresta S., Puglisi G., 2011. Magma intrusion mechanisms and redistribution of seismogenic stress at Mt. Etna volcano (1997-1998). Terra Nova, 23, 339-348, doi: 10.1111/j.1365-3121.2011.01019.x, 2011.

  7. Volcanoes.

    ERIC Educational Resources Information Center

    Tilling, Robert I.

    One of a series of general interest publications on science topics, this booklet provides a non-technical introduction to the subject of volcanoes. Separate sections examine the nature and workings of volcanoes, types of volcanoes, volcanic geological structures such as plugs and maars, types of eruptions, volcanic-related activity such as geysers…

  8. Amplitude and Recurrence Time of LP activity at Mt. Etna, Italy

    NASA Astrophysics Data System (ADS)

    Cauchie, Léna; Saccorotti, Gilberto; Bean, Christopher

    2013-04-01

    , similar for both families, differ instead significantly from the Gutenberg-Richter law, and the inter-event times distributions don't follow a typical Gamma-law. In order to compare these results with a catalogue for which the source mechanism is well-established, we applied the same analysis procedure to a dataset from Stromboli Volcano, where LP activity is closely related to VLP (Very-Long-Period) pulses, in turn associated with the summit explosions. Again, catalogues of thousands of LP events were achieved over one month of seismic records (July 2011). Our results indicate a similar behaviour in terms of both amplitude and inter-event time distributions, with respect to what observed at Mt. Etna. This suggests that the Etna's LP data are likely related with a degassing process occurring at depth. Nonetheless, further studies are needed in order to quantify the time recurrence and amplitude distribution of brittle failure in viscous, stressed magmas. Hopefully, these steps will lead to an improved understanding of LP activity in different volcanic contexts, in turn clarifying its significance in terms of eruption forecasting.

  9. Activity at Shiveluch Volcano

    NASA Image and Video Library

    2017-12-08

    NASA image acquired Sept 7, 2010 Shiveluch (also spelled Sheveluch) is one of the largest and most active volcanoes on Russia’s Kamchatka Peninsula. It has been spewing ash and steam intermittently—with occasional dome collapses, pyroclastic flows, and lava flows, as well—for the past decade. Shiveluch is a stratovolcano, a steep-sloped formation of alternating layers of hardened lava, ash, and rocks thrown out by earlier eruptions. A lava dome has been growing southwest of the 3,283-meter (10,771-foot) summit. The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite acquired this image on September 7, 2010. Brown and tan debris—perhaps ash falls, perhaps mud from lahars—covers the southern landscape of the volcano, while the hills on the northern side remain covered in snow and ice. The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that seismic activity at Shiveluch was "above background levels" from September 3-10. Ash plumes rose to an altitude of 6.5 kilometers (21,300 feet) on September 3-4, and gas-and-ash plumes were reported on September 7, when this image was acquired. According to the Smithsonian Institution's volcano program, at least 60 large eruptions of Shiveluch have occurred during the current Holocene Epoch of geological history. Intermittent explosive eruptions began in the 1990s, and the largest historical eruptions from Shiveluch occurred in 1854 and 1964. NASA Earth Observatory image created by Jesse Allen and Robert Simmon, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Caption by Mike Carlowicz. Instrument: EO-1 - ALI Credit: NASA Earth Observatory NASA Goddard Space Flight Center contributes to NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s endeavors by providing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on

  10. Active Volcano Monitoring using a Space-based Hyperspectral Imager

    NASA Astrophysics Data System (ADS)

    Cipar, J. J.; Dunn, R.; Cooley, T.

    2010-12-01

    Active volcanoes occur on every continent, often in close proximity to heavily populated areas. While ground-based studies are essential for scientific research and disaster mitigation, remote sensing from space can provide rapid and continuous monitoring of active and potentially active volcanoes [Ramsey and Flynn, 2004]. In this paper, we report on hyperspectral measurements of Kilauea volcano, Hawaii. Hyperspectral images obtained by the US Air Force TacSat-3/ARTEMIS sensor [Lockwood et al, 2006] are used to obtain estimates of the surface temperatures for the volcano. ARTEMIS measures surface-reflected light in the visible, near-infrared, and short-wave infrared bands (VNIR-SWIR). The SWIR bands are known to be sensitive to thermal radiation [Green, 1996]. For example, images from the NASA Hyperion hyperspectral sensor have shown the extent of wildfires and active volcanoes [Young, 2009]. We employ the methodology described by Dennison et al, (2006) to obtain an estimate of the temperature of the active region of Kilauea. Both day and night-time images were used in the analysis. To improve the estimate, we aggregated neighboring pixels. The active rim of the lava lake is clearly discernable in the temperature image, with a measured temperature exceeding 1100o C. The temperature decreases markedly on the exterior of the summit crater. While a long-wave infrared (LWIR) sensor would be ideal for volcano monitoring, we have shown that the thermal state of an active volcano can be monitored using the SWIR channels of a reflective hyperspectral imager. References: Dennison, Philip E., Kraivut Charoensiri, Dar A. Roberts, Seth H. Peterson, and Robert O. Green (2006). Wildfire temperature and land cover modeling using hyperspectral data, Remote Sens. Environ., vol. 100, pp. 212-222. Green, R. O. (1996). Estimation of biomass fire temperature and areal extent from calibrated AVIRIS spectra, in Summaries of the 6th Annual JPL Airborne Earth Science Workshop, Pasadena, CA

  11. Global data collection and the surveillance of active volcanoes

    USGS Publications Warehouse

    Ward, P.L.

    1990-01-01

    Data relay systems on existing earth-orbiting satellites provide an inexpensive way to collect environmental data from numerous remote sites around the world. This technology could be used effectively for fundamental monitoring of most of the world's active volcanoes. Such global monitoring would focus attention on the most dangerous volcanoes that are likely to significantly impact the geosphere and the biosphere. ?? 1990.

  12. Crustal contamination and crystal entrapment during polybaric magma evolution at Mt. Somma-Vesuvius volcano, Italy: Geochemical and Sr isotope evidence

    USGS Publications Warehouse

    Piochi, M.; Ayuso, R.A.; de Vivo, B.; Somma, R.

    2006-01-01

    New major and trace element analyses and Sr-isotope determinations of rocks from Mt. Somma-Vesuvius volcano produced from 25 ky BP to 1944 AD are part of an extensive database documenting the geochemical evolution of this classic region. Volcanic rocks include silica undersaturated, potassic and ultrapotassic lavas and tephras characterized by variable mineralogy and different crystal abundance, as well as by wide ranges of trace element contents and a wide span of initial Sr-isotopic compositions. Both the degree of undersaturation in silica and the crystal content increase through time, being higher in rocks produced after the eruption at 472 AD (Pollena eruption). Compositional variations have been generally thought to reflect contributions from diverse types of mantle and crust. Magma mixing is commonly invoked as a fundamental process affecting the magmas, in addition to crystal fractionation. Our assessment of geochemical and Sr-isotopic data indicates that compositional variability also reflects the influence of crustal contamination during magma evolution during upward migration to shallow crustal levels and/or by entrapment of crystal mush generated during previous magma storage in the crust. Using a variant of the assimilation fractional crystallization model (Energy Conservation-Assimilation Fractional Crystallization; [Spera and Bohrson, 2001. Energy-constrained open-system magmatic processes I: General model and energy-constrained assimilation and fractional crystallization (EC-AFC) formulation. J. Petrol. 999-1018]; [Bohrson, W.A. and Spera, F.J., 2001. Energy-constrained open-system magmatic process II: application of energy-constrained assimilation-fractional crystallization (EC-AFC) model to magmatic systems. J. Petrol. 1019-1041]) we estimated the contributions from the crust and suggest that contamination by carbonate rocks that underlie the volcano (2 km down to 9-10 km) is a fundamental process controlling magma compositions at Mt. Somma

  13. Evaluating life-safety risk of fieldwork at New Zealand's active volcanoes

    NASA Astrophysics Data System (ADS)

    Deligne, Natalia; Jolly, Gill; Taig, Tony; Webb, Terry

    2014-05-01

    Volcano observatories monitor active or potentially active volcanoes. Although the number and scope of remote monitoring instruments and methods continues to grow, in-person field data collection is still required for comprehensive monitoring. Fieldwork anywhere, and especially in mountainous areas, contains an element of risk. However, on volcanoes with signs of unrest, there is an additional risk of volcanic activity escalating while on site, with potentially lethal consequences. As an employer, a volcano observatory is morally and sometimes legally obligated to take reasonable measures to ensure staff safety and to minimise occupational risk. Here we present how GNS Science evaluates life-safety risk for volcanologists engaged in fieldwork on New Zealand volcanoes with signs of volcanic unrest. Our method includes several key elements: (1) an expert elicitation for how likely an eruption is within a given time frame, (2) quantification of, based on historical data when possible, given a small, moderate, or large eruption, the likelihood of exposure to near-vent processes, ballistics, or surge at various distances from the vent, and (3) estimate of fatality rate given exposure to these volcanic hazards. The final product quantifies hourly fatality risk at various distances from a volcanic vent; various thresholds of risk (for example, zones with more than 10-5 hourly fatality risk) trigger different levels of required approval to undertake work. Although an element of risk will always be present when conducting fieldwork on potentially active volcanoes, this is a first step towards providing objective guidance for go/no go decisions for volcanic monitoring.

  14. Catalog of the historically active volcanoes of Alaska

    USGS Publications Warehouse

    Miller, T.P.; McGimsey, R.G.; Richter, D.H.; Riehle, J.R.; Nye, C.J.; Yount, M.E.; Dumoulin, Julie A.

    1998-01-01

    Alaska hosts within its borders over 80 major volcanic centers that have erupted during Holocene time (< 10,000 years). At least 29 of these volcanic centers (table 1) had historical eruptions and 12 additional volcanic centers may have had historical eruptions. Historical in Alaska generally means the period since 1760 when explorers, travelers, and inhabitants kept written records. These 41 volcanic centers have been the source for >265 eruptions reported from Alaska volcanoes. With the exception of Wrangell volcano, all the centers are in, or near, the Aleutian volcanic arc, which extends 2500 km from Hayes volcano 145 km west of Anchorage in the Alaska-Aleutian Range to Buldir Island in the western Aleutian Islands (fig. 1). The volcanic arc, a subduction-related feature associated with underthrusting of the Pacific plate beneath the North American plate is divided between oceanic island arc and continental margin segments, the boundary occurring at about 165° W longitude (fig. 1). An additional 7 volcanic centers in the Aleutian arc (table 2; fig. 1 A) have active fumarole fields but no reported historical eruptions.This report discusses the location, physiography and structure, eruptive history, and geology of those volcanoes in Alaska that have experienced one or more eruptions that have been recorded in the written history (i.e., in historical time). It is part of the group of catalogs entitled Catalogue of Active Volcanoes of the World published beginning in 1951 under the auspices of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI). A knowledge of the information contained in such catalogs aids in understanding the type and scale of activity that might be expected during a particular eruption, the hazards the eruption may pose, and even the prediction of eruptions. The catalog will thus be of value not only to the inhabitants of Alaska but to government agencies concerned with emergency response, air traffic

  15. Critical Role of Transient Activity of MT1-MMP for ECM Degradation in Invadopodia

    PubMed Central

    Watanabe, Ayako; Hosino, Daisuke; Koshikawa, Naohiko; Seiki, Motoharu; Suzuki, Takashi; Ichikawa, Kazuhisa

    2013-01-01

    Focal degradation of extracellular matrix (ECM) is the first step in the invasion of cancer cells. MT1-MMP is a potent membrane proteinase employed by aggressive cancer cells. In our previous study, we reported that MT1-MMP was preferentially located at membrane protrusions called invadopodia, where MT1-MMP underwent quick turnover. Our computer simulation and experiments showed that this quick turnover was essential for the degradation of ECM at invadopodia (Hoshino, D., et al., (2012) PLoS Comp. Biol., 8: e1002479). Here we report on characterization and analysis of the ECM-degrading activity of MT1-MMP, aiming at elucidating a possible reason for its repetitive insertion in the ECM degradation. First, in our computational model, we found a very narrow transient peak in the activity of MT1-MMP followed by steady state activity. This transient activity was due to the inhibition by TIMP-2, and the steady state activity of MT1-MMP decreased dramatically at higher TIMP-2 concentrations. Second, we evaluated the role of the narrow transient activity in the ECM degradation. When the transient activity was forcibly suppressed in computer simulations, the ECM degradation was heavily suppressed, indicating the essential role of this transient peak in the ECM degradation. Third, we compared continuous and pulsatile turnover of MT1-MMP in the ECM degradation at invadopodia. The pulsatile insertion showed basically consistent results with the continuous insertion in the ECM degradation, and the ECM degrading efficacy depended heavily on the transient activity of MT1-MMP in both models. Unexpectedly, however, low-frequency/high-concentration insertion of MT1-MMP was more effective in ECM degradation than high-frequency/low-concentration pulsatile insertion even if the time-averaged amount of inserted MT1-MMP was the same. The present analysis and characterization of ECM degradation by MT1-MMP together with our previous report indicate a dynamic nature of MT1-MMP at

  16. "Mediterranean volcanoes vs. chain volcanoes in the Carpathians"

    NASA Astrophysics Data System (ADS)

    Chivarean, Radu

    2017-04-01

    Volcanoes have always represent an attractive subject for students. Europe has a small number of volcanoes and Romania has none active ones. The curricula is poor in the study of volcanoes. We want to make a parallel between the Mediterranean active volcanoes and the old extinct ones in the Oriental Carpathians. We made an comparison of the two regions in what concerns their genesis, space and time distribution, the specific relief and the impact in the landscape, consequences of their activities, etc… The most of the Mediterranean volcanoes are in Italy, in the peninsula in Napoli's area - Vezuviu, Campi Flegrei, Puzzoli, volcanic islands in Tirenian Sea - Ischia, Aeolian Islands, Sicily - Etna and Pantelleria Island. Santorini is located in Aegean Sea - Greece. Between Sicily and Tunisia there are 13 underwater volcanoes. The island called Vulcano, it has an active volcano, and it is the origin of the word. Every volcano in the world is named after this island, just north of Sicily. Vulcano is the southernmost of the 7 main Aeolian Islands, all volcanic in origin, which together form a small island arc. The cause of the volcanoes appears to be a combination of an old subduction event and tectonic fault lines. They can be considered as the origin of the science of volcanology. The volcanism of the Carpathian region is part of the extensive volcanic activity in the Mediterranean and surrounding regions. The Carpathian Neogene/Quaternary volcanic arc is naturally subdivided into six geographically distinct segments: Oas, Gutai, Tibles, Calimani, Gurghiu and Harghita. It is located roughly between the Carpathian thrust-and-fold arc to the east and the Transylvanian Basin to the west. It formed as a result of the convergence between two plate fragments, the Transylvanian micro-plate and the Eurasian plate. Volcanic edifices are typical medium-sized andesitic composite volcanoes, some of them attaining the caldera stage, complicated by submittal or peripheral domes

  17. A Broadly-Based Training Program in Volcano Hazards Monitoring at the Center for the Study of Active Volcanoes

    NASA Astrophysics Data System (ADS)

    Thomas, D. M.; Bevens, D.

    2015-12-01

    The Center for the Study of Active Volcanoes, in cooperation with the USGS Volcano Hazards Program at HVO and CVO, offers a broadly based volcano hazards training program targeted toward scientists and technicians from developing nations. The program has been offered for 25 years and provides a hands-on introduction to a broad suite of volcano monitoring techniques, rather than detailed training with just one. The course content has evolved over the life of the program as the needs of the trainees have changed: initially emphasizing very basic monitoring techniques (e.g. precise leveling, interpretation of seismic drum records, etc.) but, as the level of sophistication of the trainees has increased, training in more advanced technologies has been added. Currently, topics of primary emphasis have included volcano seismology and seismic networks; acquisition and modeling of geodetic data; methods of analysis and monitoring of gas geochemistry; interpretation of volcanic deposits and landforms; training in LAHARZ, GIS mapping of lahar risks; and response to and management of volcanic crises. The course also provides training on public outreach, based on CSAV's Hawaii-specific hazards outreach programs, and volcano preparedness and interactions with the media during volcanic crises. It is an intensive eight week course with instruction and field activities underway 6 days per week; it is now offered in two locations, Hawaii Island, for six weeks, and the Cascades volcanoes of the Pacific Northwest, for two weeks, to enable trainees to experience field conditions in both basaltic and continental volcanic environments. The survival of the program for more than two decades demonstrates that a need for such training exists and there has been interaction and contribution to the program by the research community, however broader engagement with the latter continues to present challenges. Some of the reasons for this will be discussed.

  18. Mt. Elgon, Africa, Shaded Relief and Colored Height

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The striking contrast of geologic structures in Africa is shown in this shaded relief image of Mt. Elgon on the left and a section of the Great Rift Valley on the right.

    Mt. Elgon is a solitary extinct volcano straddling the border between Uganda and Kenya, and at 4,321 meters (14,178 feet) tall is the eighth highest mountain in Africa. It is positioned on the Pre-Cambriam bedrock of the Trans Nzoia Plateau, and is similar to other such volcanoes in East Africa in that it is associated with the formation of the Rift Valley. However one thing that sets Mt. Elgon apart is its age.

    Although there is no verifiable evidence of its earliest volcanic activity, Mt. Elgon is estimated to be at least 24 million years old, making it the oldest extinct volcano in East Africa. This presents a striking comparison to Mt. Kilimanjaro, the highest mountain in Africa at 5,895 meters (19,341 feet), which is just over one million years old. Judging by the diameter of its base, it is a common belief among geological experts that Mt. Elgon was once the highest mountains in Africa, however erosion has played a significant role in reducing the height to its present value.

    Juxtaposed with this impressive mountain is a section of the Great Rift Valley, a geological fault system that extends for about 4,830 kilometers (2,995 miles) from Syria to central Mozambique. Erosion has concealed some sections, but in some sections like that shown here, there are sheer cliffs several thousand feet high. The present configuration of the valley, which dates from the mid-Pleistocene epoch, results from a rifting process associated with thermal currents in the Earth's mantle.

    Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly

  19. Linking petrology and seismology at an active volcano.

    PubMed

    Saunders, Kate; Blundy, Jon; Dohmen, Ralf; Cashman, Kathy

    2012-05-25

    Many active volcanoes exhibit changes in seismicity, ground deformation, and gas emissions, which in some instances arise from magma movement in the crust before eruption. An enduring challenge in volcano monitoring is interpreting signs of unrest in terms of the causal subterranean magmatic processes. We examined over 300 zoned orthopyroxene crystals from the 1980-1986 eruption of Mount St. Helens that record pulsatory intrusions of new magma and volatiles into an existing larger reservoir before the eruption occurred. Diffusion chronometry applied to orthopyroxene crystal rims shows that episodes of magma intrusion correlate temporally with recorded seismicity, providing evidence that some seismic events are related to magma intrusion. These time scales are commensurate with monitoring signals at restless volcanoes, thus improving our ability to forecast volcanic eruptions by using petrology.

  20. Alaska Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Murray, Tom; Read, Cyrus

    2008-01-01

    Steam plume from the 2006 eruption of Augustine volcano in Cook Inlet, Alaska. Explosive ash-producing eruptions from Alaska's 40+ historically active volcanoes pose hazards to aviation, including commercial aircraft flying the busy North Pacific routes between North America and Asia. The Alaska Volcano Observatory (AVO) monitors these volcanoes to provide forecasts of eruptive activity. AVO is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Augustine volcano and AVO at http://www.avo.alaska.edu.

  1. Volcanic Tremor at Mt. Etna, Italy, Preceding and Accompanying the Eruption of July August, 2001

    NASA Astrophysics Data System (ADS)

    Falsaperla, S.; Alparone, S.; D'Amico, S.; Grazia, G.; Ferrari, F.; Langer, H.; Sgroi, T.; Spampinato, S.

    2005-11-01

    The July 17 August 9, 2001 flank eruption of Mt. Etna was preceded and accompanied by remarkable changes in volcanic tremor. Based on the records of stations belonging to the permanent seismic network deployed on the volcano, we analyze amplitude and frequency content of the seismic signal. We find considerable changes in the volcanic tremor which mark the transition to different styles of eruptive activity, e.g., lava fountains, phreatomagmatic activity, Strombolian explosions. In particular, the frequency content of the signal decreases from 5 Hz to 3 Hz at our reference station ETF during episodes of lava fountains, and further decreases at about 2 Hz throughout phases of intense lava emission. The frequency content and the ratios of the signal amplitude allow us to distinguish three seismic sources, i.e., the peripheral dike which fed the eruption, the reservoir which fed the lava fountains, and the central conduit. Based on the analysis of the amplitude decay of the signal, we highlight the migration of the dike from a depth of ca. 5 km to about 1 km between July 10 and 12. After the onset of the effusive phase, the distribution of the amplitude decay at our stations can be interpreted as the overall result of sources located within the first half kilometer from the surface. Although on a qualitative basis, our findings shed some light on the complex feeding system of Mt. Etna, and integrate other volcanological and geophysical studies which tackle the problem of magma replenishment for the July August, 2001 flank eruption. We conclude that volcanic tremor is fundamental in monitoring Mt. Etna, not only as a marker of the different sources which act within the volcano edifice, but also of the diverse styles of eruptive activity.

  2. Catalogue of satellite photography of the active volcanoes of the world

    NASA Technical Reports Server (NTRS)

    Heiken, G.

    1976-01-01

    A catalogue is presented of active volcanoes as viewed from Earth-orbiting satellites. The listing was prepared of photographs, which have been screened for quality, selected from the earth resources technology satellite (ERTS) and Skylab, Apollo and Gemini spacecraft. There is photography of nearly every active volcano in the world; the photographs are particularly useful for regional studies of volcanic fields.

  3. Unifying tephrostratigraphic approaches to redefine major Holocene marker tephras, Mt. Taranaki, New Zealand

    NASA Astrophysics Data System (ADS)

    Damaschke, M.; Cronin, S. J.; Torres-Orozco, R.; Wallace, R. C.

    2017-05-01

    In this study, geochemical fingerprinting of glass shards and titanomagnetite phenocrysts was used to match twenty complex pyroclastic deposits from the flanks of Mt. Taranaki to major tephra fall ;marker beds; in medial and distal deposition sites. These correlations hinged upon identifying time-bound compositional changes (a chemostratigraphy) in distal Taranaki tephra-fall sequences preserved in lake and peat sediment records around the volcano. The current work shows that previous soil-stratigraphy based studies led to miscorrelations, because they relied upon radiocarbon dates, a ;counting back; approach, and an underestimate of the number of eruptions that actually occurred in any time frame. The new tephrostratigraphy proposed at Mt. Taranaki resulted from stratigraphic rearranging of several earlier-defined units. Some tephra units are older than previously determined (e.g., Waipuku, Tariki, and Mangatoki; 6 to 9 cal ka BP), while one of the most prominent Taranaki marker tephra deposit, the Korito, is shown to lie stratigraphically above a widespread rhyolitic marker bed from Taupo volcano, the Stent Tephra (also known as unit Q; 4.3 cal ka BP). Pyroclastic tephra deposits previously dated between 6 to 4 cal ka BP at a key tephra section, c. 40 km NE of Mt. Taranaki's summit, were misidentified and are now shown to comprise new marker tephra deposits, including the Kokowai ( 4.7 cal ka BP), which is a prominent marker horizon on the eastern flanks of the volcano. A new local proximal stratigraphy for < 5 cal ka BP tephra units can be well correlated to tephra layers within distal lake and peat sequences, but the differences between the two records indicates an overall larger number of eruptions have occurred at this volcano than previously thought. This study additionally demonstrates the utility of titanomagnetite chemistry for discrimination and correlation of groups or sequences of tephra deposits - even if unique compositions cannot be identified.

  4. Risk-Free Volcano Observations Using an Unmanned Autonomous Helicopter: seismic observations near the active vent of Sakurajima volcano, Japan

    NASA Astrophysics Data System (ADS)

    Ohminato, T.; Kaneko, T.; Koyama, T.; Yasuda, A.; Watanabe, A.; Takeo, M.; Honda, Y.; Kajiwara, K.; Kanda, W.; Iguchi, M.; Yanagisawa, T.

    2010-12-01

    Observations in the vicinity of summit area of active volcanoes are important not only for understanding physical processes in the volcanic conduit but also for eruption prediction and volcanic hazards mitigation. It is, however, challenging to install observation sensors near active vents because of the danger of sudden eruptions. We need safe and efficient ways of installing sensors near the summit of active volcanoes. We have been developing an volcano observation system based on an unmanned autonomous vehicle (UAV) for risk-free volcano observations. Our UAV is an unmanned autonomous helicopter manufactured by Yamaha-Motor Co., Ltd. The UAV is 3.6m long and weighs 84kg with maximum payload of 10kg. The UAV can aviate autonomously along a previously programmed path within a meter accuracy using real-time kinematics differential GPS equipment. The maximum flight time and distance from the operator are 90 minutes and 5km, respectively. We have developed various types of volcano observation techniques adequate for the UAV, such as aeromagnetic survey, taking infrared and visible images from onboard high-resolution cameras, volcanic ash sampling in the vicinity of active vents. Recently, we have developed an earthquake observation module (EOM), which is exclusively designed for the UAV installation in the vicinity of active volcanic vent. In order to meet the various requirements for UAV installation, the EOM is very compact, light-weight (5-6kg), and is solar-powered. It is equipped with GPS for timing, a communication device using cellular-phone network, and triaxial accelerometers. Our first application of the EOM installation using the UAV is one of the most active volcanoes in Japan, Sakurajima volcano. Since 2006, explosive eruptions have been continuing at the reopened Showa crater at the eastern flank near the summit of Sakurajima. Entering the area within 2 km from the active craters is prohibited, and thus there were no observation station in the vicinity

  5. Topographic Change at Mt. Pinatubo, Philippines, from SRTM and TOPSAR Observations

    NASA Astrophysics Data System (ADS)

    Mouginis-Mark, P. J.; Garbeil, H.; Torres, R.

    2001-12-01

    Data from the Shuttle Radar Topographic Mission (SRTM) will permit extensive analysis of volcanoes and volcanic processes in many parts of the world that are infrequently studied by field volcanologists. In preparation for the release of the SRTM data, we have been studying Mt. Pinatubo volcano in the Philippines, using digital elevation data collected from the TOPSAR airborne interferometric radar. We report here on our results from these preparatory studies, and suggest how SRTM observations may enhance future work on Mt. Pinatubo and other volcanoes. The 1991 eruption of Mt. Pinatubo, Philippines, provides a unique opportunity to study the effects of a large eruption in part because it took place after the advent of satellite-based observations. Using five SPOT multispectral satellite images (obtained 4/88, 12/91, 12/94, 2/96 and 12/98), we have documented the drainage evolution on the "Western Fan", which is a large (>100 km2) ignimbrite deposit extending from O'Donnell Valley in the north to Marella Valley in the SW. Detailed knowledge of topography and slopes is important for documenting these changes, and are relevant for the study of the evolving "sediment budget" (near-summit sediments eroded during storms and deposited at lower elevations) which controls lahar production. These lahars can result in extensive damage downstream even years after the eruption. Our topographic studies have so far relied on the morphologic analysis of TOPSAR data of the western fan collected during the 1996 and 2000 PacRim deployments. Co-registering the TOPSAR and SPOT data enables the degree of erosion to be assessed over the 5 year 4 month period between the eruption and TOPSAR data collection. A maximum of >50 m of erosion has been identified in areas buried by the eruption. Numerous small (10 - 15 m deep) new canyons have also been measured. Because they were obtained in the same year as PacRim 2 data, the SRTM observations promise to provide the regional context for these

  6. Output rate of magma from active central volcanoes

    NASA Technical Reports Server (NTRS)

    Wadge, G.

    1980-01-01

    For part of their historic records, nine of the most active volcanoes on earth have each erupted magma at a nearly constant rate. These output rates are very similar and range from 0.69 to 0.26 cu m/s. The volcanoes discussed - Kilauea, Mauna Loa, Fuego, Santiaguito, Nyamuragira, Hekla, Piton de la Fournaise, Vesuvius and Etna - represent almost the whole spectrum of plate tectonic settings of volcanism. A common mechanism of buoyantly rising magma-filled cracks in the upper crust may contribute to the observed restricted range of the rates of output.

  7. Propagation of dikes at Vesuvio (Italy) and the effect of Mt. Somma

    NASA Astrophysics Data System (ADS)

    Acocella, V.; Porreca, M.; Neri, M.; Massimi, E.; Mattei, M.

    2006-04-01

    Dikes provide crucial information on how magma propagates within volcanoes. Somma-Vesuvio (Italy) consists of the active Vesuvio cone, partly bordered by the older Mt. Somma edifice. Historical chronicles on the fissure eruptions in 1694-1944 are matched with an analytical solution to define the propagation path of the related dikes and to study any control of the Mt. Somma relief. The fissures always consisted of the downslope migration of vents from an open summit conduit, indicating lateral propagation as the predominant mechanism for shallow dike emplacement. No fissure emplaced beyond Mt. Somma, suggesting that its buttressing hinders the propagation of the radial dikes. An analytical solution is defined to describe the mechanism of formation of the laterally propagating dikes and to evaluate the effect of topography. The application to Somma-Vesuvio suggests that, under ordinary excess magmatic pressures, the dikes should not propagate laterally at depths >240-480 m below the surface, as the increased lithostatic pressure requires magmatic pressures higher than average. This implies that, when the conduit is open, the lateral emplacement of dikes is expectable on the S, W and E slopes. The lack of fissures N of Mt. Somma is explained by its buttressing, which hinders dike propagation.

  8. Galileo Near-Infrared Mapping Spectrometer Detects Active Lava Flows at Prometheus Volcano, Io

    NASA Image and Video Library

    1999-11-04

    The active volcano Prometheus on Jupiter moon Io was imaged by NASA Galileo spacecraft during the close flyby of Io on Oct.10, 1999. The spectrometer can detect active volcanoes on Io by measuring their heat in the near-infrared wavelengths.

  9. Shallow magma-mingling-driven Strombolian eruptions at Mt. Yasur volcano, Vanuatu

    NASA Astrophysics Data System (ADS)

    Kremers, S.; Hanson, J. B.; Lavallee, Y.; Hess, K.-U.; Chevrel, M. O.; Wassermann, J.; Dingwell, D. B.

    2012-04-01

    Mt. Yasur volcano (Tanna, Vanuatu) has been increasingly recognized for its high-frequency Strombolian eruptions for the last 300 years. Currently, this activity takes place at three vents with highly varying recurrence rates, denoted as A, B and C from south to north, respectively. During a 6-week field campaign in August-September 2008, we installed four seismic and four infrasound arrays at site to record seismic and acoustic signals. Two Doppler-Radars measured the exit velocities of the erupted material, and a thermal camera was used to determine the temperature at the vent mouth. At the time of the fieldwork, the three active craters showed very different styles of activity. Crater A, the most active vent, had an eruption recurrence of under a minute. Crater B showed very irregular ash-venting with variable periodicity ranging between minutes and days, while crater C was producing the strongest eruptions approximately every 10 minutes. We sampled the eruptive products of craters A and C for further analysis in the lab. In total, three bombs were collected, two were juvenile and one exotic lithic material, in order to investigate the chemical, physical, rheological and textural variations in the erupted products from the different craters. The collected basaltic-andesite scoria bombs exhibit a relatively constant whole rock major element geochemistry (~56 wt.% SiO2). Petrographic texture and structure analysis revealed a large variation in porosity (~30 - 78 %) and microlite content. Both juvenile bombs revealed bimodal textures; that is, they contain regions of microlite-free glass (sideromelane) and regions of microlite-rich groundmass which suggests the occurrence of mingling and mixing of magma batches with different crystallization histories. In the exotic sample, almost no regions of sideromelane are observed; instead, the sample is nearly entirely crystallized. Interstitial glass chemistry from electron microprobe analysis shows a range of glass

  10. Digital Data for Volcano Hazards at Newberry Volcano, Oregon

    USGS Publications Warehouse

    Schilling, S.P.; Doelger, S.; Sherrod, D.R.; Mastin, L.G.; Scott, W.E.

    2008-01-01

    Newberry volcano is a broad shield volcano located in central Oregon, the product of thousands of eruptions, beginning about 600,000 years ago. At least 25 vents on the flanks and summit have been active during the past 10,000 years. The most recent eruption 1,300 years ago produced the Big Obsidian Flow. Thus, the volcano's long history and recent activity indicate that Newberry will erupt in the future. Newberry Crater, a volcanic depression or caldera has been the focus of Newberry's volcanic activity for at least the past 10,000 years. Newberry National Volcanic Monument, which is managed by the U.S. Forest Service, includes the caldera and extends to the Deschutes River. Newberry volcano is quiet. Local earthquake activity (seismicity) has been trifling throughout historic time. Subterranean heat is still present, as indicated by hot springs in the caldera and high temperatures encountered during exploratory drilling for geothermal energy. The report USGS Open-File Report 97-513 (Sherrod and others, 1997) describes the kinds of hazardous geologic events that might occur in the future at Newberry volcano. A hazard-zonation map is included to show the areas that will most likely be affected by renewed eruptions. When Newberry volcano becomes restless, the eruptive scenarios described herein can inform planners, emergency response personnel, and citizens about the kinds and sizes of events to expect. The geographic information system (GIS) volcano hazard data layers used to produce the Newberry volcano hazard map in USGS Open-File Report 97-513 are included in this data set. Scientists at the USGS Cascades Volcano Observatory created a GIS data layer to depict zones subject to the effects of an explosive pyroclastic eruption (tephra fallout, pyroclastic flows, and ballistics), lava flows, volcanic gasses, and lahars/floods in Paulina Creek. A separate GIS data layer depicts drill holes on the flanks of Newberry Volcano that were used to estimate the probability

  11. A new SO2 emissions budget for Anatahan volcano (Mariana Islands) based on ten years of satellite observations

    NASA Astrophysics Data System (ADS)

    McCormick, Brendan; Popp, Christoph; Andrews, Benjamin; Cottrell, Elizabeth

    2015-04-01

    Satellite remote sensing offers great potential for the study of sulphur dioxide (SO2) gas emissions from volcanoes worldwide. Anatahan is a remote volcano in the Mariana Islands, SW Pacific. Existing SO2 emissions data from Anatahan, from ground-based UV spectrometer measurements, place the volcano among the largest natural SO2 sources worldwide. However, these measurements are limited in number and only available from intervals of eruptive activity. Activity varies widely at Anatahan: over the past decade, records held in the Smithsonian Institution Global Volcanism Program Volcanoes of the World database describe the alternation of intense eruptions with long intervals of quiescence, where much lower intensity activity took place. We present ten years of satellite-based measurements of SO2 in the atmosphere over Anatahan, using data from the UV spectrometers OMI, GOME-2, and SCIAMACHY, and the IR spectrometer AIRS. We find Anatahan's emissions to be highly variable both within and between intervals of eruption and quiescence. We demonstrate a close agreement between trends in SO2 emission evident from our remote sensing data and records of activity compiled from a range of other sources and instruments, across daily to annual temporal scales. Mean eruptive SO2 emissions at Anatahan are ~6400 t/d, and range from <1000 to >18000 t/d. Quiescent emissions are below our instrument detection limits and are therefore unlikely to exceed 150-300 t/d. Overall, accounting for both eruptive and quiescent emissions, we calculate a revised decadal mean SO2 emission rate of 1060-1200 t/d. We further calculate a total decadal SO2 yield from Anatahan of 4-5 Mt, significantly lower than the 17-34 Mt calculated if ground-based campaign data are used in isolation. The use of isolated measurements to extrapolate longer term emissions budgets is subject to clear uncertainty, and we argue that our satellite observations, covering a longer interval of Anatahan's history, are better

  12. The Alaska Volcano Observatory - Expanded Monitoring of Volcanoes Yields Results

    USGS Publications Warehouse

    Brantley, Steven R.; McGimsey, Robert G.; Neal, Christina A.

    2004-01-01

    Recent explosive eruptions at some of Alaska's 52 historically active volcanoes have significantly affected air traffic over the North Pacific, as well as Alaska's oil, power, and fishing industries and local communities. Since its founding in the late 1980s, the Alaska Volcano Observatory (AVO) has installed new monitoring networks and used satellite data to track activity at Alaska's volcanoes, providing timely warnings and monitoring of frequent eruptions to the aviation industry and the general public. To minimize impacts from future eruptions, scientists at AVO continue to assess volcano hazards and to expand monitoring networks.

  13. An active seismic experiment at Tenerife Island (Canary Island, Spain): Imaging an active volcano edifice

    NASA Astrophysics Data System (ADS)

    Garcia-Yeguas, A.; Ibañez, J. M.; Rietbrock, A.; Tom-Teidevs, G.

    2008-12-01

    An active seismic experiment to study the internal structure of Teide Volcano was carried out on Tenerife, a volcanic island in Spain's Canary Islands. The main objective of the TOM-TEIDEVS experiment is to obtain a 3-dimensional structural image of Teide Volcano using seismic tomography and seismic reflection/refraction imaging techniques. At present, knowledge of the deeper structure of Teide and Tenerife is very limited, with proposed structural models mainly based on sparse geophysical and geological data. This multinational experiment which involves institutes from Spain, Italy, the United Kingdom, Ireland, and Mexico will generate a unique high resolution structural image of the active volcano edifice and will further our understanding of volcanic processes.

  14. Adakitic volcanism in the eastern Aleutian arc: Petrology and geochemistry of Hayes volcano, Cook Inlet, Alaska

    NASA Astrophysics Data System (ADS)

    McHugh, K.; Hart, W. K.; Coombs, M. L.

    2012-12-01

    Located in south-central Alaska, 135 km northwest of Anchorage, Hayes volcano is responsible for the most widespread tephra fall deposit in the regional Holocene record (~3,500 BP). Hayes is bounded to the west by the Cook Inlet volcanoes (CIV; Mt. Spurr, Redoubt, Iliamna, and Augustine) and separated from the nearest volcanism to the east, Mount Drum of the Wrangell Volcanic Field (WVF), by a 400 km-wide volcanic gap. We report initial results of the first systematic geochemical and petrologic study of Hayes volcano. Hayes eruptive products are calc-alkaline dacites and rhyolites that have anomalous characteristics within the region. Major and trace element analyses reveal that the Hayes rhyolites are more silicic (~74 wt. % SiO2) than compositions observed in other CIV, and its dacitic products possess the distinctive geochemical signatures of adakitic magmas. Key aspects of the Hayes dacite geochemistry include: 16.03 - 17.54 wt. % Al2O3, 0.97 - 2.25 wt. % MgO, Sr/Y = 60 - 78, Yb = 0.9 - 1.2 ppm, Ba/La = 31 - 79. Such signatures are consistent with melting of a metamorphosed basaltic source that leaves behind a residue of garnet ± amphibole ± pyroxene via processes such as melting of a subducting oceanic slab or underplated mafic lower crust, rather than flux melting of the mantle wedge by dehydration of the down-going slab. Additionally, Hayes tephras display a distinctive mineralogy of biotite with amphibole in greater abundance than pyroxene, a characteristic not observed at other CIV. Furthermore, Hayes rhyolites and dacites exhibit little isotopic heterogeneity (87Sr/86Sr = 0.70384 - 0.70395, 206Pb/204Pb = 18.866 - 18.889) suggesting these lavas originate from the same source. Hayes volcano is approximately situated above the western margin of the subducting Yakutat terrane and where the dip of the Pacific slab beneath Cook Inlet shallows northward. Due to its position along the margin of the subducting Yakutat terrane, it is plausible that Hayes magmas

  15. Soufriere Hills Volcano Resumes Activity

    NASA Image and Video Library

    2017-12-08

    A massive eruption of Montserrat’s Soufrière Hills Volcano covered large portions of the island in debris. The eruption was triggered by a collapse of Soufrière Hills’ summit lava dome on February 11, 2010. Pyroclastic flows raced down the northern flank of the volcano, leveling trees and destroying buildings in the village of Harris, which was abandoned after Soufrière Hills became active in 1995. The Montserrat Volcano Observatory reported that some flows, about 15 meters (49 feet) thick, reached the sea at Trant’s Bay. These flows extended the island’s coastline up to 650 meters (2,100 feet). These false-color satellite images show the southern half of Montserrat before and after the dome collapse. The top image shows Montserrat on February 21, 2010, just 10 days after the event. For comparison, the bottom image shows the same area on March 17, 2007. Red areas are vegetated, clouds are white, blue/black areas are ocean water, and gray areas are covered by flow deposits. Fresh deposits tend to be lighter than older deposits. On February 21, the drainages leading down from Soufrière Hills, including the White River Valley, the Tar River Valley, and the Belham River Valley, were filled with fresh debris. According to the Montserrat Volcano Observatory, pyroclastic flows reached the sea through Aymers Ghaut on January 18, 2010, and flows entered the sea near Plymouth on February 5, 2010. NASA Earth Observatory image by Robert Simmon, using data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Caption by Robert Simmon. To read more go to: earthobservatory.nasa.gov/IOTD/view.php?id=42792 NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

  16. A Probabilistic Approach for Real-Time Volcano Surveillance

    NASA Astrophysics Data System (ADS)

    Cannavo, F.; Cannata, A.; Cassisi, C.; Di Grazia, G.; Maronno, P.; Montalto, P.; Prestifilippo, M.; Privitera, E.; Gambino, S.; Coltelli, M.

    2016-12-01

    Continuous evaluation of the state of potentially dangerous volcanos plays a key role for civil protection purposes. Presently, real-time surveillance of most volcanoes worldwide is essentially delegated to one or more human experts in volcanology, who interpret data coming from different kind of monitoring networks. Unfavorably, the coupling of highly non-linear and complex volcanic dynamic processes leads to measurable effects that can show a large variety of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data, the volcano state needs to be expressed in probabilistic terms, thus making the fast volcano state assessment sometimes impracticable for the personnel on duty at the control rooms. With the aim of aiding the personnel on duty in volcano surveillance, we present a probabilistic graphical model to estimate automatically the ongoing volcano state from all the available different kind of measurements. The model consists of a Bayesian network able to represent a set of variables and their conditional dependencies via a directed acyclic graph. The model variables are both the measurements and the possible states of the volcano through the time. The model output is an estimation of the probability distribution of the feasible volcano states. We tested the model on the Mt. Etna (Italy) case study by considering a long record of multivariate data from 2011 to 2015 and cross-validated it. Results indicate that the proposed model is effective and of great power for decision making purposes.

  17. Mt. Erebus, Antarctica

    NASA Image and Video Library

    2016-01-15

    This image from NASA Terra spacecraft shows Mount Erebus, the world southernmost historically active volcano, overlooking the McMurdo research station on Ross Island. The 3794-m-high Erebus is the largest of three major volcanoes forming the crudely triangular Ross Island. An elliptical 500 x 600 m wide, 110-m-deep crater truncates the summit and contains an active lava lake within a 250-m-wide, 100-m-deep inner crater. The glacier-covered volcano was erupting when first sighted by Captain James Ross in 1841. Continuous lava-lake activity with minor explosions, punctuated by occasional larger strombolian explosions that eject bombs onto the crater rim, has been documented since 1972, but has probably been occurring for much of the volcano's recent history. The image was acquired December 31, 2013, covers an area of 63 x 73 km, and is located at 77.5 degrees south, 167.1 degrees east. http://photojournal.jpl.nasa.gov/catalog/PIA20239

  18. Hazard assessment in geothermal exploration: The case of Mt. Parker, Southern Philippines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Delfin, F.G. Jr.; Salonga, N.D.; Bayon, F.E.B.

    1996-12-31

    Hazard assessment of the Mt. Parker geothermal prospect, conducted in parallel with the surface exploration from 1992 to 1994, was undertaken to determine the long-term suitability of the prospect for development. By comparison with other acidic magmatic-hydrothermal systems in the Philippines, the geochemical data indicated minimal input of acidic magmatic fluids into Mt. Parker`s hydrothermal system. This system was regarded to be a neutral-pH and high-enthalpy chloride reservoir with temperature of at least 200-250{degrees}C. These favorable geochemical indications contrasted sharply with the C-14 and volcanological data indicating a shallow magmatic body with a potential for future eruption. This hazard ledmore » PNOC EDC to discontinue the survey and abandon the prospect by late 1994. On September 6, 1995, a flashflood of non-volcanic origin from the caldera lake killed nearly 100 people on the volcano`s northwestern flank.« less

  19. Deconvolving the process-origin of sediments on volcanic mountains and implications for paleoclimatic reconstruction: Mt Ruapehu area, New Zealand

    NASA Astrophysics Data System (ADS)

    Brook, Martin; Winkler, Stefan

    2016-04-01

    Glaciation on the central North Island of New Zealand is limited to the volcanoes of Tongariro National Park, including Mt Ruapehu, the largest and most active andesitic stratovolcano on the North Island. At 2797 m asl, Mt Ruapehu represents the only peak in the North Island to currently intercept the permanent snowline, with small cirque glaciers descending to an altitude of ~2300 m. During the last glacial maximum (LGM), small ice-caps existed on Mt Ruapehu and the Tongariro Massif (15 km to the NNE of Ruapehu), with a series of small (<10 km-long) valley glaciers radiating out from domes centered on the summit areas to altitudes of ~1200 m. Holocene glacier advances have left smaller deposits inboard of some of the LGM moraines. However, understanding of moraine deposition and reconstructing former glacier extent is limited by: (1) the fragmentary nature of glacier moraines in this high precipitation environment; and (2) the broad range of possible process-origins for unconsolidated debris ridges on active volcanoes. Here, we describe the clast roundness, clast shape and textural characteristics associated with active and former glaciers on Mt Ruaephu and the Tongariro Massif, in order to assist in classifying the process-origin of sediments on glaciated volcanic mountains. Supraglacial inputs include rockfall, tephra, and avalanche material delivered to the surface of glaciers. Basal debris, where observed at the terminus of active cirque glaciers, consists mainly of incorporated fluvial material. Following deposition, reworking is mainly by proglacial streams, debris flows and lahars. Within the vicinity of glaciers, the dominant facies appear to be: (i) bouldery gravel with angular clasts on steep slopes surrounding glaciers, (ii) silty-sandy boulder gravel, with mainly subangular clasts, forming lateral moraines, (iii) boulder/cobble gravel with mainly subrounded clasts and associated laminated sediments representing fluvially-reworked material; and (iv

  20. A Preliminary Study of Hazus-MH Volcano for Korea

    NASA Astrophysics Data System (ADS)

    Yu, S.; An, H.; Oh, J.

    2013-12-01

    This presentation will introduce our design to develop a volcano risk modeling capacity within the Hazus-MH loss estimation framework. In particular, we will present how to build fragility curves within the Hazus-MH framework for loss estimation from volcanoes. This capability is designed to analyze the risk from volcanic hazards in Korea. The Korean peninsula has Mt. Baekdu in North Korea, which will soon enter an active phase, according to some volcanologists. The anticipated eruption will be explosive given the viscous and grassy silica-rich magma, and is expected to be one of the largest in recent millennia. We aim to assess the impacts of this eruption, in particular to South Korea. There are several types of hazards related to volcanic eruption, including ash, pyroclastic flows, volcanic floods and earthquakes. However, our initial efforts focus on modeling losses from volcanic ash. The proposed volcanic ash model is anticipated to be used to estimate losses caused by yellow dust in East Asia as well. Also, many countries, which are exposed to potentially dangerous volcanoes, can benefit from the proposed Hazus-MH Volcano risk model. Acknowledgement: this research was supported by a grant [NEMA-BAEKDUSAN-2012-1-3] from the Volcanic Disaster Preparedness Research Center sponsored by National Emergency Management Agency of Korea. We would like to thank Federal Emergency Management Agency which develops Hazus-MH and allows the international use of Hazus-MH.

  1. Helicopter magnetic and electromagnetic surveys at Mounts Adams, Baker and Rainier, Washington: implications for debris flow hazards and volcano hydrology

    USGS Publications Warehouse

    Finn, Carol A.; Deszcz-Pan, Maria

    2011-01-01

    High‐resolution helicopter magnetic and electromagnetic (HEM) data flown over the rugged, ice‐covered Mt. Adams, Mt. Baker and Mt. Rainier volcanoes (Washington), reveal the distribution of alteration, water and ice thickness essential to evaluating volcanic landslide hazards. These data, combined with geological mapping and rock property measurements, indicate the presence of appreciable thicknesses (>500 m) of water‐saturated hydrothermally altered rock west of the modern summit of Mount Rainier in the Sunset Amphitheater region and in the central core of Mount Adams north of the summit. Alteration at Mount Baker is restricted to thinner (<300 m) zones beneath Sherman Crater and the Dorr Fumarole Fields. The EM data identified water‐saturated rocks from the surface to the detection limit (100–200 m) in discreet zones at Mt. Rainier and Mt Adams and over the entire summit region at Mt. Baker. The best estimates for ice thickness are obtained over relatively low resistivity (<800 ohm‐m) ground for the main ice cap on Mt. Adams and over most of the summit of Mt. Baker. The modeled distribution of alteration, pore fluids and partial ice volumes on the volcanoes helps identify likely sources for future alteration‐related debris flows, including the Sunset Amphitheater region at Mt. Rainier, steep cliffs at the western edge of the central altered zone at Mount Adams and eastern flanks of Mt. Baker.

  2. CO2 driven weathering vs plume driven weathering as inferred from the groundwater of a persistently degassing basaltic volcano: Mt. Etna

    NASA Astrophysics Data System (ADS)

    Liotta, Marcello; D'Alessandro, Walter

    2016-04-01

    probably also at other volcanoes characterized by huge open-conduit degassing activity.

  3. 2014 volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Cameron, Cheryl E.; Dixon, James P.; Neal, Christina A.; Waythomas, Christopher F.; Schaefer, Janet R.; McGimsey, Robert G.

    2017-09-07

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest or suspected unrest, and seismic events at 18 volcanic centers in Alaska during 2014. The most notable volcanic activity consisted of intermittent ash eruptions from long-active Cleveland and Shishaldin Volcanoes in the Aleutian Islands, and two eruptive episodes at Pavlof Volcano on the Alaska Peninsula. Semisopochnoi and Akutan volcanoes had seismic swarms, both likely the result of magmatic intrusion. The AVO also installed seismometers and infrasound instruments at Mount Cleveland during 2014.

  4. Evidence for partial melt in the crust beneath Mt. Paektu (Changbaishan), Democratic People’s Republic of Korea and China

    USGS Publications Warehouse

    Kyong-Song, Ri; Hammond, James O. S.; Chol-Nam, Ko; Hyok, Kim; Yong-Gun, Yun; Gil-Jong, Pak; Chong-Song, Ri; Oppenheimer, Clive; Liu, Kosima W.; Iacovino, Kayla D.; Kum-Ran, Ryu

    2016-01-01

    Mt. Paektu (also known as Changbaishan) is an enigmatic volcano on the border between the Democratic People’s Republic of Korea (DPRK) and China. Despite being responsible for one of the largest eruptions in history, comparatively little is known about its magmatic evolution, geochronology, or underlying structure. We present receiver function results from an unprecedented seismic deployment in the DPRK. These are the first estimates of the crustal structure on the DPRK side of the volcano and, indeed, for anywhere beneath the DPRK. The crust 60 km from the volcano has a thickness of 35 km and a bulk VP/VS of 1.76, similar to that of the Sino-Korean craton. The VP/VS ratio increases ~20 km from the volcano, rising to >1.87 directly beneath the volcano. This shows that a large region of the crust has been modified by magmatism associated with the volcanism. Such high values of VP/VS suggest that partial melt is present in the crust beneath Mt. Paektu. This region of melt represents a potential source for magmas erupted in the last few thousand years and may be associated with an episode of volcanic unrest observed between 2002 and 2005.

  5. Preliminary volcano-hazard assessment for Great Sitkin Volcano, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Miller, Thomas P.; Nye, Christopher J.

    2003-01-01

    Great Sitkin Volcano is a composite andesitic stratovolcano on Great Sitkin Island (51°05’ N latitude, 176°25’ W longitude), a small (14 x 16 km), circular volcanic island in the western Aleutian Islands of Alaska. Great Sitkin Island is located about 35 kilometers northeast of the community of Adak on Adak Island and 130 kilometers west of the community of Atka on Atka Island. Great Sitkin Volcano is an active volcano and has erupted at least eight times in the past 250 years (Miller and others, 1998). The most recent eruption in 1974 caused minor ash fall on the flanks of the volcano and resulted in the emplacement of a lava dome in the summit crater. The summit of the composite cone of Great Sitkin Volcano is 1,740 meters above sea level. The active crater is somewhat lower than the summit, and the highest point along its rim is about 1,460 meters above sea level. The crater is about 1,000 meters in diameter and is almost entirely filled by a lava dome emplaced in 1974. An area of active fumaroles, hot springs, and bubbling hot mud is present on the south flank of the volcano at the head of Big Fox Creek (see the map), and smaller ephemeral fumaroles and steam vents are present in the crater and around the crater rim. The flanking slopes of the volcano are gradual to steep and consist of variously weathered and vegetated blocky lava flows that formed during Pleistocene and Holocene eruptions. The modern edifice occupies a caldera structure that truncates an older sequence of lava flows and minor pyroclastic rocks on the east side of the volcano. The eastern sector of the volcano includes the remains of an ancestral volcano that was partially destroyed by a northwest-directed flank collapse. In winter, Great Sitkin Volcano is typically completely snow covered. Should explosive pyroclastic eruptions occur at this time, the snow would be a source of water for volcanic mudflows or lahars. In summer, much of the snowpack melts, leaving only a patchy

  6. Information Modeling to Assess Eruptive Behavior and Possible Threats on Mt. Etna, Italy

    NASA Astrophysics Data System (ADS)

    Pshenichny, C.; Behncke, B.

    2008-12-01

    One of the best-studied volcanoes of the world, Mt. Etna in Sicily repeatedly exhibits eruptive scenarios that depart from the behavior considered typical for this volcano. Episodes of intense explosive activity, pyroclastic density currents, dome growth, cone collapse, and phreatomagmatic explosions pose a variety of previously underestimated threats to human lives in the summit area of the volcano. However, retrospective analysis of these events shows that they were likely caused by the same very sets of premises and starting conditions as "normal" effusive eruptions, yet combined in an unexpected, probably unique, way. Physical modeling tells us what may happen in terms of physical parameters but not what events we will actually see on a volcano. Bayesian modeling of volcanoes can unite physical parameters and observed events but, unlike physics, it lacks strictness of terms used to describe the events and, hence, may fail to provide a reasonably impartial, complete and self-consistent set of possible scenarios to be expected. Therefore, a tool is needed to process the observational knowledge as strictly as physical matters are treated by mathematics to provide an appropriate event-based framework for assessment of natural hazards during volcanic eruptions. This task requires a modeling not of the volcano itself but of our knowledge of it, and therefore falls into the field of informatis, knowledge engineering, and artificial intelligence. We involved an approach of artificial intelligence developed specially for the needs of geoscience, the method of event bush. Scenarios inferred from event bush fit the observed ones and allow one to foresee other low-probable events that may occur at the volcano. Application of the event bush provides a more impartial vision of volcanic phenomena and may serve as an intermediary between physical modeling, the expert knowledge and numerical assessment, e.g., by means of Bayesian belief networks.

  7. 2013 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Dixon, James P.; Cameron, Cheryl; McGimsey, Robert G.; Neal, Christina A.; Waythomas, Chris

    2015-08-14

    The Alaska Volcano Observatory (AVO) responded to eruptions, volcanic unrest or suspected unrest, and seismic events at 18 volcanic centers in Alaska during 2013. Beginning with the 2013 AVO Summary of Events, the annual description of the AVO seismograph network and activity, once a stand-alone publication, is now part of this report. Because of this change, the annual summary now contains an expanded description of seismic activity at Alaskan volcanoes. Eruptions occurred at three volcanic centers in 2013: Pavlof Volcano in May and June, Mount Veniaminof Volcano in June through December, and Cleveland Volcano throughout the year. None of these three eruptive events resulted in 24-hour staffing at AVO facilities in Anchorage or Fairbanks.

  8. Embedded ARM system for volcano monitoring in remote areas: application to the active volcano on Deception Island (Antarctica).

    PubMed

    Peci, Luis Miguel; Berrocoso, Manuel; Fernández-Ros, Alberto; García, Alicia; Marrero, José Manuel; Ortiz, Ramón

    2014-01-02

    This paper describes the development of a multi-parameter system for monitoring volcanic activity. The system permits the remote access and the connection of several modules in a network. An embedded ARM™ processor has been used, allowing a great flexibility in hardware configuration. The use of a complete Linux solution (Debian™) as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular Volcano Monitoring System (MVMS) described has been deployed on the active Deception Island (Antarctica) volcano, within the Spanish Antarctic Program, and has proved successful for monitoring the volcano, with proven reliability and efficient operation under extreme conditions. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands) in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis.

  9. Embedded ARM System for Volcano Monitoring in Remote Areas: Application to the Active Volcano on Deception Island (Antarctica)

    PubMed Central

    Peci, Luis Miguel; Berrocoso, Manuel; Fernández-Ros, Alberto; García, Alicia; Marrero, José Manuel; Ortiz, Ramón

    2014-01-01

    This paper describes the development of a multi-parameter system for monitoring volcanic activity. The system permits the remote access and the connection of several modules in a network. An embedded ARM™™ processor has been used, allowing a great flexibility in hardware configuration. The use of a complete Linux solution (Debian™) as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular Volcano Monitoring System (MVMS) described has been deployed on the active Deception Island (Antarctica) volcano, within the Spanish Antarctic Program, and has proved successful for monitoring the volcano, with proven reliability and efficient operation under extreme conditions. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands) in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis. PMID:24451461

  10. Volcano-Tectonic Activity at Deception Island Volcano Following a Seismic Swarm in the Bransfield Rift (2014-2015)

    NASA Astrophysics Data System (ADS)

    Almendros, J.; Carmona, E.; Jiménez, V.; Díaz-Moreno, A.; Lorenzo, F.

    2018-05-01

    In September 2014 there was a sharp increase in the seismic activity of the Bransfield Strait, Antarctica. More than 9,000 earthquakes with magnitudes up to 4.6 located SE of Livingston Island were detected over a period of 8 months. A few months after the series onset, local seismicity at the nearby (˜35 km) Deception Island volcano increased, displaying enhanced long-period seismicity and several outbursts of volcano-tectonic (VT) earthquakes. Before February 2015, VT earthquakes occurred mainly at 5-20 km SW of Deception Island. In mid-February the numbers and sizes of VT earthquakes escalated, and their locations encompassed the whole volcanic edifice, suggesting a situation of generalized unrest. The activity continued in anomalously high levels at least until May 2015. Given the spatial and temporal coincidence, it is unlikely that the Livingston series and the Deception VT swarm were unrelated. We propose that the Livingston series may have produced a triggering effect on Deception Island volcano. Dynamic stresses associated to the seismic swarm may have induced overpressure in the unstable volcanic system, leading to a magmatic intrusion that may in turn have triggered the VT swarm. Alternatively, both the Livingston earthquakes and the VT swarm could be consequences of a magmatic intrusion at Deception Island. The Livingston series would be an example of precursory distal VT swarm, which seems to be a common feature preceding volcanic eruptions and magma intrusions in long-dormant volcanoes.

  11. Measuring thermal budgets of active volcanoes by satellite remote sensing

    NASA Technical Reports Server (NTRS)

    Glaze, L.; Francis, P. W.; Rothery, D. A.

    1989-01-01

    Thematic Mapper measurements of the total radiant energy flux Q at Lascar volcano in north Chile for December 1984 are reported. The results are consistent with the earlier suggestion that a lava lake is the source of a reported thermal budget anomaly, and with values for 1985-1986 that are much lower, suggesting that fumarolic activity was then a more likely heat source. The results show that satellite remote sensing may be used to monitor the activity of a volcano quantitatively, in a way not possible by conventional ground studies, and may provide a method for predicting eruptions.

  12. Magma transfer processes at persistently active volcanoes: insights from gravity observations

    NASA Astrophysics Data System (ADS)

    Locke, Corinne A.; Rymer, Hazel; Cassidy, John

    2003-09-01

    Magma transfer processes at persistently active volcanoes are distinguished by the large magma flux required to sustain the prodigious quantities of heat and gas emitted at the surface. Although the resulting degassed magma has been conjectured to accumulate either deep within the volcanic edifice or in the upper levels of the sub-edifice system, no direct evidence for such active accumulation has been reported. Temporal gravity data are unique in being able to quantify mass changes and have been successfully used to model shallow magma movements on different temporal scales, but have not generally been applied to the investigation of postulated long-term accumulation of magma at greater spatial scales within volcanic systems. Here, we model the critical data acquisition parameters required to detect mass flux at volcanoes, we review existing data from a number of volcanoes that exemplify the measurement of shallow mass changes and present new data from Poas and Telica volcanoes. We show that if a substantial proportion of degassed magma lodges within the sub-edifice region, it would result in measurable annual to decadal gravity increases occurring over spatial scales of tens of kilometres and propose that existing microgravity data from Sakurajima and, possibly, Etna volcanoes could be interpreted in these terms. Furthermore, such repeat microgravity data could be used to determine whether the accumulation rate is in equilibrium with the rate of production of degassed magma as calculated from the surface gas flux and hence identify the build-up of gas-rich magma at depth that may be significant in terms of eruption potential. We also argue that large magma bodies, both molten and frozen, modelled beneath volcanoes from seismic and gravity data, could represent endogenous or cryptic intrusions of degassed magma based on order of magnitude calculations using present-day emission rates and typical volcano lifetimes.

  13. Long-lived structural control of Mt. Shasta's plumbing system illuminated by 40Ar/39Ar geochronology

    NASA Astrophysics Data System (ADS)

    Calvert, A. T.; Christiansen, R. L.

    2013-12-01

    Mt. Shasta is the largest stratovolcano in the Cascade Arc, surpassed in volume only by the large rear-arc Medicine Lake and Newberry composite volcanoes. Including the material in the ~350 ka debris avalanche, it has produced more than 500 km3 of andesite and dacite from several superimposed central vents over its 700-850 kyr history. Earlier, between at least 970 to 1170 ka, the Rainbow Mountain volcano of similar composition and size occupied this latitude of the arc ~20 km further east. This shift of magmatic focus from within the arc axis (as defined by 6 Ma and younger calc-alkaline centers) to the arc front is poorly understood, but the current center's location appears structurally controlled. Most identifiable volcanic vents on Mt. Shasta lie within 1 km of a N-S line through the active summit cone. 40Ar/39Ar ages of map units occupying the vent alignment range from the Holocene (5×1 ka) current summit dome to at least the Middle Pleistocene (464×9 ka McKenzie Butte). The vast majority of eruptions have issued from central vents (Sargents Ridge, 300-135 ka; Misery Hill, 100-15 ka; and Hotlum, <10 ka), each 500 to 1000m north of its predecessor. A central vent for the pre-avalanche edifice is impossible to locate precisely, but was possibly on the same N-S trend and certainly no more than 4 km to the west, likely south of the Sargents Ridge central vent. ~15 of ~25 mapped flank vents lie on the alignment and the other ten lie west of the line. No identified volcanic vents lie east of the line until >12 km from Mt. Shasta (Ash Creek Butte, 227 ka; Basalt of McCloud River, 38 ka; The Whaleback, 102 ka), and monogenetic and polygenetic centers further east and northeast. From these observations we infer that: (1) magmas are localized along a ~20 km, long-lived, N-S trending structure running through the summit; (2) the upper crustal structure appears impermeable to magmas and resistant to dikes on its eastern side; (3) the western half of the area beneath

  14. Preliminary volcano-hazard assessment for Kanaga Volcano, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Miller, Thomas P.; Nye, Christopher J.

    2002-01-01

    Kanaga Volcano is a steep-sided, symmetrical, cone-shaped, 1307 meter high, andesitic stratovolcano on the north end of Kanaga Island (51°55’ N latitude, 177°10’ W longitude) in the western Aleutian Islands of Alaska. Kanaga Island is an elongated, low-relief (except for the volcano) island, located about 35 kilometers west of the community of Adak on Adak Island and is part of the Andreanof Islands Group of islands. Kanaga Volcano is one of the 41 historically active volcanoes in Alaska and has erupted numerous times in the past 11,000 years, including at least 10 eruptions in the past 250 years (Miller and others, 1998). The most recent eruption occurred in 1993-95 and caused minor ash fall on Adak Island and produced blocky aa lava flows that reached the sea on the northwest and west sides of the volcano (Neal and others, 1995). The summit of the volcano is characterized by a small, circular crater about 200 meters in diameter and 50-70 meters deep. Several active fumaroles are present in the crater and around the crater rim. The flanking slopes of the volcano are steep (20-30 degrees) and consist mainly of blocky, linear to spoonshaped lava flows that formed during eruptions of late Holocene age (about the past 3,000 years). The modern cone sits within a circular caldera structure that formed by large-scale collapse of a preexisting volcano. Evidence for eruptions of this preexisting volcano mainly consists of lava flows exposed along Kanaton Ridge, indicating that this former volcanic center was predominantly effusive in character. In winter (October-April), Kanaga Volcano may be covered by substantial amounts of snow that would be a source of water for lahars (volcanic mudflows). In summer, much of the snowpack melts, leaving only a patchy distribution of snow on the volcano. Glacier ice is not present on the volcano or on other parts of Kanaga Island. Kanaga Island is uninhabited and is part of the Alaska Maritime National Wildlife Refuge, managed by

  15. Analysis of active volcanoes from the Earth Observing System

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, Peter; Rowland, Scott; Crisp, Joy; Glaze, Lori; Jones, Kenneth; Kahle, Anne; Pieri, David; Zebker, Howard; Krueger, Arlin; Walter, Lou

    1991-01-01

    The Earth Observing System (EOS) scheduled for launch in 1997 and 1999 is briefly described, and the EOS volcanology investigation objectives are discussed. The volcanology investigation will include long- and short-term monitoring of selected volcanoes, the detection of precursor activity associated with unanticipated eruptions, and a detailed study of on-going eruptions. A variety of instruments on the EOS platforms will enable the study of local- and regional-scale thermal and deformational features of volcanoes, and the chemical and structural features of volcanic eruption plumes and aerosols.

  16. Time-dependent brittle deformation at Mt. Etna volcano

    NASA Astrophysics Data System (ADS)

    Baud, Patrick; Heap, Michael; Meredith, Philip; Vinciguerra, Sergio; Bell, Andrew; Main, Ian

    2010-05-01

    Time-dependent weakening mechanisms, leading to slow fracturing, are likely to act during the build up to flank eruptions at Mt. Etna volcano and are potentially a primary control on pre-eruptive patterns of seismicity and deformation. Due to the high permeability of its volcanic rocks, the volcanic edifice hosts a large water reservoir (Ogniben, 1966). The presence of a fluid phase in cracks within rock has been shown to dramatically affect both mechanical and chemical interactions. Chemically, it promotes time-dependent brittle deformation through such mechanisms as stress corrosion cracking that allows rocks to deform at stresses far below their short-term failure strength. Such crack growth is highly non-linear and accelerates towards dynamic failure over extended periods of time, even under constant applied stress; a phenomenon known as ‘brittle creep'. Here we report results from a study of time-dependent brittle creep in water-saturated samples of Etna basalt (EB) under triaxial stress conditions (confining pressure of 50 MPa and pore fluid pressure of 20 MPa). Samples of EB were loaded at a constant strain rate of 10-5 s-1 to a pre-determined percentage of the short-term strength and left to deform under constant stress until failure. Crack damage evolution was monitored throughout each experiment by measuring the independent damage proxies of axial strain, pore volume change and output of acoustic emission (AE) energy, during brittle creep of creep strain rates ranging over four orders of magnitude. Our data not only demonstrates that basalt creeps in the brittle regime but also that the applied differential stress exerts a crucial influence on both time-to-failure and creep strain rate in EB. Furthermore, stress corrosion is considered to be responsible for the acceleratory cracking and seismicity prior to volcanic eruptions and is invoked as an important mechanism in forecasting models. Stress-stepping creep experiments were then performed to allow the

  17. Application of the Landsat Thematic Mapper to the identification of potentially active volcanoes in the Central Andes

    NASA Technical Reports Server (NTRS)

    Francis, P. W.; De Silva, S. L.

    1989-01-01

    A systematic study of the potentially active volcanoes in the Central Andes (14 deg S to 28 deg S) was carried out on the basis of Landsat Thematic Mapper images which provided consistent coverage of the area. More than 60 major volcanoes were identified as potentially active, as compared to 16 that are listed in the Catalog of Active Volcanoes of the World (Casertano, 1963; Hantke and Parodi, 1966). Most of these volcanoes are large (up to 6000 m in height) composite cones. Some of them could threaten nearby settlements, especially those in southern Peru, where the volcanoes rise above deep canyons with settlements along them.

  18. The failed eruption of Mt. Etna in December 2005: Evidence from volcanic tremor analyses

    NASA Astrophysics Data System (ADS)

    Falsaperla, S.; Barberi, G.; Cocina, O.

    2013-12-01

    Strong changes in seismic radiation, comparable to those preceding and/or accompanying eruptive activity in recent years, were recorded at Mt. Etna volcano, Italy, from November 2005 to January 2006. The amplitude of volcanic tremor peaked in mid-December 2005 after a continuous, slow increase from August 2005 onward, during which neither effusive nor paroxysmal activity was observed by volcanologists and alpine guides. During this time span, the centroid locations of volcanic tremor moved toward the surface, more and more clustered below the summit craters. The application of pattern classification analysis based on Self-Organizing Maps and fuzzy clustering to volcanic tremor data highlighted variations in the frequency domain as well. These changes were temporally associated with ground deformation variations, as indicative of a mild inflation of the summit of the volcano, and with a conspicuous increase in the SO2 plume-flux emission. Overall, we interpret this evidence as the result of recharging of the volcanic feeder at depth (>3 km below sea level) during which magma did not reach the shallow plumbing system.

  19. Volcano Hazards Assessment for Medicine Lake Volcano, Northern California

    USGS Publications Warehouse

    Donnelly-Nolan, Julie M.; Nathenson, Manuel; Champion, Duane E.; Ramsey, David W.; Lowenstern, Jacob B.; Ewert, John W.

    2007-01-01

    Medicine Lake volcano (MLV) is a very large shield-shaped volcano located in northern California where it forms part of the southern Cascade Range of volcanoes. It has erupted hundreds of times during its half-million-year history, including nine times during the past 5,200 years, most recently 950 years ago. This record represents one of the highest eruptive frequencies among Cascade volcanoes and includes a wide variety of different types of lava flows and at least two explosive eruptions that produced widespread fallout. Compared to those of a typical Cascade stratovolcano, eruptive vents at MLV are widely distributed, extending 55 km north-south and 40 km east-west. The total area covered by MLV lavas is >2,000 km2, about 10 times the area of Mount St. Helens, Washington. Judging from its long eruptive history and its frequent eruptions in recent geologic time, MLV will erupt again. Although the probability of an eruption is very small in the next year (one chance in 3,600), the consequences of some types of possible eruptions could be severe. Furthermore, the documented episodic behavior of the volcano indicates that once it becomes active, the volcano could continue to erupt for decades, or even erupt intermittently for centuries, and very likely from multiple vents scattered across the edifice. Owing to its frequent eruptions, explosive nature, and proximity to regional infrastructure, MLV has been designated a 'high threat volcano' by the U.S. Geological Survey (USGS) National Volcano Early Warning System assessment. Volcanic eruptions are typically preceded by seismic activity, but with only two seismometers located high on the volcano and no other USGS monitoring equipment in place, MLV is at present among the most poorly monitored Cascade volcanoes.

  20. A pilot GIS database of active faults of Mt. Etna (Sicily): A tool for integrated hazard evaluation

    NASA Astrophysics Data System (ADS)

    Barreca, Giovanni; Bonforte, Alessandro; Neri, Marco

    2013-02-01

    A pilot GIS-based system has been implemented for the assessment and analysis of hazard related to active faults affecting the eastern and southern flanks of Mt. Etna. The system structure was developed in ArcGis® environment and consists of different thematic datasets that include spatially-referenced arc-features and associated database. Arc-type features, georeferenced into WGS84 Ellipsoid UTM zone 33 Projection, represent the five main fault systems that develop in the analysed region. The backbone of the GIS-based system is constituted by the large amount of information which was collected from the literature and then stored and properly geocoded in a digital database. This consists of thirty five alpha-numeric fields which include all fault parameters available from literature such us location, kinematics, landform, slip rate, etc. Although the system has been implemented according to the most common procedures used by GIS developer, the architecture and content of the database represent a pilot backbone for digital storing of fault parameters, providing a powerful tool in modelling hazard related to the active tectonics of Mt. Etna. The database collects, organises and shares all scientific currently available information about the active faults of the volcano. Furthermore, thanks to the strong effort spent on defining the fields of the database, the structure proposed in this paper is open to the collection of further data coming from future improvements in the knowledge of the fault systems. By layering additional user-specific geographic information and managing the proposed database (topological querying) a great diversity of hazard and vulnerability maps can be produced by the user. This is a proposal of a backbone for a comprehensive geographical database of fault systems, universally applicable to other sites.

  1. Volcanoes: Nature's Caldrons Challenge Geochemists.

    ERIC Educational Resources Information Center

    Zurer, Pamela S.

    1984-01-01

    Reviews various topics and research studies on the geology of volcanoes. Areas examined include volcanoes and weather, plate margins, origins of magma, magma evolution, United States Geological Survey (USGS) volcano hazards program, USGS volcano observatories, volcanic gases, potassium-argon dating activities, and volcano monitoring strategies.…

  2. Spine growth mechanisms: friction and seismicity at Mt. Unzen, Japan

    NASA Astrophysics Data System (ADS)

    Hornby, Adrian; Kendrick, Jackie; Hirose, Takehiro; Henton De Angelis, Sarah; De Angelis, Silvio; Umakoshi, Kodo; Miwa, Takahiro; Wadsworth, Fabian; Dingwell, Don; Lavallee, Yan

    2014-05-01

    The final episode of dome growth during the 1991-1995 eruption of Mt. Unzen was characterised by spine extrusion accompanied by repetitive seismicity. This type of cyclic activity has been observed at several dome-building volcanoes and recent work suggests a source mechanism of brittle failure of magma in the conduit. Spine growth may proceed by densification and closure of permeable pathways within the uppermost conduit magma, leading to sealing of the dome and inflation of the edifice. Amplified stresses on the wall rock and plug cause brittle failure near the conduit wall once static friction forces are overcome, and during spine growth these fractures may propagate to the dome surface. The preservation of these features is rare, and the conduit is typically inaccessible; therefore spines, the extruded manifestation of upper conduit material, provide the opportunity to study direct evidence of brittle processes in the conduit. At Mt. Unzen the spine retains evidence for brittle deformation and slip, however mechanical constraints on the formation of these features and their potential impact on eruption dynamics have not been well constrained. Here, we conduct an investigation into the process of episodic spine growth using high velocity friction apparatus at variable shear slip rate (0.4-1.5 m.s-1) and normal stress (0.4-3.5 MPa) on dome rock from Mt. Unzen, generating frictional melt at velocity >0.4 m.s-1 and normal stress >0.7 MPa. Our results show that the presence of frictional melt causes a deviation from Byerlee's frictional rule for rock friction. Melt generation is a disequilibrium process: initial amphibole breakdown leads to melt formation, followed by chemical homogenization of the melt layer. Ultimately, the experimentally generated frictional melts have a similar final chemistry, thickness and comminuted clast size distribution, thereby facilitating the extrapolation of a single viscoelastic model to describe melt-lubricated slip events at Mt

  3. Monitoring active volcanoes

    USGS Publications Warehouse

    Tilling, Robert I.

    1987-01-01

    One of the most spectacular, awesomely beautiful, and at times destructive displays of natural energy is an erupting volcano, belching fume and ash thousands of meters into the atmosphere and pouring out red-hot molten lava in fountains and streams. Countless eruptions in the geologic past have produced volcanic rocks that form much of the Earth's present surface. The gradual disintegration and weathering of these rocks have yielded some of the richest farmlands in the world, and these fertile soils play a significant role in sustaining our large and growing population. Were it not for volcanic activity, the Hawaiian Islands with their sugar cane and pineapple fields and magnificent landscapes and seascapes would not exist to support their residents and to charm their visitors. Yet, the actual eruptive processes are catastrophic and can claim life and property.

  4. MT1 and MT2 Melatonin Receptors: A Therapeutic Perspective

    PubMed Central

    Liu, Jiabei; Clough, Shannon J.; Hutchinson, Anthony J.; Adamah-Biassi, Ekue B.; Popovska-Gorevski, Marina; Dubocovich, Margarita L.

    2016-01-01

    Melatonin, or 5-methoxy-N-acetyltryptamine, is synthesized and released by the pineal gland and locally in the retina following a circadian rhythm, with low levels during the day and elevated levels at night. Melatonin activates two high-affinity G protein–coupled receptors, termed MT1 and MT2, to exert beneficial actions in sleep and circadian abnormality, mood disorders, learning and memory, neuroprotection, drug abuse, and cancer. Progress in understanding the role of melatonin receptors in the modulation of sleep and circadian rhythms has led to the discovery of a novel class of melatonin agonists for treating insomnia, circadian rhythms, mood disorders, and cancer. This review describes the pharmacological properties of a slow-release melatonin preparation (i.e., Circadin®) and synthetic ligands (i.e., agomelatine, ramelteon, tasimelteon), with emphasis on identifying specific therapeutic effects mediated through MT1 and MT2 receptor activation. Discovery of selective ligands targeting the MT1 or the MT2 melatonin receptors may promote the development of novel and more efficacious therapeutic agents. PMID:26514204

  5. Magma plumbing system and seismicity of an active mid-ocean ridge volcano.

    PubMed

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-02-20

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

  6. Volcano-hazard zonation for San Vicente volcano, El Salvador

    USGS Publications Warehouse

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Howell, M.M.

    2001-01-01

    San Vicente volcano, also known as Chichontepec, is one of many volcanoes along the volcanic arc in El Salvador. This composite volcano, located about 50 kilometers east of the capital city San Salvador, has a volume of about 130 cubic kilometers, rises to an altitude of about 2180 meters, and towers above major communities such as San Vicente, Tepetitan, Guadalupe, Zacatecoluca, and Tecoluca. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and major transportation routes are located near the lowermost southern and eastern flanks of the volcano. The population density and proximity around San Vicente volcano, as well as the proximity of major transportation routes, increase the risk that even small landslides or eruptions, likely to occur again, can have serious societal consequences. The eruptive history of San Vicente volcano is not well known, and there is no definitive record of historical eruptive activity. The last significant eruption occurred more than 1700 years ago, and perhaps long before permanent human habitation of the area. Nevertheless, this volcano has a very long history of repeated, and sometimes violent, eruptions, and at least once a large section of the volcano collapsed in a massive landslide. The oldest rocks associated with a volcanic center at San Vicente are more than 2 million years old. The volcano is composed of remnants of multiple eruptive centers that have migrated roughly eastward with time. Future eruptions of this volcano will pose substantial risk to surrounding communities.

  7. Space-Time Evolution of Magma Storage and Transfer at Mt. Etna Volcano (Italy): The 2015-2016 Reawakening of Voragine Crater

    NASA Astrophysics Data System (ADS)

    Cannata, Andrea; Di Grazia, Giuseppe; Giuffrida, Marisa; Gresta, Stefano; Palano, Mimmo; Sciotto, Mariangela; Viccaro, Marco; Zuccarello, Francesco

    2018-02-01

    The eruptions of December 2015 and May 2016 at Voragine crater were among the most explosive recorded during the last two decades at Mt. Etna volcano. Here we present data coming from geophysics (infrasound, LP, VLP, volcanic tremor, VT earthquakes, and ground deformations) and petrology (textural and microanalytical data on plagioclase and olivine crystals) to investigate the preeruptive magma storage and transfer dynamics leading to these exceptional explosive eruptions. Integration of all the available data has led us to constrain chemically, physically, and kinetically the environments where magmas were stored before the eruption, and how they have interacted during the transfer en-route to the surface. Although the evolution and behavior of volcanic phenomena at the surface was rather similar, some differences in storage and transfer dynamics were observed for 2015 and 2016 eruptions. Specifically, the 2015 eruptions have been fed by magmas stored at shallow levels that were pushed upward as a response of magma injections from deeper environments, whereas evidence of chemical interaction between shallow and deep magmatic environments becomes more prominent during the 2016 eruptions. Main findings evidence the activation of magmatic environments deeper than those generally observed for other recent Etnean eruptions, with involvement of deep basic magmas that were brought to shallow crustal levels in very short time scales (˜1 month). The fast transfer from the deepest levels of the plumbing system of basic, undegassed magmas might be viewed as the crucial triggering factor leading to development of exceptionally violent volcanic phenomena even with only basic magma involved.

  8. Spatial distribution of soil radon as a tool to recognize active faulting on an active volcano: the example of Mt. Etna (Italy).

    PubMed

    Neri, Marco; Giammanco, Salvatore; Ferrera, Elisabetta; Patanè, Giuseppe; Zanon, Vittorio

    2011-09-01

    This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquakes depth and intensity can give some hints on the source of gas and/or on fault dynamics. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. 2011 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Maharrey, J. Zebulon; Neal, Christina A.

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near three separate volcanic centers in Alaska during 2011. The year was highlighted by the unrest and eruption of Cleveland Volcano in the central Aleutian Islands. AVO annual summaries no longer report on activity at Russian volcanoes.

  10. A Scientific Excursion: Volcanoes.

    ERIC Educational Resources Information Center

    Olds, Henry, Jr.

    1983-01-01

    Reviews an educationally valuable and reasonably well-designed simulation of volcanic activity in an imaginary land. VOLCANOES creates an excellent context for learning information about volcanoes and for developing skills and practicing methods needed to study behavior of volcanoes. (Author/JN)

  11. Activity at Klyuchevskaya Volcano Resumes

    NASA Image and Video Library

    2017-12-08

    NASA image acquired December 4, 2010 After a respite of less than a month, Klyuchevskaya Volcano resumed erupting in late November 2010. The Global Volcanism Program reported several ash plumes that rose up to 7.9 kilometers (26,000 feet) above sea level from November 25–29. According to the Kamchatka Volcanic Eruption Response Team (KVERT) seismicity was “slightly above background levels” on November 26th and 27th, and they reported observations of strombolian activity on December 1st and 2nd. A plume of ash, steam, and other volcanic gases streamed from Klyuchevskaya on December 4, 2010, visible in this natural-color image acquired by the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite. In the large image, a much smaller plume is visible above neighboring Bezymianny Volcano. NASA Earth Observatory image by Jesse Allen & Robert Simmon, using ALI data from the NASA EO-1 team. Caption by Robert Simmon. Instrument: EO-1 - ALI Credit: NASA Earth Observatory NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

  12. Active volcanoes observed through Art: the contribution offered by the social networks

    NASA Astrophysics Data System (ADS)

    Neri, Marco; Neri, Emilia

    2015-04-01

    Volcanoes have always fascinated people for the wild beauty of their landscapes and also for the fear that they arouse with their eruptive actions, sometimes simply spectacular, but other times terrifying and catastrophic for human activities. In the past, volcanoes were sometimes imagined as a metaphysical gateway to the otherworld; they have inspired the creation of myths and legends ever since three thousand years ago, also represented by paintings of great artistic impact. Modern technology today offers very sophisticated and readily accessed digital tools, and volcanoes continue to be frequently photographed and highly appreciated natural phenomena. Moreover, in recent years, the spread of social networks (Facebook, Twitter, YouTube, Instagram, etc.) have made the widespread dissemination of graphic contributions even easier. The result is that very active and densely inhabited volcanoes such as Etna, Vesuvius and Aeolian Islands, in Italy, have become among the most photographed subjects in the world, providing a popular science tool with formidable influence and usefulness. The beauty of these landscapes have inspired both professional artists and photographers, as well as amateurs, who compete in the social networks for the publication of the most spectacular, artistic or simply most informative images. The end result of this often frantic popular scientific activity is at least two-fold: on one hand, it provides geoscientists and science communicators a quantity of documentation that is almost impossible to acquire through the normal systems of volcano monitoring, while on the other it raises awareness and respect for the land among the civil community.

  13. Factors Determining Forest Diversity and Biomass on a Tropical Volcano, Mt. Rinjani, Lombok, Indonesia

    PubMed Central

    Dossa, Gbadamassi G. O.; Paudel, Ekananda; Fujinuma, Junichi; Yu, Haiying; Chutipong, Wanlop; Zhang, Yuan; Paz, Sherryl; Harrison, Rhett D.

    2013-01-01

    Tropical volcanoes are an important but understudied ecosystem, and the relationships between plant species diversity and compositional change and elevation may differ from mountains created by uplift, because of their younger and more homogeneous soils. We sampled vegetation over an altitudinal gradient on Mt. Rinjani, Lombok, Indonesia. We modeled alpha- (plot) and beta- (among plot) diversity (Fisher's alpha), compositional change, and biomass against elevation and selected covariates. We also examined community phylogenetic structure across the elevational gradient. We recorded 902 trees and shrubs among 92 species, and 67 species of ground-cover plants. For understorey, subcanopy and canopy plants, an increase in elevation was associated with a decline in alpha-diversity, whereas data for ground-cover plants suggested a hump-shaped pattern. Elevation was consistently the most important factor in determining alpha-diversity for all components. The alpha-diversity of ground-cover vegetation was also negatively correlated with leaf area index, which suggests low light conditions in the understorey may limit diversity at lower elevations. Beta-diversity increased with elevation for ground-cover plants and declined at higher elevations for other components of the vegetation. However, statistical power was low and we could not resolve the relative importance to beta-diversity of different factors. Multivariate GLMs of variation in community composition among plots explained 67.05%, 27.63%, 18.24%, and 19.80% of the variation (deviance) for ground-cover, understorey, subcanopy and canopy plants, respectively, and demonstrated that elevation was a consistently important factor in determining community composition. Above-ground biomass showed no significant pattern with elevation and was also not significantly associated with alpha-diversity. At lower elevations communities had a random phylogenetic structure, but from 1600 m communities were phylogenetically clustered

  14. Volcanic hazards at Atitlan volcano, Guatemala

    USGS Publications Warehouse

    Haapala, J.M.; Escobar Wolf, R.; Vallance, James W.; Rose, William I.; Griswold, J.P.; Schilling, S.P.; Ewert, J.W.; Mota, M.

    2006-01-01

    Atitlan Volcano is in the Guatemalan Highlands, along a west-northwest trending chain of volcanoes parallel to the mid-American trench. The volcano perches on the southern rim of the Atitlan caldera, which contains Lake Atitlan. Since the major caldera-forming eruption 85 thousand years ago (ka), three stratovolcanoes--San Pedro, Toliman, and Atitlan--have formed in and around the caldera. Atitlan is the youngest and most active of the three volcanoes. Atitlan Volcano is a composite volcano, with a steep-sided, symmetrical cone comprising alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs. Eruptions of Atitlan began more than 10 ka [1] and, since the arrival of the Spanish in the mid-1400's, eruptions have occurred in six eruptive clusters (1469, 1505, 1579, 1663, 1717, 1826-1856). Owing to its distance from population centers and the limited written record from 200 to 500 years ago, only an incomplete sample of the volcano's behavior is documented prior to the 1800's. The geologic record provides a more complete sample of the volcano's behavior since the 19th century. Geologic and historical data suggest that the intensity and pattern of activity at Atitlan Volcano is similar to that of Fuego Volcano, 44 km to the east, where active eruptions have been observed throughout the historical period. Because of Atitlan's moderately explosive nature and frequency of eruptions, there is a need for local and regional hazard planning and mitigation efforts. Tourism has flourished in the area; economic pressure has pushed agricultural activity higher up the slopes of Atitlan and closer to the source of possible future volcanic activity. This report summarizes the hazards posed by Atitlan Volcano in the event of renewed activity but does not imply that an eruption is imminent. However, the recognition of potential activity will facilitate hazard and emergency preparedness.

  15. Leveraging increased cytoplasmic nucleoside kinase activity to target mtDNA and oxidative phosphorylation in AML.

    PubMed

    Liyanage, Sanduni U; Hurren, Rose; Voisin, Veronique; Bridon, Gaëlle; Wang, Xiaoming; Xu, ChangJiang; MacLean, Neil; Siriwardena, Thirushi P; Gronda, Marcela; Yehudai, Dana; Sriskanthadevan, Shrivani; Avizonis, Daina; Shamas-Din, Aisha; Minden, Mark D; Bader, Gary D; Laposa, Rebecca; Schimmer, Aaron D

    2017-05-11

    Mitochondrial DNA (mtDNA) biosynthesis requires replication factors and adequate nucleotide pools from the mitochondria and cytoplasm. We performed gene expression profiling analysis of 542 human acute myeloid leukemia (AML) samples and identified 55% with upregulated mtDNA biosynthesis pathway expression compared with normal hematopoietic cells. Genes that support mitochondrial nucleotide pools, including mitochondrial nucleotide transporters and a subset of cytoplasmic nucleoside kinases, were also increased in AML compared with normal hematopoietic samples. Knockdown of cytoplasmic nucleoside kinases reduced mtDNA levels in AML cells, demonstrating their contribution in maintaining mtDNA. To assess cytoplasmic nucleoside kinase pathway activity, we used a nucleoside analog 2'3'-dideoxycytidine (ddC), which is phosphorylated to the activated antimetabolite, 2'3'-dideoxycytidine triphosphate by cytoplasmic nucleoside kinases. ddC is a selective inhibitor of the mitochondrial DNA polymerase γ. ddC was preferentially activated in AML cells compared with normal hematopoietic progenitor cells. ddC treatment inhibited mtDNA replication, oxidative phosphorylation, and induced cytotoxicity in a panel of AML cell lines. Furthermore, ddC preferentially inhibited mtDNA replication in a subset of primary human leukemia cells and selectively targeted leukemia cells while sparing normal progenitor cells. In animal models of human AML, treatment with ddC decreased mtDNA, electron transport chain proteins, and induced tumor regression without toxicity. ddC also targeted leukemic stem cells in secondary AML xenotransplantation assays. Thus, AML cells have increased cytidine nucleoside kinase activity that regulates mtDNA biogenesis and can be leveraged to selectively target oxidative phosphorylation in AML. © 2017 by The American Society of Hematology.

  16. Leveraging increased cytoplasmic nucleoside kinase activity to target mtDNA and oxidative phosphorylation in AML

    PubMed Central

    Liyanage, Sanduni U.; Hurren, Rose; Voisin, Veronique; Bridon, Gaëlle; Wang, Xiaoming; Xu, ChangJiang; MacLean, Neil; Siriwardena, Thirushi P.; Gronda, Marcela; Yehudai, Dana; Sriskanthadevan, Shrivani; Avizonis, Daina; Shamas-Din, Aisha; Minden, Mark D.; Bader, Gary D.; Laposa, Rebecca

    2017-01-01

    Mitochondrial DNA (mtDNA) biosynthesis requires replication factors and adequate nucleotide pools from the mitochondria and cytoplasm. We performed gene expression profiling analysis of 542 human acute myeloid leukemia (AML) samples and identified 55% with upregulated mtDNA biosynthesis pathway expression compared with normal hematopoietic cells. Genes that support mitochondrial nucleotide pools, including mitochondrial nucleotide transporters and a subset of cytoplasmic nucleoside kinases, were also increased in AML compared with normal hematopoietic samples. Knockdown of cytoplasmic nucleoside kinases reduced mtDNA levels in AML cells, demonstrating their contribution in maintaining mtDNA. To assess cytoplasmic nucleoside kinase pathway activity, we used a nucleoside analog 2′3′-dideoxycytidine (ddC), which is phosphorylated to the activated antimetabolite, 2′3′-dideoxycytidine triphosphate by cytoplasmic nucleoside kinases. ddC is a selective inhibitor of the mitochondrial DNA polymerase γ. ddC was preferentially activated in AML cells compared with normal hematopoietic progenitor cells. ddC treatment inhibited mtDNA replication, oxidative phosphorylation, and induced cytotoxicity in a panel of AML cell lines. Furthermore, ddC preferentially inhibited mtDNA replication in a subset of primary human leukemia cells and selectively targeted leukemia cells while sparing normal progenitor cells. In animal models of human AML, treatment with ddC decreased mtDNA, electron transport chain proteins, and induced tumor regression without toxicity. ddC also targeted leukemic stem cells in secondary AML xenotransplantation assays. Thus, AML cells have increased cytidine nucleoside kinase activity that regulates mtDNA biogenesis and can be leveraged to selectively target oxidative phosphorylation in AML. PMID:28283480

  17. 1997 volcanic activity in Alaska and Kamchatka: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Wallace, Kristi L.

    1999-01-01

    The Alaska Volcano Observatory (AVO) monitors over 40 historically active volcanoes along the Aleutian Arc. Twenty are seismically monitored and for the rest, the AVO monitoring program relies mainly on pilot reports, observations of local residents and ship crews, and daily analysis of satellite images. In 1997, AVO responded to eruptive activity or suspect volcanic activity at 11 volcanic centers: Wrangell, Sanford, Shrub mud volcano, Iliamna, the Katmai group (Martin, Mageik, Snowy, and Kukak volcanoes), Chiginagak, Pavlof, Shishaldin, Okmok, Cleveland, and Amukta. Of these, AVO has real-time, continuously recording seismic networks at Iliamna, the Katmai group, and Pavlof. The phrase “suspect volcanic activity” (SVA), used to characterize several responses, is an eruption report or report of unusual activity that is subsequently determined to be normal or enhanced fumarolic activity, weather-related phenomena, or a non-volcanic event. In addition to responding to eruptive activity at Alaska volcanoes, AVO also disseminated information for the Kamchatkan Volcanic Eruption Response Team (KVERT) about the 1997 activity of 5 Russian volcanoes--Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Alaid (SVA). This report summarizes volcanic activity and SVA in Alaska during 1997 and the AVO response, as well as information on the reported activity at the Russian volcanoes. Only those reports or inquiries that resulted in a “significant” investment of staff time and energy (here defined as several hours or more for reaction, tracking, and follow-up) are included. AVO typically receives dozens of reports throughout the year of steaming, unusual cloud sightings, or eruption rumors. Most of these are resolved quickly and are not tabulated here as part of the 1997 response record.

  18. Heteromeric MT1/MT2 Melatonin Receptors Modulate Photoreceptor Function

    PubMed Central

    Baba, Kenkichi; Benleulmi-Chaachoua, Abla; Journé, Anne-Sophie; Kamal, Maud; Guillaume, Jean-Luc; Dussaud, Sébastien; Gbahou, Florence; Yettou, Katia; Liu, Cuimei; Contreras-Alcantara, Susana; Jockers, Ralf; Tosini, Gianluca

    2013-01-01

    The formation of G protein-coupled receptor (GPCR) heteromers elicits signaling diversification and holds great promise for improved drug selectivity. Most studies have been conducted in heterologous expression systems; however, in vivo validation is missing from most cases thus questioning the physiological significance of GPCR heteromerization. Melatonin MT1 and MT2 receptors have been shown to exist as homo- and heteromers in vitro. We show here that the effect of melatonin on rod photoreceptor light sensitivity is mediated by melatonin MT1/MT2 receptor heteromers. This effect involves activation of the heteromer-specific PLC/PKC pathway and is abolished in MT1−/− and MT2−/− mice as well as in mice overexpressing a non-functional MT2 receptor mutant that competes with the formation of functional MT1/MT2 heteromers in photoreceptor cells. This study establishes the essential role of melatonin receptor heteromers in retinal function and supports the physiological importance of GPCR heteromerization. Finally, our work may have important therapeutic implications, as the heteromer complex may provide a unique pharmacological target to improve photoreceptor functioning and to extend the viability of photoreceptors during aging. PMID:24106342

  19. Tree-ring width reveals the preparation of the 1974 Mt. Etna eruption

    PubMed Central

    Seiler, Ruedi; Houlié, Nicolas; Cherubini, Paolo

    2017-01-01

    Reduced near-infrared reflectance observed in September 1973 in Skylab images of the western flank of Mt. Etna has been interpreted as an eruption precursor of the January 1974 eruption. Until now, it has been unclear when this signal started, whether it was sustained and which process(es) could have caused it. By analyzing tree-ring width time-series, we show that the reduced near-infrared precursory signal cannot be linked to a reduction in annual tree growth in the area. However, comparing the tree-ring width time-series with both remote sensing observations and volcano-seismic activity enables us to discuss the starting date of the pre-eruptive period of the 1974 eruption. PMID:28266610

  20. Klyuchevskaya Volcano

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Klyuchevskaya Volcano on Russia's Kamchatka Peninsula continued its ongoing activity by releasing another plume on May 24, 2007. The same day, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image, at 01:00 UTC. In this image, a hotspot marks the volcano's summit. Outlined in red, the hotspot indicates where MODIS detected unusually warm surface temperatures. Blowing southward from the summit is the plume, which casts its shadow on the clouds below. Near the summit, the plume appears gray, and it lightens toward the south. With an altitude of 4,835 meters (15,863 feet), Klyuchevskaya (sometimes spelled Klyuchevskoy or Kliuchevskoi) is both the highest and most active volcano on the Kamchatka Peninsula. As part of the Pacific 'Ring of Fire,' the peninsula experiences regular seismic activity as the Pacific Plate slides below other tectonic plates in the Earth's crust. Klyuchevskaya is estimated to have experienced more than 100 flank eruptions in the past 3,000 years. Since its formation 6,000 years ago, the volcano has seen few periods of inactivity. NASA image courtesy the MODIS Rapid Response Team at NASA GSFC. The Rapid Response Team provides daily images of this region.

  1. A volcanic event forecasting model for multiple tephra records, demonstrated on Mt. Taranaki, New Zealand

    NASA Astrophysics Data System (ADS)

    Damaschke, Magret; Cronin, Shane J.; Bebbington, Mark S.

    2018-01-01

    Robust time-varying volcanic hazard assessments are difficult to develop, because they depend upon having a complete and extensive eruptive activity record. Missing events in eruption records are endemic, due to poor preservation or erosion of tephra and other volcanic deposits. Even with many stratigraphic studies, underestimation or overestimation of eruption numbers is possible due to mis-matching tephras with similar chemical compositions or problematic age models. It is also common to have gaps in event coverage due to sedimentary records not being available in all directions from the volcano, especially downwind. Here, we examine the sensitivity of probabilistic hazard estimates using a suite of four new and two existing high-resolution tephra records located around Mt. Taranaki, New Zealand. Previous estimates were made using only single, or two correlated, tephra records. In this study, tephra data from six individual sites in lake and peat bogs covering an arc of 120° downwind of the volcano provided an excellent temporal high-resolution event record. The new data confirm a previously identified semi-regular pattern of variable eruption frequency at Mt. Taranaki. Eruption intervals exhibit a bimodal distribution, with eruptions being an average of 65 years apart, and in 2% of cases, centuries separate eruptions. The long intervals are less common than seen in earlier studies, but they have not disappeared with the inclusion of our comprehensive new dataset. Hence, the latest long interval of quiescence, since AD 1800, is unusual, but not out of character with the volcano. The new data also suggest that one of the tephra records (Lake Rotokare) used in earlier work had an old carbon effect on age determinations. This shifted ages of the affected tephras so that they were not correlated to other sites, leading to an artificially high eruption frequency in the previous combined record. New modelled time-varying frequency estimates suggest a 33

  2. Exploring Interactions Between Subduction Zone Earthquakes and Volcanic Activity in the South Central Alaskan Subduction Zone

    NASA Astrophysics Data System (ADS)

    Lanagan, K. M.; Richardson, E.

    2012-12-01

    Although great earthquakes such as the recent moment-magnitude (M) 9 Tohoku-Oki earthquake have been shown to trigger remote seismicity in volcanoes, the extent to which subduction zone earthquakes can trigger shallow seismic swarms at volcanoes is largely unexplored. Unknowns in this relationship include the upper limit of distance, the lower limit of magnitude, the upper time limit between events, and the effects of rupture directivity. We searched the Advanced National Seismic System earthquake catalog from 1989 - 2011 for correlations in space and time between M > 5.0 earthquakes in the south central Alaskan subduction zone (between 58.5°N and 62.5°N, and 150.7°W and 154.7°W) and volcanic activity at Mt. Redoubt, Mt. Iliamna, and Mt. Spurr volcanoes. There are 48 earthquakes M > 5 in this catalog; five of these are M > 6. The depths of the 48 M>5 events range from 49km to 220km, and they are all between 100km and 350km of the three volcanoes. Preliminary analysis of our catalog shows that four of the five M > 6 earthquakes are followed by a volcanic earthquake swarm at either Redoubt or Spurr within 100 days, and three of them are followed by a volcanic earthquake swarm within a month. None of these events correlated in space and time with swarms at Mt. Iliamna. We are also searching for swarms and moderate earthquakes occurring in time windows far removed from each other. The likeliest case of remotely triggered seismicity in our search area to date occurred on January 24 2009, when a magnitude 5.8 earthquake beneath the Kenai Peninsula at 59.4°N, 152.8°W, and 95km depth was immediately followed by an increase of volcanic activity at Mt. Redoubt approximately 153km away. The first swarm began on Jan 25 2009. On Jan 30 2009, volcanologists at the Alaskan Volcano observatory determined the increased volcanic seismicity was indicative of an impending eruption. Mt. Redoubt erupted on March 15 2009. Proposed mechanisms for triggering of volcanoes by

  3. Confirmation and calibration of computer modeling of tsunamis produced by Augustine volcano, Alaska

    USGS Publications Warehouse

    Beget, James E.; Kowalik, Zygmunt

    2006-01-01

    Numerical modeling has been used to calculate the characteristics of a tsunami generated by a landslide into Cook Inlet from Augustine Volcano. The modeling predicts travel times of ca. 50-75 minutes to the nearest populated areas, and indicates that significant wave amplification occurs near Mt. Iliamna on the western side of Cook Inlet, and near the Nanwelak and the Homer-Anchor Point areas on the east side of Cook Inlet. Augustine volcano last produced a tsunami during an eruption in 1883, and field evidence of the extent and height of the 1883 tsunamis can be used to test and constrain the results of the computer modeling. Tsunami deposits on Augustine Island indicate waves near the landslide source were more than 19 m high, while 1883 tsunami deposits in distal sites record waves 6-8 m high. Paleotsunami deposits were found at sites along the coast near Mt. Iliamna, Nanwelak, and Homer, consistent with numerical modeling indicating significant tsunami wave amplification occurs in these areas. 

  4. InSAR observations of active volcanoes in Latin America

    NASA Astrophysics Data System (ADS)

    Morales Rivera, A. M.; Chaussard, E.; Amelung, F.

    2012-12-01

    Over the last decade satellite-based interferometric synthetic aperture radar (InSAR) has developed into a well-known technique to gauge the status of active volcanoes. The InSAR technique can detect the ascent of magma to shallow levels of the volcanic plumbing system because new arriving magma pressurizes the system. This is likely associated with the inflation of the volcanic edifice and the surroundings. Although the potential of InSAR to detect magma migration is well known, the principal limitation was that only for few volcanoes frequent observations were acquired. The ALOS-1 satellite of the Japanese Aerospace Exploration Agency (JAXA) acquired a global L-band data set of 15-20 acquisitions during 2006-2011. Here we use ALOS InSAR and Small Baseline (SB) time-series methods for a ground deformation survey of Latin America with emphasis on the northern Andes. We present time-dependent ground deformation data for the volcanoes in Colombia, Ecuador and Peru and interpret the observations in terms of the dynamics of the volcanic systems.

  5. Volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory 1993

    USGS Publications Warehouse

    Neal, Christina A.; McGimsey, Robert G.; Doukas, Michael P.

    1996-01-01

    During 1993, the Alaska Volcano Observatory (AVO) responded to episodes of eruptive activity or false alarms at nine volcanic centers in the state of Alaska. Additionally, as part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also responded to eruptions on the Kamchatka Peninsula, details of which are summarized in Miller and Kurianov (1993). In 1993, AVO maintained seismic instrumentation networks on four volcanoes of the Cook Inlet region--Spurr, Redoubt, Iliamna, and Augustine--and two stations at Dutton Volcano near King Cove on the Alaska Peninsula. Other routine elements of AVO's volcano monitoring program in Alaska include periodic airborne measurement of volcanic SO2 and CO2 at Cook Inlet volcanoes (Doukas, 1995) and maintenance of a lightning detection system in Cook Inlet (Paskievitch and others, 1995).

  6. Preliminary volcano-hazard assessment for Iliamna Volcano, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Miller, Thomas P.

    1999-01-01

    Iliamna Volcano is a 3,053-meter-high, ice- and snow-covered stratovolcano in the southwestern Cook Inlet region about 225 kilometers southwest of Anchorage and about 100 kilometers northwest of Homer. Historical eruptions of Iliamna Volcano have not been positively documented; however, the volcano regularly emits steam and gas, and small, shallow earthquakes are often detected beneath the summit area. The most recent eruptions of the volcano occurred about 300 years ago, and possibly as recently as 90-140 years ago. Prehistoric eruptions have generated plumes of volcanic ash, pyroclastic flows, and lahars that extended to the volcano flanks and beyond. Rock avalanches from the summit area have occurred numerous times in the past. These avalanches flowed several kilometers down the flanks and at least two large avalanches transformed to cohesive lahars. The number and distribution of known volcanic ash deposits from Iliamna Volcano indicate that volcanic ash clouds from prehistoric eruptions were significantly less voluminous and probably less common relative to ash clouds generated by eruptions of other Cook Inlet volcanoes. Plumes of volcanic ash from Iliamna Volcano would be a major hazard to jet aircraft using Anchorage International Airport and other local airports, and depending on wind direction, could drift at least as far as the Kenai Peninsula and beyond. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Because Iliamna Volcano has not erupted for several hundred years, a future eruption could involve significant amounts of ice and snow that could lead to the formation of large lahars and downstream flooding. The greatest hazards in order of importance are described below and shown on plate 1.

  7. Volcanic unrest leading to the July-August 2001 lateral eruption at Mt. Etna: Seismological constraints

    NASA Astrophysics Data System (ADS)

    Sicali, Simona; Barberi, Graziella; Cocina, Ornella; Musumeci, Carla; Patanè, Domenico

    2015-10-01

    A close relationship between earthquake swarms, volcanic eruptions, and ground deformation at Mt. Etna was well documented shortly before the beginning of the July-August 2001 eruption. Past experiences at this volcano suggest how magma/dike intrusion in the shallow crust or in the upper part of the volcanic pile normally occurs after several years/months of internal recharging. Since seismic investigations provide a means to study the scale and origin of stress perturbations at active volcanoes, allowing to better investigating the preparation phase of an eruption, in this paper, we performed a close examination of the seismic activity recorded at Mt. Etna in the months preceding the 2001 eruption and in particular between November 2000 and July 2001. After integrating data recorded by the two networks operating during that time and run by the Istituto Internazionale di Vulcanologia and SISTEMA POSEIDON, we relocated 522 earthquakes by using the tomoDD code in a 3D velocity model, and then we computed their fault plane solutions. The application of different selection criteria enabled obtaining a good-quality revised data set consisting of 111 fault plane solutions. The high-precision locations identified well-defined seismic clusters, in different periods, suggesting a link with the magma migration from a depth of 8-13 km b.s.l. towards shallower zones. Moreover, the computed maximum compressive stress axis, as inferred from earthquake focal mechanisms, indicated a roughly W-E-oriented σ1. This findings reflect an overpressure of the mid to shallow crust due to the progressive magma uprising in central portion of the volcano and also highlighted a rotation of the local stress field with respect to the regional one N-S trending. In addition, P-axis distribution pointed out the presence of a center of pressure located to the south of the Central Craters. These results provide particularly compelling evidence for a direct causal link between pressurization of the

  8. What more have we learned from thermal infrared remote sensing of active volcanoes other than they are hot? (Invited)

    NASA Astrophysics Data System (ADS)

    Ramsey, M.

    2009-12-01

    Thermal infrared (TIR) remote sensing has been used for decades to detect changes in the heat output of active and reawakening volcanoes. The data from these thermally anomalous pixels are commonly used either as a monitoring tool or to calculate parameters such as effusion rate and eruptive style. First and second generation TIR data have been limited in the number of spectral channels and/or the spatial resolution. Two spectral channels with only one km spatial resolution has been the norm and therefore the number of science applications is limited to very large or very hot events. The one TIR channel of the Landsat ETM+ instrument improved the spatial resolution to 60 m, but it was not until the launch of ASTER in late 1999 that orbital TIR spectral resolution increased to five channels at 90 m per pixel. For the first time, the ability existed to capture multispectral emitted radiance from volcanic surfaces, which has allowed the extraction of emissivity as well as temperature. Over the past decade ASTER TIR emissivity data have been examined for a variety of volcanic processes including lava flow emplacement at Kilauea and Kluichevskoi, silicic lava dome composition at Sheveluch, Bezymianny and Mt. St. Helens, low temperature fumaroles emissions at Cerro Negro, and textural changes on the pyroclastic flow deposits at Merapi, Sheveluch and Bezymianny. Thermal-temporal changes at the 90 m scale are still an important monitoring tool for active volcanoes using ASTER TIR data. However, the ability to extract physical parameters such as micron-scale roughness and bulk mineralogy has added tremendously to the science derived from the TIR region. This new information has also presented complications such as the effects of sub-pixel thermal heterogeneities and amorphous glass on the emissivity spectra. If better understood, these complications can provide new insights into the physical state of the volcanic surfaces. Therefore, new data processing algorithms

  9. Small Tharsis Volcano

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 August 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small volcano located southwest of the giant volcano, Pavonis Mons, near 2.5oS, 109.4oW. Lava flows can be seen to have emanated from the summit region, which today is an irregularly-shaped collapse pit, or caldera. A blanket of dust mantles this volcano. Dust covers most martian volcanoes, none of which are young or active today. This picture covers an area about 3 km (1.9 mi) across; sunlight illuminates the scene from the left.

  10. Dueling Volcanoes: How Activity Levels At Kilauea Influence Eruptions At Mauna Loa

    NASA Astrophysics Data System (ADS)

    Trusdell, F.

    2011-12-01

    The eruption of Kilauea at Pu`u `O`o is approaching its 29th anniversary. During this time, Mauna Loa has slowly inflated following its most recent eruption in 1984. This is Mauna Loa's longest inter-eruptive interval observed in HVO's 100 years of operation. When will the next eruption of Mauna Loa take place? Is the next eruption of Mauna Loa tied to the current activity at Kilauea? Historically, eruptive periods at Kilauea and Mauna Loa volcanoes appear to be inversely correlated. In the past, when Mauna Loa was exceptionally active, Kilauea Volcano was in repose, recovery, or in sustained lava lake activity. Swanson and co-workers (this meeting) have noted that explosive activity on Kilauea, albeit sporadic, was interspersed between episodes of effusive activity. Specifically, Swanson and co-workers note as explosive the time periods between 300 B.C.E.-1000 C.E and 1500-1800 C.E. They also point to evidence for low magma supply to Kilauea during these periods and few flank eruptions. During the former explosive period, Mauna Loa was exceedingly active, covering approximately 37% of its surface or 1882 km2, an area larger than Kilauea. This period is also marked by summit activity at Mauna Loa sustained for 300 years. In the 1500-1800 C.E. period, Mauna Loa was conspicuously active with 29 eruptions covering an area of 446 km2. In the late 19th and early 20th century, Kilauea was dominated by nearly continuous lava-lake activity. Meanwhile Mauna Loa was frequently active from 1843 C.E. to 1919 C.E., with 24 eruptions for an average repose time of 3.5 years. I propose that eruptive activity at one volcano may affect eruptions at the other, due to factors that impact magma supply, volcanic plumbing, and flank motion. This hypothesis is predicated on the notion that when the rift zones of Kilauea, and in turn its mobile south flank, are active, Mauna Loa's tendency to erupt is diminished. Kilauea's rift zones help drive the south flank seaward, in turn, as Mauna

  11. Methods of InSAR atmosphere correction for volcano activity monitoring

    USGS Publications Warehouse

    Gong, W.; Meyer, F.; Webley, P.W.; Lu, Z.

    2011-01-01

    When a Synthetic Aperture Radar (SAR) signal propagates through the atmosphere on its path to and from the sensor, it is inevitably affected by atmospheric effects. In particular, the applicability and accuracy of Interferometric SAR (InSAR) techniques for volcano monitoring is limited by atmospheric path delays. Therefore, atmospheric correction of interferograms is required to improve the performance of InSAR for detecting volcanic activity, especially in order to advance its ability to detect subtle pre-eruptive changes in deformation dynamics. In this paper, we focus on InSAR tropospheric mitigation methods and their performance in volcano deformation monitoring. Our study areas include Okmok volcano and Unimak Island located in the eastern Aleutians, AK. We explore two methods to mitigate atmospheric artifacts, namely the numerical weather model simulation and the atmospheric filtering using Persistent Scatterer processing. We investigate the capability of the proposed methods, and investigate their limitations and advantages when applied to determine volcanic processes. ?? 2011 IEEE.

  12. Instrumentation Recommendations for Volcano Monitoring at U.S. Volcanoes Under the National Volcano Early Warning System

    USGS Publications Warehouse

    Moran, Seth C.; Freymueller, Jeff T.; LaHusen, Richard G.; McGee, Kenneth A.; Poland, Michael P.; Power, John A.; Schmidt, David A.; Schneider, David J.; Stephens, George; Werner, Cynthia A.; White, Randall A.

    2008-01-01

    As magma moves toward the surface, it interacts with anything in its path: hydrothermal systems, cooling magma bodies from previous eruptions, and (or) the surrounding 'country rock'. Magma also undergoes significant changes in its physical properties as pressure and temperature conditions change along its path. These interactions and changes lead to a range of geophysical and geochemical phenomena. The goal of volcano monitoring is to detect and correctly interpret such phenomena in order to provide early and accurate warnings of impending eruptions. Given the well-documented hazards posed by volcanoes to both ground-based populations (for example, Blong, 1984; Scott, 1989) and aviation (for example, Neal and others, 1997; Miller and Casadevall, 2000), volcano monitoring is critical for public safety and hazard mitigation. Only with adequate monitoring systems in place can volcano observatories provide accurate and timely forecasts and alerts of possible eruptive activity. At most U.S. volcanoes, observatories traditionally have employed a two-component approach to volcano monitoring: (1) install instrumentation sufficient to detect unrest at volcanic systems likely to erupt in the not-too-distant future; and (2) once unrest is detected, install any instrumentation needed for eruption prediction and monitoring. This reactive approach is problematic, however, for two reasons. 1. At many volcanoes, rapid installation of new ground-1. based instruments is difficult or impossible. Factors that complicate rapid response include (a) eruptions that are preceded by short (hours to days) precursory sequences of geophysical and (or) geochemical activity, as occurred at Mount Redoubt (Alaska) in 1989 (24 hours), Anatahan (Mariana Islands) in 2003 (6 hours), and Mount St. Helens (Washington) in 1980 and 2004 (7 and 8 days, respectively); (b) inclement weather conditions, which may prohibit installation of new equipment for days, weeks, or even months, particularly at

  13. Klyuchevskaya, Volcano, Kamchatka Peninsula, CIS

    NASA Image and Video Library

    1991-05-06

    STS039-151-179 (28 April-6 May 1991) --- A large format frame of one of the USSR's volcanic complex (Kamchatka area) with the active volcano Klyuchevskaya (Kloo-chevs'-ska-ya), 15,584 feet in elevation. The last reported eruption of the volcano was on April 8, but an ash and steam plume extending to the south was observed by the STS-39 crew almost three weeks later. The south side of the volcano is dirty from the ash fall and landslide activity. The summit is clearly visible, as is the debris flow from an earlier eruption. Just north of the Kamchatka River is Shiveluch, a volcano which was active in early April. There are more than 100 volcanic edifices recognized on Kamchatka, with 15 classified as active.

  14. Klyuchevskaya, Volcano, Kamchatka Peninsula, CIS

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Klyuchevskaya, Volcano, Kamchatka Peninsula, CIS (56.0N, 160.5E) is one of several active volcanoes in the CIS and is 15,584 ft. in elevation. Fresh ash fall on the south side of the caldera can be seen as a dirty smudge on the fresh snowfall. Just to the north of the Kamchatka River is Shiveluch, a volcano which had been active a short time previously. There are more than 100 volcanic edifices recognized on Kamchatka, 15 of which are still active.

  15. High Resolution, Low Altitude Aeromagnetic and Electromagnetic Survey of Mt Rainier

    USGS Publications Warehouse

    Rystrom, V.L.; Finn, C.; Deszcz-Pan, Maryla

    2000-01-01

    In October 1996, the USGS conducted a high resolution airborne magnetic and electromagnetic survey in order to discern through-going sections of exposed altered rocks and those obscured beneath snow, vegetation and surficial unaltered rocks. Hydrothermally altered rocks weaken volcanic edifices, creating the potential for catastrophic sector collapses and ensuing formation of destructive volcanic debris flows. This data once compiled and interpreted, will be used to examine the geophysical properties of the Mt. Rainier volcano, and help assist the USGS in its Volcanic Hazards Program and at its Cascades Volcano Observatory. Aeromagnetic and electromagnetic data provide a means for seeing through surficial layers and have been tools for delineating structures within volcanoes. However, previously acquired geophysical data were not useful for small-scale geologic mapping. In this report, we present the new aeromagnetic and electromagnetic data, compare results from previously obtained, low-resolution aeromagnetic data with new data collected at a low-altitude and closely spaced flightlines, and provide information on potential problems with using high-resolution data.

  16. Did the Eruption of the Mt. Pinatubo Volcano Affect Cirrus Properties?

    NASA Technical Reports Server (NTRS)

    Luo, Zhengzhao; Rossow, William B.; Inoue, Toshiro; Stubenrauch, Claudia J.; Hansen, James E. (Technical Monitor)

    2001-01-01

    Some observations suggest that the volcanic aerosols produced by the Mt. Pinatubo eruption may have altered cirrus properties. We look for evidence that such modification of cirrus is extensive enough to be climatically significant by comparing three satellite-based cirrus datasets produced by the ISCCP (International Satellite Cloud Climatology Project) analysis, the 'split-window' analysis, and 3I analysis. Since the former two have not been compared in detail before, we conduct such a comparison here. When applied to AVHRR (Advanced Very High Resolution Radiometer) data, both the ISCCP and split-window analyses identify about 0.2 - 0.3 cirrus cloud amount in tropical latitudes; however, there are detailed differences of classification for about half of these clouds. The discrepancies are attributed to the simplified assumptions made by both methods. The latter two datasets are derived from infrared radiances, so they are much less sensitive to volcanic aerosols than the ISCCP analysis. After the Mt. Pinatubo eruption, the ISCCP results indicate a dramatic decrease of thin cirrus (cloud top pressure less than 440 mb and visible optical thickness less than 1.3) over ocean, accompanied by a comparable increase of altocumulus and cumulus clouds; over land, there are no significant changes. In contrast, results from the split-window and 3I analyses show little change in thin cirrus amount over either ocean or land that is associated with the volcanic eruption. The ISCCP results can, therefore, be understood as a misclassification of thin cirrus because the additional reflected sunlight by the volcanic aerosol makes the cirrus clouds appear to be optically thicker. Examination of the split-window signature and the infrared emissivities from 3I show no significant change in infrared emissivity (or optical thickness). These results indicate that the Mt. Pinatubo volcanic aerosol did not have a significant systematic effect on tropical cirrus properties, but rather

  17. The New USGS Volcano Hazards Program Web Site

    NASA Astrophysics Data System (ADS)

    Venezky, D. Y.; Graham, S. E.; Parker, T. J.; Snedigar, S. F.

    2008-12-01

    The U.S. Geological Survey's (USGS) Volcano Hazard Program (VHP) has launched a revised web site that uses a map-based interface to display hazards information for U.S. volcanoes. The web site is focused on better communication of hazards and background volcano information to our varied user groups by reorganizing content based on user needs and improving data display. The Home Page provides a synoptic view of the activity level of all volcanoes for which updates are written using a custom Google® Map. Updates are accessible by clicking on one of the map icons or clicking on the volcano of interest in the adjacent color-coded list of updates. The new navigation provides rapid access to volcanic activity information, background volcano information, images and publications, volcanic hazards, information about VHP, and the USGS volcano observatories. The Volcanic Activity section was tailored for emergency managers but provides information for all our user groups. It includes a Google® Map of the volcanoes we monitor, an Elevated Activity Page, a general status page, information about our Volcano Alert Levels and Aviation Color Codes, monitoring information, and links to monitoring data from VHP's volcano observatories: Alaska Volcano Observatory (AVO), Cascades Volcano Observatory (CVO), Long Valley Observatory (LVO), Hawaiian Volcano Observatory (HVO), and Yellowstone Volcano Observatory (YVO). The YVO web site was the first to move to the new navigation system and we are working on integrating the Long Valley Observatory web site next. We are excited to continue to implement new geospatial technologies to better display our hazards and supporting volcano information.

  18. Prokaryotic diversity of an active mud volcano in the Usu City of Xinjiang, China.

    PubMed

    Yang, Hong-Mei; Lou, Kai; Sun, Jian; Zhang, Tao; Ma, Xiao-Long

    2012-02-01

    The Usu mud volcanoes are the largest group of terrestrial mud volcanoes in China. The volcanoes are located in a typical arid and semi-arid region, and the group consists of 36 erupting active mud volcanoes. In this study, the prokaryotic diversity and community structure in the sediment of an active mud volcano were investigated by constructing bacterial and archaeal clone libraries of the 16S rRNA gene. A total of 100 bacterial and 100 archaeal clones were analysed and found to comprise 11 and 7 distinct phylotypes, respectively. The bacterial phylotypes were classified into three phyla (Proteobacteria, Actinobacteria, and Fusobacteria). Of these, Proteobacteria were the most abundant bacterial group, with Deltaproteobacteria dominating the sediment community, and these were affiliated with the order Desulfuromonadales. The archaeal phylotypes were all closely related to uncultivated species, and the majority of the members were related to the orders Methanosarcinales and Halobacteriales of the Euryarchaeota originating from methane hydrate bearing or alkaline sediments. The rest of the archaeal phylotypes belonged to the phylum Crenarchaeota, with representatives from similar habitats. These results suggested that a large number of novel microbial groups and potential methanogenesis may exist in this unique ecosystem. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Dante's Volcano

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This video contains two segments: one a 0:01:50 spot and the other a 0:08:21 feature. Dante 2, an eight-legged walking machine, is shown during field trials as it explores the inner depths of an active volcano at Mount Spurr, Alaska. A NASA sponsored team at Carnegie Mellon University built Dante to withstand earth's harshest conditions, to deliver a science payload to the interior of a volcano, and to report on its journey to the floor of a volcano. Remotely controlled from 80-miles away, the robot explored the inner depths of the volcano and information from onboard video cameras and sensors was relayed via satellite to scientists in Anchorage. There, using a computer generated image, controllers tracked the robot's movement. Ultimately the robot team hopes to apply the technology to future planetary missions.

  20. Elastostatic effects around a magma reservoir and pathway due to historic earthquakes: a case study of Mt. Fuji, Japan

    NASA Astrophysics Data System (ADS)

    Hosono, Masaki; Mitsui, Yuta; Ishibashi, Hidemi; Kataoka, Jun

    2016-12-01

    We discuss elastostatic effects on Mt. Fuji, the tallest volcano in Japan, due to historic earthquakes in Japan. The 1707 Hoei eruption, which was the most explosive historic eruption of Mt. Fuji, occurred 49 days after the Hoei earthquake (Mw 8.7) along the Nankai Trough. It was previously suggested that the Hoei earthquake induced compression of a basaltic magma reservoir and unclamping of a dike-intruded region at depth, possibly triggering magma mixing and the subsequent Plinian eruption. Here, we show that the 1707 Hoei earthquake was a special case of induced volumetric strain and normal stress changes around the magma reservoir and pathway of Mt. Fuji. The 2011 Tohoku earthquake (Mw 9), along the Japan Trench, dilated the magma reservoir. It has been proposed that dilation of a magma reservoir drives the ascent of gas bubbles with magma and further depressurization, leading to a volcanic eruption. In fact, seismicity notably increased around Mt. Fuji during the first month after the 2011 Tohoku earthquake, even when we statistically exclude aftershocks, but the small amount of strain change (< 1 μ strain) may have limited the ascent of magma. For many historic earthquakes, the magma reservoir was compressed and the magma pathway was wholly clamped. This type of interaction has little potential to mechanically trigger the deformation of a volcano. Thus, Mt. Fuji may be less susceptible to elastostatic effects because of its location relative to the sources of large tectonic earthquakes. As an exception, a possible local earthquake in the Fujikawa-kako fault zone could induce a large amount of magma reservoir dilation beneath the southern flank of Mt. Fuji.

  1. Alaska volcanoes guidebook for teachers

    USGS Publications Warehouse

    Adleman, Jennifer N.

    2011-01-01

    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  2. {Linking permeability and mechanical damage for basalt from Mt Etna Volcano, Italy}

    NASA Astrophysics Data System (ADS)

    Faoro, I.; Vinciguerra, S.; Marone, C.; Elsworth, D.

    2009-04-01

    Volcanic edifices, such as Mt. Etna volcano (Italy), are affected from repeated episodes of pressurisation due to magma emplacement from deep reservoirs to shallow depths. This mechanism pressurizes the large aquifers within the edifice and increases the level of crack damage within the rocks of the edifice over extended periods of times. In order to improve our understanding of the complex coupling between circulating fluids and the development of crack damage, we performed flow-through tests using cylindrical cores of Etna Basalt (Etna, Italy) to evaluate permeabilty changes as a function of approach to failure under non-hydrostatic stresses at confining pressures from 5 to 60 MPa. Samples were loaded to failure by increasing increments of axial stress or by cyclic stresses of increasing amplitude. Both intact samples and pre-drilled samples (1.18mm) were tested. Under hydrostatic stresses, the permeability values of the intact sample decrease linearly with the increments of pressure and range between 5.2*10-17 m2and 1.5*10-17m2Under non-hydrostatic conditions, at low deviatoric stresses from (up to 18 MPa), the permeability values ranged between 5.5*10-17 m2and 4*10-17m2 and tended to completely recover the initial value each time the sample was unloaded, indicating an elastic regime. At higher deviatoric stresses (up to 60 MPa) the permeability values range between 2*10-17 m2 and 0.6*10-17m2. We hypothesize that from 5MPa to 40MPa axial stress, anelastic deformation mechanisms start to occur, with progressive pore collapse and opening of microfractures, resulting in a change of permeability. Under incremental uniaxial cyclic loading up to peak stresses of 160 MPa permeability decreases up to 2 orders of magnitude from initial values of 1*10-15 m2 to 2*10-14m2 Higher initial permeability values are related to the presence of an open fracture in the sample. We interpreted the reduction as a result of progressive closure of the voids space, as the axial load is

  3. The effects of growth and collapse on the magmatic system below Mt Taranaki, New Zealand.

    NASA Astrophysics Data System (ADS)

    Procter, Jonathan; Marcroft, Grace; Zellmer, Georg; Zernack, Anke

    2017-04-01

    Mt. Taranaki exhibits one of the best long-term records of volcanic growth and destruction of any volcano worldwide, making it ideal for understanding the long-term effects of changing lithostatic pressure, or loading and unloading, on the magma chamber and magma supply. The ring-plain around Mt. Taranaki houses volcaniclastic deposits that provide a near continuous record of the evolution of the volcano, yet these records have remained relatively unexploited when investigating the interrelated cyclical phases of volcano collapse and growth, the geochemical evolution of the centre, and the consequent time-varying hazard potential. In this study, we systematically sampled pumice-rich tephra and pumice-rich mass flow deposits that were stratigraphically immediately before and after the 24,801 ± 268 years BP Pungarehu Formation debris avalanche ( 7.5 km3). Crystals (clinopyroxene and plagioclase) were characterised in detail. Mg and Fe zoning across selected crystals from samples pre-and post-debris avalanche were found to have completely equilibrated, yet zoning patterns in Al remained intact and showed major differences in their formation, allowing for the calculation of diffusion rates. These have enabled the determination of maximum residence times (depths and pressure regimes) of the magma system. It is intended that this technique will be applied across the stratigraphic record, which contains 14 collapse events. This will provide insights into crustal magma transport and residence times, and the propagation of fissures and the buoyancy of the magma pre- and post-collapse, in order to characterise the evolution of the centre and quantify the long-term relationship between magmatic rise and volcano growth and destruction.

  4. Preliminary volcano-hazard assessment for Mount Spurr Volcano, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Nye, Christopher J.

    2001-01-01

    Mount Spurr volcano is an ice- and snow-covered stratovolcano complex located in the north-central Cook Inlet region about 100 kilometers west of Anchorage, Alaska. Mount Spurr volcano consists of a breached stratovolcano, a lava dome at the summit of Mount Spurr, and Crater Peak vent, a small stratocone on the south flank of Mount Spurr volcano. Historical eruptions of Crater Peak occurred in 1953 and 1992. These eruptions were relatively small but explosive, and they dispersed volcanic ash over areas of interior, south-central, and southeastern Alaska. Individual ash clouds produced by the 1992 eruption drifted east, north, and south. Within a few days of the eruption, the south-moving ash cloud was detected over the North Atlantic. Pyroclastic flows that descended the south flank of Crater Peak during both historical eruptions initiated volcanic-debris flows or lahars that formed temporary debris dams across the Chakachatna River, the principal drainage south of Crater Peak. Prehistoric eruptions of Crater Peak and Mount Spurr generated clouds of volcanic ash, pyroclastic flows, and lahars that extended to the volcano flanks and beyond. A flank collapse on the southeast side of Mount Spurr generated a large debris avalanche that flowed about 20 kilometers beyond the volcano into the Chakachatna River valley. The debris-avalanche deposit probably formed a large, temporary debris dam across the Chakachatna River. The distribution and thickness of volcanic-ash deposits from Mount Spurr volcano in the Cook Inlet region indicate that volcanic-ash clouds from most prehistoric eruptions were as voluminous as those produced by the 1953 and 1992 eruptions. Clouds of volcanic ash emitted from the active vent, Crater Peak, would be a major hazard to all aircraft using Ted Stevens Anchorage International Airport and other local airports and, depending on wind direction, could drift a considerable distance beyond the volcano. Ash fall from future eruptions could disrupt many

  5. Napoli and Volcanism - Vesuvius and Mt. Etna

    NASA Technical Reports Server (NTRS)

    2002-01-01

    For more than 240 million years the region now known as Italy has been the scene of episodic volcanic activity. East-southeast of Napoli (Naples) stands the imposing cone of Vesuvius, which erupted explosively in 79 A.D. to bury Pompeii and Herculaneum. More recently, when the crew of Space Shuttle mission STS-104 captured this view, Mt. Etna (Sicily, not seen in this image, but photographed the day before) was spewing ash and gas thousands of meters into the air, some of which can be seen as a brownish smear over Isola d' Ischia and the Tyrrhenian Sea. The Appenine ranges extend from northern Italy, down the boot of the peninsula and westward into Sicily. This photograph of the Appenino Napoletano is part of an 18-frame stereophoto mapping strip that spans the entire mountain chain. The almost 1200-km-long belt of volcanoes and folded/faulted mountains is a result of the ongoing collision of Africa and Eurasia, accompanied by the progressive closing of the Mediterranean Sea. Using overlapping pairs of stereophotos, and a special viewer, scientists can get a three-dimensional perspective on the ranges that surpasses any image viewed alone. For more information, see another image of Mt. Vesuvius, taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). References: Behncke, Boris, 2000, Vesuvio - The eruption of A.D. 79: Italy's Volcanoes - The Cradle of Volcanology [http://www.geo.mtu.edu/boris/VESUVIO_79.html (accessed 10/18/01)] Doglioni, C., and Flores, G., 1997, Italy, in Moores, E. M., and Fairbridge, R. W., editors, Encyclopedia of European and Asian Regional Geology: London, Chapman and Hall, p. 414-435 Shuttle photograph STS104-710-60 was taken 23 July 2001 from the orbiter Atlantis using a Hasselblad camera with 250-mm lens. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. The entire mapping series (of frames numbered in sequence from 50 through 68) can also be downloaded from the

  6. Pharmacological characterization of human recombinant melatonin mt1 and MT2 receptors

    PubMed Central

    Browning, Christopher; Beresford, Isabel; Fraser, Neil; Giles, Heather

    2000-01-01

    We have pharmacologically characterized recombinant human mt1 and MT2 receptors, stably expressed in Chinese hamster ovary cells (CHO-mt1 and CHO-MT2), by measurement of [3H]-melatonin binding and forskolin-stimulated cyclic AMP (cAMP) production. [3H]-melatonin bound to mt1 and MT2 receptors with pKD values of 9.89 and 9.56 and Bmax values of 1.20 and 0.82 pmol mg−1 protein, respectively. Whilst most melatonin receptor agonists had similar affinities for mt1 and MT2 receptors, a number of putative antagonists had substantially higher affinities for MT2 receptors, including luzindole (11 fold), GR128107 (23 fold) and 4-P-PDOT (61 fold). In both CHO-mt1 and CHO-MT2 cells, melatonin inhibited forskolin-stimulated accumulation of cyclic AMP in a concentration-dependent manner (pIC50 9.53 and 9.74, respectively) causing 83 and 64% inhibition of cyclic AMP production at 100 nM, respectively. The potencies of a range of melatonin receptor agonists were determined. At MT2 receptors, melatonin, 2-iodomelatonin and 6-chloromelatonin were essentially equipotent, whilst at the mt1 receptor these agonists gave the rank order of potency of 2-iodomelatonin>melatonin>6-chloromelatonin. In both CHO-mt1 and CHO-MT2 cells, melatonin-induced inhibition of forskolin-stimulated cyclic AMP production was antagonized in a concentration-dependent manner by the melatonin receptor antagonist luzindole, with pA2 values of 5.75 and 7.64, respectively. Melatonin-mediated responses were abolished by pre-treatment of cells with pertussis toxin, consistent with activation of Gi/Go G-proteins. This is the first report of the use of [3H]-melatonin for the characterization of recombinant mt1 and MT2 receptors. Our results demonstrate that these receptor subtypes have distinct pharmacological profiles. PMID:10696085

  7. Aerial monitoring in active mud volcano by UAV technique

    NASA Astrophysics Data System (ADS)

    Pisciotta, Antonino; Capasso, Giorgio; Madonia, Paolo

    2016-04-01

    UAV photogrammetry opens various new applications in the close range domain, combining aerial and terrestrial photogrammetry, but also introduces low-cost alternatives to the classical manned aerial photogrammetry. Between 2014 and 2015 tree aerial surveys have been carried out. Using a quadrotor drone, equipped with a compact camera, it was possible to generate high resolution elevation models and orthoimages of The "Salinelle", an active mud volcanoes area, located in territory of Paternò (South Italy). The main risks are related to the damages produced by paroxysmal events. Mud volcanoes show different cyclic phases of activity, including catastrophic events and periods of relative quiescence characterized by moderate activity. Ejected materials often are a mud slurry of fine solids suspended in liquids which may include water and hydrocarbon fluids, the bulk of released gases are carbon dioxide, with some methane and nitrogen, usually pond-shaped of variable dimension (from centimeters to meters in diameter). The scope of the presented work is the performance evaluation of a UAV system that was built to rapidly and autonomously acquire mobile three-dimensional (3D) mapping data in a volcanic monitoring scenario.

  8. Infrasound Monitoring of the Volcanic Activities of Japanese Volcanoes in Korea

    NASA Astrophysics Data System (ADS)

    Lee, H. I.; Che, I. Y.; Shin, J. S.

    2015-12-01

    Since 1999 when our first infrasound array station(CHNAR) has been installed at Cheolwon, Korea Institute of Geoscience and Mineral Resources(KIGAM) is continuously observing infrasound signals with an infrasound array network, named KIN(Korean Infrasound Network). This network is comprised of eight seismo-acoustic array stations(BRDAR, YPDAR, KMPAR, CHNAR, YAGAR, KSGAR, ULDAR, TJIAR). The aperture size of the smallest array is 300m and the largest is about 1.4km. The number of infrasound sensors are between 4(TJIAR) and 18(YAGAR), and 1~5 seismometers are collocated with infrasound sensors. Many interesting infrasound signals associated with different type of sources, such as blasting, large earthquake, bolide, volcanic explosion are detected by KIN in the past 15 years. We have analyzed the infrasound signals possibly associated with the japanese volcanic explosions with reference to volcanic activity report published by Japanese Meteorological Agency. Analysis results of many events, for example, Asama volcano explosion in 2004 and Shinmoe volcano in 2011, are well matched with the official report. In some cases, however, corresponding infrasound signals are not identified. By comparison of the infrasound signals from different volcanoes, we also found that the characteristics of signals are distinguishing. It may imply that the specific volcano has its own unique fingerprint in terms of infrasound signal. It might be investigated by long-term infrasound monitoring for a specific volcano as a ground truth generating repetitive infrasound signal.

  9. Indonesia's Active Mount Agung Volcano Imaged by NASA Spacecraft

    NASA Image and Video Library

    2017-12-10

    After a new small eruption sent an ash cloud 1.24 miles (2 kilometers) into the sky on Dec. 7, 2017, Indonesia's Mount Agung volcano quieted down. This image was acquired Dec. 8 after the latest activity by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite. The image shows vegetation in red colors. The summit crater has a hot spot (yellow) as detected by ASTER's thermal infrared channels. More than 65,00 residents continue to be evacuated from the volcano's danger zone in case of a major eruption. The image covers an area of 11 by 12.3 miles (17.8 by 19.8 kilometers), and is located at 8.3 degrees south, 115.5 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA22121

  10. A compilation of sulfur dioxide and carbon dioxide emission-rate data from Cook Inlet volcanoes (Redoubt, Spurr, Iliamna, and Augustine), Alaska during the period from 1990 to 1994

    USGS Publications Warehouse

    Doukas, Michael P.

    1995-01-01

    Airborne sulfur dioxide (SO2) gas sampling of the Cook Inlet volcanoes (Mt. Spurr, Redoubt, Iliamna, and Augustine) began in 1986 when several measurements were carried out at Augustine volcano during the eruption of 1986 (Rose and others, 1988). More systematic monitoring for SO2 began in March 1990 and for carbon dioxide (CO2) began in June, 1990 at Redoubt Volcano (Brantley, 1990 and Casadevall and others, 1994) and continues to the present. This report contains all of the available daily SO2 and CO2 emission rates determined by the U.S. Geological Survey (USGS) from March 1990 through July 1994. Intermittent measurements (four to six month intervals) at Augustine and Iliamna began in 1990 and continues to the present. Intermittent measurements began at Mt. Spurr volcano in 1991, and were continued at more regular intervals from June, 1992 through the 1992 eruption at the Crater Peak vent to the present.

  11. Detection of plumes at Redoubt and Etna volcanoes using the GPS SNR method

    NASA Astrophysics Data System (ADS)

    Larson, Kristine M.; Palo, Scott; Roesler, Carolyn; Mattia, Mario; Bruno, Valentina; Coltelli, Mauro; Fee, David

    2017-09-01

    Detection and characterization of volcanic eruptions is important both for public health and aircraft safety. A variety of ground sensors are used to monitor volcanic eruptions. Data from these ground sensors are subsequently incorporated into models that predict the movement of ash. Here a method to detect volcanic plumes using GPS signals is described. Rather than carrier phase data used by geodesists, the method takes advantage of attenuations in signal to noise ratio (SNR) data. Two datasets are evaluated: the 2009 Redoubt Volcano eruptions and the 2013/2015 eruptions at Mt. Etna. SNR-based eruption durations are compared with previously published seismic, infrasonic, and radar studies at Redoubt Volcano. SNR-based plume detections from Mt. Etna are compared with L-band radar and tremor observations. To place these SNR observations from Redoubt and Etna in context, a model of the propagation of GPS signals through both water/water vapor and tephra is developed. Neither water nor fine ash particles will produce the observed attenuation of GPS signals, while scattering caused by particles > 1 cm in diameter potentially could.

  12. Thematic mapper studies of Andean volcanoes

    NASA Technical Reports Server (NTRS)

    Francis, P. W.

    1986-01-01

    The primary objective was to identify all the active volcanoes in the Andean region of Bolivia. Morphological features of the Tata Sabaya volcano, Bolivia, were studied with the thematic mapper. Details include marginal levees on lava and pyroclastic flows, and summit crater structure. Valley glacier moraine deposits, not easily identified on the multispectral band scanner, were also unambiguous, and provide useful marker horizons on large volcanic edifices which were built up in preglacial times but which were active subsequently. With such high resolution imagery, it is not only possible to identify potentially active volcanoes, but also to use standard photogeological interpretation to outline the history of individual volcanoes.

  13. Volcano Observations Using an Unmanned Autonomous Helicopter : seismic and GPS observations near the active summit area of Sakurajima and Kirishima volcano, Japan

    NASA Astrophysics Data System (ADS)

    Ohminato, T.; Kaneko, T.; Koyama, T.; Watanabe, A.; Takeo, M.; Iguchi, M.; Honda, Y.

    2012-04-01

    Observations in the vicinity of summit area of active volcanoes are very important from various viewpoints such as understanding physical processes in the volcanic conduit. It is, however, highly difficult to install observation sensors near active vents because of the risk of sudden eruptions. We have been developing a safe volcano observation system based on an unmanned aerial vehicle (UAV). As an UAV, we adopted an unmanned autonomous helicopter manufactured by Yamaha-Motor Co., Ltd. We have also developed earthquake observation modules and GPS receiver modules that are exclusively designed for UAV installation at summit areas of active volcanoes. These modules are light weight, compact size, and solar powered. For data transmission, a commercial cellular-phone network is used. Our first application of the sensor installation by the UAV is Sakurajima, one of the most active volcanos in Japan. In November 2009, 2010, and 2011, we installed up to four seismic sensors within 2km from the active summit crater. In the 2010 and 2011 operations, we succeeded in pulling up and collecting the sensor modules by using the UAV. In the 2011 experiment, we installed two GPS receivers near the summit area of Sakurajima volcano. We also applied the UAV installation to another active volcano, Shinmoedake in Kirishima volcano group. Since the sub-plinian eruption in February 2011, entering the area 3km from the summit of Shinmoe-dake has been prohibited. In May and November 2011, we installed seismic sensors and GPS receivers in the off-limit zone. Although the ground coupling of the seismic modules is not perfect due to the way they are installed, the signal-to-noise ratio of the seismic signals recorded by these modules is fairly good. Despite the low antenna height of 50 cm from the ground surface, the location errors in horizontal and vertical GPS components are 1cm and 3cm, respectively. For seismic signals associated with eruptions at Sakurajima from November 2010 to

  14. 3D Gravity Inversion by Growing Bodies and Shaping Layers at Mt. Vesuvius (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Berrino, Giovanna; Camacho, Antonio G.

    2008-06-01

    To improve our knowledge of the structural pattern of Mt. Vesuvius and its magmatic system, which represents one of the three volcanoes located in the Neapolitan area (together with Campi Flegrei and Ischia; southern Italy), we analyze here the Bouguer gravity map that is already available through its interpretation by means of 2.5-dimensional modelling. We have carried out a three-dimensional interpretation using a new and original algorithm, known as ‘Layers’, that has been especially processed for this purpose. Layers works in an automatic and non-subjective way, and allows the definition of the structural settings in terms of several layers, each representing a specific geological formation. The same data are also interpreted in terms of isolated and shallow anomalous density bodies using a well tested algorithm known as ‘Growth’. We focus our inversions on the Mt. Vesuvius volcano, while globally analyzing the entire Neapolitan area, in order to investigate the deep structures, and in particular the deep extended ‘sill’ that has been revealed by seismic tomography. The final models generally confirm the global setting of the area as outlined by previous investigations, mainly for the shape and depth of the carbonate basement below Mt. Vesuvius. The presence of lateral density contrasts inside the volcano edifice is also shown, which was only hypothesized in the 2.5-dimensional inversion. Moreover, the models allow us to note a high density body that rises from the top of the carbonate basement and further elongates above sea level. This probably represents an uprising of the same basement, which is just below the volcano and which coincides with the VP and VP/VS anomalies detected under the crater. The three-dimensional results also reveal that the two inversion methods provide very similar models, where the high density isolated body in the Growth model can be associated with the rising high density anomaly in the Layers model. Taking into account

  15. Origin and transport of CH4 in two maar lakes fed by mantle-derived volatiles (Mt. Vulture volcano, Italy)

    NASA Astrophysics Data System (ADS)

    Caracausi, Antonio; Cosenza, Paolo; Favara, Rocco; Foresta Martin, Luigi; Galli, Nunzio; Grassa, Fausto; Nuccio, Pasquale Mario; Paternoster, Michele; Riccobono, Giuseppe

    2014-05-01

    It has been assessed that lakes contribute 6 to 16% to global CH4 emission in atmosphere. Accumulation of CH4 in the water is strongly dependent on the input of gas and the dynamic of the lake's water. Lakes located on tectonically and volcanically active areas (e.g., Kivu, Nyos) generally contain relevant amount of mantle-derived volatiles. This generated an open debate on the origin of CO2 and CH4 in volcanic lakes because the complex bio-geological cycling of these two gases. This study is a part of larger investigation carried out on two maar lakes (LPM and LGM) formed about 140.000 years ago during the last eruption of Mt. Vulture (Italy). In spite of it generally is considered to be extinct, both lakes are characterized by an active inflow of mantle-derived fluids (Caracausi et al., 2013). Although the two lakes are only 150 m apart, their respective dynamics are different being LPM a meromictic lake, while LGM a monomictic one (Caracausi et al., 2013). The stagnant waters of LPM are enriched in CO2 and CH4 but the total gas pressure is below the hydrostatic pressure, so that the transfer of gas towards the surface doesn't occur via bubbles. Vertical profiles at LPM reveal a marked decrease of the dissolved CH4 content in the shallower layers due to aerated water. The amount of CH4 dissolved in LGM water column shows seasonal variations: in autumn it is comparable to that of LPM at the same depth; in winter CH4 is fully released into atmosphere through overturn of waters. C and H isotopes of CH4 clearly indicate in both lakes an active production both by acetoclastic methanogenesis and by CO2 reduction although with different proportions. Historical reports describe intense episodic releases of gases from both lakes occurred up to about 200 years ago. Caracausi et al. (2013) highlight that these events could be caused by a release of mantle-derived CO2 accumulated in the crust or directly linked to magma degassing. In the present study the knowledge gained

  16. 3D electrical conductivity tomography of volcanoes

    NASA Astrophysics Data System (ADS)

    Soueid Ahmed, A.; Revil, A.; Byrdina, S.; Coperey, A.; Gailler, L.; Grobbe, N.; Viveiros, F.; Silva, C.; Jougnot, D.; Ghorbani, A.; Hogg, C.; Kiyan, D.; Rath, V.; Heap, M. J.; Grandis, H.; Humaida, H.

    2018-05-01

    Electrical conductivity tomography is a well-established galvanometric method for imaging the subsurface electrical conductivity distribution. We characterize the conductivity distribution of a set of volcanic structures that are different in terms of activity and morphology. For that purpose, we developed a large-scale inversion code named ECT-3D aimed at handling complex topographical effects like those encountered in volcanic areas. In addition, ECT-3D offers the possibility of using as input data the two components of the electrical field recorded at independent stations. Without prior information, a Gauss-Newton method with roughness constraints is used to solve the inverse problem. The roughening operator used to impose constraints is computed on unstructured tetrahedral elements to map complex geometries. We first benchmark ECT-3D on two synthetic tests. A first test using the topography of Mt. St Helens volcano (Washington, USA) demonstrates that we can successfully reconstruct the electrical conductivity field of an edifice marked by a strong topography and strong variations in the resistivity distribution. A second case study is used to demonstrate the versatility of the code in using the two components of the electrical field recorded on independent stations along the ground surface. Then, we apply our code to real data sets recorded at (i) a thermally active area of Yellowstone caldera (Wyoming, USA), (ii) a monogenetic dome on Furnas volcano (the Azores, Portugal), and (iii) the upper portion of the caldera of Kīlauea (Hawai'i, USA). The tomographies reveal some of the major structures of these volcanoes as well as identifying alteration associated with high surface conductivities. We also review the petrophysics underlying the interpretation of the electrical conductivity of fresh and altered volcanic rocks and molten rocks to show that electrical conductivity tomography cannot be used as a stand-alone technique due to the non-uniqueness in

  17. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, Ashley G.; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  18. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, A.G.; Keszthelyi, L.; McEwen, A.S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 ??m) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale. ?? 2011 by the American Geophysical Union.

  19. Revisiting Jorullo volcano (Mexico): monogenetic or polygenetic volcano?

    NASA Astrophysics Data System (ADS)

    Delgado Granados, H.; Roberge, J.; Farraz Montes, I. A.; Victoria Morales, A.; Pérez Bustamante, J. C.; Correa Olan, J. C.; Gutiérrez Jiménez, A. J.; Adán González, N.; Bravo Cardona, E. F.

    2007-05-01

    Jorullo volcano is located near the volcanic front of the westernmost part of the Trans-Mexican Volcanic Belt, which is related to the subduction of the Cocos plate beneath the North American plate. This part of the TMVB is known as the Michoacán-Guanajuato Volcanic Field, a region where widespread monogenetic volcanism is present although polygenetic volcanism is also recognized (i. e. Tancítaro volcano; Ownby et al., 2006). Jorullo volcano was born in the middle of crop fields. During its birth several lava flows were emitted and several cones were constructed. The main cone is the Jorullo proper, but there is a smaller cone on the north (Volcán del Norte), and three smaller cones aligned N-S on the south (Unnamed cone, UC; Volcán de Enmedio, VE; and Volcán del Sur, VS). The cone of Jorullo volcano is made up of tephra and lava flows erupted from the crater. The three southern cones show very interesting histories not described previously. VE erupted highly vesiculated tephras including xenoliths from the granitic basement. VS is made of spatter and bombs. A very well preserved hummocky morphology reveals that VE and VS collapsed towards the west. After the collapses, phreatomagmatic activity took place at the UC blanketing VE, VS and the southern flank of the Jorullo cone with sticky surge deposits. The excellent study by Luhr and Carmichael (1985) indicates that during the course of the eruption, lavas evolved from primitive basalt to basaltic andesite, although explosive products show a reverse evolution pattern (Johnson et al., 2006). We mapped lava flows not described by the observers in the 18th century nor considered in previous geologic reports as part of the Jorullo lavas. These lavas are older, distributed to the west and south, and some of them resemble the lava flows from La Pilita volcano, a cone older than Jorullo (Luhr and Carmichael, 1985). These lava flows were not considered before because they were not extruded during the 1759

  20. Preliminary volcano-hazard assessment for Aniakchak Volcano, Alaska

    USGS Publications Warehouse

    Neal, Christina A.; McGimsey, Robert G.; Miller, Thomas P.; Riehle, James R.; Waythomas, Christopher F.

    2000-01-01

    Aniakchak is an active volcano located on the Alaska Peninsula 670 kilometers southwest of Anchorage. The volcano consists of a dramatic, 10-kilometer-diameter, 0.5 to 1.0-kilometer-deep caldera that formed during a catastrophic eruption 3,500 years ago. Since then, at least a dozen separate vents within the caldera have erupted, often explosively, to produce lava flows and widespread tephra (ash) deposits. The most recent eruption at Aniakchak occurred in 1931 and was one of the largest explosive eruptions in Alaska in the last 100 years. Although Aniakchak volcano presently shows no signs of unrest, explosive and nonexplosive eruptions will occur in the future. Awareness of the hazards posed by future eruptions is a key factor in minimizing impact.

  1. Assessment of eruption intensity using infrasound waveform inversion at Mt. Etna, Italy.

    NASA Astrophysics Data System (ADS)

    Diaz Moreno, A.; Iezzi, A. M.; Lamb, O. D.; Zuccarello, L.; Fee, D.; De Angelis, S.

    2017-12-01

    Mt. Etna, Italy, a 3,330 m stratovolcano, is one of the most active volcanoes in the world. It is topped by five craters: Voragine, Bocca Nuova, the North-East, South-East, and New South-East Crater. Its activity during the past decade can be separated into two main types: i) nearly-continuous degassing interspersed by mild-to-vigorous Strombolian activity within the summit craters, and ii) effusive flank eruptions. In June 2017, we deployed a large temporary network of 14 infrasound sensors (Chaparral UHP60) and 12 broadband seismometers (Guralp EX-120s). We also recorded Thermal Infrared (TIR) and Unmanned Aerial Vehicle images of activity at the summit vents. Our primary objective is to quantify the intensity and mechanisms of infrasound sources at Mt. Etna, and use these results to improve models of volcanic plumes. From June 2017 until the time of writing, the infrasound network detected signals associated with nearly-continuous degassing and discrete small-to-moderate explosions originating at two distinct locations within the Voragine Crater and the New South-East Crater, respectively. During periods of increased explosive activity, we recorded 20-30 discrete events/day with infrasonic amplitudes of up to 7.5 Pa at 1 km distance from the active vent. The explosions exhibited sinusoidal acoustic waveforms, often with similar characteristics, durations of 1-3 s, and a 2 Hz peak frequency. Due to the relatively dense station coverage and the azimuthal distribution of the network, our deployment offers an opportunity to characterize, with unprecedented resolution, infrasound sources at Mt. Etna. Here we present preliminary results of 3D acoustic wave-field simulations, using a Finite Difference Time Domain modelling scheme, and a preliminary assessment of volumetric eruption rates through acoustic waveform inversion. We investigate the effects of local topography and atmospheric winds on the propagation of the acoustic wavefield, and discuss the implications for

  2. Eruptive history, current activity and risk estimation using geospatial information in the Colima volcano, Mexico

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Camarena-Garcia, M.; Nunez-Cornu, F. J.; Flores-Peña, S.

    2013-12-01

    Colima volcano, also known as Volcan de Fuego (19 30.696 N, 103 37.026 W), is located on the border between the states of Jalisco and Colima, and is the most active volcano in Mexico. In January 20, 1913, Colima had its biggest explosion of the twentieth century, with VEI 4, after the volcano had been dormant for almost 40 years. In 1961, a dome reached the northeastern edge of the crater and started a new lava flow, and from this date maintains constant activity. In February 10, 1999, a new explosion occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching altitudes between 4,500 and 9,000 masl, further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events, ash emissions were generated in all directions reaching distances up to 100 km, slightly affecting the nearby villages: Tuxpan, Tonila, Zapotlan, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During 2005 to July 2013, this volcano has had an intense effusive-explosive activity; similar to the one that took place during the period of 1890 through 1905. That was before the Plinian eruption of 1913, where pyroclastic flows reached a distance of 15 km from the crater. In this paper we estimate the risk of Colima volcano through the analysis of the vulnerability variables, hazard and exposure, for which we use: satellite imagery, recurring Fenix helicopter over flights of the state government of Jalisco, the use of the images of Google Earth and the population census 2010 INEGI. With this information and data identified changes in economic activities, development, and use of land. The expansion of the agricultural frontier in the lower sides of the volcano Colima, and with the advancement of traditional crops of sugar cane and corn, increased the growth of

  3. Sheveluch Volcano, Kamchatka, Russia

    NASA Image and Video Library

    2010-04-05

    Sheveluch Volcano in Kamchatka, Siberia, is one of the frequently active volcanoes located in eastern Siberia. In this image from NASA Terra spacecraft, brownish ash covers the southern part of the mountain, under an ash-laden vertical eruption plume.

  4. Colima Volcano, Mexico

    NASA Image and Video Library

    1995-10-29

    STS073-E-5274 (3 Nov. 1995) --- Colima was photographed with a color Electronic Still Camera (ESC) onboard the Earth-orbiting space shuttle Columbia. The volcano lies due south of Guadalajara and Lake Chapala. It is considered to be one of Mexico's most active and most dangerous volcanoes, lying not far from heavily populated areas.

  5. Rapid response of a hydrologic system to volcanic activity: Masaya volcano, Nicaragua

    USGS Publications Warehouse

    Pearson, S.C.P.; Connor, C.B.; Sanford, W.E.

    2008-01-01

    Hydrologic systems change in response to volcanic activity, and in turn may be sensitive indicators of volcanic activity. Here we investigate the coupled nature of magmatic and hydrologic systems using continuous multichannel time series of soil temperature collected on the flanks of Masaya volcano, Nicaragua, one of the most active volcanoes in Central America. The soil temperatures were measured in a low-temperature fumarole field located 3.5 km down the flanks of the volcano. Analysis of these time series reveals that they respond extremely rapidly, on a time scale of minutes, to changes in volcanic activity also manifested at the summit vent. These rapid temperature changes are caused by increased flow of water vapor through flank fumaroles during volcanism. The soil temperature response, ~5 °C, is repetitive and complex, with as many as 13 pulses during a single volcanic episode. Analysis of the frequency spectrum of these temperature time series shows that these anomalies are characterized by broad frequency content during volcanic activity. They are thus easily distinguished from seasonal trends, diurnal variations, or individual rainfall events, which triggered rapid transient increases in temperature during 5% of events. We suggest that the mechanism responsible for the distinctive temperature signals is rapid change in pore pressure in response to magmatism, a response that can be enhanced by meteoric water infiltration. Monitoring of distal fumaroles can therefore provide insight into coupled volcanic-hydrologic-meteorologic systems, and has potential as an inexpensive monitoring tool.

  6. Mapping the Active Vents of Stromboli Volcano with an Unmanned Aerial Vehicle

    NASA Astrophysics Data System (ADS)

    Turner, N.; Houghton, B. F.; von der Lieth, J.; Hort, M. K.; Taddeucci, J.; Kueppers, U.; Ricci, T.; Gaudin, D.

    2016-12-01

    We present a new detailed map of the active vents of Stromboli volcano obtained from UAV flights in May 2016, when the active NE and SW craters were repeatedly mapped. Due to high levels of gas emissions and frequent explosions, fine-scale measurements of vent geometry from single flights were challenging. However, the compilation of data acquired over 12 flights used with Structure from Motion software allowed us to create a 10 cm Digital Elevation Model (DEM) offering a non-obstructed view into the active craters. Such direct observations permits us to constrain parameters such as vent geometry and depth with an unprecedented precision, thus potentially reducing the uncertainty of models depending on such inputs (e.g. conduit and acoustic models). Furthermore, the low-cost and safety of UAVs allows mapping changes at small temporal and spatial resolutions, making this technique complementary to monitoring efforts at active volcanoes.

  7. Ten-year helium anomaly prior to the 2014 Mt Ontake eruption

    PubMed Central

    Sano, Yuji; Kagoshima, Takanori; Takahata, Naoto; Nishio, Yoshiro; Roulleau, Emilie; Pinti, Daniele L.; Fischer, Tobias P.

    2015-01-01

    Mt Ontake in central Japan suddenly erupted on 27th September 2014, killing 57 people with 6 still missing. It was a hydro-volcanic eruption and new magmatic material was not detected. There were no precursor signals such as seismicity and edifice inflation. It is difficult to predict hydro-volcanic eruptions because they are local phenomena that only affect a limited area surrounding the explosive vent. Here we report a long-term helium anomaly measured in hot springs close to the central cone. Helium-3 is the most sensitive tracer of magmatic volatiles. We have conducted spatial surveys around the volcano at once per few years since November 1981. The 3He/4He ratios of the closest site to the cone stayed constant until June 2000 and increased significantly from June 2003 to November 2014, while those of distant sites showed no valuable change. These observations suggest a recent re-activation of Mt Ontake and that helium-3 enhancement may have been a precursor of the 2014 eruption. We show that the eruption was ultimately caused by the increased input of magmatic volatiles over a ten-year period which resulted in the slow pressurization of the volcanic conduit leading to the hydro-volcanic event in September 2014. PMID:26286468

  8. Ten-year helium anomaly prior to the 2014 Mt Ontake eruption

    NASA Astrophysics Data System (ADS)

    Sano, Yuji; Kagoshima, Takanori; Takahata, Naoto; Nishio, Yoshiro; Roulleau, Emilie; Pinti, Daniele L.; Fischer, Tobias P.

    2015-08-01

    Mt Ontake in central Japan suddenly erupted on 27th September 2014, killing 57 people with 6 still missing. It was a hydro-volcanic eruption and new magmatic material was not detected. There were no precursor signals such as seismicity and edifice inflation. It is difficult to predict hydro-volcanic eruptions because they are local phenomena that only affect a limited area surrounding the explosive vent. Here we report a long-term helium anomaly measured in hot springs close to the central cone. Helium-3 is the most sensitive tracer of magmatic volatiles. We have conducted spatial surveys around the volcano at once per few years since November 1981. The 3He/4He ratios of the closest site to the cone stayed constant until June 2000 and increased significantly from June 2003 to November 2014, while those of distant sites showed no valuable change. These observations suggest a recent re-activation of Mt Ontake and that helium-3 enhancement may have been a precursor of the 2014 eruption. We show that the eruption was ultimately caused by the increased input of magmatic volatiles over a ten-year period which resulted in the slow pressurization of the volcanic conduit leading to the hydro-volcanic event in September 2014.

  9. Ten-year helium anomaly prior to the 2014 Mt Ontake eruption.

    PubMed

    Sano, Yuji; Kagoshima, Takanori; Takahata, Naoto; Nishio, Yoshiro; Roulleau, Emilie; Pinti, Daniele L; Fischer, Tobias P

    2015-08-19

    Mt Ontake in central Japan suddenly erupted on 27(th) September 2014, killing 57 people with 6 still missing. It was a hydro-volcanic eruption and new magmatic material was not detected. There were no precursor signals such as seismicity and edifice inflation. It is difficult to predict hydro-volcanic eruptions because they are local phenomena that only affect a limited area surrounding the explosive vent. Here we report a long-term helium anomaly measured in hot springs close to the central cone. Helium-3 is the most sensitive tracer of magmatic volatiles. We have conducted spatial surveys around the volcano at once per few years since November 1981. The (3)He/(4)He ratios of the closest site to the cone stayed constant until June 2000 and increased significantly from June 2003 to November 2014, while those of distant sites showed no valuable change. These observations suggest a recent re-activation of Mt Ontake and that helium-3 enhancement may have been a precursor of the 2014 eruption. We show that the eruption was ultimately caused by the increased input of magmatic volatiles over a ten-year period which resulted in the slow pressurization of the volcanic conduit leading to the hydro-volcanic event in September 2014.

  10. Earth's Volcanoes and their Eruptions; the 3rd edition of the Smithsonian Institution's Volcanoes of the World

    NASA Astrophysics Data System (ADS)

    Siebert, L.; Simkin, T.; Kimberly, P.

    2010-12-01

    The 3rd edition of the Smithsonian Institution’s Volcanoes of the World incorporates data on the world’s volcanoes and their eruptions compiled since 1968 by the Institution’s Global Volcanism Program (GVP). Published this Fall jointly by the Smithsonian and the University of California Press, it supplements data from the 1994 2nd edition and includes new data on the number of people living in proximity to volcanoes, the dominant rock lithologies at each volcano, Holocene caldera-forming eruptions, and preliminary lists of Pleistocene volcanoes and large-volume Pleistocene eruptions. The 3rd edition contains data on nearly 1550 volcanoes of known or possible Holocene age, including chronologies, characteristics, and magnitudes for >10,400 Holocene eruptions. The standard 20 eruptive characteristics of the IAVCEI volcano catalog series have been modified to include dated vertical edifice collapse events due to magma chamber evacuation following large-volume explosive eruptions or mafic lava effusion, and lateral sector collapse. Data from previous editions of Volcanoes of the World are also supplemented by listings of up to the 5 most dominant lithologies at each volcano, along with data on population living within 5, 10, 30, and 100 km radii of each volcano or volcanic field. Population data indicate that the most populated regions also contain the most frequently active volcanoes. Eruption data document lava and tephra volumes and Volcanic Explosivity Index (VEI) assignments for >7800 eruptions. Interpretation of VRF data has led to documentation of global eruption rates and the power law relationship between magnitude and frequency of volcanic eruptions. Data with volcanic hazards implications include those on fatalities and evacuations and the rate at which eruptions reach their climax. In recognition of the hazards implications of potential resumption of activity at pre-Holocene volcanoes, the 3rd edition includes very preliminary lists of Pleistocene

  11. Active Volcanoes of the Kurile Islands: A Reference Guide for Aviation Users

    USGS Publications Warehouse

    Neal, Christina A.; Rybin, Alexander; Chibisova, Marina; Miller, Edward

    2008-01-01

    Introduction: The many volcanoes of the remote and mostly uninhabited Kurile Island arc (fig. 1; table 1) pose a serious hazard for air traffic in the North Pacific. Ash clouds from Kurile eruptions can impact some of the busiest air travel routes in the world and drift quickly into airspace managed by three countries: Russia, Japan, and the United States. Prevailing westerly winds throughout the region will most commonly send ash from any Kurile eruption directly across the parallel North Pacific airways between North America and Asia (Kristine A. Nelson, National Weather Service, oral commun., 2006; fig. 1). This report presents maps showing locations of the 36 most active Kurile volcanoes plotted on Operational Navigational Charts published by the Defense Mapping Agency (map sheets ONC F-10, F-11, and E-10; figs. 1, 2, 3, 4). These maps are intended to assist aviation and other users in the identification of restless Kurile volcanoes. A regional map is followed by three subsections of the Kurile volcanic arc (North, Central, South). Volcanoes and selected primary geographic features are labeled. All maps contain schematic versions of the principal air routes and selected air navigational fixes in this region.

  12. Evaluation of the eruptive potential and probability in open conduit volcano (Mt Etna) based on soil CO2 flux measurements

    NASA Astrophysics Data System (ADS)

    De Gregorio, Sofia; Camarda, Marco

    2016-04-01

    The evaluation of the amount of magma that might be potentially erupted, i.e. the eruptive potential (EP), and the probability of eruptive event occurrence, i.e. eruptive probability (EPR) of active volcano is one of the most compelling and challenging topic addressed by the volcanology community in the last years. The evaluation of the EP in open conduit volcano is generally based on constant magma supply rate deduced by long-term series of eruptive rate. This EP computation gives good results on long-term (centuries) evaluations, but resulted less effective when short-term (years or months) estimations are needed. Actually the rate of magma supply can undergo changes both on long-term and short-term. At steady condition it can be supposed that the regular supply of magma determines an almost constant level of magma in the feeding system (FS) whereas episodic surplus of magma inputs, with respect the regular supply, can cause large variations in the magma level. Follow that the surplus of magma occasionally entered in the FS represents a supply of material that sooner or later will be disposed, i.e. it will be emitted. Afterwards the amount of surplus of magma inward the FS nearly corresponds to the amount of magma that must be erupted in order to restore the equilibrium. Further, larger is the amount of surplus of magma stored in the system higher is the energetic level of the system and its propensity to erupt or in other words its EPR. On the light of the above consideration herein, we present an innovative methodology to evaluate the EP based on the quantification of surplus of magma with respect the regular supply, progressively intruded in the FS. To estimate the surplus of magma supply we used soil CO2 emission data measured monthly at 130 sites in two peripheral areas of Mt Etna Volcano. Indeed as reported by many authors soil CO2 emissions in the areas are linked to magma supply dynamics and more, anomalous discharges of CO2 are ascribable to surplus of

  13. Validation and Analysis of SRTM and VCL Data Over Tropical Volcanoes

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, Peter J.

    2004-01-01

    The focus of our investigation was on the application of digital topographic data in conducting first-order volcanological and structural studies of tropical volcanoes, focusing on the Java, the Philippines and the Galapagos Islands. Kilauea volcano, Hawaii, served as our test site for SRTM data validation. Volcanoes in humid tropical environments are frequently cloud covered, typically densely vegetated and erode rapidly, so that it was expected that new insights into the styles of eruption of these volcanoes could be obtained from analysis of topographic data. For instance, in certain parts of the world, such as Indonesia, even the regional structural context of volcanic centers is poorly known, and the distribution of volcanic products (e.g., lava flows, pyroclastic flows, and lahars) are not well mapped. SRTM and Vegetation Canopy Lidar (VCL) data were expected to provide new information on these volcanoes. Due to the cancellation of the VCL mission, we did not conduct any lidar studies during the duration of this project. Digital elevation models (DEMs) such as those collected by SRTM provide quantitative information about the time-integrated typical activity on a volcano and allow an assessment of the spatial and temporal contributions of various constructional and destructional processes to each volcano's present morphology. For basaltic volcanoes, P_c?w!m-d and Garbed (2000) have shown that gradual slopes (less than 5 deg.) occur where lava and tephra pond within calderas or in the saddles between adjacent volcanoes, as well as where lava deltas coalesce to form coastal plains. Vent concentration zones (axes of rift zones) have slopes ranging from 10 deg. to 12 deg. Differential vertical growth rates between vent concentration zones and adjacent mostly-lava flanks produce steep constructional slopes up to 40". The steepest slopes (locally approaching 90 deg.) are produced by fluvial erosion, caldera collapse, faulting, and catastrophic avalanches, all of

  14. Mud volcanoes of the Orinoco Delta, Eastern Venezuela

    USGS Publications Warehouse

    Aslan, A.; Warne, A.G.; White, W.A.; Guevara, E.H.; Smyth, R.C.; Raney, J.A.; Gibeaut, J.C.

    2001-01-01

    Mud volcanoes along the northwest margin of the Orinoco Delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the Caribbean-South American plate boundary. Field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents. Inactive vents and mud flows are densely vegetated, whereas active vents are sparsely vegetated. Four out of the five mud volcanoes studied are currently active. Orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition. Preliminary analysis suggests that the mud volcano sediment is derived from underlying Miocene and Pliocene strata. Hydrocarbon seeps are associated with several of the active mud volcanoes. Orinoco mud volcanoes overlie the crest of a mud-diapir-cored anticline located along the axis of the Eastern Venezuelan Basin. Faulting along the flank of the Pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline. Orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development. Evaluation of the Orinoco Delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins. ?? 2001 Elsevier Science B.V. All rights reserved.

  15. Catalog of earthquake hypocenters at Redoubt Volcano and Mt. Spurr, Alaska: October 12, 1989 - December 31, 1990

    USGS Publications Warehouse

    Power, John A.; March, Gail D.; Lahr, John C.; Jolly, Arthur D.; Cruse, Gina R.

    1993-01-01

    Following a 23 year period of quiescence, Redoubt Volcano erupted between December 14,1989 and April 21,1990. The eruption was accompanied by thousands of earthquakes (Alaska Volcano Observatory Staff, 1990). Throughout the eruption sequence, data from the PC/AT system provided the primary means of determining earthquake hypocenters. This report catalogs the earthquake hypocenters and magnitudes calculated from data collected between October 12, 1989 and December 31, 1990 on the PC/AT acquisition system, provides station locations, statistics, and calibrations, and outlines which stations were recorded and used in triggering the PC/AT system.

  16. Activation of the Human MT Complex by Motion in Depth Induced by a Moving Cast Shadow

    PubMed Central

    Katsuyama, Narumi; Usui, Nobuo; Taira, Masato

    2016-01-01

    A moving cast shadow is a powerful monocular depth cue for motion perception in depth. For example, when a cast shadow moves away from or toward an object in a two-dimensional plane, the object appears to move toward or away from the observer in depth, respectively, whereas the size and position of the object are constant. Although the cortical mechanisms underlying motion perception in depth by cast shadow are unknown, the human MT complex (hMT+) is likely involved in the process, as it is sensitive to motion in depth represented by binocular depth cues. In the present study, we examined this possibility by using a functional magnetic resonance imaging (fMRI) technique. First, we identified the cortical regions sensitive to the motion of a square in depth represented via binocular disparity. Consistent with previous studies, we observed significant activation in the bilateral hMT+, and defined functional regions of interest (ROIs) there. We then investigated the activity of the ROIs during observation of the following stimuli: 1) a central square that appeared to move back and forth via a moving cast shadow (mCS); 2) a segmented and scrambled cast shadow presented beside the square (sCS); and 3) no cast shadow (nCS). Participants perceived motion of the square in depth in the mCS condition only. The activity of the hMT+ was significantly higher in the mCS compared with the sCS and nCS conditions. Moreover, the hMT+ was activated equally in both hemispheres in the mCS condition, despite presentation of the cast shadow in the bottom-right quadrant of the stimulus. Perception of the square moving in depth across visual hemifields may be reflected in the bilateral activation of the hMT+. We concluded that the hMT+ is involved in motion perception in depth induced by moving cast shadow and by binocular disparity. PMID:27597999

  17. Human area MT+ shows load-dependent activation during working memory maintenance with continuously morphing stimulation.

    PubMed

    Galashan, Daniela; Fehr, Thorsten; Kreiter, Andreas K; Herrmann, Manfred

    2014-07-11

    Initially, human area MT+ was considered a visual area solely processing motion information but further research has shown that it is also involved in various different cognitive operations, such as working memory tasks requiring motion-related information to be maintained or cognitive tasks with implied or expected motion.In the present fMRI study in humans, we focused on MT+ modulation during working memory maintenance using a dynamic shape-tracking working memory task with no motion-related working memory content. Working memory load was systematically varied using complex and simple stimulus material and parametrically increasing retention periods. Activation patterns for the difference between retention of complex and simple memorized stimuli were examined in order to preclude that the reported effects are caused by differences in retrieval. Conjunction analysis over all delay durations for the maintenance of complex versus simple stimuli demonstrated a wide-spread activation pattern. Percent signal change (PSC) in area MT+ revealed a pattern with higher values for the maintenance of complex shapes compared to the retention of a simple circle and with higher values for increasing delay durations. The present data extend previous knowledge by demonstrating that visual area MT+ presents a brain activity pattern usually found in brain regions that are actively involved in working memory maintenance.

  18. The Past 20,000 Years of Plinian Explosive Activity at Mt Pelée Volcano (Lesser Antilles)

    NASA Astrophysics Data System (ADS)

    Carazzo, G.; Michaud-Dubuy, A.; Kaminski, E. C.; Tait, S.

    2017-12-01

    Major volcanic hazards in the Lesser Antilles arc include powerful Plinian explosive eruptions that inject ash into the atmosphere and produce dangerous pyroclastic density currents (PDC) on the ground. Reconstructions of past eruptive activities based on stratigraphic records are crucial to assessing specific hazards in this region where large eruptions do not occur frequently. The present study focuses on the dynamics of the last Plinian eruptions of Mount Pelée volcano in Martinique. Previous field-based studies identified 6 major Plinian eruptions over the past 5,000 years but limited information on their dynamics exist, except for the most recent one dated at AD 1300. Based on a new comprehensive field study and physical models of volcanic plumes, we largely improve our knowledge of the number of Plinian eruptions that occurred in Martinique over the past 20,000 years. We also provide a detailed reconstruction of important eruptive parameters such as mass eruption rates, maximum column heights, volumes, and impacted areas. Among the 6 Plinian eruptions newly identified during our field campaign, one is found to have produced voluminous pyroclastic density currents that reached the sea and partially rose as a co-PDC plume above a region that is beyond the existing hazard map. The estimated mass eruption rates for the 12 Plinian eruptions identified over the last 20,000 years range from 107 to 108 kg/s, producing 15-30 km-high Plinian columns, initially stable but ultimately collapsing and forming PDC. Empirical models of deposit thinning suggest that the minimum volume of pyroclastic deposits systematically ranges between 0.1 and 1 km3, corresponding to VEI 4 to 5 events. Archaeological evidences suggest that the impact of several eruptions forced the first Caribbean inhabitants to flee to other islands for decades.

  19. Costa Rica's Chain of laterally collapsed volcanoes.

    NASA Astrophysics Data System (ADS)

    Duarte, E.; Fernandez, E.

    2007-05-01

    From the NW extreme to the SW end of Costa Rica's volcanic backbone, a number of laterally collapsed volcanoes can be observed. Due to several factors, attention has been given to active volcanoes disregarding the importance of collapsed features in terms of assessing volcanic hazards for future generations around inhabited volcanoes. In several cases the typical horseshoe shape amphitheater-like depression can be easily observed. In other cases due to erosion, vegetation, topography, seismic activity or drastic weather such characteristics are not easily recognized. In the order mentioned above appear: Orosi-Cacao, Miravalles, Platanar, Congo, Von Frantzius, Cacho Negro and Turrialba volcanoes. Due to limited studies on these structures it is unknown if sector collapse occurred in one or several phases. Furthermore, in the few studied cases no evidence has been found to relate collapses to actual eruptive episodes. Detailed studies on the deposits and materials composing dome-like shapes will shed light on unsolved questions about petrological and chemical composition. Volume, form and distance traveled by deposits are part of the questions surrounding most of these collapsed volcanoes. Although most of these mentioned structures are extinct, at least Irazú volcano (active volcano) has faced partial lateral collapses recently. It did presented strombolian activity in the early 60s. Collapse scars show on the NW flank show important mass removal in historic and prehistoric times. Moreover, in 1994 a minor hydrothermal explosion provoked the weakening of a deeply altered wall that holds a crater lake (150m diameter, 2.6x106 ). A poster will depict images of the collapsed volcanoes named above with mayor descriptive characteristics. It will also focus on the importance of deeper studies to assess the collapse potential of Irazú volcano with related consequences. Finally, this initiative will invite researchers interested in such topic to join future studies in

  20. Statistical analysis of dispersal and deposition patterns of volcanic emissions from Mt. Sakurajima, Japan

    NASA Astrophysics Data System (ADS)

    Poulidis, Alexandros P.; Takemi, Tetsuya; Shimizu, Atsushi; Iguchi, Masato; Jenkins, Susanna F.

    2018-04-01

    With the eruption of Eyjafjallajökull (Iceland) in 2010, interest in the transport of volcanic ash after moderate to major eruptions has increased with regards to both the physical and the emergency hazard management aspects. However, there remain significant gaps in the understanding of the long-term behaviour of emissions from volcanoes with long periods of activity. Mt. Sakurajima (Japan) provides us with a rare opportunity to study such activity, due to its eruptive behaviour and dense observation network. In the 6-year period from 2009 to 2015, the volcano was erupting at an almost constant rate introducing approximately 500 kt of ash per month to the atmosphere. The long-term characteristics of the transport and deposition of ash and SO2 in the area surrounding the volcano are studied here using daily surface observations of suspended particulate matter (SPM) and SO2 and monthly ashfall values. Results reveal different dispersal patterns for SO2 and volcanic ash, suggesting volcanic emissions' separation in the long-term. Peak SO2 concentrations at different locations on the volcano vary up to 2 orders of magnitude and decrease steeply with distance. Airborne volcanic ash increases SPM concentrations uniformly across the area surrounding the volcano, with distance from the vent having a secondary effect. During the period studied here, the influence of volcanic emissions was identifiable both in SO2 and SPM concentrations which were, at times, over the recommended exposure limits defined by the Japanese government, European Union and the World Health Organisation. Depositional patterns of volcanic ash exhibit elements of seasonality, consistent with previous studies. Climatological and topographic effects are suspected to impact the deposition of volcanic ash away from the vent: for sampling stations located close to complex topographical elements, sharp changes in the deposition patterns were observed, with ash deposits for neighbouring stations as close as

  1. Klyuchevskaya, Volcano, Kamchatka Peninsula, CIS

    NASA Image and Video Library

    1991-05-06

    STS039-77-010 (28 April 1991) --- The Kamchatka Peninsula, USSR. This oblique view of the eastern margin of the Kamchatka Peninsula shows pack-ice along the coast, which is drifting along with local currents and delineates the circulation patterns. Also visible are the Kamchatka River (left of center), and the volcanic complex with the active volcano Klyuchevskaya (Kloo-chevs'-ska-ya), 15,584 feet in elevation. The last reported eruption of the volcano was on April 8, but an ash and steam plume extending to the south can be seen in this photograph, taken almost three weeks later (April 28). On April 29, the crew observed and photographed the volcano again, and it was no longer visibly active. However, the flanks of the mountain are dirty from the ash fall. Just north of the Kamchatka River (to the left, just off frame) is Shiveluch, a volcano which was active in early April. There are more than 100 volcanic edifices recognized on Kamchatka, with 15 classified as active.

  2. Volcanic gas composition changes during the gradual decrease of the gigantic degassing activity of Miyakejima volcano, Japan, 2000-2015

    NASA Astrophysics Data System (ADS)

    Shinohara, Hiroshi; Geshi, Nobuo; Matsushima, Nobuo; Saito, Genji; Kazahaya, Ryunosuke

    2017-02-01

    The composition of volcanic gases discharged from Miyakejima volcano has been monitored during the intensive degassing activity that began after the eruption in 2000. During the 15 years from 2000 to 2015, Miyakejima volcano discharged 25.5 Mt of SO2, which required degassing of 3 km3 of basaltic magma. The SO2 emission rate peaked at 50 kt/day at the end of 2000 and quickly decreased to 5 kt/day by 2003. During the early degassing period, the volcanic gas composition was constant with the CO2/SO2 = 0.8 (mol ratio), H2O/SO2 = 35, HCl/SO2 = 0.08, and SO2/H2S = 15. The SO2 emission rate decreased gradually to 0.5 kt/day by 2012, and the gas composition also changed gradually to CO2/SO2 = 1.5, H2O/SO2 = 150, HCl/SO2 = 0.15, and SO2/H2S = 6. The compositional changes are not likely caused by changes in degassing pressure or volatile heterogeneity of a magma chamber but are likely attributed to an increase of hydrothermal scrubbing caused by large decrease of the volcanic gas emission rate, suggesting a supply of gases with constant composition during the 15 years. The intensive degassing was modeled based on degassing of a convecting magma conduit. The gradual SO2 emission rate that decrease without changes in volcanic gas composition is attributed to a reduction of diameter of the convecting magma conduit.

  3. The 2014 eruptions of Pavlof Volcano, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Haney, Matthew M.; Wallace, Kristi; Cameron, Cheryl E.; Schneider, David J.

    2017-12-22

    Pavlof Volcano is one of the most frequently active volcanoes in the Aleutian Island arc, having erupted more than 40 times since observations were first recorded in the early 1800s . The volcano is located on the Alaska Peninsula (lat 55.4173° N, long 161.8937° W), near Izembek National Wildlife Refuge. The towns and villages closest to the volcano are Cold Bay, Nelson Lagoon, Sand Point, and King Cove, which are all within 90 kilometers (km) of the volcano (fig. 1). Pavlof is a symmetrically shaped stratocone that is 2,518 meters (m) high, and has about 2,300 m of relief. The volcano supports a cover of glacial ice and perennial snow roughly 2 to 4 cubic kilometers (km3) in volume, which is mantled by variable amounts of tephra fall, rockfall debris, and pyroclastic-flow deposits produced during historical eruptions. Typical Pavlof eruptions are characterized by moderate amounts of ash emission, lava fountaining, spatter-fed lava flows, explosions, and the accumulation of unstable mounds of spatter on the upper flanks of the volcano. The accumulation and subsequent collapse of spatter piles on the upper flanks of the volcano creates hot granular avalanches, which erode and melt snow and ice, and thereby generate watery debris-flow and hyperconcentrated-flow lahars. Seismic instruments were first installed on Pavlof Volcano in the early 1970s, and since then eruptive episodes have been better characterized and specific processes have been documented with greater certainty. The application of remote sensing techniques, including the use of infrasound data, has also aided the study of more recent eruptions. Although Pavlof Volcano is located in a remote part of Alaska, it is visible from Cold Bay, Sand Point, and Nelson Lagoon, making distal observations of eruptive activity possible, weather permitting. A busy air-travel corridor that is utilized by a numerous transcontinental and regional air carriers passes near Pavlof Volcano. The frequency of air travel

  4. Costa Rica Turrialba Volcano, Continued Activity seen by NASA Spacecraft

    NASA Image and Video Library

    2015-04-06

    The March, 2015 eruption of Turrialba Volcano in Costa Rica caught everyone by surprise as seen in this image from the ASTER instrument onboard NASA Terra spacecraft. Activity had greatly diminished when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft acquired this nighttime thermal infrared image on April 2, 2015. The hot summit crater appears in white, indicating continued volcanic unrest. To the west, Poas Volcano's hot crater lake also appears white, though its temperature is considerably less than Turrialba's crater. The large image covers an area of 28 by 39 miles (45 by 63 kilometers); the insets 2 by 2 miles (3.1 by 3.1 kilometers). The image is centered at 10.1 degrees north, 84 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA19355

  5. Reunion Island Volcano Erupts

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On January 16, 2002, lava that had begun flowing on January 5 from the Piton de la Fournaise volcano on the French island of Reunion abruptly decreased, marking the end of the volcano's most recent eruption. These false color MODIS images of Reunion, located off the southeastern coast of Madagascar in the Indian Ocean, were captured on the last day of the eruption (top) and two days later (bottom). The volcano itself is located on the southeast side of the island and is dark brown compared to the surrounding green vegetation. Beneath clouds (light blue) and smoke, MODIS detected the hot lava pouring down the volcano's flanks into the Indian Ocean. The heat, detected by MODIS at 2.1 um, has been colored red in the January 16 image, and is absent from the lower image, taken two days later on January 18, suggesting the lava had cooled considerably even in that short time. Earthquake activity on the northeast flank continued even after the eruption had stopped, but by January 21 had dropped to a sufficiently low enough level that the 24-hour surveillance by the local observatory was suspended. Reunion is essentially all volcano, with the northwest portion of the island built on the remains of an extinct volcano, and the southeast half built on the basaltic shield of 8,630-foot Piton de la Fournaise. A basaltic shield volcano is one with a broad, gentle slope built by the eruption of fluid basalt lava. Basalt lava flows easily across the ground remaining hot and fluid for long distances, and so they often result in enormous, low-angle cones. The Piton de la Fournaise is one of Earth's most active volcanoes, erupting over 150 times in the last few hundred years, and it has been the subject of NASA research because of its likeness to the volcanoes of Mars. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  6. Ground survey of active Central American volcanoes in November - December 1973

    NASA Technical Reports Server (NTRS)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.

    1974-01-01

    The author has identified the following significant results. Thermal anomalies at two volcanoes, Santiaguito and Izalco, have grown in size in the past six months, based on repeated ground survey. Thermal anomalies at Pacaya volcano have became less intense in the same period. Large (500 m diameter) thermal anomalies exist at 3 volcanoes presently, and smaller scale anomalies are found at nine other volcanoes.

  7. International Space Station (ISS)

    NASA Image and Video Library

    2001-07-22

    An Expedition Two crewmember aboard the International Space Station (ISS) captured this overhead look at the smoke and ash regurgitated from the erupting volcano Mt. Etna on the island of Sicily, Italy. At an elevation of 10,990 feet (3,350 m), the summit of the Mt. Etna volcano, one of the most active and most studied volcanoes in the world, has been active for a half-million years and has erupted hundreds of times in recorded history.

  8. Preliminary volcano-hazard assessment for Augustine Volcano, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Waitt, Richard B.

    1998-01-01

    Augustine Volcano is a 1250-meter high stratovolcano in southwestern Cook Inlet about 280 kilometers southwest of Anchorage and within about 300 kilometers of more than half of the population of Alaska. Explosive eruptions have occurred six times since the early 1800s (1812, 1883, 1935, 1964-65, 1976, and 1986). The 1976 and 1986 eruptions began with an initial series of vent-clearing explosions and high vertical plumes of volcanic ash followed by pyroclastic flows, surges, and lahars on the volcano flanks. Unlike some prehistoric eruptions, a summit edifice collapse and debris avalanche did not occur in 1812, 1935, 1964-65, 1976, or 1986. However, early in the 1883 eruption, a portion of the volcano summit broke loose forming a debris avalanche that flowed to the sea. The avalanche initiated a small tsunami reported on the Kenai Peninsula at English Bay, 90 kilometers east of the volcano. Plumes of volcanic ash are a major hazard to jet aircraft using Anchorage International and other local airports. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Eruptions similar to the historical and prehistoric eruptions are likely in Augustine's future.

  9. Volcano monitoring at the U.S. Geological Survey's Hawaiian Volcano Observatory

    USGS Publications Warehouse

    Heliker, Christina C.; Griggs, J. D.; Takahashi, T. Jane; Wright, Thomas L.; Spall, Henry

    1986-01-01

    The island of Hawaii has one of the youngest landscapes on Earth, formed by frequent addition of new lava to its surface.  Because Hawaiian are generally nonexplosive and easily accessible, the island has long attracted geologists interested in studying the extraordinary power of volcanic eruptions.  The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO), now nearing its 75th anniversary. has been in the forefront of volcanology since the 1900's.  This issue of Earthquakes and volcanoes is devoted to the work of the Observatory and its role in studying the most recent eruptions of Hawaii's two currently active volcanoes, Kilauea and Mauna Loa.

  10. Volcano monitoring at the U.S. Geological Survey's Hawaiian Volcano Observatory

    USGS Publications Warehouse

    1986-01-01

    The island of Hawaii has one of the youngest landscapes on Earth, formed by the frequent addition of new lava to its surface. Because Hawaiian eruptions are generally nonexplosive and easily accessible, the island has long attracted geologists interested in studying the extraordinary power of volcanic eruption. The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO), now nearing its 75th anniversary, has been in the forefront of volcanology since the early 1900s. This issue of Earthquakes and Volcanoes is devoted to the work of the Observatory and its role in studying the most recent eruptions of Hawaii's two currently active volcanoes, Kilauea and Mauna Loa.

  11. High-Resolution, Low-Altitude Helicopter-Borne Aeromagnetic Survey over Unzen Volcano, Kyushu, Japan

    NASA Astrophysics Data System (ADS)

    Okubo, A.; Tanaka, Y.; Utsugi, M.; Kitada, N.; Shimizu, H.; Matsushima, T.

    2003-12-01

    We try to use repeated high-resolution aeromagnetic surveys at low altitudes to detect the geomagnetic field changes associated with volcanic activity. Previous magnetic studies in volcanic areas using fixed station distributions have detected small temporal changes, however, they do not have the spatial resolution to detect spatial changes. It may be possible to make repeated magnetic surveys even during active volcano eruptions using, for example, unmanned helicopters. On September 18, 2002, we conducted a high-resolution and low-altitude helicopter-borne magnetic surveys in and around Unzen Volcano in Kyushu, Japan. Unzen is an active volcano that had a sequence of eruptions from November, 1990 to 1995, after a quiescence of 198 years. The first flight covers an area over the Futsu, Chijiwa, and Kanahama faults, which are major normal faults that form the Unzen graben system. The second andthird flights cover the summit area of Unzen volcano with spiral trajectories at altitudes of 1000 and 500 ft, respectively. The spacing between the survey lines is about 50 m. The total geomagnetic was recorded by an optical pumping magnetometer installed in the sensor bird and the sampling intervals are 0.1 sec. Precise positioning data of the sensor bird was obtained by a differential GPS technique, with a time resolution of 1 sec. Diurnal magnetic variations of extra-terrestrial origin were removed by subtracting the total field data recorded at a nearby temporary station. In order to eliminate the effects of topography, the average terrain magnetization was estimated using a statistical correlation method (Grauch, 1987). Finally, an inversion was carried out for the terrain corrected anomalies, after removing the linear regional trend. From the results of this inversion, a low magnetized area was seen around the lava dome, while high magnetization is distributed around Mt.Fugen. The low magnetized area suggests that the rock bodies with remanent magnetization is fractured

  12. Vertical Motions of Oceanic Volcanoes

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Moore, J. G.

    2006-12-01

    Oceanic volcanoes offer abundant evidence of changes in their elevations through time. Their large-scale motions begin with a period of rapid subsidence lasting hundreds of thousands of years caused by isostatic compensation of the added mass of the volcano on the ocean lithosphere. The response is within thousands of years and lasts as long as the active volcano keeps adding mass on the ocean floor. Downward flexure caused by volcanic loading creates troughs around the growing volcanoes that eventually fill with sediment. Seismic surveys show that the overall depression of the old ocean floor beneath Hawaiian volcanoes such as Mauna Loa is about 10 km. This gross subsidence means that the drowned shorelines only record a small part of the total subsidence the islands experienced. In Hawaii, this history is recorded by long-term tide-gauge data, the depth in drill holes of subaerial lava flows and soil horizons, former shorelines presently located below sea level. Offshore Hawaii, a series of at least 7 drowned reefs and terraces record subsidence of about 1325 m during the last half million years. Older sequences of drowned reefs and terraces define the early rapid phase of subsidence of Maui, Molokai, Lanai, Oahu, Kauai, and Niihau. Volcanic islands, such as Maui, tip down toward the next younger volcano as it begins rapid growth and subsidence. Such tipping results in drowned reefs on Haleakala as deep as 2400 m where they are tipped towards Hawaii. Flat-topped volcanoes on submarine rift zones also record this tipping towards the next younger volcano. This early rapid subsidence phase is followed by a period of slow subsidence lasting for millions of years caused by thermal contraction of the aging ocean lithosphere beneath the volcano. The well-known evolution along the Hawaiian chain from high to low volcanic island, to coral island, and to guyot is due to this process. This history of rapid and then slow subsidence is interrupted by a period of minor uplift

  13. 2010 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Neal, Christina A.; Herrick, Julie; Girina, O.A.; Chibisova, Marina; Rybin, Alexander; McGimsey, Robert G.; Dixon, Jim

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest or suspected unrest at 12 volcanic centers in Alaska during 2010. The most notable volcanic activity consisted of intermittent ash emissions from long-active Cleveland volcano in the Aleutian Islands. AVO staff also participated in hazard communication regarding eruptions or unrest at seven volcanoes in Russia as part of an ongoing collaborative role in the Kamchatka and Sakhalin Volcanic Eruption Response Teams.

  14. San Cristobal Volcano, Nicaragua

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A white plume of smoke, from San Cristobal Volcano (13.0N, 87.5W) on the western coast of Nicaragua, blows westward along the Nicaraguan coast just south of the Gulf of Fonseca and the Honduran border. San Csistobal is a strato volcano some 1,745 meters high and is frequently active.

  15. Volcano deformation and gravity workshop synopsis and outcomes: The 2008 volcano deformation and temporal gravity change workshop

    USGS Publications Warehouse

    Dzurisin, Daniel; Lu, Zhong

    2009-01-01

    A volcano workshop was held in Washington State, near the U.S. Geological Survey (USGS) Cascades Volcano Observatory. The workshop, hosted by the USGS Volcano Hazards Program (VHP), included more than 40 participants from the United States, the European Union, and Canada. Goals were to promote (1) collaboration among scientists working on active volcanoes and (2) development of new tools for studying volcano deformation. The workshop focused on conventional and emerging techniques, including the Global Positioning System (GPS), borehole strain, interferometric synthetic aperture radar (InSAR), gravity, and electromagnetic imaging, and on the roles of aqueous and magmatic fluids.

  16. The use of EO Optical data for the Italian Supersites volcanoes monitoring

    NASA Astrophysics Data System (ADS)

    Silvestri, Malvina

    2016-04-01

    This work describes the INGV experience in the capability to import many different EO optical data into in house developed systems and to maintain a repository where the acquired data have been stored. These data are used for generating selected products which are functional to face the different volcanic activity phases. Examples on the processing of long time series based EO data of Mt Etna activity and Campi Flegrei observation by using remote sensing techniques and at different spatial resolution data (ASTER - 90mt, AVHRR -1km, MODIS-1km, MSG SEVIRI-3km) are also showed. Both volcanoes belong to Italian Supersites initiative of the geohazard scientific community. In the frame of the EC FP7 MED-SUV project (call FP7 ENV.2012.6.4-2), this work wants to describe the main activities concerning the generation of brightness temperature map from the satellite data acquired in real-time from INGV MEOS Multi-mission Antenna (for MODIS, Moderate Resolution Imaging Spectroradiometer and geostationary satellite data) and AVHRR-TERASCAN (for AVHRR, Advanced Very High Resolution Radiometer data). The advantage of direct download of EO data by means INGV antennas (with particular attention to AVHRR and MODIS) even though low spatial resolution offers the possibility of a systematic data processing having a daily updating of information for prompt response and hazard mitigation. At the same time it has been necessary the use of large archives to inventory and monitor dynamic and dangerous phenomena, like volcanic activity, globally.

  17. Mt. Fuji Holocene eruption history reconstructed from proximal lake sediments and high-density radiocarbon dating

    NASA Astrophysics Data System (ADS)

    Obrochta, S.; Yokoyama, Y.; Yoshimoto, M.; Yamamoto, S.; Miyairi, Y.; Nagano, G.; Nakamura, A.; Tsunematsu, K.; Lamair, L.; Hubert-Ferrari, A.; Heyvaert, V.; De Batist, M. A. O.; Fujiwara, O.

    2017-12-01

    Understanding the eruption history of volcanos located near large population centers is of direct societal relevance. Here we present a 8,000-year lacustrine record that includes previously unreported eruptions of the active Mt. Fuji volcano, which receives approximately 47 million annual visitors with another 40 million living in the adjacent Kanto Plain. A high-fidelity age model is constructed from a number of terrestrial macrofossil and bulk organic radiocarbon measurements and is extremely consistent with the independently determined age of diagnostic tephra layers. In addition to reporting new eruptions, we also present more accurate ages for known eruptions and detect a wider distribution of ejecta for the most recent summit eruption, that latter of which will alter modeled prevailing wind vector during eruption. Furthermore, closely spaced fall-scoria layers, unlikely to be differentiated as separate events in land-based surveys, will lower the estimated mass of ejecta erupted and in turn reduce calculated magnitude. These results, the first of their kind from a highly populated region, demonstrate the utility of lacustrine sediments as powerful tools for understanding characteristics of volcanic eruptions and will improve disaster mitigation plans for the region.

  18. Methanogenic activity and diversity in the centre of the Amsterdam Mud Volcano, Eastern Mediterranean Sea.

    PubMed

    Lazar, Cassandre Sara; John Parkes, R; Cragg, Barry A; L'Haridon, Stephane; Toffin, Laurent

    2012-07-01

    Marine mud volcanoes are geological structures emitting large amounts of methane from their active centres. The Amsterdam mud volcano (AMV), located in the Anaximander Mountains south of Turkey, is characterized by intense active methane seepage produced in part by methanogens. To date, information about the diversity or the metabolic pathways used by the methanogens in active centres of marine mud volcanoes is limited. (14)C-radiotracer measurements showed that methylamines/methanol, H(2)/CO(2) and acetate were used for methanogenesis in the AMV. Methylotrophic methanogenesis was measured all along the sediment core, Methanosarcinales affiliated sequences were detected using archaeal 16S PCR-DGGE and mcrA gene libraries, and enrichments of methanogens showed the presence of Methanococcoides in the shallow sediment layers. Overall acetoclastic methanogenesis was higher than hydrogenotrophic methanogenesis, which is unusual for cold seep sediments. Interestingly, acetate porewater concentrations were extremely high in the AMV sediments. This might be the result of organic matter cracking in deeper hotter sediment layers. Methane was also produced from hexadecanes. For the most part, the methanogenic community diversity was in accordance with the depth distribution of the H(2)/CO(2) and acetate methanogenesis. These results demonstrate the importance of methanogenic communities in the centres of marine mud volcanoes. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  19. 2009 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Neal, Christina A.; Girina, Olga A.; Chibisova, Marina; Rybin, Alexander

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest, and reports of unusual activity at or near eight separate volcanic centers in Alaska during 2009. The year was highlighted by the eruption of Redoubt Volcano, one of three active volcanoes on the western side of Cook Inlet and near south-central Alaska's population and commerce centers, which comprise about 62 percent of the State's population of 710,213 (2010 census). AVO staff also participated in hazard communication and monitoring of multiple eruptions at ten volcanoes in Russia as part of its collaborative role in the Kamchatka and Sakhalin Volcanic Eruption Response Teams.

  20. Analysis of Active Lava Flows on Kilauea Volcano, Hawaii, Using SIR-C Radar Correlation Measurements

    NASA Technical Reports Server (NTRS)

    Zebker, H. A.; Rosen, P.; Hensley, S.; Mouginis-Mark, P. J.

    1995-01-01

    Precise eruption rates of active pahoehoe lava flows on Kilauea volcano, Hawaii, have been determined using spaceborne radar data acquired by the Space Shuttle Imaging Radar-C (SIR-C). Measurement of the rate of lava flow advance, and the determination of the volume of new material erupted in a given period of time, are among the most important observations that can be made when studying a volcano.

  1. Catalogue of Icelandic Volcanoes

    NASA Astrophysics Data System (ADS)

    Ilyinskaya, Evgenia; Larsen, Gudrun; Gudmundsson, Magnus T.; Vogfjord, Kristin; Pagneux, Emmanuel; Oddsson, Bjorn; Barsotti, Sara; Karlsdottir, Sigrun

    2016-04-01

    The Catalogue of Icelandic Volcanoes is a newly developed open-access web resource in English intended to serve as an official source of information about active volcanoes in Iceland and their characteristics. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the effort of FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene (the time since the end of the last glaciation - approximately the last 11,500 years). In the last 50 years, over 20 eruptions have occurred in Iceland displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and the distribution lava and tephra. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in numerous scientific papers and other publications. In 2010, the International Civil Aviation Organisation (ICAO) funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU through the FP7 project FUTUREVOLC. The Catalogue of Icelandic Volcanoes is a collaboration of the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere. The Catalogue is built up of chapters with texts and various

  2. Imaging the Magmatic System of Erebus Volcano, Antarctica using the Magnetotelluric Method

    NASA Astrophysics Data System (ADS)

    Hill, G.; Wannamaker, P. E.; Stodt, J. A.; Unsworth, M. J.; Maris, V.; Bedrosian, P.; Wallin, E.; Kordy, M. A.; Ogawa, Y.; Kyle, P. R.; Uhlmann, D. F.

    2017-12-01

    Erebus volcano, on Ross Island, Antarctica, in the south west Ross Sea, offers a unique opportunity to understand the magmatic system of an active alkaline volcano, and rifting within the West Antarctica Rift System. Erebus has the world's only persistent phonolite lava lake in its summit crater, and thus provides a window into the heart of a degassing volcano's magmatic system. Phonolite magmas like those at Erebus have been responsible for devastating eruptions (e.g. Pompeii 79 AD; Tambora 1815). Petrologic models suggest that Erebus is undergoing fractional crystallisation of deep mantle-derived parental basanite magma in one or more crustal magma chambers. We are using magnetotelluric (MT) methods and instrumentation, especially developed for use in Antarctica, to image the resistivity structure (magmatic system) of Erebus and the older volcanoes forming Ross Island. In addition, we mapping the rifted crustal structure and examining the mantle source of the magma and the role that the Terror Rift system plays in the active volcanism. Data collection occurred over three field seasons from 2014-2017. Measurements were made at 129 locations on Ross Island and vicinity. A pool of 11 Phoenix Geophysics V5 systems coupled with Numeric Resources high impedance preamplifiers were used. A primary goal of this work is to constrain the distribution of melt within and beneath the volcanic edifice. In addition, we are imaging the interpreted mantle source region for Erebus magmas and investigating the role that the Terror Rift system plays in generating and focusing magmatism. Preliminary modelling suggests that we are able to resolve the crustal residence zones and the path taken by the magma as it ascends from the mantle to the surface. Our work provides new insight into the formation of phonolite magma and has implications for understanding the magmatic process occurring in rift systems globally. It further provides an opportunity to compare volcanic processes in both

  3. Integrating science and education during an international, multi-parametric investigation of volcanic activity at Santiaguito volcano, Guatemala

    NASA Astrophysics Data System (ADS)

    Lavallée, Yan; Johnson, Jeffrey; Andrews, Benjamin; Wolf, Rudiger; Rose, William; Chigna, Gustavo; Pineda, Armand

    2016-04-01

    In January 2016, we held the first scientific/educational Workshops on Volcanoes (WoV). The workshop took place at Santiaguito volcano - the most active volcano in Guatemala. 69 international scientists of all ages participated in this intensive, multi-parametric investigation of the volcanic activity, which included the deployment of seismometers, tiltmeters, infrasound microphones and mini-DOAS as well as optical, thermographic, UV and FTIR cameras around the active vent. These instruments recorded volcanic activity in concert over a period of 3 to 9 days. Here we review the research activities and present some of the spectacular observations made through this interdisciplinary efforts. Observations range from high-resolution drone and IR footage of explosions, monitoring of rock falls and quantification of the erupted mass of different gases and ash, as well as morphological changes in the dome caused by recurring explosions (amongst many other volcanic processes). We will discuss the success of such integrative ventures in furthering science frontiers and developing the next generation of geoscientists.

  4. Volcano monitoring with an infrared camera: first insights from Villarrica Volcano

    NASA Astrophysics Data System (ADS)

    Rosas Sotomayor, Florencia; Amigo Ramos, Alvaro; Velasquez Vargas, Gabriela; Medina, Roxana; Thomas, Helen; Prata, Fred; Geoffroy, Carolina

    2015-04-01

    This contribution focuses on the first trials of the, almost 24/7 monitoring of Villarrica volcano with an infrared camera. Results must be compared with other SO2 remote sensing instruments such as DOAS and UV-camera, for the ''day'' measurements. Infrared remote sensing of volcanic emissions is a fast and safe method to obtain gas abundances in volcanic plumes, in particular when the access to the vent is difficult, during volcanic crisis and at night time. In recent years, a ground-based infrared camera (Nicair) has been developed by Nicarnica Aviation, which quantifies SO2 and ash on volcanic plumes, based on the infrared radiance at specific wavelengths through the application of filters. Three Nicair1 (first model) have been acquired by the Geological Survey of Chile in order to study degassing of active volcanoes. Several trials with the instruments have been performed in northern Chilean volcanoes, and have proven that the intervals of retrieved SO2 concentration and fluxes are as expected. Measurements were also performed at Villarrica volcano, and a location to install a ''fixed'' camera, at 8km from the crater, was discovered here. It is a coffee house with electrical power, wifi network, polite and committed owners and a full view of the volcano summit. The first measurements are being made and processed in order to have full day and week of SO2 emissions, analyze data transfer and storage, improve the remote control of the instrument and notebook in case of breakdown, web-cam/GoPro support, and the goal of the project: which is to implement a fixed station to monitor and study the Villarrica volcano with a Nicair1 integrating and comparing these results with other remote sensing instruments. This works also looks upon the strengthen of bonds with the community by developing teaching material and giving talks to communicate volcanic hazards and other geoscience topics to the people who live "just around the corner" from one of the most active volcanoes

  5. Understanding how active volcanoes work: a contribution from synchrotron X-ray computed microtomography

    NASA Astrophysics Data System (ADS)

    Polacci, M.; Baker, D. R.; Mancini, L.

    2009-04-01

    Volcanoes are complex systems that require the integration of many different geoscience disciplines to understand their behaviour and to monitor and forecast their activity. In the last two decades an increasing amount of information on volcanic processes has been obtained by studying the textures and compositions of volcanic rocks. Five years ago we started a continuing collaboration with the SYRMEP beamline of Elettra Sincrotrone, a third generation synchrotron light source near Trieste, Italy, with the goal of performing high-resolution, phase-contrast X-ray tomographic scans and reconstructing 3-D digital volumes of volcanic specimens. These volumes have been then used for the visualization of the internal structure of rocks and for the quantification of rock textures (i.e., vesicle and crystal volume fraction, individual vesicle volumes and shapes, vesicle connectivity, vesicle volume distributions, permeability simulations etc.). We performed tomographic experiments on volcanic products erupted from different hazardous volcanic systems in Italy and around the world: Campi Flegrei, Stromboli, Etna (Southern Italy), Villarrica (Chile), Yasur and Ambrym (Vanuatu Islands). As an example, we used the results of these studies to constrain the dynamics of vesiculation and degassing in basaltic (Polacci et al., 2006; Burton et al., 2007; Colò et al., 2007; Andronico et al., 2008; Polacci et al., 2008a) and trachytic (Piochi et al., 2008) magmas. A better knowledge of how gas is transported and lost from magmas has led us in turn to draw new implications on the eruptive style of these active, hazardous volcanoes (Polacci et al., 2008b). Work in progress consists of optimizing our procedure by establishing a precise protocol that will enable us to quantitatively study the 3-D texture and composition of rocks in a statistically representative way. Future work will concentrate on the study of the spatial relations between phases (crystals, vesicles and glass) in rocks

  6. 2005 Volcanic Activity in Alaska, Kamchatka, and the Kurile Islands: Summary of Events and Response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, R.G.; Neal, C.A.; Dixon, J.P.; Ushakov, Sergey

    2008-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptive activity or suspected volcanic activity at or near 16 volcanoes in Alaska during 2005, including the high profile precursory activity associated with the 2005?06 eruption of Augustine Volcano. AVO continues to participate in distributing information about eruptive activity on the Kamchatka Peninsula, Russia, and in the Kurile Islands of the Russian Far East, in conjunction with the Kamchatkan Volcanic Eruption Response Team (KVERT) and the Sakhalin Volcanic Eruption Response Team (SVERT), respectively. In 2005, AVO helped broadcast alerts about activity at 8 Russian volcanoes. The most serious hazard posed from volcanic eruptions in Alaska, Kamchatka, or the Kurile Islands is the placement of ash into the atmosphere at altitudes traversed by jet aircraft along the North Pacific and Russian Trans East air routes. AVO, KVERT, and SVERT work collaboratively with the National Weather Service, Federal Aviation Administration, and the Volcanic Ash Advisory Centers to provide timely warnings of volcanic eruptions and the production and movement of ash clouds.

  7. Co-ordinated expression of MMP-2 and its putative activator, MT1-MMP, in human placentation.

    PubMed

    Bjørn, S F; Hastrup, N; Lund, L R; Danø, K; Larsen, J F; Pyke, C

    1997-08-01

    The spatial expression of mRNA for matrix metalloproteinase 2 (MMP-2), its putative activator, the membrane-type 1 matrix metalloproteinase (MT1-MMP), and the MMP-2 substrate type IV collagen was investigated in human placentas of both normal and tubal ectopic pregnancies and in cyclic endometrium using in-situ hybridization. Cytokeratin staining applied to adjacent sections was used to identify epithelial and trophoblast cells. In both normal and tubal pregnancies MT1-MMP, MMP-2 and type IV collagen mRNA were highly expressed and co-localized in the extravillous cytotrophoblasts of anchoring villi, in cytotrophoblasts that had penatrated into the placental bed and in cytotrophoblastic cell islands. In addition, the decidual cells of normal pregnancies in some areas co-expressed MT1-MMP and MMP-2 mRNA, with moderate signals for both components. Fibroblast-like stromal cells in tubal pregnancies were positive for MMP-2 mRNA but generally negative for MT1-MMP mRNA. The consistent co-localization of MT1-MMP with MMP-2 and type IV collagen in the same subset of cytotrophoblasts strongly suggests that all three components co-operate in the tightly regulated fetal invasion process. The co-expression of MT1-MMP and MMP-2 mRNA in some of the decidual cells indicates that these cells are also actively involved in the placentation process.

  8. Preliminary Study on Ground-Magnetic Data Near the Active Volcanoes in Konga Bay, East Flores Indonesia

    NASA Astrophysics Data System (ADS)

    Laesanpura, Agus; Dahrin, Darharta; Nurseptian, Ivan

    2017-04-01

    East Flores is part of Nusa Tenggara island belongs to volcanic arc zone, hence the active volcanoes surround the area about 60 × 50 square km. It is located at latitude south 8° 30’, and longitude east 122° 45’. Geologically, the rock is mostly of volcanic material since Miocene age. The Intriguing question is where the volcanic feeder, pyroclastic, and how it vanish in subsurface. The magnetic data acquisitions were executed on land for 500 meter interval and denser through the bay surrounded by volcanoes. The combine reduction to pole and forward modelling is apply for serve interpretation using forward modelling technique. The two interpretation sections, show the body of magmatic may present at depth about 2 to 3 km. The observation show no significant decreasing or loosening of magnetic anomaly although near the active volcano. We suggest the thermal anomaly is just disturbing magnetic data in near surface but not in the depth one. Meanwhile the reduction to pole’s section could distinguish the two group of rock. In assuming the layer is flat. The inferred peak of magmatic body near the existing volcano; and the active demagnetization associated through evidence of hot spring and inferred fault structure.

  9. Methanogenic diversity and activity in hypersaline sediments of the centre of the Napoli mud volcano, Eastern Mediterranean Sea.

    PubMed

    Lazar, Cassandre Sara; Parkes, R John; Cragg, Barry A; L'Haridon, Stéphane; Toffin, Laurent

    2011-08-01

    Submarine mud volcanoes are a significant source of methane to the atmosphere. The Napoli mud volcano, situated in the brine-impacted Olimpi Area of the Eastern Mediterranean Sea, emits mainly biogenic methane particularly at the centre of the mud volcano. Temperature gradients support the suggestion that Napoli is a cold mud volcano with moderate fluid flow rates. Biogeochemical and molecular genetic analyses were carried out to assess the methanogenic activity rates, pathways and diversity in the hypersaline sediments of the centre of the Napoli mud volcano. Methylotrophic methanogenesis was the only significant methanogenic pathway in the shallow sediments (0-40 cm) but was also measured throughout the sediment core, confirming that methylotrophic methanogens could be well adapted to hypersaline environments. Hydrogenotrophic methanogenesis was the dominant pathway below 50 cm; however, low rates of acetoclastic methanogenesis were also present, even in sediment layers with the highest salinity, showing that these methanogens can thrive in this extreme environment. PCR-DGGE and methyl coenzyme M reductase gene libraries detected sequences affiliated with anaerobic methanotrophs (mainly ANME-1) as well as Methanococcoides methanogens. Results show that the hypersaline conditions in the centre of the Napoli mud volcano influence active biogenic methane fluxes and methanogenic/methylotrophic diversity. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  10. Magnetotelluric Forward Modeling and Inversion In 3 -d Conductivity Model of The Vesuvio Volcano

    NASA Astrophysics Data System (ADS)

    Spichak, V.; Patella, D.

    Three-dimensional forward modeling of MT fields in the simplified conductivity model of the Vesuvio volcano (T=0.1, 1, 10, 100 and 1000s) indicates that the best image of the magma chamber could be obtained basing on the pseudo-section of the determinant apparent resitivity phase as well as on the real and imaginary components of the electric field. Another important result of the studies conducted is that it was demonstrated the principal opportunity of detection and contouring the magma chamber by 2-D pseudo-sections constructed basing on the data transforms mentioned above. Bayesian three-dimensional inversion of synthetic MT data in the volcano model indicates that it is possible to determine the depth and vertical size of the magma chamber, however, simultaneous detection of the conductivity distribution inside the domain of search is of pure quality. However, if the geometrical parameters of the magma chamber are determined in advance, it becomes quite realistic to find out the conductivity distribution inside. The accuracy of such estimation strongly depends on the uncertainty in its prior value: the more narrow is the prior conductivity palette the closer could be the posterior conductivity distribution to the true one.

  11. Preliminary volcano-hazard assessment for Akutan Volcano east-central Aleutian Islands, Alaska

    USGS Publications Warehouse

    Waythomas, Christopher F.; Power, John A.; Richter, Donlad H.; McGimsey, Robert G.

    1998-01-01

    Akutan Volcano is a 1100-meter-high stratovolcano on Akutan Island in the east-central Aleutian Islands of southwestern Alaska. The volcano is located about 1238 kilometers southwest of Anchorage and about 56 kilometers east of Dutch Harbor/Unalaska. Eruptive activity has occurred at least 27 times since historical observations were recorded beginning in the late 1700?s. Recent eruptions produced only small amounts of fine volcanic ash that fell primarily on the upper flanks of the volcano. Small amounts of ash fell on the Akutan Harbor area during eruptions in 1911, 1948, 1987, and 1989. Plumes of volcanic ash are the primary hazard associated with eruptions of Akutan Volcano and are a major hazard to all aircraft using the airfield at Dutch Harbor or approaching Akutan Island. Eruptions similar to historical Akutan eruptions should be anticipated in the future. Although unlikely, eruptions larger than those of historical time could generate significant amounts of volcanic ash, fallout, pyroclastic flows, and lahars that would be hazardous to life and property on all sectors of the volcano and other parts of the island, but especially in the major valleys that head on the volcano flanks. During a large eruption an ash cloud could be produced that may be hazardous to aircraft using the airfield at Cold Bay and the airspace downwind from the volcano. In the event of a large eruption, volcanic ash fallout could be relatively thick over parts of Akutan Island and volcanic bombs could strike areas more than 10 kilometers from the volcano.

  12. Increased mortality of respiratory diseases, including lung cancer, in the area with large amount of ashfall from Mount Sakurajima volcano.

    PubMed

    Higuchi, Kenta; Koriyama, Chihaya; Akiba, Suminori

    2012-01-01

    Mount Sakurajima in Japan is one of the most active volcanoes in the world. This work was conducted to examine the effect of volcanic ash on the chronic respiratory disease mortality in the vicinity of Mt. Sakurajima. The present work examined the standardized mortality ratios (SMRs) of respiratory diseases during the period 1968-2002 in Sakurajima town and Tarumizu city, where ashfall from the volcano recorded more than 10.000 g/m2/yr on average in the 1980s. The SMR of lung cancer in the Sakurajima-Tarumizu area was 1.61 (95% CI=1.44-1.78) for men and 1.67 (95% CI=1.39-1.95) for women while it was nearly equal to one in Kanoya city, which neighbors Tarumizu city but located at the further position from Mt. Sakurajima, and therefore has much smaller amounts of ashfall. Sakurajima-Tarumizu area had elevated SMRs for COPDs and acute respiratory diseases while Kanoya did not. Cristobalite is the most likely cause of the increased deaths from those chronic respiratory diseases since smoking is unlikely to explain the increased mortality of respiratory diseases among women since the proportion of smokers in Japanese women is less than 20%, and SPM levels in the Sakurajima-Tarumizu area were not high. Further studies seem warranted.

  13. 1995 volcanic activity in Alaska and Kamchatka: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Neal, Christina A.

    1996-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptive activity or suspected volcanic activity (SVA) at 6 volcanic centers in 1995: Mount Martin (Katmai Group), Mount Veniaminof, Shishaldin, Makushin, Kliuchef/Korovin, and Kanaga. In addition to responding to eruptive activity at Alaska volcanoes, AVO also disseminated information for the Kamchatkan Volcanic Eruption Response Team (KVERT) on the 1995 eruptions of 2 Russian volcanoes: Bezymianny and Karymsky. This report summarizes volcanic activity in Alaska during 1995 and the AVO response, as well as information on the 2 Kamchatkan eruptions. Only those reports or inquiries that resulted in a "significant" investment of staff time and energy (here defined as several hours or more for reaction, tracking, and follow-up) are included. AVO typically receives dozens of phone calls throughout the year reporting steaming, unusual cloud sightings, or eruption rumors. Most of these are resolved quickly and are not tabulated here as part of the 1995 response record.

  14. Preliminary Volcano-Hazard Assessment for Gareloi Volcano, Gareloi Island, Alaska

    USGS Publications Warehouse

    Coombs, Michelle L.; McGimsey, Robert G.; Browne, Brandon L.

    2008-01-01

    Gareloi Volcano (178.794 degrees W and 51.790 degrees N) is located on Gareloi Island in the Delarof Islands group of the Aleutian Islands, about 2,000 kilometers west-southwest of Anchorage and about 150 kilometers west of Adak, the westernmost community in Alaska. This small (about 8x10 kilometer) volcano has been one of the most active in the Aleutians since its discovery by the Bering expedition in the 1740s, though because of its remote location, observations have been scant and many smaller eruptions may have gone unrecorded. Eruptions of Gareloi commonly produce ash clouds and lava flows. Scars on the flanks of the volcano and debris-avalanche deposits on the adjacent seafloor indicate that the volcano has produced large landslides in the past, possibly causing tsunamis. Such events are infrequent, occurring at most every few thousand years. The primary hazard from Gareloi is airborne clouds of ash that could affect aircraft. In this report, we summarize and describe the major volcanic hazards associated with Gareloi.

  15. Lava-flow hazard on the SE flank of Mt. Etna (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Crisci, G. M.; Iovine, G.; Di Gregorio, S.; Lupiano, V.

    2008-11-01

    A method for mapping lava-flow hazard on the SE flank of Mt. Etna (Sicily, Southern Italy) by applying the Cellular Automata model SCIARA -fv is described, together with employed techniques of calibration and validation through a parallel Genetic Algorithm. The study area is partly urbanised; it has repeatedly been affected by lava flows from flank eruptions in historical time, and shows evidence of a dominant SSE-trending fracture system. Moreover, a dormant deep-seated gravitational deformation, associated with a larger volcano-tectonic phenomenon, affects the whole south-eastern flank of the volcano. The Etnean 2001 Mt. Calcarazzi lava-flow event has been selected for model calibration, while validation has been performed by considering the 2002 Linguaglossa and the 1991-93 Valle del Bove events — suitable data for back analysis being available for these recent eruptions. Quantitative evaluation of the simulations, with respect to the real events, has been performed by means of a couple of fitness functions, which consider either the areas affected by the lava flows, or areas and eruption duration. Sensitivity analyses are in progress for thoroughly evaluating the role of parameters, topographic input data, and mesh geometry on model performance; though, preliminary results have already given encouraging responses on model robustness. In order to evaluate lava-flow hazard in the study area, a regular grid of n.340 possible vents, uniformly covering the study area and located at 500 m intervals, has been hypothesised. For each vent, a statistically-significant number of simulations has been planned, by adopting combinations of durations, lava volumes, and effusion-rate functions, selected by considering available volcanological data. Performed simulations have been stored in a GIS environment for successive analyses and map elaboration. Probabilities of activation, empirically based on past behaviour of the volcano, can be assigned to each vent of the grid, by

  16. 3-D density modeling of Mt. Paekdu (N Korea/China) stratovolcano and its evolution by a combination of EGM2008/terrestrial gravity field

    NASA Astrophysics Data System (ADS)

    Götze, Hans-Jürgen; Choi, Sungchan

    2015-04-01

    We combined the global gravity dataset EGM2008 and a local terrestrial gravity data survey to conduct constrained 3-D crustal density modeling of a strato-volcanic complex and the surrounding area located close to the border of North Korea and China. The independent geophysical (seismic, seismology, geochemistry) and petrological constraints will be presented together with the preprocessing of data base by curvature analysis and Euler deconvolution. The multiple data base is used to assist a general interpretation of the investigated area, and the 3D density model (modelled by the in-house IGMAS+ software). Mt. Paekdu is characterized by a low of Bouguer anomaly of some -110 × 10-5 m/s2, which is caused by the combined gravity effects of (1) Moho depth of about 40 km, (2) a zone with both lower P-wave velocity and density than the surrounding, (3) low density volcanic rocks at the surface, and (4) the presence of a magma chamber that has not previously been identified. The terrestrial gravity field measured along the seismic profile shows a remarkable anomaly descending from the southern- to the northern flank of the Mt. Paekdu volcano, which should be a typical anomaly pattern generally observed over the active volcanic area in the world (e.g. the Yellow Stone volcano). The trend is interpreted to be caused by a prominent density difference between a serious of high density mid crustal sill beneath the southern flank and a predicted partial melted zone locating in the northern flank. With the help of several geoscientific observations (seismic, electromagnetic, gravity and geochemistry) and the 3D density model we conclude that a high density sill was formed in Pliocene and early Pleistocene after pre-shield plateau-forming eruption. Since the Pliocene, volcanic activity in the Mt. Paekdu region might be migrated from the southeastern of North Korea to the northwest, following the path of NW-SE-trending faults. Recently observed seismic tremors can be explained

  17. 3-D Density Modeling of the Combined EGM2008/Terrestrial Gravity Field over the Mt. Paekdu (N Korea/China) Stratovolcano and Its Evolution

    NASA Astrophysics Data System (ADS)

    Goetze, H. J.; Choi, S.

    2014-12-01

    In the presentation we get use of the global gravity dataset EGM2008 and a local terrestrial gravity data survey for a constrained 3-D crustal density modeling of a stratovolcano and its surrounding area located close to the border of North Korea and China. The independent geophysical (seismic, seismology, geochemistry) and petrological constraints will be presented together with the preprocessing of data base by curvature analysis and Euler deconvolution. The multiple data base is used to assist a general interpretation of the investigated area in time, and the 3D density model (modelled by the inhouse IGMAS+ software). Mt. Paekdu is characterized by a low of Bouguer anomaly of some -110 ´ 10-5 m/s2, which is caused by the combined gravity effects of (1) Moho depth of about 40 km, (2) a zone with both lower P-wave velocity and density than the surrounding, (3) low density volcanic rocks at the surface, and (4) the presence of a magma chamber that has not previously been identified. The terrestrial gravity field measured along the seismic profile shows a remarkable anomaly descending from the southern- to the northern flank of the Mt. Paekdu volcano, which should be a typical anomaly pattern generally obsered over the active volcanic area in the world (e.g. the Yellow Stone volcano). The trend is interpreted to be caused by a prominent density difference between a serious of high density mid crustal sill beneath the southern flank and a predicted partial melted zone locating in the northern flank. With the help of several geoscientific observations (seismic, electromagnetic, gravity and geochemistry) and the 3D density model we conclude that a high density sill was formed in Pliocene and early Pleistocene after pre-shield plateau-forming eruption. Since the Pliocene, volcanic activity in the Mt. Paekdu region might be migrated from the southeastern of North Korea to the northwest, following the path of NW-SE-trending faults. Recently observed seismic tremors can

  18. Understanding causality and uncertainty in volcanic observations: An example of forecasting eruptive activity on Soufrière Hills Volcano, Montserrat

    NASA Astrophysics Data System (ADS)

    Sheldrake, T. E.; Aspinall, W. P.; Odbert, H. M.; Wadge, G.; Sparks, R. S. J.

    2017-07-01

    Following a cessation in eruptive activity it is important to understand how a volcano will behave in the future and when it may next erupt. Such an assessment can be based on the volcano's long-term pattern of behaviour and insights into its current state via monitoring observations. We present a Bayesian network that integrates these two strands of evidence to forecast future eruptive scenarios using expert elicitation. The Bayesian approach provides a framework to quantify the magmatic causes in terms of volcanic effects (i.e., eruption and unrest). In October 2013, an expert elicitation was performed to populate a Bayesian network designed to help forecast future eruptive (in-)activity at Soufrière Hills Volcano. The Bayesian network was devised to assess the state of the shallow magmatic system, as a means to forecast the future eruptive activity in the context of the long-term behaviour at similar dome-building volcanoes. The findings highlight coherence amongst experts when interpreting the current behaviour of the volcano, but reveal considerable ambiguity when relating this to longer patterns of volcanism at dome-building volcanoes, as a class. By asking questions in terms of magmatic causes, the Bayesian approach highlights the importance of using short-term unrest indicators from monitoring data as evidence in long-term forecasts at volcanoes. Furthermore, it highlights potential biases in the judgements of volcanologists and identifies sources of uncertainty in terms of magmatic causes rather than scenario-based outcomes.

  19. Evidence for a seismic activity mainly constituted of hybrid events at Cayambe volcano, Ecuador. Interpretation in a iced-domes volcano context

    NASA Astrophysics Data System (ADS)

    Guillier, Bertrand; Chatelain, Jean-Luc

    2006-06-01

    The high activity level of Hybrid Events (HE) detected beneath the Cayambe volcano since 1989 has been more thoroughly investigated with data from a temporary array. The unusual HE spectral content allows separating a high-frequency signal riding on a low-frequency one, with a probable single source. HEs are interpreted as high frequency VT events, produced by the interaction between magmatic heat and an underground water system fed by thaw water from the summital glacier, which trigger simultaneous low-frequency fluid resonance in the highly fractured adjacent medium. Pure VTs are interpreted as 'aborted' HEs occurring probably in the oldest and coldest part of the volcano complex. To cite this article: B. Guillier, J.-L. Chatelain, C. R. Geoscience 338 (2006).

  20. VEPP Exercise: Volcanic Activity and Monitoring of Pu`u `O`o, Kilauea Volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Rodriguez, L. A.

    2010-12-01

    A 10-week project will be tested during the Fall semester 2010, for a Volcanic Hazards elective course, for undergraduate Geology students of the University of Puerto Rico at Mayaguez. This exercise was developed during the Volcanoes Exploration Project: Pu`u `O`o (VEPP) Workshop, held on the Big Island of Hawaii in July 2010. For the exercise the students will form groups (of 2-4 students), and each group will be assigned a monitoring technique or method, among the following: seismic (RSAM data), deformation (GPS and tilt data), observations (webcam and lava flow maps), gas and thermal monitoring. The project is designed for Geology undergraduates who have a background in introductory geology, types of volcanoes and eruptions, magmatic processes, characteristics of lava flows, and other related topics. It is divided in seven tasks, starting with an introduction and demonstration of the VEPP website and the VALVE3 software, which is used to access monitoring data from the current eruption of Pu`u `O`o, Kilauea volcano, Hawaii. The students will also familiarize themselves with the history of Kilauea volcano and its current eruption. At least weekly the groups will acquire data (mostly near-real-time) from the different monitoring techniques, in the form of time series, maps, videos, and images, in order to identify trends in the data. The groups will meet biweekly in the computer laboratory to work together in the analysis and interpretation of the data, with the support of the instructor. They will give reports on the progress of the exercise, and will get feedback from the instructor and from the other expert groups. All groups of experts will relate their findings to the recent and current activity of Kilauea volcano, and the importance of their specific type of monitoring. The activity will culminate with a written report and an oral presentation. The last task of the project consists of a wrap-up volcano monitoring exercise, in which the students will

  1. Iridium emissions from Hawaiian volcanoes

    NASA Technical Reports Server (NTRS)

    Finnegan, D. L.; Zoller, W. H.; Miller, T. M.

    1988-01-01

    Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes.

  2. Iceland's Grímsvötn volcano erupts

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-05-01

    About 13 months after Iceland's Eyjafjallajökull volcano began erupting on 14 April 2010, which led to extensive air traffic closures over Europe, Grímsvötn volcano in southeastern took its turn. Iceland's most active volcano, which last erupted in 2004 and lies largely beneath the Vatnajökull ice cap, began its eruption activity on 21 May, with the ash plume initially reaching about 20 kilometers in altitude, according to the Icelandic Meteorological Office. Volcanic ash from Grímsvötn has cancelled hundreds of airplane flights and prompted U.S. president Barack Obama to cut short his visit to Ireland. As Eos went to press, activity at the volcano was beginning to subside.

  3. Magnetotelluric Investigations of Convergent Margins and of Incipient Rifting: Preliminary Results from the EarthScope MT Transportable Array and MT FlexArray Deployments in Cascadia and in the North American Mid-Continent Region

    NASA Astrophysics Data System (ADS)

    Schultz, A.; Bedrosian, P.; Key, K.; Livelybrooks, D.; Egbert, G. D.; Bowles-martinez, E.; Wannamaker, P. E.

    2014-12-01

    We report on preliminary analyses of data from the EarthScope MT Transportable Array, and from two high-resolution EarthScope MT studies in Cascadia. The first of these, iMUSH, is acquiring wideband MT data at 150 sites, as well as active and passive seismic data in SW Washington (including Mounts Saint Helens, Adams and Rainier). iMUSH seeks to determine details of crustal magma transport and storage, and to resolve major tectonic controls on volcanism along the arc. iMUSH may help to settle a debate over the origin of the SW Washington Crustal Conductor (SWCC), which covers ~5000 km2and that has alternately been attributed to accreted Eocene metasediments or to an extensive region of partial melt in the lower crust beneath the three volcanoes. The iMUSH array is continguous with an amphibious ~150 station MT experiment (MOCHA) onshore and offshore of the Washington and Oregon forearc. MOCHA iwill image the crust and upper mantle of the subduction system in 3D, constraining the fluid input to the system from offshore and the distribution of fluids released from the down-going slab, including along the transitional zone where Episodic Tremor and Slip occurs. Our goal is to refine our understanding of the segmentation, structure and fluid distribution along the convergent margin segments, and their relationship to the spatial pattern of ETS. In contrast to the active Cascadia margin, the Mid-Continent Rift (MCR) is the trace of a massive igneous event that nearly split North America 1.1 billion years ago. Initial results from 3D inversion of MT Transportable Array data show less fine-scale heterogeneity in the upper mantle (250 km depth) than is evident in western, tectonic North America, but a division at the base of thick lithosphere, with higher conductivities beneath and immediately south of the Great Lakes, than to the south. From the base of the lithosphere to the Moho, this high conductivity feature narrows, ultimately disappearing in the mid-crust. In the

  4. Elemental characterization of Mt. Sinabung volcanic ash, Indonesia by Neutron Activation Analysis

    NASA Astrophysics Data System (ADS)

    Kusmartini, I.; Syahfitri, W. Y. N.; Kurniawati, S.; Lestiani, D. D.; Santoso, M.

    2017-06-01

    Mount Sinabung is a volcano located in North Sumatera, Indonesia which has been recorded not erupted since 1600. However in 2013 it has been erupted and cause of black thick smog, rain sand and volcanic ash. Volcanic ash containing trace elements material that can be utilized in various applications but still has potential danger of heavy metals. In order to obtain an elemental composition data of volcanic ash, the characterization of volcanic ash were carried out using Neutron Activation Analysis. The volcanic ash was taken from Mt. Sinabung eruption. Samples were irradiated at the rabbit system in the reactor G.A Siwabessy facilities with neutron flux ˜ 1013 n.cm-2.s-1 and then counted using HPGe detector. Method validation was carried out by SRM NIST Coal Fly Ash 1633b and NIST 2711a Montana II Soil with recovery values were in the range of 96-108% and 95-106% respectively. The results showed that major elements; Al, Na, Ca and Fe, concentrations were 8.7, 1.05, 2.98 and 7.44 %, respectively, minor elements K, Mg, Mn, Ti, V and Zn were 0.87%, 0.78%, 0.18%, 0.62%, 197.13 ppm and 109.35 ppm, respectively, heavy metals; As, Cr, Co and Sb, contents were 4.48, 11.75, 17.13 and 0.35 ppm, respectively while rare earth elements such as Ce, Eu, La, Nd, Sm, Yb were 45.33, 1.22, 19.63, 20.34, 3.86, and 2.57 ppm respectively. The results of the elemental contents of volcanic ash that has been obtained can be used as the scientific based data for volcanic material utilization by considering the economic potential of elements contained and also the danger of the heavy metals content.

  5. Volcanoes and the Environment

    NASA Astrophysics Data System (ADS)

    Marti, Edited By Joan; Ernst, Gerald G. J.

    2005-10-01

    Volcanoes and the Environment is a comprehensive and accessible text incorporating contributions from some of the world's authorities in volcanology. This book is an indispensable guide for those interested in how volcanism affects our planet's environment. It spans a wide variety of topics from geology to climatology and ecology; it also considers the economic and social impacts of volcanic activity on humans. Topics covered include how volcanoes shape the environment, their effect on the geological cycle, atmosphere and climate, impacts on health of living on active volcanoes, volcanism and early life, effects of eruptions on plant and animal life, large eruptions and mass extinctions, and the impact of volcanic disasters on the economy. This book is intended for students and researchers interested in environmental change from the fields of earth and environmental science, geography, ecology and social science. It will also interest policy makers and professionals working on natural hazards. An all-inclusive text that goes beyond the geological working of volcanoes to consider their environmental and sociological impacts Each chapter is written by one of the world's leading authorities on the subject Accessible to students and researchers from a wide variety of backgrounds

  6. Cellular immune responses and phagocytic activity of fishes exposed to pollution of volcano mud.

    PubMed

    Risjani, Yenny; Yunianta; Couteau, Jerome; Minier, Christophe

    2014-05-01

    Since May 29, 2006, a mud volcano in the Brantas Delta of the Sidoarjo district has emitted mud that has inundated nearby villages. Pollution in this area has been implicated in detrimental effects on fish health. In fishes, leukocyte and phagocytic cells play a vital role in body defenses. We report for the first time the effect of "LUSI" volcano mud on the immune systems of fish in the Brantas Delta. The aim of this study was to find biomarkers to allow the evaluation of the effects of volcanic mud and anthropogenic pollution on fish health in the Brantas Delta. The study took places at the Brantas Delta, which was polluted by volcano mud, and at reference sites in Karangkates and Pasuruan. Leukocyte numbers were determined using a Neubauer hemocytometer and a light microscope. Differential leukocyte counts were determined using blood smears stained with May Grunwald-Giemsa, providing neutrophil, lymphocyte and monocyte counts. Macrophages were taken from fish kidney, and their phagocytic activity was measured. In vitro analyses revealed that leukocyte and differential leukocyte counts (DLC) were higher in Channa striata and Chanos chanos caught from the polluted area. Macrophage numbers were higher in Oreochromis mossambicus than in the other species, indicating that this species is more sensitive to pollution. In areas close to volcanic mud eruption, all specimens had lower phagocytic activity. Our results show that immune cells were changed and phagocytic activity was reduced in the polluted area indicating cytotoxicity and alteration of the innate immune system in fishes exposed to LUSI volcano mud and anthropogenic pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Modeling Gas Slug Break-up in the Lava Lake at Mt. Erebus, Antarctica

    NASA Astrophysics Data System (ADS)

    Velazquez, L. C.; Qin, Z.; Suckale, J.; Soldati, A.; Rust, A.; Cashman, K. V.

    2017-12-01

    Lava lakes are perhaps the most direct look scientists can take inside a volcano. They have thus become a fundamental component in our understanding of the dynamics of magmatic systems. Mount Erebus, Ross Island, Antarctica contains one of the most persistent and long-lived lava lakes on Earth, creating a unique and complex area of study. Its persistent magma degassing, convective overturns, and Strombolian eruptions have been studied through extensive field campaigns and analog as well as computational models. These provide diverse insights into the plumbing system not only at Mt. Erebus, but at other volcanoes as well. Eruptions at Erebus are episodic. One of the leading hypotheses to explain this episodicity is the rise and burst of large conduit-filling bubbles, known as gas slugs, at the lava lake surface. These slugs are thought to form deep in the plumbing system, rise through the conduit, and exit through the lava lake. The goal of this study is to investigate the stability of the hypothesized slugs as they transition from the conduit into the lava lake. Analogue laboratory results suggest that the flaring geometry at the transition point may trigger slug breakup and formation of separate daughter bubbles that then burst through the surface separately. We test this hypothesis through numerical simulations. Our model solves the two-fluid Navier-Stokes equations by calculating the conservation of mass and momentum in the gas and liquid. The laboratory experiments use a Hele-Shaw cell, in which the flaring geometry of the lava lake walls can be adjusted. A gas slug of variable volume is then injected into a liquid at different viscosities. We first validate our numerical simulations against these laboratory experiments and then proceed to investigate the same dynamics at the volcanic scale. At the natural scale, we investigate the same system parameters as at the lab scale. First results indicate that simulations reproduce experiments well. The results

  8. Pressure and Temperature Effects on the Activity and Structure of the Catalytic Domain of Human MT1-MMP

    PubMed Central

    Decaneto, Elena; Suladze, Saba; Rosin, Christopher; Havenith, Martina; Lubitz, Wolfgang; Winter, Roland

    2015-01-01

    Membrane type 1-matrix metalloproteinase (MT1-MMP or MMP-14) is a zinc-transmembrane metalloprotease involved in the degradation of extracellular matrix and tumor invasion. While changes in solvation of MT1-MMP have been recently studied, little is known about the structural and energetic changes associated with MT1-MMP while interacting with substrates. Steady-state kinetic and thermodynamic data (including activation energies and activation volumes) were measured over a wide range of temperatures and pressures by means of a stopped-flow fluorescence technique. Complementary temperature- and pressure-dependent Fourier-transform infrared measurements provided corresponding structural information of the protein. MT1-MMP is stable and active over a wide range of temperatures (10–55°C). A small conformational change was detected at 37°C, which is responsible for the change in activity observed at the same temperature. Pressure decreases the enzymatic activity until complete inactivation occurs at 2 kbar. The inactivation is associated with changes in the rate-limiting step of the reaction caused by additional hydration of the active site upon compression and/or minor conformational changes in the active site region. Based on these data, an energy and volume diagram could be established for the various steps of the enzymatic reaction. PMID:26636948

  9. The MtDMI2-MtPUB2 Negative Feedback Loop Plays a Role in Nodulation Homeostasis1[OPEN

    PubMed Central

    Deng, Jie; Zhu, Fugui; Lu, Zheng

    2018-01-01

    DOES NOT MAKE INFECTION 2 (MtDMI2) is a Leu rich repeat-type receptor kinase required for signal transduction in the Medicago truncatula/Sinorhizobium meliloti symbiosis pathway. However, the mechanisms through which MtDMI2 participates in nodulation homeostasis are poorly understood. In this study, we identified MtPUB2—a novel plant U-box (PUB)–type E3 ligase—and showed that it interacts with MtDMI2. MtDMI2 and MtPUB2 accumulation were shown to be similar in various tissues. Roots of plants in which MtPUB2 was silenced by RNAi (MtPUB2-RNAi plants) exhibited impaired infection threads, fewer nodules, and shorter primary root lengths compared to those of control plants transformed with empty vector. Using liquid chromatography-tandem mass spectrometry, we showed that MtDMI2 phosphorylates MtPUB2 at Ser-316, Ser-421, and Thr-488 residues. When MtPUB2-RNAi plants were transformed with MtPUB2S421D, which mimics the phosphorylated state, MtDMI2 was persistently ubiquitinated and degraded by MtPUB2S421D, resulting in fewer nodules than observed in MtPUB2/MtPUB2-RNAi-complemented plants. However, MtPUB2S421A/MtPUB2-RNAi-complemented plants showed no MtPUB2 ubiquitination activity, and their nodulation phenotype was similar to that of MtPUB2-RNAi plants transformed with empty vector. Further studies demonstrated that these proteins form a negative feedback loop of the prey (MtDMI2)-predator (MtPUB2) type. Our results suggest that the MtDMI2-MtPUB2 negative feedback loop, which displays crosstalk with the long-distance autoregulation of nodulation via MtNIN, plays an important role in nodulation homeostasis. PMID:29440269

  10. Vestibular Activation Differentially Modulates Human Early Visual Cortex and V5/MT Excitability and Response Entropy

    PubMed Central

    Guzman-Lopez, Jessica; Arshad, Qadeer; Schultz, Simon R; Walsh, Vincent; Yousif, Nada

    2013-01-01

    Head movement imposes the additional burdens on the visual system of maintaining visual acuity and determining the origin of retinal image motion (i.e., self-motion vs. object-motion). Although maintaining visual acuity during self-motion is effected by minimizing retinal slip via the brainstem vestibular-ocular reflex, higher order visuovestibular mechanisms also contribute. Disambiguating self-motion versus object-motion also invokes higher order mechanisms, and a cortical visuovestibular reciprocal antagonism is propounded. Hence, one prediction is of a vestibular modulation of visual cortical excitability and indirect measures have variously suggested none, focal or global effects of activation or suppression in human visual cortex. Using transcranial magnetic stimulation-induced phosphenes to probe cortical excitability, we observed decreased V5/MT excitability versus increased early visual cortex (EVC) excitability, during vestibular activation. In order to exclude nonspecific effects (e.g., arousal) on cortical excitability, response specificity was assessed using information theory, specifically response entropy. Vestibular activation significantly modulated phosphene response entropy for V5/MT but not EVC, implying a specific vestibular effect on V5/MT responses. This is the first demonstration that vestibular activation modulates human visual cortex excitability. Furthermore, using information theory, not previously used in phosphene response analysis, we could distinguish between a specific vestibular modulation of V5/MT excitability from a nonspecific effect at EVC. PMID:22291031

  11. Development of PEGylated peptide probes conjugated with (18)F-labeled BODIPY for PET/optical imaging of MT1-MMP activity.

    PubMed

    Kondo, Naoya; Temma, Takashi; Deguchi, Jun; Sano, Kohei; Ono, Masahiro; Saji, Hideo

    2015-12-28

    Since the processing activity of the matrix metalloproteinase MT1-MMP regulates various cellular functions such as motility, invasion, growth, differentiation and apoptosis, precise in vivo evaluation of MT1-MMP activity in cancers can provide beneficial information for both basic and clinical studies. For this purpose, we designed a cleavable Positron Emission Tomography (PET)/optical imaging probe consisting of BODIPY650/665 and polyethylene glycol (PEG) conjugated to opposite ends of MT1-MMP substrate peptides. We used in vitro and in vivo fluorescence experiments to select suitable substrate peptide sequences and PEG sizes for the MT1-MMP probes and obtained an optimized structure referred to here as MBP-2k. Radiofluorinated MBP-2k ([(18)F]MBP-2k) was then successfully synthesized via an (18)F-(19)F isotopic exchange reaction in BODIPY650/665. After intravenous injection into mice with xenografted tumors, [(18)F]MBP-2k showed significantly higher accumulation in HT1080 tumors with high MT1-MMP activity than in A549 tumors that have low MT1-MMP activity. Moreover, PET images showed better contrast in HT1080 tumors. These results show that [(18)F]MBP-2k can be used as a hybrid PET/optical imaging agent and is a promising probe for non-invasive monitoring of MT1-MMP activity in cancers. This probe may also efficiently combine targeted tumor imaging with image-guided surgery that could be beneficial for patients in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Dendrogeomorphic reconstruction of lahar activity and triggers: Shiveluch volcano, Kamchatka Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Salaorni, E.; Stoffel, M.; Tutubalina, O.; Chernomorets, S.; Seynova, I.; Sorg, A.

    2017-01-01

    Lahars are highly concentrated, water-saturated volcanic hyperconcentrated flows or debris flows containing pyroclastic material and are a characteristic mass movement process on volcanic slopes. On Kamchatka Peninsula (Russian Federation), lahars are widespread and may affect remote settlements. Historical records of past lahar occurrences are generally sparse and mostly limited to events which damaged infrastructure on the slopes or at the foot of volcanoes. In this study, we present a tree-ring-based reconstruction of spatiotemporal patterns of past lahar activity at Shiveluch volcano. Using increment cores and cross sections from 126 Larix cajanderi trees, we document 34 events covering the period AD 1729-2012. Analyses of the seasonality of damage in trees reveal that 95% of all lahars occurred between October and May and thus point to the predominant role of the sudden melt of the snow cover by volcanic material. These observations suggest that most lahars were likely syn-eruptive and that lahar activity is largely restricted to periods of volcanic activity. By contrast, rainfall events do not seem to play a significant role in lahar triggering.

  13. Probabilistic reasoning over seismic RMS time series: volcano monitoring through HMMs and SAX technique

    NASA Astrophysics Data System (ADS)

    Aliotta, M. A.; Cassisi, C.; Prestifilippo, M.; Cannata, A.; Montalto, P.; Patanè, D.

    2014-12-01

    During the last years, volcanic activity at Mt. Etna was often characterized by cyclic occurrences of fountains. In the period between January 2011 and June 2013, 38 episodes of lava fountains has been observed. Automatic recognition of the volcano's states related to lava fountain episodes (Quiet, Pre-Fountaining, Fountaining, Post-Fountaining) is very useful for monitoring purposes. We discovered that such states are strongly related to the trend of RMS (Root Mean Square) of the seismic signal recorded in the summit area. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management) work, we tried to model the system generating its sampled values (assuming to be a Markov process and assuming that RMS time series is a stochastic process), by using Hidden Markov models (HMMs), that are a powerful tool for modeling any time-varying series. HMMs analysis seeks to discover the sequence of hidden states from the observed emissions. In our framework, observed emissions are characters generated by SAX (Symbolic Aggregate approXimation) technique. SAX is able to map RMS time series values with discrete literal emissions. Our experiments showed how to predict volcano states by means of SAX and HMMs.

  14. Magma Vesiculation and Infrasonic Activity in Open Conduit Volcanoes

    NASA Astrophysics Data System (ADS)

    Colo', L.; Baker, D. R.; Polacci, M.; Ripepe, M.

    2007-12-01

    At persistently active basaltic volcanoes such as Stromboli, Italy degassing of the magma column can occur in "passive" and "active" conditions. Passive degassing is generally understood as a continuous, non explosive release of gas mainly from the open summit vents and subordinately from the conduit's wall or from fumaroles. In passive degassing generally gas is in equilibrium with atmospheric pressure, while in active degassing the gas approaches the surface at overpressurized conditions. During active degassing (or puffing), the magma column is interested by the bursting of small gas bubbles at the magma free surface and, as a consequence, the active degassing process generates infrasonic signals. We postulated, in this study, that the rate and the amplitude of infrasonic activity is somehow linked to the rate and the volume of the overpressured gas bubbles, which are generated in the magma column. Our hypothesis is that infrasound is controlled by the quantities of gas exsolved in the magma column and then, that a relationship between infrasound and the vesiculation process should exist. In order to achieve this goal, infrasonic records and bubble size distributions of scoria samples from normal explosive activity at Stromboli processed via X ray tomography have been compared. We observed that the cumulative distribution for both data sets follow similar power laws, indicating that both processes are controlled by a scale invariant phenomenon. However the power law is not stable but changes in different scoria clasts, reflecting when gas bubble nucleation is predominant over bubbles coalescence and viceversa. The power law also changes for the infrasonic activity from time to time, suggesting that infrasound may be controlled also by a different gas exsolution within the magma column. Changes in power law distributions are the same for infrasound and scoria indicating that they are linked to the same process acting in the magmatic system. We suggest that

  15. First determination of dissolved volatiles in magmas of Mt Garet (Vanuatu arc). Origin of sulfur emissions

    NASA Astrophysics Data System (ADS)

    Floury, P.; Metrich, N.; Bertagnini, A.; Garaebiti, E.; Hidalgo, S.; Beaumais, A.; Neuville, D.

    2012-12-01

    Mt Garet, on Gaua island, is one of the active volcanoes of the Vanuatu arc in the Southwest Pacific. This 360 m high cone emerges from the lake Letas in the summit caldera of a composite volcano. Since 1962, Mt Garet produced ash and gas plumes recurrently, the last explosive events being documented in 2009 - 2010. Airborne measurements of SO2 emission rates, the only data set presently available for this volcano, were realized in 2009 and revealed a high SO2 flux of, on average, 2955 tons per day [1]. We report here the very first data on the geochemistry of the scoriae emitted in January 2010, together with analyses of major elements and volatiles (H2O, Cl, S) in crystal-hosted melt inclusions and a detailed mineralogy of the samples. The 2010 scoriae are basaltic-andesites and are more evolved that the pre-1962 basaltic lava flows of Mt Garet. Their major and trace element evolution cannot be reconciled with a single process of fractional crystallization, but suggest mixing between a pre-1962 like basalt and an evolved trachydacitic end-member. This observation strongly suggests the recent development of a small reservoir beneath Mt Garet. The plagioclases (An89-73) and clinopyroxenes (Fs5-16) display a significant chemical range but do not clearly evidence reverse zoning. The paragenesis is complemented by Fe-Ti oxides (USP39-40) and scarce olivines (Fo72.7). Some crystals are obviously inherited (e.g., An-poor plagioclase). The melt inclusions are ubiquitous but of small size in each mineral phase. Their H2O content was specifically determined using micro-Raman spectroscopy (IPGP), with a series of basaltic glass standards previously developed for Raman calibration [2]. Data and spectrum are treated following [3]. As a whole melt inclusion compositions cover the whole chemical spectrum from basalt to trachydacite. Their contents in H2O (2.7-0.8 wt%), S (1570 - <100 ppm), and Cl (2800-950 ppm) widely vary. Volatile-rich basaltic inclusions are found in

  16. Degassing vs. eruptive styles at Mt. Etna volcano (Sicily, Italy): Volatile stocking, gas fluxing, and the shift from low-energy to highly-explosive basaltic eruptions

    NASA Astrophysics Data System (ADS)

    Moretti, Roberto; Métrich, Nicole; Di Renzo, Valeria; Aiuppa, Alessandro; Allard, Patrick; Arienzo, Ilenia

    2017-04-01

    Basaltic magmas can transport and release large amounts of volatiles into the atmosphere, especially in subduction zones, where slab-derived fluids enrich the mantle wedge. Depending on magma volatile content, basaltic volcanoes thus display a wide spectrum of eruptive styles, from common Strombolian-type activity to Plinian events. Mt. Etna in Sicily, is a typical basaltic volcano where the volatile control on such a variable activity can be investigated. Based on a melt inclusion study in products from Strombolian or lava-fountain activity to Plinian eruptions, here we show that for the same initial volatile content, different eruptive styles reflect variable degassing paths throughout the composite Etnean plumbing system. The combined influence of i) crystallization, ii) deep degassing and iii) CO2 gas fluxing can explain the evolution of H2O, CO2, S and Cl in products from such a spectrum of activity. Deep crystallization produces the CO2-rich gas fluxing the upward magma portions, which will become buoyant and easily mobilized in small gas-rich batches stored within the plumbing system. When reaching gas dominated conditions (i.e., a gas/melt mass ratio of 0.3 and CO2,gas/H2Ogas molar ratio 5 ), these will erupt effusively or mildly explosively, whilst in case of the 122 BC Plinian eruption, open-system degassing conditions took place within the plumbing system, such that continuous CO2-fluxing determined gas accumulation on top of the magmatic system. The emission of such a cap in the early eruptive phase triggered the arrival of deep H2O-rich whose fast decompression and bubble nucleation lead to the highly explosive character, enhanced by abundant microlite crystallization and consequent increase of magma effective viscosity. This could explain why open system basaltic systems like Etna may experience highly explosive or even Plinian episodes during eruptions that start with effusive to mildly explosive phases. The proposed mechanism also determines a

  17. Space Radar Image of Colombian Volcano

    NASA Image and Video Library

    1999-01-27

    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by NASA Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar SIR-C/X-SAR. The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations of Colombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. http://photojournal.jpl.nasa.gov/catalog/PIA01722

  18. Thermal surveillance of active volcanoes

    NASA Technical Reports Server (NTRS)

    Friedman, J. D. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. There are three significant scientific results of the discovery of 48 pinpoint anomalies on the upper flanks of Mt. Rainier: (1) Many of these points may actually be the location of fumarolic vapor emission or warm ground considerably below the summit crater. (2) Discovery of these small anomalies required specific V/H scanner settings for precise elevation on Mt. Rainier's flank, to avoid smearing the anomalies to the point of nonrecognition. Several past missions flown to map the thermal anomalies of the summit area did not/detect the flank anomalies. (3) This illustrates the value of the aerial IR scanner as a geophysical tool suited to specific problem-oriented missions, in contrast to its more general value in a regional or reconnaissance anomaly-mapping role.

  19. Characteristics and petrology of the effusive-explosive activity of Colima volcano, in the years 2015-2017

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Nuñez-Cornu, F. J.; Arreola-Ochoa, L. C.; Suarez, G. B. V.; Carrillo-Gonzalez, D. A.

    2017-12-01

    The Colima volcano, during the years 2015-2017, presented an important effusive and explosive activity, which began in January 2015 with the growth of a dome that was destroyed by explosions, forming pyroclastic flows reaching distances of up to 2 km by the north and south flanks of the volcano. In May a new dome was extruded, forming three thick lava flows along the northern and southern slopes; the extruded volume was approximately 6 million cubic meters, with a rate in 52 days of 1.3 m3/sec. On July 11 merapi flows were formed it flowed through by the ravines of Montegrande and San Antonio, on the south and southwest flank, reaching distances of 10.4 km. The following days the activity had decreased substantially, leaving a crater of 60 m of depth and 270 m of diameter. In February 2016, a small dome occupied the central part of the main crater, and it was until September that an episode of volcanic tremor began, that was associated with its rapid growth, which in 48 hours filled the crater and formed a lava flow that descended by the south slope. By October 2, 2.3 million m3 of lava were extruded, which caused a deflation of the dome. In October 7, the volcano emitted a great amount of gases and steam of water that formed an acid rain that affected forests and crops of the south and southwest slope, causing losses by 1 million dollars. In November, a series of explosions occurred that destroyed two thirds of the dome. In January 2017, the explosive activity increased and again destroyed the dome. Five events were recorded that reached between 3 km and 4 km of height on the top of the volcano, the dispersion of the ash generally went to the northeast, reaching distances of up to 200 km. Currently the volcano is sustaining reduced seismic and fumarole activity. In 2005, 2015 and 2017, the geochemical analysis of major elements such as SiO2 from the ash emitted by the volcano showed an increase from 54.51% to 60.05% and 60.24%, respectively, which was associated

  20. MEditerranean Supersite Volcanoes (MED-SUV) project: from objectives to results

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe; Spampinato, Letizia

    2017-04-01

    The MEditerranean Supersite Volcanoes (MED-SUV) was a FP7 3-year lasting project aimed at improving the assessment of volcanic hazards at two of the most active European volcanic areas - Campi Flegrei/Vesuvius and Mt. Etna. More than 3 million people are exposed to potential hazards in the two areas, and the geographic location of the volcanoes increases the number of people extending the impact to a wider region. MED-SUV worked on the (1) optimisation and integration of the existing and new monitoring systems, (2) understanding of volcanic processes, and on the (3) relationship between the scientific and end-user communities. MED-SUV fully exploited the unique multidisciplinary long-term in-situ datasets available for these volcanoes and integrated them with Earth observations. Technological developments and implemented algorithms allowed better constraint of pre-, sin- and post-eruptive phases. The wide range of styles and intensities of the volcanic phenomena observed at the targeted volcanoes - archetypes of 'closed' and 'open' conduit systems - observed by using the long-term multidisciplinary datasets, exceptionally upgraded the understanding of a variety of geo-hazards. Proper experiments and studies were carried out to advance the understanding of the volcanoes' internal structure and processes, and to recognise signals related to impending unrest/eruptive phases. Indeed, the hazard quantitative assessment benefitted from the outcomes of these studies and from their integration with cutting edge monitoring approaches, thus leading to step-changes in hazard awareness and preparedness, and leveraging the close relationship between scientists, SMEs, and end-users. Among the MED-SUV achievements, we can list the (i) implementation of a data policy compliant with the GEO Open Data Principles for ruling the exploitation and shared use of the project outcomes; (ii) MED-SUV e-infrastructure creation as test bed for designing an interoperable infrastructure to

  1. NASA Satellite Images Erupting Russian Volcano

    NASA Image and Video Library

    2017-08-22

    Klyuchevskoi, one of the world's most active volcanoes, is seen poking through above a solid cloud deck, with an ash plume streaming to the west. Located on the Kamchatka Peninsula in far eastern Russia, it is one of many active volcanoes on the Peninsula. Nearby, to the south, the smaller Bezymianny volcano can be seem with a small steam plume coming from its summit. The image was acquired Aug. 20, 2017, covers an area of 12 by 14 miles (19.5 by 22.7 kilometers), and is located at 56.1 degrees north, 160.6 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA21878

  2. 2008 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Neal, Christina A.; McGimsey, Robert G.; Dixon, James P.; Cameron, Cheryl E.; Nuzhdaev, Anton A.; Chibisova, Marina

    2011-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest or suspected unrest at seven separate volcanic centers in Alaska during 2008. Significant explosive eruptions at Okmok and Kasatochi Volcanoes in July and August dominated Observatory operations in the summer and autumn. AVO maintained 24-hour staffing at the Anchorage facility from July 12 through August 28. Minor eruptive activity continued at Veniaminof and Cleveland Volcanoes. Observed volcanic unrest at Cook Inlet's Redoubt Volcano presaged a significant eruption in the spring of 2009. AVO staff also participated in hazard communication regarding eruptions or unrest at nine volcanoes in Russia as part of a collaborative role in the Kamchatka and Sakhalin Volcanic Eruption Response Teams.

  3. Dual origins for pantellerites, and other puzzles, at Mount Takahe volcano, Marie Byrd Land, West Antarctica

    NASA Astrophysics Data System (ADS)

    LeMasurier, Wesley; Choi, Sung Hi; Kawachi, Yosuke; Mukasa, Sam; Rogers, Nick

    2018-01-01

    Mt. Takahe is a large, late Quaternary trachyte shield volcano that rises through 2000 + m of the West Antarctic ice sheet. It is composed mostly of ne-trachyte, hy-ol-trachyte, and qz-trachyte flows, with subordinate basanite, intermediate rocks, and pantellerites. All rock types can be adequately modeled by fractional crystallization of basanite - the only basaltic rock exposed here. The ne-trachytes can be explained by a single stage of low-pressure fractionation near the base of the upper crust. Models of oversaturated rocks require a period of evolution at a depth of 35 km, below the stability field of plagioclase, where fractionation of kaersutite and associated high pressure minerals will yield silica oversaturated residual magmas. This is then followed by a period of fractionation at a depth of 3 km, where peralkalinity and Fe-enrichment are acquired. Pantellerite compositions span virtually the entire spectrum of peralkalinity, Fe-enrichment, LILE-enrichment, and SiO2 values, and seem to represent a range of residence times in upper crustal vs., upper mantle magma chambers. Mt. Takahe is unusual among Marie Byrd Land volcanoes for its geochemical anomalies. These include the lowest 143Nd/144Nd ratios in West Antarctica, and unusually high but unpredictable Ba values. These anomalies are believed to originate in a pre-85 Ma subduction mélange at the base of the lithosphere, which seems to be the source of Mt. Takahe basaltic rocks.

  4. Implications for future activity of Grímsvötn volcano, Iceland, from compositional time series of historical tephra

    NASA Astrophysics Data System (ADS)

    Carpentier, Marion; Sigmarsson, Olgeir; Larsen, Gudrun

    2014-05-01

    The nature of future eruptions of active volcanoes is hard to predict. Improved understanding of the past volcanic activity is probably the best way to infer future eruptive scenarios. The most active volcano in Iceland, Grímsvötn, last erupted in 2011 with consequences for habitants living close to the volcano and aviation in the North-Atlantic. In an effort to better understand the magmatic system of the volcano, we have investigated the compositions of 23 selected tephra layers representing the last 8 centuries of volcanic activity at Grímsvötn. The tephra was collected in the ablation area of outlet glaciers from Vatnajökull ice cap. The ice-conserved tephra are less prone to alteration than those exposed in soil sections. Major element analyses are indistinguishable and of quartz-normative tholeiite composition, and Sr and Nd isotope ratios are constant. In contrast, both trace element concentrations (Th range from 0.875 ppm to 1.37 ppm and Ni from 28.5 ppm to 56.6 ppm) in the basalts and Pb isotopes show small but significant variations. The high-precision analyses of Pb isotope ratios allow the identification of tephra samples (3 in total) with more radiogenic ratios than the bulk of the samples. The tephra of constant isotope ratios show linear increase in incompatible element concentrations with time. The rate of increasing concentrations permits exploring possible future scenarios assuming that the magmatic system beneath the volcano follows the established historical evolution. Assuming similar future behaviour of the magma system beneath Grímsvötn volcano, the linear increase in e.g. Th concentration suggests that the volcano is likely to principally produce basalts for the next 500-1000 years. Evolution of water concentration will most likely follow those of incompatible elements with consequent increases in explosiveness of future Grímsvötn eruptions.

  5. Remote sensing of volcanos and volcanic terrains

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, Peter J.; Francis, Peter W.; Wilson, Lionel; Pieri, David C.; Self, Stephen; Rose, William I.; Wood, Charles A.

    1989-01-01

    The possibility of using remote sensing to monitor potentially dangerous volcanoes is discussed. Thermal studies of active volcanoes are considered along with using weather satellites to track eruption plumes and radar measurements to study lava flow morphology and topography. The planned use of orbiting platforms to study emissions from volcanoes and the rate of change of volcanic landforms is considered.

  6. TOMO-ETNA Experiment -Etna volcano, Sicily, investigated with active and passive seismic methods

    NASA Astrophysics Data System (ADS)

    Luehr, Birger-G.; Ibanez, Jesus M.; Díaz-Moreno, Alejandro; Prudencio, Janire; Patane, Domenico; Zieger, Toni; Cocina, Ornella; Zuccarello, Luciano; Koulakov, Ivan; Roessler, Dirk; Dahm, Torsten

    2017-04-01

    The TOMO-ETNA experiment, as part of the European Union project "MEDiterranean SUpersite Volcanoes (MED-SUV)", was devised to image the crustal structure beneath Etna by using state of the art passive and active seismic methods. Activities on-land and offshore are aiming to obtain new high-resolution seismic images to improve the knowledge of crustal structures existing beneath the Etna volcano and northeast Sicily up to the Aeolian Islands. In a first phase (June 15 - July 24, 2014) at Etna volcano and surrounding areas two removable seismic networks were installed composed by 80 Short Period and 20 Broadband stations, additionally to the existing network belonging to the "Istituto Nazionale di Geofisica e Vulcanologia" (INGV). So in total air-gun shots could be recorded by 168 stations onshore plus 27 ocean bottom instruments offshore in the Tyrrhenian and Ionian Seas. Offshore activities were performed by Spanish and Italian research vessels. In a second phase the broadband seismic network remained operative until October 28, 2014, as well as offshore surveys during November 19 -27, 2014. Active seismic sources were generated by an array of air-guns mounted in the Spanish Oceanographic vessel "Sarmiento de Gamboa" with a power capacity of up to 5.200 cubic inches. In total more than 26.000 shots were fired and more than 450 local and regional earthquakes could be recorded and will be analyzed. For resolving a volcanic structure the investigation of attenuation and scattering of seismic waves is important. In contrast to existing studies that are almost exclusively based on S-wave signals emitted by local earthquakes, here air-gun signals were investigated by applying a new methodology based on the coda energy ratio defined as the ratio between the energy of the direct P-wave and the energy in a later coda window. It is based on the assumption that scattering caused by heterogeneities removes energy from direct P-waves that constitutes the earliest possible

  7. Contrasting expression of membrane metalloproteinases, MT1-MMP and MT3-MMP, suggests distinct functions in skeletal development.

    PubMed

    Yang, Maozhou; Zhang, Bingbing; Zhang, Liang; Gibson, Gary

    2008-07-01

    Membrane-type 1 matrix metalloproteinase (MT1-MMP) is the most ubiquitous and widely studied of the membrane-type metalloproteinases (MT-MMPs). It was thus surprising to find no published data on chicken MT1-MMP. We report here the characterization of the chicken gene. Its low sequence identity with the MT1-MMP genes of other species, high GC content, and divergent catalytic domain explains the absence of data and our difficulties in characterizing the gene. The absence of structural features in the chicken gene that have been suggested to be critical for the activation of MMP-2 by MT1-MMP; for the effect of MT1-MMP on cell migration and for the recycling of MT1-MMP suggest these features are either not essential or that MT1-MMP does not perform these functions in chickens. Comparison of the expression of chicken MT1-MMP with MT3-MMP and with MMP-2 and MMP-13 has confirmed the previously recognized co-expression of MT1-MMP with MMP-2 and MMP-13 in fibrous and vascular tissues, particularly those surrounding the developing long bones in other species. By contrast, MT3-MMP expression differs markedly from that of MT1-MMP and of both MMP-2 and MMP-13. MT3-MMP is expressed by chondrocytes of the developing articular surface. Similar expression patterns of this group of MT-MMPs and MMPs have been observed in mouse embryos and suggest distinct and specific functions for MT1-MMP and MT3-MMP in skeletal development.

  8. Strong S-wave attenuation and actively degassing magma beneath Taal volcano, Philippines, inferred from source location analysis using high-frequency seismic amplitudes

    NASA Astrophysics Data System (ADS)

    Kumagai, H.; Lacson, R. _Jr., Jr.; Maeda, Y.; Figueroa, M. S., II; Yamashina, T.

    2014-12-01

    Taal volcano, Philippines, is one of the world's most dangerous volcanoes given its history of explosive eruptions and its close proximity to populated areas. A key feature of these eruptions is that the eruption vents were not limited to Main Crater but occurred on the flanks of Volcano Island. This complex eruption history and the fact that thousands of people inhabit the island, which has been declared a permanent danger zone, together imply an enormous potential for disasters. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) constantly monitors Taal, and international collaborations have conducted seismic, geodetic, electromagnetic, and geochemical studies to investigate the volcano's magma system. Realtime broadband seismic, GPS, and magnetic networks were deployed in 2010 to improve monitoring capabilities and to better understand the volcano. The seismic network has recorded volcano-tectonic (VT) events beneath Volcano Island. We located these VT events based on high-frequency seismic amplitudes, and found that some events showed considerable discrepancies between the amplitude source locations and hypocenters determined by using onset arrival times. Our analysis of the source location discrepancies points to the existence of a region of strong S-wave attenuation near the ground surface beneath the east flank of Volcano Island. This region is beneath the active fumarolic area and above sources of pressure contributing inflation and deflation, and it coincides with a region of high electrical conductivity. The high-attenuation region matches that inferred from an active-seismic survey conducted at Taal in 1993. Our results, synthesized with previous results, suggest that this region represents actively degassing magma near the surface, and imply a high risk of future eruptions on the east flank of Volcano Island.

  9. Volcano Hazards Program

    USGS Publications Warehouse

    Venezky, Dina Y.; Myers, Bobbie; Driedger, Carolyn

    2008-01-01

    Diagram of common volcano hazards. The U.S. Geological Survey Volcano Hazards Program (VHP) monitors unrest and eruptions at U.S. volcanoes, assesses potential hazards, responds to volcanic crises, and conducts research on how volcanoes work. When conditions change at a monitored volcano, the VHP issues public advisories and warnings to alert emergency-management authorities and the public. See http://volcanoes.usgs.gov/ to learn more about volcanoes and find out what's happening now.

  10. Temporal Variations of Magnetic Field Associated with Seismic Activity at Cerro Machin Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Londono, J. M.; Serna, J. P.; Guzman, J.

    2011-12-01

    A study of magnetic variations was carried out at Cerro Machin Volcano, Colombia for the period 2009 -2010, with two permanent magnetometers located at South and North of the central dome, separated about 2.5 km each other. After corrections, we found that there is no clear correlation between volcanic seismicity and temporal changes of magnetic field for each magnetometer station, if they are analyzed individually. On the contrary, when we calculated the residual Magnetic field (RMF), for each magnetometer, and then we made the subtraction between them, and plot it vs time, we found a clear correlation of changes in local magnetic field with the occurrence of volcanic seismicity (ML >1.6). We found a change in the RMF between 1584 nT and 1608 nT, each time that a volcano-tectonic earthquake occurred. The máximum lapse time between the previous change in RMF and the further occurrence of the earthquake is 24 days, with an average of 11 days. This pattern occurred more than 9 times during the studied period. Based on the results, we believed that the simple methodology proposed here, is a good tool for monitoring changes in seismicity associated with activity at Cerro Machín volcano. We suggest that the temporal changes of RMF at Cerro Machín Volcano, are associated with piezo-magnetic effects, due to changes in strain-stress inside the volcano, produced by the interaction between local faulting and magma movement.

  11. Shiveluch and Klyuchevskaya Volcanoes

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A distance of about 80 kilometers (50 miles) separates Shiveluch and Klyuchevskaya Volcanoes on Russia's Kamchatka Peninsula. Despite this distance, however, the two acted in unison on April 26, 2007, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite caught them both erupting simultaneously. ASTER 'sees' a slightly different portion of the light spectrum than human eyes. Besides a portion of visible light, ASTER detects thermal energy, meaning it can detect volcanic activity invisible to human eyes. Inset in each image above is a thermal infrared picture of the volcano's summit. In these insets, dark red shows where temperatures are coolest, and yellowish-white shows where temperatures are hottest, heated by molten lava. Both insets show activity at the crater. In the case of Klyuchevskaya, some activity at the crater is also visible in the larger image. In the larger images, the landscapes around the volcanoes appear in varying shades of blue-gray. Dark areas on the snow surface are likely stains left over from previous eruptions of volcanic ash. Overhead, clouds dot the sky, casting their shadows on the snow, especially southeast of Shiveluch and northeast of Klyuchevskaya. To the northwest of Klyuchevskaya is a large bank of clouds, appearing as a brighter white than the snow surface. Shiveluch (sometimes spelled Sheveluch) and Klyuchevskaya (sometimes spelled Klyuchevskoy or Kliuchevskoi) are both stratovolcanoes composed of alternating layers of hardened lava, solidified ash, and rocks from earlier eruptions. Both volcanoes rank among Kamchatka's most active. Because Kamchatka is part of the Pacific 'Ring of Fire,' the peninsula experiences regular seismic activity as the Pacific Plate slides below other tectonic plates in the Earth's crust. Large-scale plate tectonic activity causing simultaneous volcanic eruptions in Kamchatka is not uncommon.

  12. Linking space observations to volcano observatories in Latin America: Results from the CEOS DRM Volcano Pilot

    NASA Astrophysics Data System (ADS)

    Delgado, F.; Pritchard, M. E.; Biggs, J.; Arnold, D. W. D.; Poland, M. P.; Ebmeier, S. K.; Wauthier, C.; Wnuk, K.; Parker, A. L.; Amelug, F.; Sansosti, E.; Mothes, P. A.; Macedo, O.; Lara, L.; Zoffoli, S.; Aguilar, V.

    2015-12-01

    Within Latin American, about 315 volcanoes that have been active in the Holocene, but according to the United Nations Global Assessment of Risk 2015 report (GAR15) 202 of these volcanoes have no seismic, deformation or gas monitoring. Following the 2012 Santorini Report on satellite Earth Observation and Geohazards, the Committee on Earth Observation Satellites (CEOS) has developed a 3-year pilot project to demonstrate how satellite observations can be used to monitor large numbers of volcanoes cost-effectively, particularly in areas with scarce instrumentation and/or difficult access. The pilot aims to improve disaster risk management (DRM) by working directly with the volcano observatories that are governmentally responsible for volcano monitoring, and the project is possible thanks to data provided at no cost by international space agencies (ESA, CSA, ASI, DLR, JAXA, NASA, CNES). Here we highlight several examples of how satellite observations have been used by volcano observatories during the last 18 months to monitor volcanoes and respond to crises -- for example the 2013-2014 unrest episode at Cerro Negro/Chiles (Ecuador-Colombia border); the 2015 eruptions of Villarrica and Calbuco volcanoes, Chile; the 2013-present unrest and eruptions at Sabancaya and Ubinas volcanoes, Peru; the 2015 unrest at Guallatiri volcano, Chile; and the 2012-present rapid uplift at Cordon Caulle, Chile. Our primary tool is measurements of ground deformation made by Interferometric Synthetic Aperture Radar (InSAR) but thermal and outgassing data have been used in a few cases. InSAR data have helped to determine the alert level at these volcanoes, served as an independent check on ground sensors, guided the deployment of ground instruments, and aided situational awareness. We will describe several lessons learned about the type of data products and information that are most needed by the volcano observatories in different countries.

  13. Hazard maps of Colima volcano, Mexico

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Escudero Ayala, C. R.

    2011-12-01

    Colima volcano, also known as Volcan de Fuego (19° 30.696 N, 103° 37.026 W), is located on the border between the states of Jalisco and Colima and is the most active volcano in Mexico. Began its current eruptive process in February 1991, in February 10, 1999 the biggest explosion since 1913 occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching attitudes between 4,500 and 9,000 m.a.s.l., further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events ash emissions were generated in all directions reaching distances up to 100 km, slightly affected nearby villages as Tuxpan, Tonila, Zapotlán, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During the 2005 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano due to low population density and low socio-economic activities at the time. Shows the updating of the volcanic hazard maps published in 2001, where we identify whit SPOT satellite imagery and Google Earth, change in the land use on the slope of volcano, the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano, the population inhabiting the area is approximately 517,000 people, and growing at an annual rate of 4.77%, also the region that has shown an increased in the vulnerability for the development of economic activities, supported by the construction of highways, natural gas pipelines and electrical infrastructure that connect to the Port of Manzanillo to Guadalajara city. The update the hazard maps are: a) Exclusion areas and moderate hazard for explosive events

  14. Geoflicks Reviewed--Films about Hawaiian Volcanoes.

    ERIC Educational Resources Information Center

    Bykerk-Kauffman, Ann

    1994-01-01

    Reviews 11 films on volcanic eruptions in the United States. Films are given a one- to five-star rating and the film's year, length, source and price are listed. Top films include "Inside Hawaiian Volcanoes" and "Kilauea: Close up of an Active Volcano." (AIM)

  15. Ice-clad volcanoes

    USGS Publications Warehouse

    Waitt, Richard B.; Edwards, B.R.; Fountain, Andrew G.; Huggel, C.; Carey, Mark; Clague, John J.; Kääb, Andreas

    2015-01-01

    An icy volcano even if called extinct or dormant may be active at depth. Magma creeps up, crystallizes, releases gas. After decades or millennia the pressure from magmatic gas exceeds the resistance of overlying rock and the volcano erupts. Repeated eruptions build a cone that pokes one or two kilometers or more above its surroundings - a point of cool climate supporting glaciers. Ice-clad volcanic peaks ring the northern Pacific and reach south to Chile, New Zealand, and Antarctica. Others punctuate Iceland and Africa (Fig 4.1). To climb is irresistible - if only “because it’s there” in George Mallory’s words. Among the intrepid ascents of icy volcanoes we count Alexander von Humboldt’s attempt on 6270-meter Chimborazo in 1802 and Edward Whymper’s success there 78 years later. By then Cotopaxi steamed to the north.

  16. mtDNA, Metastasis, and the Mitochondrial Unfolded Protein Response (UPRmt).

    PubMed

    Kenny, Timothy C; Germain, Doris

    2017-01-01

    While several studies have confirmed a link between mitochondrial DNA (mtDNA) mutations and cancer cell metastasis, much debate remains regarding the nature of the alternations in mtDNA leading to this effect. Meanwhile, the mitochondrial unfolded protein response (UPR mt ) has gained much attention in recent years, with most studies of this pathway focusing on its role in aging. However, the UPR mt has also been studied in the context of cancer. More recent work suggests that rather than a single mutation or alternation, specific combinatorial mtDNA landscapes able to activate the UPR mt may be those that are selected by metastatic cells, while mtDNA landscapes unable to activate the UPR mt do not. This review aims at offering an overview of the confusing literature on mtDNA mutations and metastasis and the more recent work on the UPR mt in this setting.

  17. Radon surveys and monitoring at active volcanoes: an open window on deep hydrothermal systems and their dynamics

    NASA Astrophysics Data System (ADS)

    Cigolini, Corrado; Laiolo, Marco; Coppola, Diego

    2017-04-01

    The behavior of fluids in hydrothermal systems is critical in volcano monitoring and geothermal prospecting. Analyzing the time series of radon emissions on active volcanoes is strategic for detecting and interpreting precursory signals of changes in volcanic activity, eventually leading to eruptions. Radon is a radioactive gas generated from the decay of U bearing rocks, soils and magmas. Although radon has been regarded as a potential precursor of earthquakes, radon anomalies appear to be better suited to forecast volcanic eruptions since we know where paroxysms may occur and we can follow the evolution of volcanic activity. Radon mapping at active volcanoes is also a reliable tool to assess diffuse and concentrated degassing as well as efficiently detecting earthquake-volcano interactions. Systematic radon monitoring has been shown to be a key factor for evaluating the rise of volcanic and hydrothermal fluids. In fact, the decay properties of radon, the duration of radon anomalies together with sampling rates may be cross-checked with the chemistry of hydrothermal fluids (and their transport properties) to constrain fluids ascent rates and to infer the permeability and porosity of rocks in sectors surrounding the active conduits. We hereby further discuss the data of radon surveys and monitoring at Somma-Vesuvius, Stromboli and La Soufrière (Guadeloupe, Lesser Antilles). The integrated analysis of seismic and geochemical data, including radon emissions, may be successfully used in testing temperature distributions and variations of porosity and permeability in volcanic hydrothermal systems and can be used as a proxy to analyze geothermal reservoirs.

  18. 2. BUILDING MT76A AND MT76B FROM STREET, BUILDING MT76A IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. BUILDING MT-76-A AND MT-76-B FROM STREET, BUILDING MT-76-A IN FOREGROUND - Fort Keogh, Livestock & Range Research Station, 3 miles west of Miles City on U.S. Highway 10, Miles City, Custer County, MT

  19. Eruption of Kliuchevskoi volcano

    NASA Image and Video Library

    1994-10-05

    STS068-155-094 (30 September-11 October 1994) --- (Kliuchevskoi Volcano) The crewmembers used a Linhof large format Earth observation camera to photograph this nadir view of the Kamchatka peninsula's week-old volcano. The eruption and the follow-up environmental activity was photographed from 115 nautical miles above Earth. Six NASA astronauts spent a week and a half aboard the Space Shuttle Endeavour in support of the Space Radar Laboratory 2 (SRL-2) mission.

  20. Mt. Etna Eruption

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Vis/NIR Image CloseupFigure 2: Difference Image

    October 2002 Mt. Etna, a volcano on the island of Sicily, erupted on October 26, 2002. Preliminary analysis of data taken by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on October 28 shows the instrument can provide an excellent means to study the evolution and structure of the sulfur dioxide (SO2) plume emitted from volcanoes. These data also demonstrate that AIRS can be used to obtain the total mass of SO2 injected into the atmosphere during a volcanic event, information that may help us to better understand these dangerous natural occurrences in the future.

    This image was made from a sensor on the AIRS instrument that is sensitive to the visible and near-infrared portions of the spectrum. The visible/near infrared data show the smoke plume from Mt. Etna. The view is of Europe and the central Mediterranean with Italy in the center. Since the visible/near infrared sensor on AIRS is sensitive to wavelengths that are different than the human eye, vegetated regions appear red (compare the red color of Europe with the tan desert of North Africa in the lower left). Figure 1 is a closer view of Sicily and shows a long, brownish smoke plume extending across the Mediterranean to Africa. This is consistent with the enhanced feature in the difference image in Figure 2 and helps validate the information inferred from that image.

    Figure 2 clearly shows the SO2 plume. This image was created by comparing data taken at two different frequencies, or channels, and creating one image that highlights the differences between these two channels. Both channels are sensitive to water vapor, but one of the channels is also sensitive to SO2. By subtracting out the common water vapor signal in both channels, the SO2 feature remains and shows up as an enhancement in the difference image.

    The

  1. 2007 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    McGimsey, Robert G.; Neal, Christina A.; Dixon, James P.; Malik, Nataliya; Chibisova, Marina

    2011-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near nine separate volcanic centers in Alaska during 2007. The year was highlighted by the eruption of Pavlof, one of Alaska's most frequently active volcanoes. Glaciated Fourpeaked Mountain, a volcano thought to have been inactive in the Holocene, produced a phreatic eruption in the autumn of 2006 and continued to emit copious amounts of steam and volcanic gas into 2007. Redoubt Volcano showed the first signs of the unrest that would unfold in 2008-09. AVO staff also participated in hazard communication and monitoring of multiple eruptions at seven volcanoes in Russia as part of its collaborative role in the Kamchatka and Sakhalin Volcanic Eruption Response Teams.

  2. Volcano-hydrothermal system and activity of Sirung volcano (Pantar Island, Indonesia)

    NASA Astrophysics Data System (ADS)

    Caudron, Corentin; Bernard, Alain; Murphy, Sam; Inguaggiato, Salvatore; Gunawan, Hendra

    2018-05-01

    Sirung is a frequently active volcano located in the remote parts of Western Timor (Indonesia). Sirung has a crater with several hydrothermal features including a crater lake. We present a timeseries of satellite images of the lake and chemical and isotope data from the hyperacid hydrothermal system. The fluids sampled in the crater present the typical features of hyperacidic systems with high TDS, low pH and δ34SHSO4-δ34SS0 among the highest for such lakes. The cations concentrations are predominantly controlled by the precipitation of alunite, jarosite, silica phases, native sulfur and pyrite which dominate the shallow portions of the hydrothermal system. These minerals may control shallow sealing processes thought to trigger phreatic eruptions elsewhere. Sparse Mg/Cl and SO4/Cl ratios and lake parameters derived from satellite images suggest gradual increase in heat and gas flux, most likely SO2-rich, prior to the 2012 phreatic eruption. An acidic river was sampled 8 km far from the crater and is genetically linked with the fluids rising toward the active crater. This river would therefore be a relevant target for future remote monitoring purposes. Finally, several wells and springs largely exceeded the World Health Organization toxicity limits in total arsenic and fluoride.

  3. Volcano-Monitoring Instrumentation in the United States, 2008

    USGS Publications Warehouse

    Guffanti, Marianne; Diefenbach, Angela K.; Ewert, John W.; Ramsey, David W.; Cervelli, Peter F.; Schilling, Steven P.

    2010-01-01

    The United States is one of the most volcanically active countries in the world. According to the global volcanism database of the Smithsonian Institution, the United States (including its Commonwealth of the Northern Mariana Islands) is home to about 170 volcanoes that are in an eruptive phase, have erupted in historical time, or have not erupted recently but are young enough (eruptions within the past 10,000 years) to be capable of reawakening. From 1980 through 2008, 30 of these volcanoes erupted, several repeatedly. Volcano monitoring in the United States is carried out by the U.S. Geological Survey (USGS) Volcano Hazards Program, which operates a system of five volcano observatories-Alaska Volcano Observatory (AVO), Cascades Volcano Observatory (CVO), Hawaiian Volcano Observatory (HVO), Long Valley Observatory (LVO), and Yellowstone Volcano Observatory (YVO). The observatories issue public alerts about conditions and hazards at U.S. volcanoes in support of the USGS mandate under P.L. 93-288 (Stafford Act) to provide timely warnings of potential volcanic disasters to the affected populace and civil authorities. To make efficient use of the Nation's scientific resources, the volcano observatories operate in partnership with universities and other governmental agencies through various formal agreements. The Consortium of U.S. Volcano Observatories (CUSVO) was established in 2001 to promote scientific cooperation among the Federal, academic, and State agencies involved in observatory operations. Other groups also contribute to volcano monitoring by sponsoring long-term installation of geophysical instruments at some volcanoes for specific research projects. This report describes a database of information about permanently installed ground-based instruments used by the U.S. volcano observatories to monitor volcanic activity (unrest and eruptions). The purposes of this Volcano-Monitoring Instrumentation Database (VMID) are to (1) document the Nation's existing

  4. Volcano-tectonic interactions at Sabancaya and other Peruvian volcanoes revealed by InSAR and seismicity

    NASA Astrophysics Data System (ADS)

    Jay, J.; Pritchard, M. E.; Aron, F.; Delgado, F.; Macedo, O.; Aguilar, V.

    2013-12-01

    An InSAR survey of all 13 Holocene volcanoes in the Andean Central Volcanic Zone of Peru reveals previously undocumented surface deformation that is occasionally accompanied by seismic activity. Our survey utilizes SAR data spanning from 1992 to the present from the ERS-1, ERS-2, and Envisat satellites, as well as selected data from the TerraSAR-X satellite. We find that the recent unrest at Sabancaya volcano (heightened seismicity since 22 February 2013 and increased fumarolic output) has been accompanied by surface deformation. We also find two distinct deformation episodes near Sabancaya that are likely associated with an earthquake swarm in February 2013 and a M6 normal fault earthquake that occurred on 17 July 2013. Preliminary modeling suggests that faulting from the observed seismic moment can account for nearly all of the observed deformation and thus we have not yet found clear evidence for recent magma intrusion. We also document an earlier episode of deformation that occurred between December 2002 and September 2003 which may be associated with a M5.3 earthquake that occurred on 13 December 2002 on the Solarpampa fault, a large EW-striking normal fault located about 25 km northwest of Sabancaya volcano. All of the deformation episodes between 2002 and 2013 are spatially distinct from the inflation seen near Sabancaya from 1992 to 1997. In addition to the activity at Sabancaya, we also observe deformation near Coropuna volcano, in the Andagua Valley, and in the region between Ticsani and Tutupaca volcanoes. InSAR images reveal surface deformation that is possibly related to an earthquake swarm near Coropuna and Sabancaya volcanoes in December 2001. We also find persistent deformation in the scoria cone and lava field along the Andagua Valley, located 40 km east of Corpuna. An earthquake swarm near Ticsani volcano in 2005 produced surface deformation centered northwest of the volcano and was accompanied by a north-south elongated subsidence signal to the

  5. In vitro and in vivo activity of MT201, a fully human monoclonal antibody for pancarcinoma treatment.

    PubMed

    Naundorf, Stefanie; Preithner, Susanne; Mayer, Petra; Lippold, Sandra; Wolf, Andreas; Hanakam, Frank; Fichtner, Iduna; Kufer, Peter; Raum, Tobias; Riethmüller, Gert; Baeuerle, Patrick A; Dreier, Torsten

    2002-07-01

    In our study, a novel, fully human, recombinant monoclonal antibody of the IgG1 isotype, called MT201, was characterized for its binding properties, complement-dependent (CDC) and antibody-dependent cellular cytotoxicity (ADCC), as well as for its in vivo antitumor activity in a nude mouse model. MT201 was found to bind its target, the epithelial cell adhesion molecule (Ep-CAM; also called 17-1A antigen, KSA, EGP-2, GA733-2), with low affinity in a range similar to that of the clinically validated, murine monoclonal IgG2a antibody edrecolomab (Panorex(R)). MT201 exhibited Ep-CAM-specific CDC with a potency similar to that of edrecolomab. However, the efficacy of ADCC of MT201, as mediated by human immune effector cells, was by 2 orders of magnitude higher than that of edrecolomab. Addition of human serum reduced the ADCC of MT201 while it essentially abolished ADCC of edrecolomab within the concentration range tested. In a nude mouse xenograft model, growth of tumors derived from the human colon carcinoma line HT-29 was significantly and comparably suppressed by MT201 and edrecolomab. The fully human nature and the improved ADCC of MT201 with human effector cells will make MT201 a promising candidate for the clinical development of a novel pan-carcinoma antibody that is superior to edrecolomab. Copyright 2002 Wiley-Liss, Inc.

  6. Hawaiian Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Orr, Tim R.

    2008-01-01

    Lava from Kilauea volcano flowing through a forest in the Royal Gardens subdivision, Hawai'i, in February 2008. The Hawaiian Volcano Observatory (HVO) monitors the volcanoes of Hawai'i and is located within Hawaiian Volcanoes National Park. HVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Kilauea and HVO at http://hvo.wr.usgs.gov.

  7. Northern Arizona Volcanoes

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Northern Arizona is best known for the Grand Canyon. Less widely known are the hundreds of geologically young volcanoes, at least one of which buried the homes of local residents. San Francisco Mtn., a truncated stratovolcano at 3887 meters, was once a much taller structure (about 4900 meters) before it exploded some 400,000 years ago a la Mt. St. Helens. The young cinder cone field to its east includes Sunset Crater, that erupted in 1064 and buried Native American homes. This ASTER perspective was created by draping ASTER image data over topographic data from the U.S. Geological Survey National Elevation Data.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 20.4 by 24.6 kilometers (12.6 by 15.2 miles) Location: 35.3 degrees North latitude, 111

  8. U-series Chronology of volcanoes in the Central Kenya Peralkaline Province, East African Rift

    NASA Astrophysics Data System (ADS)

    Negron, L. M.; Ma, L.; Deino, A.; Anthony, E. Y.

    2012-12-01

    We are studying the East African Rift System (EARS) in the Central Kenya Peralkaline Province (CKPP), and specifically the young volcanoes Mt. Suswa, Longonot, and Menengai. Ar dates by Al Deino on K-feldspar phenocrysts show a strong correlation between older Ar ages and decreasing 230Th/232Th, which we interpret to reflect the age of eruption. This system has been the subject of recent research done by several UTEP alumni including Antony Wamalwa using potential field and magnetotelluric (MT) data to identify and characterize fractures and hydrothermal fluids. Also research on geochemical modeling done by John White, Vanessa Espejel and Peter Omenda led to the hypothesis of possible disequilibrium in these young, mainly obsidian samples in their post eruptive history. A pilot study of 8 samples, (also including W-2a USGS standard and a blank) establish the correlation that was seen between the ages found by Deino along with the 230/232Th ratios. All 8 samples from Mt. Suswa showed a 234U/238U ratio of (1) which indicates secular equilibrium or unity and that these are very fresh samples with no post-eruptive decay or leaching of U isotopes. The pilot set was comprised of four samples from the ring-trench group (RTG) with ages ranging from 7ka-present, two samples from the post-caldera stage ranging from 31-10ka, one sample from the syn-caldera stage dated at 41ka, and one sample from the pre-caldera stage dated at 112ka. The young RTG had a 230/232Th fractionation ratio of 0.8 ranging to the older pre-caldera stage with a 230/232Th ratio of 0.6. From this current data and research of 14C ages by Nick Rogers, the data from Longonot volcano was also similar to the 230/232Th ratio we found. Rogers' data places Longonot volcano ages to be no more than 20ka with the youngest samples also roughly around 0.8 disequilibrium. These strong correlations between the pilot study done for Mt. Suswa, 40Ar ages by Deino, along with 14C ages from Rogers have led to the

  9. Muon imaging of volcanoes with Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; La Parola, Valentina; La Rosa, Giovanni; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Sottile, Giuseppe; Zuccarello, Luciano

    2017-04-01

    The quantitative understanding of the inner structure of a volcano is a key feature to model the processes leading to paroxysmal activity and, hence, to mitigate volcanic hazards. To pursue this aim, different geophysical techniques are utilized, that are sensitive to different properties of the rocks (elastic, electrical, density). In most cases, these techniques do not allow to achieve the spatial resolution needed to characterize the shallowest part of the plumbing system and may require dense measurements in active zones, implying a high level of risk. Volcano imaging through cosmic-ray muons is a promising technique that allows to overcome the above shortcomings. Muons constantly bombard the Earth's surface and can travel through large thicknesses of rock, with an energy loss depending on the amount of crossed matter. By measuring the absorption of muons through a solid body, one can deduce the density distribution inside the target. To date, muon imaging of volcanic structures has been mainly achieved with scintillation detectors. They are sensitive to noise sourced from (i) the accidental coincidence of vertical EM shower particles, (ii) the fake tracks initiated from horizontal high-energy electrons and low-energy muons (not crossing the target) and (iii) the flux of upward going muons. A possible alternative to scintillation detectors is given by Cherenkov telescopes. They exploit the Cherenkov light emitted when charged particles (like muons) travel through a dielectric medium, with velocity higher than the speed of light. Cherenkov detectors are not significantly affected by the above noise sources. Furthermore, contrarily to scintillator-based detectors, Cherenkov telescopes permit a measurement of the energy spectrum of the incident muon flux at the installation site, an issue that is indeed relevant for deducing the density distribution inside the target. In 2014, a prototype Cherenkov telescope was installed at the Astrophysical Observatory of Serra

  10. Monitoring crater-wall collapse at active volcanoes: a study of the 12 January 2013 event at Stromboli

    NASA Astrophysics Data System (ADS)

    Calvari, Sonia; Intrieri, Emanuele; Di Traglia, Federico; Bonaccorso, Alessandro; Casagli, Nicola; Cristaldi, Antonio

    2016-05-01

    Crater-wall collapses are fairly frequent at active volcanoes and they are normally studied through the analysis of their deposits. In this paper, we present an analysis of the 12 January 2013 crater-wall collapse occurring at Stromboli volcano, investigated by means of a monitoring network comprising visible and infrared webcams and a Ground-Based Interferometric Synthetic Aperture Radar. The network revealed the triggering mechanisms of the collapse, which are comparable to the events that heralded the previous effusive eruptions in 1985, 2002, 2007 and 2014. The collapse occurred during a period of inflation of the summit cone and was preceded by increasing explosive activity and the enlargement of the crater. Weakness of the crater wall, increasing magmastatic pressure within the upper conduit induced by ascending magma and mechanical erosion caused by vent opening at the base of the crater wall and by lava fingering, are considered responsible for triggering the collapse on 12 January 2013 at Stromboli. We suggest that the combination of these factors might be a general mechanism to generate crater-wall collapse at active volcanoes.

  11. Hawaii's volcanoes revealed

    USGS Publications Warehouse

    Eakins, Barry W.; Robinson, Joel E.; Kanamatsu, Toshiya; Naka, Jiro; Smith, John R.; Takahashi, Eiichi; Clague, David A.

    2003-01-01

    Hawaiian volcanoes typically evolve in four stages as volcanism waxes and wanes: (1) early alkalic, when volcanism originates on the deep sea floor; (2) shield, when roughly 95 percent of a volcano's volume is emplaced; (3) post-shield alkalic, when small-volume eruptions build scattered cones that thinly cap the shield-stage lavas; and (4) rejuvenated, when lavas of distinct chemistry erupt following a lengthy period of erosion and volcanic quiescence. During the early alkalic and shield stages, two or more elongate rift zones may develop as flanks of the volcano separate. Mantle-derived magma rises through a vertical conduit and is temporarily stored in a shallow summit reservoir from which magma may erupt within the summit region or be injected laterally into the rift zones. The ongoing activity at Kilauea's Pu?u ?O?o cone that began in January 1983 is one such rift-zone eruption. The rift zones commonly extend deep underwater, producing submarine eruptions of bulbous pillow lava. Once a volcano has grown above sea level, subaerial eruptions produce lava flows of jagged, clinkery ?a?a or smooth, ropy pahoehoe. If the flows reach the ocean they are rapidly quenched by seawater and shatter, producing a steep blanket of unstable volcanic sediment that mantles the upper submarine slopes. Above sea level then, the volcanoes develop the classic shield profile of gentle lava-flow slopes, whereas below sea level slopes are substantially steeper. While the volcanoes grow rapidly during the shield stage, they may also collapse catastrophically, generating giant landslides and tsunami, or fail more gradually, forming slumps. Deformation and seismicity along Kilauea's south flank indicate that slumping is occurring there today. Loading of the underlying Pacific Plate by the growing volcanic edifices causes subsidence, forming deep basins at the base of the volcanoes. Once volcanism wanes and lava flows no longer reach the ocean, the volcano continues to submerge, while

  12. 2015 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Dixon, James P.; Cameron, Cheryl E.; Iezzi, Alexandra M.; Wallace, Kristi

    2017-09-28

    The Alaska Volcano Observatory (AVO) responded to eruptions, volcanic unrest or suspected unrest, and seismic events at 14 volcanic centers in Alaska during 2015. The most notable volcanic activity consisted of continuing intermittent ash eruptions from Cleveland and Shishaldin volcanoes in the Aleutian Islands. Two eruptive episodes, at Veniaminof and Pavlof, on the Alaska Peninsula ended in 2015. During 2015, AVO re-established the seismograph network at Aniakchak, installed six new broadband seismometers throughout the Aleutian Islands, and added a Multiple component Gas Analyzer System (MultiGAS) station on Augustine.

  13. NASA Spacecraft Captures Fury of Russian Volcano

    NASA Image and Video Library

    2011-01-27

    This nighttime thermal infrared image from NASA Terra spacecraft shows Shiveluch volcano, one of the largest and most active volcanoes in Russia Kamchatka Peninsula; the bright, hot summit lava dome is evident in the center of the image.

  14. Distribution of gaseous Hg in the Mercury mining district of Mt. Amiata (Central Italy): a geochemical survey prior the reclamation project.

    PubMed

    Vaselli, Orlando; Higueras, Pablo; Nisi, Barbara; María Esbrí, José; Cabassi, Jacopo; Martínez-Coronado, Alba; Tassi, Franco; Rappuoli, Daniele

    2013-08-01

    The Mt. Amiata volcano is the youngest and largest volcanic edifice in Tuscany (central-northern Italy) and is characterized by a geothermal field, exploited for the production of electrical energy. In the past Mt. Amiata was also known as a world-class Hg district whose mining activity was mainly distributed in the central-eastern part of this silicic volcanic complex, and particularly in the municipality of Abbadia San Salvatore. In the present work we report a geochemical survey on Hg(0) measurements related to the former mercury mine facilities prior the reclamation project. The Hg(0) measurements were carried out by car for long distance regional surveys, and on foot for local scale surveys by using two LUMEX (915+ and M) devices. This study presents the very first Hg(0) data obtained with this analytical technique in the Mt. Amiata area. The facilities related to the mining areas and structures where cinnabar was converted to metallic Hg are characterized by high Hg values (>50,000ngm(-3)), although the urban center of Abbadia San Salvatore, few hundred meters away, does not appear to be receiving significant pollution from the calcine area and former industrial edifices, all the recorded values being below the values recommended by the issuing Tuscany Region authorities (300ngm(-3)) and in some cases approaching the Hg background levels (3-5ngm(-3)) for the Mt. Amiata area. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Short Magma Residence Times at Mt. Rainier and the Probable Absence of a Large, Integrated, and Long-lived Magma Reservoir System

    NASA Astrophysics Data System (ADS)

    Sisson, T. W.; Lanphere, M. A.

    2003-12-01

    Intensive, high-precision K-Ar and 40Ar/39Ar geochronology have proven essential for producing modern geologic maps of volcanoes and from these determining the volcanoes' time-volume histories. If sufficiently abundant, these data can also reveal aspects of the magma supply system. For Cascade volcanoes a general result has been the demonstration that edifice growth is highly episodic. Mount Rainier grew in the last 500,000 years atop the remains of an ancestral edifice that was active in the same location 1 - 2 Myr ago. The 500,000 year history of the modern edifice falls into four stages of alternating high and low magmatic output of subequal duration, but major and trace element compositions of eruptives show no correlation with volcano growth stages. Instead, the same spectrum of magmas (andesite to low-Si dacite) erupted throughout the history of the volcano with compositions in the same relative abundances. Superimposed on this seemingly null result are at least 6 brief but pronounced excursions in magma trace-element compositions. Concentrations of Zr, Ba, or Sr can double and then return to background values passing into and out of a single flow or flow-group. Some excursions are tightly bracketed by mapping and by measured ages and have durations no more than the geochronologic measurement precision of about 10,000 years. True excursion durations are potentially much shorter. The brevity and abrupt onsets and cessations of these compositional excursions are evidence against the presence of a sizeable, long-lived magma reservoir anywhere beneath the volcano, including a MASH zone in the lower crust, that would have attenuated, dampened, and homogenized compositional excursions introduced into the magmatic system. Instead, we take 10,000 years as a probable upper limit to the average residence time of magma batches transiting the crustal portion of Mount Rainier's plumbing system. A consistent scenario is that parental magmas enter the crust, differentiate

  16. Volcanism in Eastern Africa

    NASA Technical Reports Server (NTRS)

    Cauthen, Clay; Coombs, Cassandra R.

    1996-01-01

    In 1891, the Virunga Mountains of Eastern Zaire were first acknowledged as volcanoes, and since then, the Virunga Mountain chain has demonstrated its potentially violent volcanic nature. The Virunga Mountains lie across the Eastern African Rift in an E-W direction located north of Lake Kivu. Mt. Nyamuragira and Mt. Nyiragongo present the most hazard of the eight mountains making up Virunga volcanic field, with the most recent activity during the 1970-90's. In 1977, after almost eighty years of moderate activity and periods of quiescence, Mt. Nyamuragira became highly active with lava flows that extruded from fissures on flanks circumscribing the volcano. The flows destroyed vast areas of vegetation and Zairian National Park areas, but no casualties were reported. Mt. Nyiragongo exhibited the same type volcanic activity, in association with regional tectonics that effected Mt. Nyamuragira, with variations of lava lake levels, lava fountains, and lava flows that resided in Lake Kivu. Mt. Nyiragongo, recently named a Decade volcano, presents both a direct and an indirect hazard to the inhabitants and properties located near the volcano. The Virunga volcanoes pose four major threats: volcanic eruptions, lava flows, toxic gas emission (CH4 and CO2), and earthquakes. Thus, the volcanoes of the Eastern African volcanic field emanate harm to the surrounding area by the forecast of volcanic eruptions. During the JSC Summer Fellowship program, we will acquire and collate remote sensing, photographic (Space Shuttle images), topographic and field data. In addition, maps of the extent and morphology(ies) of the features will be constructed using digital image information. The database generated will serve to create a Geographic Information System for easy access of information of the Eastem African volcanic field. The analysis of volcanism in Eastern Africa will permit a comparison for those areas from which we have field data. Results from this summer's work will permit

  17. UAVSAR Acquires False-Color Image of Galeras Volcano, Colombia

    NASA Image and Video Library

    2013-04-03

    This false-color image of Colombia Galeras Volcano, was acquired by UAVSAR on March 13, 2013. A highly active volcano, Galeras features a breached caldera and an active cone that produces numerous small to moderate explosive eruptions.

  18. Mt. Ruapehu, New Zealand

    NASA Image and Video Library

    2017-12-08

    All around the world, people live in places where the threat of natural disaster is high. On the North Island of New Zealand, the Mount Ruapehu volcano is just such a threat. A towering, active stratovolcano (the classic cone-shaped volcano), snow-capped Ruapehu Volcano is pictured in this enhanced-color image. The image is made from topography data collected by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000, and imagery collected by the Landsat satellite on October 23, 2002. Ruapehu is one of New Zealand’s most active volcanoes, with ten eruptions since 1861. The eruptions aren’t the only threat from the volcano, however. Among the most serious threats is a volcanic mudflow called a lahar. In between eruptions, a lake forms in the volcano’s caldera from melting snow. If a previous eruption has deposited a dam of ash, rocks and mud in the lake’s natural overflow point, then the lake becomes dangerously full, held back only by the temporary dam. In this scene, the lake is nestled among the ridges at the top of the volcano. Eventually, the dam gives way and a massive flow of mud and debris churns down the mountain toward farmland and towns below. Scientists estimate that Ruapehu has experienced 60 lahars in the last 150 years. A devastating lahar in 1953 killed more than 150 people, who died when a passenger train plunged into a ravine when a railroad bridge was taken out by the lahar. The flank of the volcano below the lake is deeply carved by the path of previous lahars; the gouge can be seen just left of image center. Currently scientists in the region are predicting that the lake will overflow in a lahar sometime in the next year. There is great controversy about how to deal with the threat. News reports from the region indicate that the government is planning to invest in a high-tech warning system that will alert those who might be affected well in advance of any catastrophic release. Others feel

  19. Design, synthesis and evaluation of photoactivatable derivatives of microtubule (MT)-active [1,2,4]triazolo[1,5-a]pyrimidines.

    PubMed

    Oukoloff, Killian; Kovalevich, Jane; Cornec, Anne-Sophie; Yao, Yuemang; Owyang, Zachary A; James, Michael; Trojanowski, John Q; Lee, Virginia M-Y; Smith, Amos B; Brunden, Kurt R; Ballatore, Carlo

    2018-05-05

    The [1,2,4]triazolo[1,5-a]pyrimidines comprise a promising class of non-naturally occurring microtubule (MT)-active compounds. Prior studies revealed that different triazolopyrimidine substitutions can yield molecules that either promote MT stabilization or disrupt MT integrity. These differences can have important ramifications in the therapeutic applications of triazolopyrimidines and suggest that different analogues may exhibit different binding modes within the same site or possibly interact with tubulin/MTs at alternative binding sites. To help discern these possibilities, a series of photoactivatable triazolopyrimidine congeners was designed, synthesized and evaluated in cellular assays with the goal of identifying candidate probes for photoaffinity labeling experiments. These studies led to the identification of different derivatives that incorporate a diazirine ring in the amine substituent at position 7 of the triazolopyrimidine heterocycle, resulting in molecules that either promote stabilization of MTs or disrupt MT integrity. These photoactivatable candidate probes hold promise to investigate the mode of action of MT-active triazolopyrimidines. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Interpreting Low Spatial Resolution Thermal Data from Active Volcanoes on Io and the Earth

    NASA Technical Reports Server (NTRS)

    Keszthelyi, L.; Harris, A. J. L.; Flynn, L.; Davies, A. G.; McEwen, A.

    2001-01-01

    The style of volcanism was successfully determined at a number of active volcanoes on Io and the Earth using the same techniques to interpret thermal remote sensing data. Additional information is contained in the original extended abstract.

  1. Using geochemistry as a tool for correlating proximal andesitic tephra: Case studies from Mt Rainier (USA) and Mt Ruapehu (New Zealand)

    USGS Publications Warehouse

    Donoghue, S.L.; Vallance, J.; Smith, I.E.M.; Stewart, R.B.

    2007-01-01

    Volcanic hazards assessments at andesite stratovolcanoes rely on the assessment of frequency and magnitude of past events. The identification and correlation of proximal and distal andesitic tephra, which record the explosive eruptive history, are integral to such assessments. These tephra are potentially valuable stratigraphic marker beds useful to the temporal correlation and age dating of Quaternary volcanic, volcaniclastic and epiclastic sedimentary deposits with which they are interbedded. At Mt Ruapehu (New Zealand) and Mt Rainier (USA), much of the detail of the recent volcanic record remains unresolved because of the difficulty in identifying proximal tephra. This study investigates the value of geochemical methods in discriminating andesitic tephra. Our dataset comprises petrological and geochemical analyses of tephra that span the late Quaternary eruptive record of each volcano. Our data illustrate that andesitic tephra are remarkably heterogeneous in composition. Tephra compositions fluctuate widely over short time intervals, and there are no simple or systematic temporal trends in geochemistry within either eruptive record. This complexity in tephra geochemistry limits the application of geochemical approaches to tephrostratigraphic studies, beyond a general characterisation useful to provenance assignation. Petrological and geochemical data suggest that the products of andesite systems are inherently variable and therefore intractable to discrimination by simple geochemical methods alone. Copyright ?? 2006 John Wiley & Sons, Ltd.

  2. Variations of seismic parameters during different activity levels of the Soufriere Hills Volcano, Montserrat

    NASA Astrophysics Data System (ADS)

    Powell, T.; Neuberg, J.

    2003-04-01

    The low-frequency seismic events on Montserrat are linked to conduit resonance and the pressurisation of the volcanic system. Analysis of these events tell us more about the behaviour of the volcanic system and provide a monitoring and interpretation tool. We have written an Automated Event Classification Algorithm Program (AECAP), which finds and classifies seismic events and calculates seismic parameters such as energy, intermittency, peak frequency and event duration. Comparison of low-frequency energy with the tilt cycles in 1997 allows us to link pressurisation of the volcano with seismic behaviour. An empirical relationship provides us with an estimate of pressurisation through released seismic energy. During 1997, the activity of the volcano varied considerably. We compare seismic parameters from quiet periods to those from active periods and investigate how the relationships between these parameters change. These changes are then used to constrain models of magmatic processes during different stages of volcanic activity.

  3. The chronology of the martian volcanoes

    NASA Technical Reports Server (NTRS)

    Plescia, J. B.; Saunders, R. S.

    1979-01-01

    The volcanoes of Mars have been divided into three groups based on morphology: basaltic shields, domes and composite cones, and highland patera. A fourth group can be added to include the volcano-tectonic depressions. Using crater counts and the absolute chronology of Soderblom, an attempt is made to estimate the history of the volcanoes. Early in the martian history, about 2.5 b.y. ago, all three styles of volcanoes were active at various locations on the surface. At approximately 1.7-1.8 b.y. ago a transition occurred in the style and loci of volcanic construction. Volcanoes of younger age appear to be only of the basaltic shield group and are restricted to the Tharsis region. This same transition was noted by a change in the style of the basaltic shield group. Older shields were small low features, while the younger shields are significantly broader and taller.

  4. Practical Examples of an Integrated Field Study Program at Mt. Fuji: Geosciences and the Arts

    NASA Astrophysics Data System (ADS)

    Ito, T.; Kamikuri, S. I.; Otsuji, H.; Kataguchi, N.; Maruyama, H.; Hashiura, H.

    2017-12-01

    Mt. Fuji is a symbol of existence for the Japanese and it also has been a religiously revered subject. In addition, as represented by the ukiyo-e of Hokusai and Hiroshige, it is a subject of paintings, as well as of various types of literary expression such as waka, haiku and novels. Historically, there was a time when Mt. Fuji was used as a symbol of the integration of the country; and it has long reflected the culture, life and thoughts of the Japanese. On another level, from the Earth scientific point of view, Mt. Fuji is one of the most active volcanoes in Japan. Teacher training colleges in Japan have created educational programs for all subjects taught at school. However, as there is no effective linkage among these subjects, students may have different opinions on them according to their curriculum. In this study, we adopted a multifaceted learning approach toward that most symbolic icon of our country. In FY2014 and FY2016, a course created by the College of Education at Ibaraki University, called "Fieldwork on Geology," was conducted at and around Mt. Fuji. In addition to conducting fieldwork from the viewpoint of earth science, it also had abundant artistic content. Academics in the fields of earth science, art and pedagogy worked closely together from the planning stage and participated in a field study with 25 university students. Specifically, we focused on how the experience of sketching a landscape affects field observations by broadening the viewpoint and deepening the understanding of students. To ascertain the bidirectional educational effects between earth sciences and art, students were asked: 1) to express an image of Mt. Fuji, and 2) to appreciate paintings of Mt. Fuji and express the information they garnered from the paintings, before and after the fieldwork. These two exercises are considered as providing insights into how the students' understanding had changed. In addition, reports and impressions submitted by the students were used as

  5. Eruption history of the Tharsis shield volcanoes, Mars

    NASA Technical Reports Server (NTRS)

    Plescia, J. B.

    1993-01-01

    The Tharsis Montes volcanoes and Olympus Mons are giant shield volcanoes. Although estimates of their average surface age have been made using crater counts, the length of time required to build the shields has not been considered. Crater counts for the volcanoes indicate the constructs are young; average ages are Amazonian to Hesperian. In relative terms; Arsia Mons is the oldest, Pavonis Mons intermediate, and Ascreaus Mons the youngest of the Tharsis Montes shield; Olympus Mons is the youngest of the group. Depending upon the calibration, absolute ages range from 730 Ma to 3100 Ma for Arsia Mons and 25 Ma to 100 Ma for Olympus Mons. These absolute chronologies are highly model dependent, and indicate only the time surficial volcanism ceased, not the time over which the volcano was built. The problem of estimating the time necessary to build the volcanoes can be attacked in two ways. First, eruption rates from terrestrial and extraterrestrial examples can be used to calculate the required period of time to build the shields. Second, some relation of eruptive activity between the volcanoes can be assumed, such as they all began at a speficic time or they were active sequentially, and calculate the eruptive rate. Volumes of the shield volcanoes were derived from topographic/volume data.

  6. Review of eruptive activity at Tianchi volcano, Changbaishan, northeast China: implications for possible future eruptions

    NASA Astrophysics Data System (ADS)

    Wei, Haiquan; Liu, Guoming; Gill, James

    2013-04-01

    One of the largest explosive eruptions in the past several thousand years occurred at Tianchi volcano, also known as Changbaishan, on the China-North Korea border. This historically active polygenetic central volcano consists of three parts: a lower basaltic shield, an upper trachytic composite cone, and young comendite ash flows. The Millennium Eruption occurred between 938 and 946 ad, and was preceded by two smaller and chemically different rhyolitic pumice deposits. There has been at least one additional, small eruption in the last three centuries. From 2002 to 2005, seismicity, deformation, and the helium and hydrogen gas contents of spring waters all increased markedly, causing regional concern. We attribute this event to magma recharge or volatile exhalation or both at depth, followed by two episodes of addition of magmatic fluids into the overlying aquifer without a phreatic eruption. The estimated present magma accumulation rate is too low by itself to account for the 2002-2005 unrest. The most serious volcanic hazards are ash eruption and flows, and lahars. The available geological information and volcano monitoring data provide a baseline for comprehensive assessment of future episodes of unrest and possible eruptive activity.

  7. The First Historical Eruption of Kambalny Volcano in 2017 .

    NASA Astrophysics Data System (ADS)

    Gordeev, E.

    2017-12-01

    The first historical eruption at Kambalny volcano began about 21:20 UTC on March 24, 2017 with powerful ash emissions up to 6 km above sea level from the pre-summit crater. According to tephrochronological data, it is assumed that the strong eruptions of the volcano occurred 200 (?) and 600 years ago. KVERT (Kamchatka Volcanic Eruption Response Team) of the Institute of Volcanology and Seismology FEB RAS has been monitoring Kambalny volcano since 2002. KVERT worked closely with AMC Elizovo and Tokyo VAAC during the eruption at Kambalny volcano in 2017. The maximum intensity of ash emissions occurred on 25-26 March: a continuous plume laden with ash particles spread over several thousand kilometers, changing the direction of propagation from the volcano from the south-west to the south and south-east. On 27-29 March, the ash plume extended to the west, on 30 March - to the southeast of the volcano. On March 31 and April 01, the volcano was relatively quiet. The resumption of the volcano activity after two days of rest was expressed in powerful ash emissions up to 7 km above sea level. Gas-steam plumes containing some amount of ash were noted on 02-05 April, and powerful ash emissions up to 7 km above sea level occurred on 09 April. The explosive activity at the volcano ended on 11 April. The area of ash deposits was about 1500 km2, the total area covered by ash falls, for example, on 25 March, was about 650 thousand km2. To monitor and study the Kambalny volcano eruption we mainly used satellite images of medium resolution available in the information system "Monitoring volcanic activity in Kamchatka and Kurile Islands" (VolSatView). This work was supported by the Russian Science Foundation, project No. 16-17-00042.

  8. Unmanned Aerial Technologies for Observations at Active Volcanoes: Advances and Prospects

    NASA Astrophysics Data System (ADS)

    Pieri, D. C.; Diaz, J. A.; Bland, G.; Fladeland, M.; Makel, D.; Schwandner, F. M.; Buongiorno, M. F.; Elston, J. S.

    2017-12-01

    Modern application of unmanned aerial systems' (UASs) technology allow us to conduct in situ measurements in volcanic plumes and drifting volcanic clouds that were impossible to make in the past. Thus, we are now able to explore proximal airspace near and within eruption columns and or other active vents, at very high and at very low altitudes—risk to human investigators is vastly reduced (although not eliminated). We are now on the cusp of being able to make in situ measurements and conduct sampling at altitudes of 5000-6000 meters relatively routinely. We also are developing heat tolerant electronics and sensors that will deployed on, around, and over active lava lakes and lava flows at terrestrial volcanoes, but with a view toward developing planetary applications, for instance on the surface of Venus. We report on our 2012-present systematic UAS-based observations of light gases (e.g., SO2 CO2, H2S) at Turrialba Volcano in Costa Rica, at Italian volcanic sites (e.g., Isole Vulcano; La Solfatara), and most recently at Kilauea Volcano, Hawaii in collaboration with USGS and NPS colleagues. Other deployments for Fall 2017 and Winter 2018 are in planning stages for the Salton Sea Basin and Costa Rica, which will include an airborne miniature mass spectrometer onboard several different types of UAVs. In addition, under development is the first purpose-built-for-volcanology small unmanned aircraft. We discuss strategies for acquiring airborne data from proximal ash/gas plumes during restless periods and during eruptions, from distal drifting ash/gas clouds from eruptions, and from diffuse emissions (e.g., CO2) at very low altitudes, utilizing UASs (e.g., fixed wing, multi-rotor, aerostat), especially regarding inputs for source flux reverse models. This work was carried out, in part, at the Jet Propulsion Laboratory of the California Institute of Technology under contract to NASA.

  9. Melatonin acts through MT1/MT2 receptors to activate hypothalamic Akt and suppress hepatic gluconeogenesis in rats.

    PubMed

    Faria, Juliana A; Kinote, Andrezza; Ignacio-Souza, Letícia M; de Araújo, Thiago M; Razolli, Daniela S; Doneda, Diego L; Paschoal, Lívia B; Lellis-Santos, Camilo; Bertolini, Gisele L; Velloso, Lício A; Bordin, Silvana; Anhê, Gabriel F

    2013-07-15

    Melatonin can contribute to glucose homeostasis either by decreasing gluconeogenesis or by counteracting insulin resistance in distinct models of obesity. However, the precise mechanism through which melatonin controls glucose homeostasis is not completely understood. Male Wistar rats were administered an intracerebroventricular (icv) injection of melatonin and one of following: an icv injection of a phosphatidylinositol 3-kinase (PI3K) inhibitor, an icv injection of a melatonin receptor (MT) antagonist, or an intraperitoneal (ip) injection of a muscarinic receptor antagonist. Anesthetized rats were subjected to pyruvate tolerance test to estimate in vivo glucose clearance after pyruvate load and in situ liver perfusion to assess hepatic gluconeogenesis. The hypothalamus was removed to determine Akt phosphorylation. Melatonin injections in the central nervous system suppressed hepatic gluconeogenesis and increased hypothalamic Akt phosphorylation. These effects of melatonin were suppressed either by icv injections of PI3K inhibitors and MT antagonists and by ip injection of a muscarinic receptor antagonist. We conclude that melatonin activates hypothalamus-liver communication that may contribute to circadian adjustments of gluconeogenesis. These data further suggest a physiopathological relationship between the circadian disruptions in metabolism and reduced levels of melatonin found in type 2 diabetes patients.

  10. Nighttime Look at Ambrym Volcano, Vanuatu by NASA Spacecraft

    NASA Image and Video Library

    2014-02-12

    Ambrym volcano in Vanuatu is one of the most active volcanoes in the world. A large summit caldera contains two active vent complexes, Marum and Benbow is seen in this February 12, 2014 nighttime thermal infrared image from NASA Terra spacecraft.

  11. Lahar hazards at Agua volcano, Guatemala

    USGS Publications Warehouse

    Schilling, S.P.; Vallance, J.W.; Matías, O.; Howell, M.M.

    2001-01-01

    At 3760 m, Agua volcano towers more than 3500 m above the Pacific coastal plain to the south and 2000 m above the Guatemalan highlands to the north. The volcano is within 5 to 10 kilometers (km) of Antigua, Guatemala and several other large towns situated on its northern apron. These towns have a combined population of nearly 100,000. It is within about 20 km of Escuintla (population, ca. 100,000) to the south. Though the volcano has not been active in historical time, or about the last 500 years, it has the potential to produce debris flows (watery flows of mud, rock, and debris—also known as lahars when they occur on a volcano) that could inundate these nearby populated areas.

  12. ETINDE. Improving the role of a methodological approach and ancillary ethnoarchaeological data application for place vulnerability and resilience to a multi-hazard environment: Mt. Cameroon volcano case study [MIA-VITA project -FP7-ENV-2007-1

    NASA Astrophysics Data System (ADS)

    Ilaria Pannaccione Apa, Maria; Kouokam, Emmanuel; Mbe Akoko, Robert; Peppoloni, Silvia; Fabrizia Buongiorno, Maria; Thierry, Pierre

    2013-04-01

    The FP7 MIA-VITA [Mitigate and assess risk from volcanic impact on terrain and human activities] project has been designed to address multidisciplinary aspects of volcanic threat assessment and management from prevention to crisis management recovery. In the socio-economic analysis carried out at Mt. Cameroon Bakweri and Bakossi ethnic groups, ancillary ethnoarchaeological information has been included to point out the cultural interaction between the volcano and its residents. In 2009-2011, ethnoanthropological surveys and interviews for data collection were carried out at Buea, Limbe, West Coast, Tiko and Muyuka sub-divisions adjacent to Mt. Cameroon. One of the outstanding, results from the Bakweri and Bakossi cultural tradition study: natural hazards are managed and produced by supernatural forces, as: Epasa Moto, God of the Mountain (Mt. Cameroon volcano) and Nyango Na Nwana , Goddess of the sea (Gulf of Guinea). In the case of Mount Cameroon, people may seek the spirit or gods of the mountain before farming, hunting and most recently the undertaking of the Mount Cameroon annual race are done. The spirit of this mountain must be seek to avert or stop a volcanic eruption because the eruption is attributed to the anger of the spirit. Among the Northern Bakweri, the association of spirits with the mountain could also be explained in terms of the importance of the mountain to the people. Most of their farming and hunting is done on the Mountain. Some forest products, for instance, wood for building and furniture is obtained from the forest of the mountain; this implies that the people rely on the Mountain for food, game and architecture/furniture etc. In addition, the eruption of the mountain is something which affects the people. It does not only destroy property, it frustrates people and takes away human lives when it occurs. Because of this economic importance of the Mountain and its unexpected and unwanted eruption, the tendency is to believe that it has some

  13. Nicaraguan Volcanoes

    Atmospheric Science Data Center

    2013-04-18

    article title:  Nicaraguan Volcanoes     View Larger Image Nicaraguan volcanoes, February 26, 2000 . The true-color image at left is a ... February 26, 2000 - Plumes from the San Cristobal and Masaya volcanoes. project:  MISR category:  gallery ...

  14. Linear mtDNA fragments and unusual mtDNA rearrangements associated with pathological deficiency of MGME1 exonuclease

    PubMed Central

    Nicholls, Thomas J.; Zsurka, Gábor; Peeva, Viktoriya; Schöler, Susanne; Szczesny, Roman J.; Cysewski, Dominik; Reyes, Aurelio; Kornblum, Cornelia; Sciacco, Monica; Moggio, Maurizio; Dziembowski, Andrzej; Kunz, Wolfram S.; Minczuk, Michal

    2014-01-01

    MGME1, also known as Ddk1 or C20orf72, is a mitochondrial exonuclease found to be involved in the processing of mitochondrial DNA (mtDNA) during replication. Here, we present detailed insights on the role of MGME1 in mtDNA maintenance. Upon loss of MGME1, elongated 7S DNA species accumulate owing to incomplete processing of 5′ ends. Moreover, an 11-kb linear mtDNA fragment spanning the entire major arc of the mitochondrial genome is generated. In contrast to control cells, where linear mtDNA molecules are detectable only after nuclease S1 treatment, the 11-kb fragment persists in MGME1-deficient cells. In parallel, we observed characteristic mtDNA duplications in the absence of MGME1. The fact that the breakpoints of these mtDNA rearrangements do not correspond to either classical deletions or the ends of the linear 11-kb fragment points to a role of MGME1 in processing mtDNA ends, possibly enabling their repair by homologous recombination. In agreement with its functional involvement in mtDNA maintenance, we show that MGME1 interacts with the mitochondrial replicase PolgA, suggesting that it is a constituent of the mitochondrial replisome, to which it provides an additional exonuclease activity. Thus, our results support the viewpoint that MGME1-mediated mtDNA processing is essential for faithful mitochondrial genome replication and might be required for intramolecular recombination of mtDNA. PMID:24986917

  15. The Volcano Adventure Guide

    NASA Astrophysics Data System (ADS)

    Lopes, Rosaly

    2005-02-01

    This guide contains vital information for anyone wishing to visit, explore, and photograph active volcanoes safely and enjoyably. Following an introduction that discusses eruption styles of different types of volcanoes and how to prepare for an exploratory trip that avoids volcanic dangers, the book presents guidelines to visiting 42 different volcanoes around the world. It is filled with practical information that includes tour itineraries, maps, transportation details, and warnings of possible non-volcanic dangers. Three appendices direct the reader to a wealth of further volcano resources in a volume that will fascinate amateur enthusiasts and professional volcanologists alike. Rosaly Lopes is a planetary geology and volcanology specialist at the NASA Jet Propulsion Laboratory in California. In addition to her curatorial and research work, she has lectured extensively in England and Brazil and written numerous popular science articles. She received a Latinas in Science Award from the Comision Feminil Mexicana Nacional in 1991 and since 1992, has been a co-organizer of the United Nations/European Space Agency/The Planetary Society yearly conferences on Basic Science for the Benefit of Developing Countries.

  16. Eruption mechanism as inferred from geomagnetic changes with special attention to the 1989 1990 activity of Aso volcano

    NASA Astrophysics Data System (ADS)

    Tanaka, Yoshikazu

    1993-06-01

    Geomagnetic changes associated with the volcanic activity of Aso volcano were detected with a dense network of continuously recording proton-precession magnetometers during the period from June 1989 to June 1990. Magnetic date clearly indicate that changes in the magnetization within the volcano are most probably caused by temperature changes. This activity can be divided into five stages, which are characterized by magnetization and demagnetization of the volcano. These magnetic changes with durations of a few months are definitely correlated with some typical volcanic events at the crater as well as the volcanic tremor activity. The demagnetization stage appears when the vent is covered by a water pool or the volcanic activity is enhanced. The magnetization stage follows the opening of a vent and several large explosions which make the vent permeable. The source of magnetic changes lies at a depth of about 200 m below the crater rim in the southwestern part of the active crater. Magnetic moments responsible for observed magnetic changes at stages 1, 2 and 4 are 3.4, -5.2 and -2.2 Wbm, respectively. The corresponding source volume is estimated as a single sphere of radius 40-50 m or a spherical shell of 100 m or so. An effective mechanism of rapid heating/cooling exists, which is ascribed to the interaction of groundwater and superheated vapor, i.e., a shallow hydrothermal system. This hydrothermal system driven by the surface cap of the vent, controls every feature of the eruptions at the final outlet of Aso volcano.

  17. Kamchatka and North Kurile Volcano Explosive Eruptions in 2015 and Danger to Aviation

    NASA Astrophysics Data System (ADS)

    Girina, Olga; Melnikov, Dmitry; Manevich, Alexander; Demyanchuk, Yury; Nuzhdaev, Anton; Petrova, Elena

    2016-04-01

    There are 36 active volcanoes in the Kamchatka and North Kurile, and several of them are continuously active. In 2015, four of the Kamchatkan volcanoes (Sheveluch, Klyuchevskoy, Karymsky and Zhupanovsky) and two volcanoes of North Kurile (Alaid and Chikurachki) had strong and moderate explosive eruptions. Moderate gas-steam activity was observing of Bezymianny, Kizimen, Avachinsky, Koryaksky, Gorely, Mutnovsky and other volcanoes. Strong explosive eruptions of volcanoes are the most dangerous for aircraft because they can produce in a few hours or days to the atmosphere and the stratosphere till several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2015: on 07, 12, and 15 January, 01, 17, and 28 February, 04, 08, 16, 21-22, and 26 March, 07 and 12 April: ash plumes rose up to 7-12 km a.s.l. and extended more 900 km to the different directions of the volcano. Ashfalls occurred at Ust'-Kamchatsk on 16 March, and Klyuchi on 30 October. Strong and moderate hot avalanches from the lava dome were observing more often in the second half of the year. Aviation color code of Sheveluch was Orange during the year. Activity of the volcano was dangerous to international and local aviation. Explosive-effusive eruption of Klyuchevskoy volcano lasted from 01 January till 24 March. Strombolian explosive volcanic activity began from 01 January, and on 08-09 January a lava flow was detected at the Apakhonchich chute on the southeastern flank of the volcano. Vulcanian activity of the volcano began from 10 January. Ashfalls

  18. Monitoring Active Volcanoes

    NASA Astrophysics Data System (ADS)

    Swanson, Don

    Monitoring volcanoes is a surprisingly controversial enterprise. Some volcanologists argue that monitoring promises too much and delivers too little for risk mitigation. They trust only strict land-use measures (and accompanying high insurance premiums in risky zones) and urge that funds be used for public education and awareness rather than for instrumental monitoring. Others claim that monitoring is more akin to Brownian motion than to science: lots of action but little net progress. Still other volcanologists acknowledge the potential value of monitoring for prediction and warning but despair at the difficulty of it all. And, finally, some shy from surveillance, fearing the legal consequences of a failed monitoring effort during these litigious times. They wonder, “Will I be sued if an eruption is not foreseen or if an instrument fails at a critical time?”

  19. Volcanoes

    USGS Publications Warehouse

    Tilling, Robert I.; ,

    1998-01-01

    Volcanoes destroy and volcanoes create. The catastrophic eruption of Mount St. Helens on May 18, 1980, made clear the awesome destructive power of a volcano. Yet, over a time span longer than human memory and record, volcanoes have played a key role in forming and modifying the planet upon which we live. More than 80 percent of the Earth's surface--above and below sea level--is of volcanic origin. Gaseous emissions from volcanic vents over hundreds of millions of years formed the Earth's earliest oceans and atmosphere, which supplied the ingredients vital to evolve and sustain life. Over geologic eons, countless volcanic eruptions have produced mountains, plateaus, and plains, which subsequent erosion and weathering have sculpted into majestic landscapes and formed fertile soils.

  20. Volcanic rocks and subglacial volcanism beneath the West Antarctic Ice Sheet in the West Antarctic Rift System, (WAIS) from aeromagnetic and radar ice sounding - Thiel Subglacial Volcano as possible source of the ash layer in the WAISCORE

    NASA Astrophysics Data System (ADS)

    Behrendt, J. C.

    2012-12-01

    Radar ice sounding and aeromagnetic surveys reported over the West Antarctic Ice Sheet (WAIS) have been interpreted as evidence of subglacial volcanic eruptions over a very extensive area (>500,000 km2 ) of the volcanically active West Antarctic rift system interpreted as caused by subglacial volcanic rocks. Several active volcanoes have shown evidence of eruption through the WAIS and several other active volcanoes are present beneath the WAIS reported from radar and aeromagnetic data. Five-kilometer spaced coincident aeromagnetic and radar ice sounding surveys since 1990 provide three dimensional characterization of the magnetic field and bed topography beneath the ice sheet. These 5-50-km-width, semicircular magnetic anomalies range from 100->1000 nT as observed ~1 km over the 2-3 km thick ice have been interpreted as evidence of subglacial eruptions. Comparison of a carefully selected subset of ~400 of the >1000 high-amplitude anomalies in the CWA survey having topographic expression at the glacier bed, showed >80% had less than 200-m relief. About 18 high-amplitude subglacial magnetic sources also have high topography and bed relief (>600 m) interpreted as subaerially erupted volcanic peaks when the WAIS was absent, whose competent lava flows protected their edifices from erosion. All of these would have high elevation above sea-level, were the ice removed and glacial rebound to have occurred. Nine of these subaerially erupted volcanoes are concentrated in the WAIS divide area. Behrendt et al., 1998 interpreted a circular ring of positive magnetic anomalies overlying the WAIS divide as caused by a volcanic caldera. The area is characterized by high elevation bed topography. The negative regional magnetic anomaly surrounding the caldera anomalies was interpreted as the result of a shallow Curie isotherm. High heat flow inferred from temperature logging in the WAISCORE (G. Clow 2012, personal communication; Conway, 2011) and a prominent volcanic ash layer in the

  1. Santorini Volcano

    USGS Publications Warehouse

    Druitt, T.H.; Edwards, L.; Mellors, R.M.; Pyle, D.M.; Sparks, R.S.J.; Lanphere, M.; Davies, M.; Barreirio, B.

    1999-01-01

    Santorini is one of the most spectacular caldera volcanoes in the world. It has been the focus of significant scientific and scholastic interest because of the great Bronze Age explosive eruption that buried the Minoan town of Akrotiri. Santorini is still active. It has been dormant since 1950, but there have been several substantial historic eruptions. Because of this potential risk to life, both for the indigenous population and for the large number of tourists who visit it, Santorini has been designated one of five European Laboratory Volcanoes by the European Commission. Santorini has long fascinated geologists, with some important early work on volcanoes being conducted there. Since 1980, research groups at Cambridge University, and later at the University of Bristol and Blaise Pascal University in Clermont-Ferrand, have collected a large amount of data on the stratigraphy, geochemistry, geochronology and petrology of the volcanics. The volcanic field has been remapped at a scale of 1:10 000. A remarkable picture of cyclic volcanic activity and magmatic evolution has emerged from this work. Much of this work has remained unpublished until now. This Memoir synthesizes for the first time all the data from the Cambridge/Bristol/Clermont groups, and integrates published data from other research groups. It provides the latest interpretation of the tectonic and magmatic evolution of Santorini. It is accompanied by the new 1:10 000 full-colour geological map of the island.

  2. Multi Scale Multi Temporal Near Real Time Approach for Volcanic Eruptions monitoring, Test Case: Mt Etna eruption 2017

    NASA Astrophysics Data System (ADS)

    Buongiorno, M. F.; Silvestri, M.; Musacchio, M.

    2017-12-01

    In this work a complete processing chain from the detection of the beginning of eruption to the estimation of lava flow temperature on active volcanoes using remote sensing data is presented showing the results for the Mt. Etna eruption on March 2017. The early detection of new eruption is based on the potentiality ensured by geostationary very low spatial resolution satellite (3x3 km in nadiral view), the hot spot/lava flow evolution is derived by S2 polar medium/high spatial resolution (20x20 mt) while the surface temperature is estimated by polar medium/low spatial resolution such as L8, ASTER and S3 (from 90 mt up to 1km).This approach merges two outcome derived by activity performed for monitoring purposes within INGV R&D activities and the results obtained by Geohazards Exploitation Platform ESA funded project (GEP) aimed to the development of shared platform for providing services based on EO data. Because the variety of phenomena to be analyzed a multi temporal multi scale approach has been used to implement suitable and robust algorithms for the different sensors. With the exception of Sentinel 2 (MSI) data, for which the algorithm used is based on NIR-SWIR bands, we exploit the MIR-TIR channels of L8, ASTER, S3 and SEVIRI for generating automatically the surface thermal state analysis. The developed procedure produces time series data and allows to extract information from each single co-registered pixel, to highlight variation of temperatures within specific areas. The final goal is to implement an easy tool which enables scientists and users to extract valuable information from satellite time series at different scales produced by ESA and EUMETSAT in the frame of Europe's Copernicus program and other Earth observation satellites programs such as LANDSAT (USGS) and GOES (NOAA).

  3. ICE-VOLC Project: unravelling the dynamics of Antarctica volcanoes

    NASA Astrophysics Data System (ADS)

    Cannata, Andrea; Del Carlo, Paola; Giudice, Gaetano; Giuffrida, Giovanni; Larocca, Graziano; Liuzzo, Marco

    2017-04-01

    Melbourne and Rittmann volcanoes are located in the Victoria Land. Whilst Rittmann's last eruption dates probably to Pleistocene, Melbourne's most recent eruption between 1862 and 1922, testifying it is still active. At present, both volcanoes display fumarolic activity. Melbourne was discovered in 1841 by James Clark Ross, Rittmann during the 4th Italian Expedition (1988/1989). Our knowledge on both volcanoes is really little. The position of these volcanoes in the Antarctic region (characterised by absence of anthropic noise) and its proximity with the Italian Mario Zucchelli Station makes them ideal sites for studying volcano seismic sources, geothermal emissions, seismo-acoustic signals caused by cryosphere-hydrosphere-atmosphere dynamics, and volcanic gas impact on environment. Hence, the main aim of the ICE-VOLC ("multiparametrIC Experiment at antarctica VOLCanoes: data from volcano and cryosphere-ocean-atmosphere dynamics") project is the study of Melbourne and Rittmann, by acquisition, analysis and integration of multiparametric geophysical, geochemical and thermal data. Complementary objectives include investigation of the relationship between seismo-acoustic activity recorded in Antarctica and cryosphere-hydrosphere-atmosphere dynamics, evaluation of the impact of volcanic gas in atmosphere. This project involves 26 researchers, technologists and technicians from University of Perugia and from Istituto Nazionale di Geofisica e Vulcanologia of Catania, Palermo, Pisa and Rome. In this work, we show the preliminary results obtained after the first expedition in Antarctica, aiming to perform geochemical-thermal surveys in the volcano ice caves, as well as to collect ash samples and to install temporary seismic stations.

  4. One hundred years of volcano monitoring in Hawaii

    USGS Publications Warehouse

    Kauahikaua, Jim; Poland, Mike

    2012-01-01

    In 2012 the Hawaiian Volcano Observatory (HVO), the oldest of five volcano observatories in the United States, is commemorating the 100th anniversary of its founding. HVO's location, on the rim of Kilauea volcano (Figure 1)—one of the most active volcanoes on Earth—has provided an unprecedented opportunity over the past century to study processes associated with active volcanism and develop methods for hazards assessment and mitigation. The scientifically and societally important results that have come from 100 years of HVO's existence are the realization of one man's vision of the best way to protect humanity from natural disasters. That vision was a response to an unusually destructive decade that began the twentieth century, a decade that saw almost 200,000 people killed by the effects of earthquakes and volcanic eruptions.

  5. One hundred years of volcano monitoring in Hawaii

    USGS Publications Warehouse

    Kauahikaua, J.; Poland, M.

    2012-01-01

    In 2012 the Hawaiian Volcano Observatory (HVO), the oldest of five volcano observatories in the United States, is commemorating the 100th anniversary of its founding. HVO's location, on the rim of Klauea volcano (Figure 1)one of the most active volcanoes on Earthhas provided an unprecedented opportunity over the past century to study processes associated with active volcanism and develop methods for hazards assessment and mitigation. The scientifically and societally important results that have come from 100 years of HVO's existence are the realization of one man's vision of the best way to protect humanity from natural disasters. That vision was a response to an unusually destructive decade that began the twentieth century, a decade that saw almost 200,000 people killed by the effects of earthquakes and volcanic eruptions.

  6. A novel approach to estimate the eruptive potential and probability in open conduit volcanoes

    PubMed Central

    De Gregorio, Sofia; Camarda, Marco

    2016-01-01

    In open conduit volcanoes, volatile-rich magma continuously enters into the feeding system nevertheless the eruptive activity occurs intermittently. From a practical perspective, the continuous steady input of magma in the feeding system is not able to produce eruptive events alone, but rather surplus of magma inputs are required to trigger the eruptive activity. The greater the amount of surplus of magma within the feeding system, the higher is the eruptive probability.Despite this observation, eruptive potential evaluations are commonly based on the regular magma supply, and in eruptive probability evaluations, generally any magma input has the same weight. Conversely, herein we present a novel approach based on the quantification of surplus of magma progressively intruded in the feeding system. To quantify the surplus of magma, we suggest to process temporal series of measurable parameters linked to the magma supply. We successfully performed a practical application on Mt Etna using the soil CO2 flux recorded over ten years. PMID:27456812

  7. A novel approach to estimate the eruptive potential and probability in open conduit volcanoes.

    PubMed

    De Gregorio, Sofia; Camarda, Marco

    2016-07-26

    In open conduit volcanoes, volatile-rich magma continuously enters into the feeding system nevertheless the eruptive activity occurs intermittently. From a practical perspective, the continuous steady input of magma in the feeding system is not able to produce eruptive events alone, but rather surplus of magma inputs are required to trigger the eruptive activity. The greater the amount of surplus of magma within the feeding system, the higher is the eruptive probability.Despite this observation, eruptive potential evaluations are commonly based on the regular magma supply, and in eruptive probability evaluations, generally any magma input has the same weight. Conversely, herein we present a novel approach based on the quantification of surplus of magma progressively intruded in the feeding system. To quantify the surplus of magma, we suggest to process temporal series of measurable parameters linked to the magma supply. We successfully performed a practical application on Mt Etna using the soil CO2 flux recorded over ten years.

  8. The Evolution of Galápagos Volcanoes: An Alternative Perspective

    NASA Astrophysics Data System (ADS)

    Harpp, Karen S.; Geist, Dennis J.

    2018-05-01

    The older eastern Galápagos are different in almost every way from the historically active western Galápagos volcanoes. The western Galápagos volcanoes have steep upper slopes and are topped by large calderas, whereas none of the older islands has a caldera, an observation that is supported by recent gravity measurements. Moreover, the eastern islands tend to have been constructed by linear fissure systems and many are cut by faults. Most of the western volcanoes erupt evolved basalts with an exceedingly small range of Mg#, Lan/Smn, and Smn/Ybn. This is attributed to homogenization in a crustal-scale magmatic mush column, which is maintained in a thermochemical steady state, owing to high magma supply directly over the Galápagos mantle plume. The exceptions are volcanoes at the leading edge of the hotspot, which have yet to develop mush columns, and volcanoes that are waning in activity, because they are being carried away from the plume. In contrast, the eastern volcanoes erupt relatively primitive magmas, with a large range in Mg#, Lan/Smn, and Smn/Ybn. This is attributed to isolated, ephemeral magmatic plumbing systems supplied by smaller magmatic fluxes throughout their histories. Consequently, each batch of magma follows an independent course of evolution, owing to the low volume of hypersolidus material beneath these volcanoes. The magmatic flux to Galápagos volcanoes negatively correlates with the distance to the Galápagos Spreading Center (GSC). When the ridge was close to the plume, most of the plume-derived magma was directed to the ridge. Currently, the active volcanoes are much farther from the GSC, thus most of the plume-derived magma erupts on the Nazca Plate and can be focused beneath the large young shields. We define an intermediate sub-province comprising Rabida, Santiago and Pinzon volcanoes, which were most active about 1 Ma. They have all erupted dacites, rhyolites, and trachytes, similar to the dying stage of the western volcanoes

  9. Dome-like behaviour at Mt. Etna: The case of the 28 December 2014 South East Crater paroxysm.

    PubMed

    Ferlito, C; Bruno, V; Salerno, G; Caltabiano, T; Scandura, D; Mattia, M; Coltorti, M

    2017-07-13

    On the 28 December 2014, a violent and short paroxysmal eruption occurred at the South East Crater (SEC) of Mount Etna that led to the formation of huge niches on the SW and NE flanks of the SEC edifice from which a volume of ~3 × 10 6  m 3 of lava was erupted. Two basaltic lava flows discharged at a rate of ~370 m 3 /s, reaching a maximum distance of ~5 km. The seismicity during the event was scarce and the eruption was not preceded by any notable ground deformation, which instead was dramatic during and immediately after the event. The SO 2 flux associated with the eruption was relatively low and even decreased few days before. Observations suggest that the paroxysm was not related to the ascent of volatile-rich fresh magma from a deep reservoir (dyke intrusion), but instead to a collapse of a portion of SEC, similar to what happens on exogenous andesitic domes. The sudden and fast discharge eventually triggered a depressurization in the shallow volcano plumbing system that drew up fresh magma from depth. Integration of data and observations has allowed to formulate a novel interpretation of mechanism leading volcanic activity at Mt. Etna and on basaltic volcanoes worldwide.

  10. Eruptions of Hawaiian volcanoes - Past, present, and future

    USGS Publications Warehouse

    Tilling, Robert I.; Heliker, Christina; Swanson, Donald A.

    2010-01-01

    Viewing an erupting volcano is a memorable experience, one that has inspired fear, superstition, worship, curiosity, and fascination since before the dawn of civilization. In modern times, volcanic phenomena have attracted intense scientific interest, because they provide the key to understanding processes that have created and shaped more than 80 percent of the Earth's surface. The active Hawaiian volcanoes have received special attention worldwide because of their frequent spectacular eruptions, which often can be viewed and studied with relative ease and safety. In January 1987, the Hawaiian Volcano Observatory (HVO), located on the rim of Kilauea Volcano, celebrated its 75th Anniversary. In honor of HVO's Diamond Jubilee, the U.S. Geological Survey (USGS) published Professional Paper 1350 (see list of Selected Readings, page 57), a comprehensive summary of the many studies on Hawaiian volcanism by USGS and other scientists through the mid-1980s. Drawing from the wealth of data contained in that volume, the USGS also published in 1987 the original edition of this general-interest booklet, focusing on selected aspects of the eruptive history, style, and products of two of Hawai'i's active volcanoes, Kilauea and Mauna Loa. This revised edition of the booklet-spurred by the approaching Centennial of HVO in January 2012-summarizes new information gained since the January 1983 onset of Kilauea's Pu'u 'O'o-Kupaianaha eruption, which has continued essentially nonstop through 2010 and shows no signs of letup. It also includes description of Kilauea's summit activity within Halema'uma'u Crater, which began in mid-March 2008 and continues as of this writing (late 2010). This general-interest booklet is a companion to the one on Mount St. Helens Volcano first published in 1984 and revised in 1990 (see Selected Readings). Together, these publications illustrate the contrast between the two main types of volcanoes: shield volcanoes, such as those in Hawai'i, which generally

  11. Real-time source deformation modeling through GNSS permanent stations at Merapi volcano (Indonesia

    NASA Astrophysics Data System (ADS)

    Beauducel, F.; Nurnaning, A.; Iguchi, M.; Fahmi, A. A.; Nandaka, M. A.; Sumarti, S.; Subandriyo, S.; Metaxian, J. P.

    2014-12-01

    Mt. Merapi (Java, Indonesia) is one of the most active and dangerous volcano in the world. A first GPS repetition network was setup and periodically measured since 1993, allowing detecting a deep magma reservoir, quantifying magma flux in conduit and identifying shallow discontinuities around the former crater (Beauducel and Cornet, 1999;Beauducel et al., 2000, 2006). After the 2010 centennial eruption, when this network was almost completely destroyed, Indonesian and Japanese teams installed a new continuous GPS network for monitoring purpose (Iguchi et al., 2011), consisting of 3 stations located at the volcano flanks, plus a reference station at the Yogyakarta Observatory (BPPTKG).In the framework of DOMERAPI project (2013-2016) we have completed this network with 5 additional stations, which are located on the summit area and volcano surrounding. The new stations are 1-Hz sampling, GNSS (GPS + GLONASS) receivers, and near real-time data streaming to the Observatory. An automatic processing has been developed and included in the WEBOBS system (Beauducel et al., 2010) based on GIPSY software computing precise daily moving solutions every hour, and for different time scales (2 months, 1 and 5 years), time series and velocity vectors. A real-time source modeling estimation has also been implemented. It uses the depth-varying point source solution (Mogi, 1958; Williams and Wadge, 1998) in a systematic inverse problem model exploration that displays location, volume variation and 3-D probability map.The operational system should be able to better detect and estimate the location and volume variations of possible magma sources, and to follow magma transfer towards the surface. This should help monitoring and contribute to decision making during future unrest or eruption.

  12. Development of an automatic volcanic ash sampling apparatus for active volcanoes

    NASA Astrophysics Data System (ADS)

    Shimano, Taketo; Nishimura, Takeshi; Chiga, Nobuyuki; Shibasaki, Yoshinobu; Iguchi, Masato; Miki, Daisuke; Yokoo, Akihiko

    2013-12-01

    We develop an automatic system for the sampling of ash fall particles, to be used for continuous monitoring of magma ascent and eruptive dynamics at active volcanoes. The system consists of a sampling apparatus and cameras to monitor surface phenomena during eruptions. The Sampling Apparatus for Time Series Unmanned Monitoring of Ash (SATSUMA-I and SATSUMA-II) is less than 10 kg in weight and works automatically for more than a month with a 10-kg lead battery to obtain a total of 30 to 36 samples in one cycle of operation. The time range covered in one cycle varies from less than an hour to several months, depending on the aims of observation, allowing researchers to target minute-scale fluctuations in a single eruptive event, as well as daily to weekly trends in persistent volcanic activity. The latest version, SATSUMA-II, also enables control of sampling parameters remotely by e-mail commands. Durability of the apparatus is high: our prototypes worked for several months, in rainy and typhoon seasons, at windy and humid locations, and under strong sunlight. We have been successful in collecting ash samples emitted from Showa crater almost everyday for more than 4 years (2008-2012) at Sakurajima volcano in southwest Japan.

  13. Recent uplift and hydrothermal activity at Tangkuban Parahu volcano, west Java, Indonesia

    USGS Publications Warehouse

    Dvorak, J.; Matahelumual, J.; Okamura, A.T.; Said, H.; Casadevall, T.J.; Mulyadi, D.

    1990-01-01

    Tangkuban Parahu is an active stratovolcano located 17 km north of the city of Bandung in the province west Java, Indonesia. All historical eruptive activity at this volcano has been confined to a complex of explosive summit craters. About a dozen eruptions-mostly phreatic events- and 15 other periods of unrest, indicated by earthquakes or increased thermal activity, have been noted since 1829. The last magmatic eruption occurred in 1910. In late 1983, several small phreatic explosions originated from one of the summit craters. More recently, increased hydrothermal and earthquake activity occurred from late 1985 through 1986. Tilt measurements, using a spirit-level technique, have been made every few months since February 1981 in the summit region and along the south and east flanks of the volcano. Measurements made in the summit region indicated uplift since the start of these measurements through at least 1986. From 1981 to 1983, the average tilt rate at the edges of the summit craters was 40-50 microradians per year. After the 1983 phreatic activity, the tilt rate decreased by about a factor of five. Trilateration surveys across the summit craters and on the east flank of the volcano were conducted in 1983 and 1986. Most line length changes measured during this three-year period did not exceed the expected uncertainty of the technique (4 ppm). The lack of measurable horizontal strain across the summit craters seems to contradict the several years of tilt measurements. Using a point source of dilation in an elastic half-space to model tilt measurements, the pressure center at Tangkuban Parahu is located about 1.5 km beneath the southern part of the summit craters. This is beneath the epicentral area of an earthquake swarm that occurred in late 1983. The average rate in the volume of uplift from 1981 to 1983 was 3 million m3 per year; from 1983 to 1986 it averaged about 0.4 million m3 per year. Possible causes for this uplift are increased pressure within a very

  14. Growth and degradation of Hawaiian volcanoes: Chapter 3 in Characteristics of Hawaiian volcanoes

    USGS Publications Warehouse

    Clague, David A.; Sherrod, David R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Large Hawaiian volcanoes can persist as islands through the rapid subsidence by building upward rapidly enough. But in the long run, subsidence, coupled with surface erosion, erases any volcanic remnant above sea level in about 15 m.y. One consequence of subsidence, in concert with eustatic changes in sea level, is the drowning of coral reefs that drape the submarine flanks of the actively subsiding volcanoes. At least six reefs northwest of the Island of Hawai‘i form a stairstep configuration, the oldest being deepest.

  15. Geology of kilauea volcano

    USGS Publications Warehouse

    Moore, R.B.; Trusdell, F.A.

    1993-01-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower cast rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. ?? 1993.

  16. Relationships between tectonism, volcano-tectonism and volcanism: the Ischia island (Italy) case.

    NASA Astrophysics Data System (ADS)

    Marotta, E.; de Vita, S.; Orsi, G.; Sansivero, F.

    2005-12-01

    The resurgent calderas of Ischia, Campi Flegrei and Pantelleria are characterized by differentially displaced blocks, and distribution of later eruption vents in a well defined sector of the resurgent area. These features suggest a simple shearing block resurgence mechanism. Moreover, the studies carried out on Ischia and Campi Flegrei evidenced a very complex structural pattern due to deformation related to the local stress regime induced by magmatism and volcanism and also to reactivation of regional structures. In order to better define the relationships among tectonic, volcano-tectonic and caldera resurgence mechanism, a structural study has been carried out at Ischia, where the Mt. Epomeo has been uplifted of about 900 m in the past 30 ka. The measures taken on 1,400 planar surfaces (faults, joints and fracture cleavages) show that the resurgent area is composed of differentially displaced blocks whose uplifting is maximum for the Mt. Epomeo and decreases southeastward. The resurgent area has a poligonal shape resulting from the reactivation of regional faults and by the activation of faults directly related to volcano-tectonism. The limit of the resurgent area is not defined towards the north, as beach deposits displaced at variable elevation by E-W and NW-SE trending faults, are exposed along the coastline. The western sector is bordered by inward-dipping, high-angle reverse faults, whose directions vary from N40E to NS and N50W from NW to SW of the block, testifying a compressional stress regime active in this area. These features are cut by late outward-dipping normal faults due to gravitational readjustment of the slopes. Vertical faults border the block at NE ad SW with right transtensive and left transpressive movements, respectively. The area located to the east of the most uplifted block, characterized by a tensile stress regime, has been deformed by N-S, N40-70E and N15W trending normal faults, with maximum elongation direction along N50W. The

  17. Sources of Magmatic Volatiles Discharging from Subduction Zone Volcanoes

    NASA Astrophysics Data System (ADS)

    Fischer, T.

    2001-05-01

    5.4 Mmol/a of non-mantle N2). Other subduction zone volcanoes are currently degassing a much more substantial amount of volatiles. Popocatepetl, Mexico, has degassed approximately 14 Mt of SO2 to the atmosphere over the past 6 years (Witter et al. 2000). Satsuma-Iwojima, Japan, has degassed for longer than 800 years and is currently releasing 500-1000 tones/day (Kazahaya et al. 2000). At these volcanoes CO2 and N2 discharges from the magma should also be balanced by the supply from slab and crustal sources. The rate of subduction off Mexico and Japan, however, is similar to the rate at the Kuriles. Therefore, large amounts of slab derived volatiles must be, in some fashion, stored in the "subduction factory" to supply the large amounts degassing passively from these volcanoes. Kazahaya et al. (2000) Seventh Field Workshop on Volcanic Gases, IAVCEI. Witter et al (2000) Seventh Field Workshop on Volcanic Gases, IAVCEI.

  18. Mitochondrial DNA copy number threshold in mtDNA depletion myopathy.

    PubMed

    Durham, S E; Bonilla, E; Samuels, D C; DiMauro, S; Chinnery, P F

    2005-08-09

    The authors measured the absolute amount of mitochondrial DNA (mtDNA) within single muscle fibers from two patients with thymidine kinase 2 (TK2) deficiency and two healthy controls. TK2 deficient fibers containing more than 0.01 mtDNA/microm3 had residual cytochrome c oxidase (COX) activity. This defines the minimum amount of wild-type mtDNA molecules required to maintain COX activity in skeletal muscle and provides an explanation for the mosaic histochemical pattern seen in patients with mtDNA depletion syndrome.

  19. Nyiragonga Volcano

    NASA Image and Video Library

    2002-02-01

    This image of the Nyiragonga volcano eruption in the Congo was acquired on January 28, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters about 50 to 300 feet ), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet. Image: A river of molten rock poured from the Nyiragongo volcano in the Congo on January 18, 2002, a day after it erupted, killing dozens, swallowing buildings and forcing hundreds of thousands to flee the town of Goma. The flow continued into Lake Kivu. The lave flows are depicted in red on the image indicating they are still hot. Two of them flowed south form the volcano's summit and went through the town of Goma. Another flow can be seen at the top of the image, flowing towards the northwest. One of Africa's most notable volcanoes, Nyiragongo contained an active lava lake in its deep summit crater that drained catastrophically through its outer flanks in 1977. Extremely fluid, fast-moving lava flows draining from the summit lava lake in 1977 killed 50 to 100 people, and several villages were destroyed. The image covers an area of 21 x 24 km and combines a thermal band in red, and two infrared bands in green and blue. http://photojournal.jpl.nasa.gov/catalog/PIA03462

  20. Eruption of Shiveluch Volcano, Kamchatka Peninsula

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On March 29, 2007, the Shiveluch Volcano on the Russian Federation's Kamchatka Peninsula erupted. According to the Alaska Volcano Observatory the volcano underwent an explosive eruption between 01:50 and 2:30 UTC, sending an ash cloud skyward roughly 9,750 meters (32,000 feet), based on visual estimates. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard NASA's Aqua satellite took this picture at 02:00 UTC on March 29. The top image shows the volcano and its surroundings. The bottom image shows a close-up view of the volcano at 250 meters per pixel. Satellites often capture images of volcanic ash plumes, but usually as the plumes are blowing away. Plumes have been observed blowing away from Shiveluch before. This image, however, is different. At the time the Aqua satellite passed overhead, the eruption was recent enough (and the air was apparently still enough) that the ash cloud still hovered above the summit. In this image, the bulbous cloud casts its shadow northward over the icy landscape. Volcanic ash eruptions inject particles into Earth's atmosphere. Substantial eruptions of light-reflecting particles can reduce temperatures and even affect atmospheric circulation. Large eruptions impact climate patterns for years. A massive eruption of the Tambora Volcano in Indonesia in 1815, for instance, earned 1816 the nickname 'the year without a summer.' Shiveluch is a stratovolcano--a steep-sloped volcano composed of alternating layers of solidified ash, hardened lava, and volcanic rocks. One of Kamchatka's largest volcanoes, it sports a summit reaching 3,283 meters (10,771 feet). Shiveluch is also one of the peninsula's most active volcanoes, with an estimated 60 substantial eruptions in the past 10,000 years.

  1. l-Arginine normalizes NOS activity and zinc-MT homeostasis in the kidney of mice chronically exposed to inorganic mercury.

    PubMed

    Piacenza, Francesco; Malavolta, Marco; Cipriano, Catia; Costarelli, Laura; Giacconi, Robertina; Muti, Elisa; Tesei, Silvia; Pierpaoli, Sara; Basso, Andrea; Bracci, Massimo; Bonacucina, Viviana; Santarelli, Lory; Mocchegiani, Eugenio

    2009-09-28

    Inorganic mercury (HgCl2) exposure provokes damage in many organs, especially kidney. Inducible nitric oxide synthase (iNOS) expression, total NOS activity and the profiles of zinc (Zn), copper (Cu) and Hg as well as their distribution when bound to specific intracellular proteins, including metallothioneins (MT), were studied during HgCl2 exposure and after l-arginine treatment in C57BL/6 mouse kidney. HgCl2 exposure modulates differently iNOS expression and NOS activity, increasing iNOS expression but, conversely, decreasing total NOS activity in the mouse kidney. Moreover, during Hg exposure an increased MT production occurs. The kidney damage leads to a loss of urinary proteins, increased plasma creatinine and high Zn mobilization with consequent increased urinary Zn excretion. l-arginine treatment recovers NOS activity and induces a normalization of MT induction, plasma creatinine values and urinary proteins excretion, suggesting that l-arginine may limit kidney damages by Hg exposure.

  2. Observations of reduced ozone concentrations in the tropical stratosphere after the eruption of Mt. Pinatubo

    NASA Technical Reports Server (NTRS)

    Grant, W. B.; Fishman, J.; Browell, E. V.; Brackett, V. G.; Nganga, D.; Minga, A.; Cros, B.; Veiga, R. E.; Butler, C. F.; Fenn, M. A.

    1992-01-01

    Two independent sets of data, one of aerosols from an airborne lidar system, and one of ozone from ozonesonde measurements indicate that significant ozone decreases may have happened as a result of the injection of debris by the Mt. Pinatubo volcano in June 1991. The amount of this reduction maximizes at 24-25 km, near the peak of the aerosol distribution, though a deficit is seen throughout the lower stratosphere between 19 and 28 km. The greatest differences observed prior and subsequent to the eruptions at these altitudes is 18-20 percent.

  3. Seismic unrest at Katla Volcano- southern Iceland

    NASA Astrophysics Data System (ADS)

    jeddi, zeinab; Tryggvason, Ari; Gudmundsson, Olafur; Bödvarsson, Reynir; SIL Seismology Group

    2014-05-01

    Katla volcano is located on the propagating Eastern Volcanic Zone (EVZ) in South Iceland. It is located beneath Mýrdalsjökull ice-cap which covers an area of almost 600 km2, comprising the summit caldera and the eruption vents. 20 eruptions between 930 and 1918 with intervals of 13-95 years are documented at Katla which is one of the most active subglacial volcanoes in Iceland. Eruptions at Katla are mainly explosive due to the subglacial mode of extrusion and produce high eruption columns and catastrophic melt water floods (jökulhlaups). The present long Volcanic repose (almost 96 years) at Katla, the general unrest since 1955, and the 2010 eruption of the neighbouring Eyjafjallajökull volcano has prompted concerns among geoscientists about an imminent eruption. Thus, the volcano has been densely monitored by seismologists and volcanologists. The seismology group of Uppsala University as a partner in the Volcano Anatomy (VA) project in collaboration with the University of Iceland and the Icelandic Meteorological Office (IMO) installed 9 temporary seismic stations on and around the Mýrdalsjökull glacier in 2011. Another 10 permanent seismic stations are operated by IMO around Katla. The project's data collection is now finished and temporary stations were pulled down in August 2013. According to seismicity maps of the whole recording period, thousands of microearthquakes have occurred within the caldera region. At least three different source areas are active in Katla: the caldera region, the western Godaland region and a small cluster at the southern rim of Mýrdalsjökull near the glacial stream of Hafursarjökull. Seismicity in the southern flank has basically started after June 2011. The caldera events are mainly volcano-tectonic, while western and southern events are mostly long period (lp) and can be related to glacial or magmatic movement. One motivation of the VA Katla project is to better understand the physical mechanism of these lp events. Changes

  4. Thermal history of volcanic debris flow deposits on the eastern flanks of Mt. Taranaki, New Zealand: Implications for future hazards

    NASA Astrophysics Data System (ADS)

    Turner, Gillian M.; Alloway, Brent V.; Dixon, Benjamin J.; Atkins, Cliff B.

    2018-03-01

    We use palaeomagnetic methods to decipher the thermal histories of a succession of massive to weakly stratified debris flow deposits (Ngatoro and Te Popo formations) of late Holocene age located on the eastern lower flanks of Mt. Taranaki/Egmont Volcano, western North Island, New Zealand. Results from two sites, Vickers Quarry and Surrey Road Quarry, both c. 9.6 km from the present-day summit, enable us to distinguish between clast incorporation temperatures of about 400 °C and emplacement temperatures between 150 and 200 °C, consistent with observation of superficial charring and desiccation of outer podocarp-hardwood tree trunks at Vickers Quarry. Analysis of palaeomagnetic directions and lithofacies architecture suggest that these deposits were likely initiated as a closely-spaced succession of block-and-ash flows (BAFs) that rapidly cooled as they descended the volcano flanks. Radiocarbon chronology and the widespread occurrence of a palaeosol between the products of the preceding Inglewood eruptive phase, c. 3.4 cal. ka B.P., and the overlying Ngatoro Formation suggest that these two events are temporally unrelated. Certainly, there is no field evidence of contemporaneous explosive volcanic activity that might be related to the emplacement of Ngatoro Formation. However, we suggest that these low-temperature deposits might either relate to collapse of a small emergent lava dome or a cooling dome remnant, possibly emplaced in the aftermath of the Inglewood eruption. How collapse was initiated remains uncertain: the remnant dome may have been rendered unstable by volcano-tectonic or tectonic seismic events and/or by adverse meteorological events. Nevertheless, this study demonstrates that edifice collapse events generating potentially hazardous debris flows can occur independent of specific eruptive activity.

  5. Effects of Volcanoes on the Natural Environment

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, Peter J.

    2005-01-01

    The primary focus of this project has been on the development of techniques to study the thermal and gas output of volcanoes, and to explore our options for the collection of vegetation and soil data to enable us to assess the impact of this volcanic activity on the environment. We originally selected several volcanoes that have persistent gas emissions and/or magma production. The investigation took an integrated look at the environmental effects of a volcano. Through their persistent activity, basaltic volcanoes such as Kilauea (Hawaii) and Masaya (Nicaragua) contribute significant amounts of sulfur dioxide and other gases to the lower atmosphere. Although primarily local rather than regional in its impact, the continuous nature of these eruptions means that they can have a major impact on the troposphere for years to decades. Since mid-1986, Kilauea has emitted about 2,000 tonnes of sulfur dioxide per day, while between 1995 and 2000 Masaya has emotted about 1,000 to 1,500 tonnes per day (Duffel1 et al., 2001; Delmelle et al., 2002; Sutton and Elias, 2002). These emissions have a significant effect on the local environment. The volcanic smog ("vog" ) that is produced affects the health of local residents, impacts the local ecology via acid rain deposition and the generation of acidic soils, and is a concern to local air traffic due to reduced visibility. Much of the work that was conducted under this NASA project was focused on the development of field validation techniques of volcano degassing and thermal output that could then be correlated with satellite observations. In this way, we strove to develop methods by which not only our study volcanoes, but also volcanoes in general worldwide (Wright and Flynn, 2004; Wright et al., 2004). Thus volcanoes could be routinely monitored for their effects on the environment. The selected volcanoes were: Kilauea (Hawaii; 19.425 N, 155.292 W); Masaya (Nicaragua; 11.984 N, 86.161 W); and Pods (Costa Rica; 10.2OoN, 84.233 W).

  6. Evolution of Deformation Studies on Active Hawaiian Volcanoes

    USGS Publications Warehouse

    Decker, Robert W.; Okamura, Arnold; Miklius, Asta; Poland, Michael

    2008-01-01

    Everything responds to pressure, even rocks. Deformation studies involve measuring and interpreting the changes in elevations and horizontal positions of the land surface or sea floor. These studies are variously referred to as geodetic changes or ground-surface deformations and are sometimes indexed under the general heading of geodesy. Deformation studies have been particularly useful on active volcanoes and in active tectonic areas. A great amount of time and energy has been spent on measuring geodetic changes on Kilauea and Mauna Loa Volcanoes in Hawai`i. These changes include the build-up of the surface by the piling up and ponding of lava flows, the changes in the surface caused by erosion, and the uplift, subsidence, and horizontal displacements of the surface caused by internal processes acting beneath the surface. It is these latter changes that are the principal concern of this review. A complete and objective review of deformation studies on active Hawaiian volcanoes would take many volumes. Instead, we attempt to follow the evolution of the most significant observations and interpretations in a roughly chronological way. It is correct to say that this is a subjective review. We have spent years measuring and recording deformation changes on these great volcanoes and more years trying to understand what makes these changes occur. We attempt to make this a balanced as well as a subjective review; the references are also selective rather than exhaustive. Geodetic changes caused by internal geologic processes vary in magnitude from the nearly infinitesimal - one micron or less, to the very large - hundreds of meters. Their apparent causes also are varied and include changes in material properties and composition, atmospheric pressure, tidal stress, thermal stress, subsurface-fluid pressure (including magma pressure, magma intrusion, or magma removal), gravity, and tectonic stress. Deformation is measured in units of strain or displacement. For example, tilt

  7. Insights into the dynamics of Etna volcano from 20-year time span microgravity and GPS observations

    NASA Astrophysics Data System (ADS)

    Bonforte, Alessandro; Fanizza, Giovanni; Greco, Filippo; Matera, Alfredo; Sulpizio, Roberto

    2016-04-01

    A common ground deformation and microgravity array of benchmarks lies on the southern slope of Mt. Etna volcano and is routinely measured by GPS and relative gravimetry methods. The array was installed for monitoring the ground motion and underground mass changes along the southern rift of the volcano and data are usually processed and interpreted independently. The benchmarks have been installed mainly along a main road crossing the southern side of the volcano with an E-W direction and reaching 2000 m of altitude. The gravity array covers the entire path of the road, while the ground deformation one only the upper one, due to the woods at lower altitude preventing good GPS measurements. Furthermore, microgravity surveys are usually carried out more frequently with respect to the GPS ones. In this work, an integrated analysis of microgravity and ground deformation is performed over a 20-year time span (1994-2014). Gravity variations have been first corrected for the free-air effect using the GPS observed vertical deformation and the theoretical vertical gravity gradient (-308.6 μGal/m). The free-air corrected gravity changes were then reduced from the high frequency variations (noise) and the seasonal fluctuations, mainly due to water-table fluctuations. This long-term dataset constitutes a unique opportunity to examine the behavior of Etna in a period in which the volcano exhibited different styles of activity characterized by recharging phases, flank eruptions and fountaining episodes. The gravity and deformation data allow investigating the response of the volcano in a wider perspective providing insights into the definition of its dynamic behavior and posing the basis to track the unrest evolution and to forecast the style of the eruption. The joint analysis highlights common periods, in which the signals underwent contemporaneous changes occurring mainly in the central and eastern stations. On the other hand, no significant changes in the behavior of

  8. Translating Volcano Hazards Research in the Cascades Into Community Preparedness

    NASA Astrophysics Data System (ADS)

    Ewert, J. W.; Driedger, C. L.

    2015-12-01

    Research by the science community into volcanic histories and physical processes at Cascade volcanoes in the states of Washington, Oregon, and California has been ongoing for over a century. Eruptions in the 20th century at Lassen Peak and Mount St. Helen demonstrated the active nature of Cascade volcanoes; the 1980 eruption of Mount St. Helens was a defining moment in modern volcanology. The first modern volcano hazards assessments were produced by the USGS for some Cascade volcanoes in the 1960s. A rich scientific literature exists, much of which addresses hazards at these active volcanoes. That said community awareness, planning, and preparation for eruptions generally do not occur as a result of a hazard analyses published in scientific papers, but by direct communication with scientists. Relative to other natural hazards, volcanic eruptions (or large earthquakes, or tsunami) are outside common experience, and the public and many public officials are often surprised to learn of the impacts volcanic eruptions could have on their communities. In the 1980s, the USGS recognized that effective hazard communication and preparedness is a multi-faceted, long-term undertaking and began working with federal, state, and local stakeholders to build awareness and foster community action about volcano hazards. Activities included forming volcano-specific workgroups to develop coordination plans for volcano emergencies; a concerted public outreach campaign; curriculum development and teacher training; technical training for emergency managers and first responders; and development of hazard information that is accessible to non-specialists. Outcomes include broader ownership of volcano hazards as evidenced by bi-national exchanges of emergency managers, community planners, and first responders; development by stakeholders of websites focused on volcano hazards mitigation; and execution of table-top and functional exercises, including evacuation drills by local communities.

  9. Volcanic history of El Chichon Volcano (Chiapas, Mexico) during the Holocene, and its impact on human activity

    USGS Publications Warehouse

    Espindola, J.M.; Macias, J.L.; Tilling, R.I.; Sheridan, M.F.

    2000-01-01

    Before its devastating eruption in 1982, El Chichon Volcano was little known and did not appear on any listings of hazardous volcanoes. Subsequent geologic studies, based on stratigraphic and radiocarbon investigations, showed that at least three explosive eruptions had occurred previously at this volcano. In this paper, we present the result of recent studies on the stratigraphy of the volcano and new radiocarbon ages which show that at least 11 eruptions have taken place at El Chichon in the past 8000 years. Explosive events, most of them producing block-and-ash flow and surge deposits, occurred around 550, 900, 1250, 1500, 1600, 1900, 2000, 2500, 3100, 3700 and 7700 years BP. The juvenile products of these eruptions have a trachyandesitic composition with similar degree of evolution, as evidenced from their SiO2 abundance and depletion in MgO, CaO, TiO2, as well as trace and rare earth elements. This suggests segregation of olivine and orthopyroxene from the melt. Since human settlements in southeast Mexico and Central America can be traced as far back as approximately 2500 years BP, most of these events probably affected human activity. In fact, there are reports of pottery shards and other artifacts in deposits from the eruption of 1250 BP. Pottery fragments in deposits of an eruption that took place 2500 BP are also reported in this paper. Thus, the impact of the volcano on human activities has been frequent, with most of the repose intervals lasting between 100 to 600 years. The impact of the eruptions was probably of greater than local extent, because airfall tephra could reach distant sites and possibly even affect weather. The eruptive history of El Chichon also offers clues in the investigation of the Maya civilization. Several researchers have considered the volcano as an important factor in the answer to some intriguing questions such as the extensive use of volcanic ash in Late Classic Maya ceramics or, of greater importance, the causes of the

  10. Volcanoes

    ERIC Educational Resources Information Center

    Kunar, L. N. S.

    1975-01-01

    Describes the forces responsible for the eruptions of volcanoes and gives the physical and chemical parameters governing the type of eruption. Explains the structure of the earth in relation to volcanoes and explains the location of volcanic regions. (GS)

  11. Lahar-hazard zonation for San Miguel volcano, El Salvador

    USGS Publications Warehouse

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Chesner, C.A.; Howell, M.M.

    2001-01-01

    San Miguel volcano, also known as Chaparrastique, is one of many volcanoes along the volcanic arc in El Salvador. The volcano, located in the eastern part of the country, rises to an altitude of about 2130 meters and towers above the communities of San Miguel, El Transito, San Rafael Oriente, and San Jorge. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and the PanAmerican and coastal highways cross the lowermost northern and southern flanks of the volcano. The population density around San Miguel volcano coupled with the proximity of major transportation routes increases the risk that even small volcano-related events, like landslides or eruptions, may have significant impact on people and infrastructure. San Miguel volcano is one of the most active volcanoes in El Salvador; it has erupted at least 29 times since 1699. Historical eruptions of the volcano consisted mainly of relatively quiescent emplacement of lava flows or minor explosions that generated modest tephra falls (erupted fragments of microscopic ash to meter sized blocks that are dispersed into the atmosphere and fall to the ground). Little is known, however, about prehistoric eruptions of the volcano. Chemical analyses of prehistoric lava flows and thin tephra falls from San Miguel volcano indicate that the volcano is composed dominantly of basalt (rock having silica content

  12. Lahar Hazards at Concepción volcano, Nicaragua

    USGS Publications Warehouse

    Vallance, J.W.; Schilling, S.P.; Devoli, G.; Howell, M.M.

    2001-01-01

    Concepción is one of Nicaragua’s highest and most active volcanoes. The symmetrical cone occupies the northeastern half of a dumbbell shaped island called Isla Ometepa. The dormant volcano, Maderas, occupies the southwest half of the island. A narrow isthmus connects Concepción and Maderas volcanoes. Concepción volcano towers more than 1600 m above Lake Nicaragua and is within 5 to 10 km of several small towns situated on its aprons at or near the shoreline. These towns have a combined population of nearly 5,000. The volcano has frequently produced debris flows (watery flows of mud, rock, and debris—also known as lahars when they occur on a volcano) that could inundate these nearby populated areas. Concepción volcano has erupted more than 25 times in the last 120 years. Its first recorded activity was in AD 1883. Eruptions in the past century, most of which have originated from a small summit crater, comprise moderate explosions, ash that falls out of eruption plumes (called tephra), and occasional lava flows. Near the summit area, there are accumulations of rock that were emplaced hot (pyroclastic deposits), most of which were hot enough to stick together during deposition (a process called welding). These pyroclastic rocks are rather weak, and tend to break apart easily. The loose volcanic rock remobilizes during heavy rain to form lahars. Volcanic explosions have produced blankets of tephra that are distributed downwind, which on Isla Ometepe is mostly to the west. Older deposits at the west end of the island that are up to 1 m thick indicate larger explosive events have happened at Concepción volcano in prehistoric time. Like pyroclastic-flow deposits, loose tephra on the steep slopes of the volcano provides source material that heavy rainstorms and earthquakes can mobilize to trigger debris flow.

  13. The Mediterranean Supersite Volcanoes (MED-SUV) Project: an overview

    NASA Astrophysics Data System (ADS)

    Puglisi, Giuseppe

    2013-04-01

    In response to the EC call ENV.2012.6.4-2 (Long-term monitoring experiments in geologically active regions of Europe prone to natural hazards: the Supersite concept - FP7-ENV-2012-two-stage) a wide community of volcanological institutions proposed the project Mediterranean Supersite Volcanoes (MED-SUV), which is in the negotiation phase at the time of writing. The Consortium is composed by 18 European University and research institutes, four Small or Medium Enterprises (SME) and two non-European University and research institutes. MED-SUV will improve the consortium capacity of assessment of volcanic hazards in Supersites of Southern Italy by optimising and integrating existing and new observation/monitoring systems, by a breakthrough in understanding of volcanic processes and by increasing the effectiveness of the coordination between the scientific and end-user communities. More than 3 million of people are exposed to potential volcanic hazards in a large region in the Mediterranean Sea, where two among the largest European volcanic areas are located: Mt. Etna and Campi Flegrei/Vesuvius. This project will fully exploit the unique detailed long-term in-situ monitoring data sets available for these volcanoes and integrate with Earth Observation (EO) data, setting the basic tools for a significant step ahead in the discrimination of pre-, syn- and post-eruptive phases. The wide range of styles and intensities of volcanic phenomena observed on these volcanoes, which can be assumed as archetypes of 'closed conduit ' and 'open conduit' volcano, together with the long-term multidisciplinary data sets give an exceptional opportunity to improve the understanding of a very wide spectrum of geo-hazards, as well as implementing and testing a large variety of innovative models of ground deformation and motion. Important impacts on the European industrial sector are expected, arising from a partnership integrating the scientific community and SMEs to implement together new

  14. Renewed unrest at Mount Spurr Volcano, Alaska

    USGS Publications Warehouse

    Power, John A.

    2004-01-01

    The Alaska Volcano Observatory (AVO),a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys, has detected unrest at Mount Spurr volcano, located about 125 km west of Anchorage, Alaska, at the northeast end of the Aleutian volcanic arc.This activity consists of increased seismicity melting of the summit ice cap, and substantial rates of C02 and H2S emission.The current unrest is centered beneath the volcano's 3374-m-high summit, whose last known eruption was 5000–6000 years ago. Since then, Crater Peak, 2309 m in elevation and 4 km to the south, has been the active vent. Recent eruptions occurred in 1953 and 1992.

  15. The psychosocial impact of the environmental damage caused by the MT Merapi eruption on survivors in Indonesia.

    PubMed

    Warsini, Sri; Buettner, Petra; Mills, Jane; West, Caryn; Usher, Kim

    2014-12-01

    The eruption of Indonesia's Mount Merapi volcano in 2010 caused extensive environmental degradation. Settlements and hundreds of hectares of farmlands were buried under volcanic ash. Until now, there has been no research on the psychosocial impact of living in an environment damaged by a volcanic eruption. We studied and compared the psychosocial impact of environmental damage on volcano survivors from two subdistricts-Cangkringan and Pakem. Cangkringan survivors affected by the 2010 eruption continue to live in a damaged environment. The Pakem subdistrict was damaged by eruptions of Mt Merapi in the 1990s but there is no recent damage to their environment. The Indonesian-Environmental Distress Scale (I-EDS), a translated revision of the original Environmental Distress Scale (EDS), was used to collect data. Exploratory statistical methods and multivariate linear regression analyses were performed to examine the relative contributions of demographic variables on the psychosocial impact of living in an environment damaged by volcanic eruption. A total of 348 survivors of the Mt Merapi eruption participated in the survey. The mean I-EDS score for Cangkringan district was 15.8 (SD 1.6; range 11.8-19.8) compared to 14.6 (SD 1.3; range 11.8-18.3) for Pakem district (P < 0.001). This result was confirmed by multiple linear regression analysis showing further that older respondents (P < 0.001), unemployed and retired respondents (P = 0.007), and respondents with no formal school education (P = 0.037) had lower I-EDS scores compared to the respective reference groups. Survivors of the Mt Merapi eruption who continue to live in the environment damaged by the 2010 volcanic eruption experience environmental distress. Relevant interventions should target those from low sosioeconomic groups to deal with the distress.

  16. Evidence of recent deep magmatic activity at Cerro Bravo-Cerro Machín volcanic complex, central Colombia. Implications for future volcanic activity at Nevado del Ruiz, Cerro Machín and other volcanoes

    NASA Astrophysics Data System (ADS)

    Londono, John Makario

    2016-09-01

    In the last nine years (2007-2015), the Cerro Bravo-Cerro Machín volcanic complex (CBCMVC), located in central Colombia, has experienced many changes in volcanic activity. In particular at Nevado del Ruiz volcano (NRV), Cerro Machin volcano (CMV) and Cerro Bravo (CBV) volcano. The recent activity of NRV, as well as increasing seismic activity at other volcanic centers of the CBCMVC, were preceded by notable changes in various geophysical and geochemical parameters, that suggests renewed magmatic activity is occurring at the volcanic complex. The onset of this activity started with seismicity located west of the volcanic complex, followed by seismicity at CBV and CMV. Later in 2010, strong seismicity was observed at NRV, with two small eruptions in 2012. After that, seismicity has been observed intermittently at other volcanic centers such as Santa Isabel, Cerro España, Paramillo de Santa Rosa, Quindío and Tolima volcanoes, which persists until today. Local deformation was observed from 2007 at NRV, followed by possible regional deformation at various volcanic centers between 2011 and 2013. In 2008, an increase in CO2 and Radon in soil was observed at CBV, followed by a change in helium isotopes at CMV between 2009 and 2011. Moreover, SO2 showed an increase from 2010 at NRV, with values remaining high until the present. These observations suggest that renewed magmatic activity is currently occurring at CBCMVC. NRV shows changes in its activity that may be related to this new magmatic activity. NRV is currently exhibiting the most activity of any volcano in the CBCMVC, which may be due to it being the only open volcanic system at this time. This suggests that over the coming years, there is a high probability of new unrest or an increase in volcanic activity of other volcanoes of the CBCMVC.

  17. Risk perception at a persistently active volcano: warnings and trust at Popocatépetl volcano in Mexico, 2012-2014

    NASA Astrophysics Data System (ADS)

    Donovan, Amy; Ayala, Irasema Alcántara; Eiser, J. R.; Sparks, R. S. J.

    2018-05-01

    This paper presents data from an online survey carried out in Mexico from 2012 to 2014. The survey focussed on the risk to Mexico City from Popocatépetl, an active volcano 60 km from the city. During the time period, volcanic activity was variable, and the alert level changed accordingly. The survey showed that people surveyed at the higher alert level were generally more concerned about the volcano. Since these people were measured separately from those who responded at the lower alert level and yet self-reported on the same scale as more concerned, this provides a useful indicator that the raised alert level may be associated with higher risk perception, and that alert level systems act as boundary objects in the translation of scientific information. In general, trust in various groups was most strongly explained by the perceived knowledge of the groups, followed by their perceived motivation (whether or not they are viewed as working in society's interest), with accuracy a tertiary concern. Some respondents were anxious about false alarms—these people also tended to be concerned about scientific accuracy while those who favoured precaution tended to be more trusting. The perceived effectiveness of warning and evacuation plans was also a significant predictor for trust in official groups. In general, the results suggest that there are important links between trust, warning plans and the perceived motivation of particular groups as well as between trust and perceived knowledge.

  18. Spying on volcanoes

    NASA Astrophysics Data System (ADS)

    Watson, Matthew

    2017-07-01

    Active volcanoes can be incredibly dangerous, especially to those who live nearby, but how do you get close enough to observe one in action? Matthew Watson explains how artificial drones are providing volcanologists with insights that could one day save human lives

  19. Magnetotelluric Investigation of Melt Storage Beneath Okmok Caldera, Alaska

    NASA Astrophysics Data System (ADS)

    Bennington, N. L.; Bedrosian, P.; Key, K.; Zelenak, G.

    2015-12-01

    Alaska accounts for nearly 99% of the seismic moment release within the US. Much of this is associated with the Aleutian volcanic arc, the most tectonically active region in North America, and an ideal location for studying arc magmatism. Okmok is an active volcano located in the central Aleutian arc, defined by a pair of nested, 10 km diameter calderas. The subdued topography of Okmok, relative to other Aleutian volcanoes, improves access and permits dense sampling within the caldera closer to the underlying magmatic system. Okmok volcano was selected as the site of study for this project due to frequent volcanic activity and the presence of a crustal magma reservoir as inferred from previous coarse resolution seismic studies. In June-July 2015, we carried out an amphibious geophysical field deployment at Okmok. Onshore work in and around the volcano included collection of an array of magnetotelluric (MT) stations and installation of a temporary, year-long seismic array. A ring of 3D offshore MT deployments made around the island augments the onshore array. An additional 2D tectonic-scale profile spans the trench, volcanic arc, and backarc. This new geophysical data will be used to gain a greater understanding of Aleutian arc melt generation, migration, and storage beneath an active caldera. We present results from the analysis of the newly collected amphibious 3D MT data. This data will be used to model the distribution and migration of melt within Okmok's crustal magma reservoir. Initial processing of the data shows strong MT signal levels, in particular from a geomagnetic storm that occurred from June 21-23, 2015. A companion abstract discussing the 2D tectonic scale MT profile, which constrains the mantle and deep crust beneath Okmok volcano, is discussed by Zelenak et al.

  20. Transition from phreatic to phreatomagmatic explosive activity of Zhupanovsky volcano (Kamchatka) in 2013-2016 due to volcanic cone collapse

    NASA Astrophysics Data System (ADS)

    Gorbach, Natalia; Plechova, Anastasiya; Portnyagin, Maxim

    2017-04-01

    Zhupanovsky volcano, situated 70 km north from Petropavlovsk-Kamchatsky city, resumed its activity in October 2013 [3]. In 2014 and in the first half of 2015, episodic explosions with ash plumes rising up to 6-8 km above sea level occurred on Priemish cone - one of four cones on the Zhupanovsky volcanic edifice [1]. In July 2015 after a series of seismic and explosive events, the southern sector of the active cone collapsed. The landslide and lahar deposits resulted from the collapse formed a large field on the volcano slopes [2]. In November 2015 and January-March 2016, a series of powerful explosions took place sending ash up to 8-10 km above sea level. No pure magmatic, effusive or extrusive, activity has been observed on Zhupanovsky in 2013-2016. We have studied the composition, morphology and textural features of ash particles produced by the largest explosive events of Zhupanovsky in the period from October 2013 to March 2016. The main components of the ash were found to be hydrothermally altered particles and lithics, likely originated by the defragmentation of rocks composing the volcanic edifice. Juvenile glass fragments occur in very subordinate quantities. The maximum amount of glass particles (up to 7%) was found in the ash erupted in January-March 2016, after the cone collapse. We suggest that the phreatic to phreatomagmatic explosive activity of Zhupanovsky volcano in 2013-2016 was initially caused by the intrusion of a new magma batch under the volcano. The intrusion and associated degassing of magma led to heating, overpressure and instability in the hydrothermal system of the volcano, causing episodic, predominantly phreatic explosions. Decompression of the shallow magmatic and hydrothermal system of the volcano due to the cone collapse in July 2015 facilitated a larger involvement of the magmatic component in the eruption and more powerful explosions. [1] Girina O.A. et al., 2016 Geophysical Research Abstracts Vol. 18, EGU2016-2101, doi: 10

  1. The Qartaba Structure: An Active Backthrust In Central Mt-Lebanon.

    NASA Astrophysics Data System (ADS)

    Elias, Ata Richard

    2016-04-01

    The Qartaba structure in central Mt-Lebanon is a 15x5km box fold running parallel to the restraining bend of the sinsitral Yammouneh Fault, the main fault of the central segment of the Dead Sea Transform. The Qartaba structure has long been described as a "horst" and associated with Mesozoic normal faulting. However, the Qartaba anticline is suitably oriented with the direction of maximum compression along the restraining bend. Jurassic carbonate rocks form the core of this anticline culminating at ~1953m asl to the east, of the highest structural elevation of the Mt-Lebanon range indicating important tectonic uplift rate. The fold is asymmetric. The western limb is steep and bordered by the Lebanese Flexure, a prominent continuous monocline of Upper Jurassic to Mid Cretaceous rocks, running along the western flank of Mt-Lebanon. The eastern limb of the anticline has a very steep dip, and forms a 200m high cliff well marked in the topography. Its Jurassic layers are almost vertical and end up overhanging Lower Cretaceous beds. Our study suggest that the Qartaba structure is a growing anticline, built by active thrusting over a west dipping thrust fault that cuts the surface at the base of the eastern limb of the anticline. The fault plane can be seen dipping 30-35 degrees to the west. At depth, this thrust is likely to connect with the blind thrust ramp of the Mt-Lebanon Flexure. The Qartaba backthrust with a dip to the west, is opposite to the general vergence of similar structures in the area. On some of the segments of the steep cliff forming the faulted eastern limb, a fresh scarp with smooth and polished surfaces bearing vertical slickensides can be followed over ~700m along the base of the cliff. It corresponds with the location of the thrust fault tip. Talus accumulation over the steep eastern limb covers most of the cliff base, and may be masking further extent of this scarp. We interpret this scarp as the freeface of a co-seismic rupture on the underlying

  2. Geology of Kilauea volcano

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moore, R.B.; Trusdell, F.A.

    1993-08-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailedmore » geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.« less

  3. Swarms of small volcano-tectonic events preceding paroxysmal explosions of Tungurahua volcano (Ecuador)

    NASA Astrophysics Data System (ADS)

    Battaglia, J.; Hidalgo, S.; Douchain, J. M.; Pacheco, D. A.; Cordova, J.; Alvarado, A. P.; Parra, R.

    2017-12-01

    Tungurahua (5023 m a.s.l.) is an andesitic volcano located in Central Ecuador. It has been erupting since September 1999. It's activity transitioned in late 2008 towards the occurrence of distinct eruptive phases separated by periods of quiescence. These phases display a great variability of eruptive patterns. In particular the onsets of these phases are quite variable, ranging from progressive increase of surface activity to violent paroxysmal explosions eventually generating pyroclastic flows and plumes up to 13.000 m elevation. The volcano is monitored by the Instituto Geofisico in Quito whose permanent monitoring network include 6 broadband and 6 short period stations. These instruments record various signals related to eruptive processes as well as Long Period and volcano-tectonique (VT) events. However, most of the VT events are scattered around the volcano at depths up to 5-10 km b.s.l.. Their relationship with eruptive activity and precursory aspect are unclear. Since October 2013, we operate a temporary network of 13 broadband stations located up to 4275 m a.s.l., including on the Eastern flank which is remote. We examined data from a reference station located near the summit (3900 m a.s.l.) with a detection and classification procedure, searching for families of similar events. This processing enlights the presence of several families of small VTs previously poorly identified. We located manually some of these events and proceeded with similarity picking using cross-correlation and waveform similarity for nearly 400 events. Finally we applied precise relocation techniques. These events are located 2-3 km below the summit and define vertically elongated streaks. Their temporal evolution shows that they occur in swarms during the days or hours preceding the paroxysmal vent opening explosions in February and April 2014. These short-term precursors could indicate the rupturing of a barrier prior to the large explosions of Tungurahua.

  4. Space Radar Image of Mt. Etna, Italy

    NASA Image and Video Library

    1999-04-15

    The summit of the Mount Etna volcano on the island of Sicily, Italy, one of the most active volcanoes in the world, is shown near the center of this radar image. Lava flows of different ages and surface roughness appear in shades of purple, green, yellow and pink surrounding the four small craters at the summit. Etna is one of the best-studied volcanoes in the world and scientists are using this radar image to identify and distinguish a variety of volcanic features. Etna has erupted hundreds of times in recorded history, with the most recent significant eruption in 1991-1993. Scientists are studying Etna as part of the international "Decade Volcanoes" project, because of its high level of activity and potential threat to local populations. This image was acquired on October 11, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered at 37.8 degrees North latitude and 15.1 degrees East longitude and covers an area of 51.2 kilometers by 22.6 kilometers (31.7 miles by 14.0 miles). http://photojournal.jpl.nasa.gov/catalog/PIA01776

  5. Two M-T hook residues greatly improve the antiviral activity and resistance profile of the HIV-1 fusion inhibitor SC29EK

    PubMed Central

    2014-01-01

    Background Peptides derived from the C-terminal heptad repeat (CHR) of HIV-1 gp41 such as T20 (Enfuvirtide) and C34 are potent viral fusion inhibitors. We have recently found that two N-terminal residues (Met115 and Thr116) of CHR peptides form a unique M-T hook structure that can greatly enhance the binding and anti-HIV activity of inhibitors. Here, we applied two M-T hook residues to optimize SC29EK, an electrostatically constrained peptide inhibitor with a potent anti-HIV activity. Results The resulting peptide MT-SC29EK showed a dramatically increased binding affinity and could block the six-helical bundle (6-HB) formation more efficiently. As expected, MT-SC29EK potently inhibited HIV-1 entry and infection, especially against those T20- and SC29EK-resistant HIV-1 variants. More importantly, MT-SC29EK and its short form (MT-SC22EK) suffered from the difficulty to induce HIV-1 resistance during the in vitro selection, suggesting their high genetic barriers to the development of resistance. Conclusions Our studies have verified the M-T hook structure as a vital strategy to design novel HIV-1 fusion inhibitors and offered an ideal candidate for clinical development. PMID:24884671

  6. Space Radar Image of Colombian Volcano

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations ofColombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of

  7. Single-station monitoring of volcanoes using seismic ambient noise

    NASA Astrophysics Data System (ADS)

    De Plaen, Raphael S. M.; Lecocq, Thomas; Caudron, Corentin; Ferrazzini, Valérie; Francis, Olivier

    2016-08-01

    Seismic ambient noise cross correlation is increasingly used to monitor volcanic activity. However, this method is usually limited to volcanoes equipped with large and dense networks of broadband stations. The single-station approach may provide a powerful and reliable alternative to the classical "cross-station" approach when measuring variation of seismic velocities. We implemented it on the Piton de la Fournaise in Reunion Island, a very active volcano with a remarkable multidisciplinary continuous monitoring. Over the past decade, this volcano has been increasingly studied using the traditional cross-correlation technique and therefore represents a unique laboratory to validate our approach. Our results, tested on stations located up to 3.5 km from the eruptive site, performed as well as the classical approach to detect the volcanic eruption in the 1-2 Hz frequency band. This opens new perspectives to successfully forecast volcanic activity at volcanoes equipped with a single three-component seismometer.

  8. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2003

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Moran, Seth C.; Sanchez, John J.; McNutt, Stephen R.; Estes, Steve; Paskievitch, John

    2004-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at historically active volcanoes in Alaska since 1988. The primary objectives of this program are the near real time seismic monitoring of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog presents the calculated earthquake hypocenter and phase arrival data, and changes in the seismic monitoring program for the period January 1 through December 31, 2003.The AVO seismograph network was used to monitor the seismic activity at twenty-seven volcanoes within Alaska in 2003. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai volcanic cluster (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Mount Veniaminof, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Okmok Caldera, Great Sitkin Volcano, Kanaga Volcano, Tanaga Volcano, and Mount Gareloi. Monitoring highlights in 2003 include: continuing elevated seismicity at Mount Veniaminof in January-April (volcanic unrest began in August 2002), volcanogenic seismic swarms at Shishaldin Volcano throughout the year, and low-level tremor at Okmok Caldera throughout the year. Instrumentation and data acquisition highlights in 2003 were the installation of subnetworks on Tanaga and Gareloi Islands, the installation of broadband installations on Akutan Volcano and Okmok Caldera, and the establishment of telemetry for the Okmok Caldera subnetwork. AVO located 3911 earthquakes in 2003.This catalog includes: (1) a description of instruments deployed in the field and their locations; (2) a

  9. Lahar hazards at Mombacho Volcano, Nicaragua

    USGS Publications Warehouse

    Vallance, J.W.; Schilling, S.P.; Devoli, G.

    2001-01-01

    Mombacho volcano, at 1,350 meters, is situated on the shores of Lake Nicaragua and about 12 kilometers south of Granada, a city of about 90,000 inhabitants. Many more people live a few kilometers southeast of Granada in 'las Isletas de Granada and the nearby 'Peninsula de Aseses. These areas are formed of deposits of a large debris avalanche (a fast moving avalanche of rock and debris) from Mombacho. Several smaller towns with population, in the range of 5,000 to 12,000 inhabitants are to the northwest and the southwest of Mombacho volcano. Though the volcano has apparently not been active in historical time, or about the last 500 years, it has the potential to produce landslides and debris flows (watery flows of mud, rock, and debris -- also known as lahars when they occur on a volcano) that could inundate these nearby populated areas. -- Vallance, et.al., 2001

  10. Spreading volcanoes

    USGS Publications Warehouse

    Borgia, A.; Delaney, P.T.; Denlinger, R.P.

    2000-01-01

    As volcanoes grow, they become ever heavier. Unlike mountains exhumed by erosion of rocks that generally were lithified at depth, volcanoes typically are built of poorly consolidated rocks that may be further weakened by hydrothermal alteration. The substrates upon which volcanoes rest, moreover, are often sediments lithified by no more than the weight of the volcanic overburden. It is not surprising, therefore, that volcanic deformation includes-and in the long term is often dominated by-spreading motions that translate subsidence near volcanic summits to outward horizontal displacements around the flanks and peripheries. We review examples of volcanic spreading and go on to derive approximate expressions for the time volcanoes require to deform by spreading on weak substrates. We also demonstrate that shear stresses that drive low-angle thrust faulting from beneath volcanic constructs have maxima at volcanic peripheries, just where such faults are seen to emerge. Finally, we establish a theoretical basis for experimentally derived scalings that delineate volcanoes that spread from those that do not.

  11. Halogen speciation in volcanic plumes - Development of compact denuder sampling techniques with in-situ derivatization followed by gas chromatography-mass spectrometry and their application at Mt. Etna, Mt. Nyiragongo and Mt. Nyamulagira in 2015.

    NASA Astrophysics Data System (ADS)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2016-04-01

    Volcanoes are a large source for several reactive atmospheric trace gases including sulfur and halogen containing species. The detailed knowledge of volcanic plume chemistry can give insights into subsurface processes and can be considered as a useful geochemical tool for monitoring of volcanic activity, especially halogen to sulfur ratios (e.g. Bobrowski and Giuffrida, 2012; Donovan et al., 2014). The reactive bromine species bromine monoxide (BrO) is of particular interest, because BrO as well as SO2 are readily measurable by UV spectrometer at a safe distance. Furthermore it is formed in the plume by a multiphase reaction mechanism under depletion of ozone in the plume. The abundance of BrO changes as a function of the reaction time and therefore distance from the vent as well as the spatial position in the plume. The precursor substance for the formation of BrO is HBr with Br2as an intermediate product. The reaction of HBr to BrO involves heterogeneous reactions involving aerosol particles, while Br2 reacts directly with O3 to form BrO in a UV radiation induced mechanism. Due to the lack of analytical approaches for the species analysis of halogens (HBr, Br2, Br, BrCl, HOBr) there are still uncertainties about the magnitude of volcanic halogen emissions and in particular their speciation and therefore also in the understanding of the bromine chemistry in volcanic plumes (Bobrowski et al., 2007). In this study a gas diffusion denuder sampling method using a 1,3,5-trimethoxybenzene (1,3,5-TMB) coating for the derivatization of reactive halogen species (Rüdiger et al., 2015) was characterized by reaction chamber experiments. The coating proved to be suitable to collect selectively gaseous bromine species with oxidation states of +1 or 0 (such as Br2, BrCl, BrO(H) and BrONO2), while being ignorant to HBr (OS -1). The reaction of 1,3,5-TMB with reactive bromine species gives 1-bromo-2,4,6-trimethoxybenzene (1-bromo-2,4,6-TMB) - other halogens give corresponding

  12. Soufriere Hills Volcano

    NASA Image and Video Library

    2002-11-07

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit. This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. http://photojournal.jpl.nasa.gov/catalog/PIA03880

  13. Volcano-tectonic implications of 3-D velocity structures derived from joint active and passive source tomography of the island of Hawaii

    USGS Publications Warehouse

    Park, J.; Morgan, J.K.; Zelt, C.A.; Okubo, P.G.

    2009-01-01

    We present a velocity model of the onshore and offshore regions around the southern part of the island of Hawaii, including southern Mauna Kea, southeastern Hualalai, and the active volcanoes of Mauna Loa, and Kilauea, and Loihi seamount. The velocity model was inverted from about 200,000 first-arrival traveltime picks of earthquakes and air gun shots recorded at the Hawaiian Volcano Observatory (HVO). Reconstructed volcanic structures of the island provide us with an improved understanding of the volcano-tectonic evolution of Hawaiian volcanoes and their interactions. The summits and upper rift zones of the active volcanoes are characterized by high-velocity materials, correlated with intrusive magma cumulates. These high-velocity materials often do not extend the full lengths of the rift zones, suggesting that rift zone intrusions may be spatially limited. Seismicity tends to be localized seaward of the most active intrusive bodies. Low-velocity materials beneath parts of the active rift zones of Kilauea and Mauna Loa suggest discontinuous rift zone intrusives, possibly due to the presence of a preexisting volcanic edifice, e.g., along Mauna Loa beneath Kilauea's southwest rift zone, or alternatively, removal of high-velocity materials by large-scale landsliding, e.g., along Mauna Loa's western flank. Both locations also show increased seismicity that may result from edifice interactions or reactivation of buried faults. New high-velocity regions are recognized and suggest the presence of buried, and in some cases, previously unknown rift zones, within the northwest flank of Mauna Loa, and the south flanks of Mauna Loa, Hualalai, and Mauna Kea. Copyright 2009 by the American Geophysical Union.

  14. Science at the policy interface: volcano-monitoring technologies and volcanic hazard management

    NASA Astrophysics Data System (ADS)

    Donovan, Amy; Oppenheimer, Clive; Bravo, Michael

    2012-07-01

    This paper discusses results from a survey of volcanologists carried out on the Volcano Listserv during late 2008 and early 2009. In particular, it examines the status of volcano monitoring technologies and their relative perceived value at persistently and potentially active volcanoes. It also examines the role of different types of knowledge in hazard assessment on active volcanoes, as reported by scientists engaged in this area, and interviewees with experience from the current eruption on Montserrat. Conclusions are drawn about the current state of monitoring and the likely future research directions, and also about the roles of expertise and experience in risk assessment on active volcanoes; while local knowledge is important, it must be balanced with fresh ideas and expertise in a combination of disciplines to produce an advisory context that is conducive to high-level scientific discussion.

  15. Colima Volcano, State of Jalisco, Mexico

    NASA Image and Video Library

    1991-05-06

    STS039-75-101 (28 April-6 May 1991) --- Spending over eight days in Earth orbit, the STS-39 crew was able to return with photographic coverage of highly variegated geographic scenery, including a number of volcanoes such as Mexico's Colima. Located south of Guadalajara, Colima is Mexico's most active volcano. The current activity started in the first part of March 1991 with avalanches occurring, followed by lava extrusion and ash emission. Colima is captured here in action. The steam plume drifts eastward from the 13,325 ft. summit. Scars from recent landslides can be seen on the southwest flank of the summit.

  16. Volcaniclastic stratigraphy of Gede volcano in West Java

    NASA Astrophysics Data System (ADS)

    Belousov, A.; Belousova, M.; Zaennudin, A.; Prambada, O.

    2012-12-01

    Gede volcano (2958 m a.s.l.) and the adjacent Pangrango volcano (3019 m a.s.l.) form large (base diameter 35 km) volcanic massif 60 km south of Jakarta. While Pangrango has no recorded eruptions, Gede is one of the most active volcanoes in Indonesia: eruptions were reported 26 times starting from 1747 (Petroeschevsky 1943; van Bemmelen 1949). Historic eruptions were mildly explosive (Vulcanian) with at least one lava flow. Modern activity of the volcano includes persistent solfataric activity in the summit crater and periodic seismic swarms - in 1990, 1991, 1992, 1995, 1996, 1997, 2000, 2010, and 2012 (CVGHM). Lands around the Gede-Pangrango massif are densely populated with villages up to 1500-2000 m a.s.l. Higher, the volcano is covered by rain forest of the Gede-Pangrango Natural Park, which is visited every day by numerous tourists who camp in the summit area. We report the results of the detailed reinvestigation of volcaniclastic stratigraphy of Gede volcano. This work has allowed us to obtain 24 new radiocarbon dates for the area. As a result the timing and character of activity of Gede in Holocene has been revealed. The edifice of Gede volcano consists of main stratocone (Gumuruh) with 1.8 km-wide summit caldera; intra-caldera lava cone (Gede proper) with a 900 m wide summit crater, having 2 breaches toward N-NE; and intra-crater infill (lava dome/flow capped with 3 small craters surrounded by pyroclastic aprons). The Gumuruh edifice, composed mostly of lava flows, comprises more than 90% of the total volume of the volcano. Deep weathering of rocks and thick (2-4 m) red laterite soil covering Gumuruh indicates its very old age. Attempts to get 14C dates in 4 different locations of Gumuruh (including a large debris avalanche deposit on its SE foot) provided ages older than 45,000 years - beyond the limit for 14C dating. Outside the summit caldera, notable volumes of fresh, 14C datable volcaniclastic deposits were found only in the NNE sector of the volcano

  17. Catalogue of Icelandic Volcanoes

    NASA Astrophysics Data System (ADS)

    Ilyinskaya, Evgenia; Larsen, Gudrún; Gudmundsson, Magnús T.; Vogfjörd, Kristin; Jonsson, Trausti; Oddsson, Björn; Reynisson, Vidir; Pagneux, Emmanuel; Barsotti, Sara; Karlsdóttir, Sigrún; Bergsveinsson, Sölvi; Oddsdóttir, Thorarna

    2017-04-01

    The Catalogue of Icelandic Volcanoes (CIV) is a newly developed open-access web resource (http://icelandicvolcanoes.is) intended to serve as an official source of information about volcanoes in Iceland for the public and decision makers. CIV contains text and graphic information on all 32 active volcanic systems in Iceland, as well as real-time data from monitoring systems in a format that enables non-specialists to understand the volcanic activity status. The CIV data portal contains scientific data on all eruptions since Eyjafjallajökull 2010 and is an unprecedented endeavour in making volcanological data open and easy to access. CIV forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the European Union funded effort FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. The supersite concept implies integration of space and ground based observations for improved monitoring and evaluation of volcanic hazards, and open data policy. This work is a collaboration of the Icelandic Meteorological Office, the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere.

  18. Not one extrastriate body area: Using anatomical landmarks, hMT+, and visual field maps to parcellate limb-selective activations in human lateral occipitotemporal cortex

    PubMed Central

    Weiner, Kevin S.; Grill-Spector, Kalanit

    2011-01-01

    The prevailing view of human lateral occipitotemporal cortex (LOTC) organization suggests a single area selective for images of the human body (extrastriate body area, EBA) that highly overlaps with the human motion-selective complex (hMT+). Using functional magnetic resonance imaging with higher resolution (1.5mm voxels) than past studies (3–4mm voxels), we examined the fine-scale spatial organization of these activations relative to each other, as well as to visual field maps in LOTC. Rather than one contiguous EBA highly overlapping hMT+, results indicate three limb-selective activations organized in a crescent surrounding hMT+: (1) an activation posterior to hMT+ on the lateral occipital sulcus/middle occipital gyrus (LOS/MOG) overlapping the lower vertical meridian shared between visual field maps LO-2 and TO-1, (2) an activation anterior to hMT+ on the middle temporal gyrus (MTG) consistently overlapping the lower vertical meridian of TO-2 and extending outside presently defined visual field maps, and (3) an activation inferior to hMT+ on the inferotemporal gyrus (ITG) overlapping the parafoveal representation of the TO cluster. This crescent organization of limb-selective activations surrounding hMT+ is reproducible over a span of three years and is consistent across different image types used for localization. Further, these regions exhibit differential position properties: preference for contralateral image presentation decreases and preference for foveal presentation increases from the limb-selective LOS to the MTG. Finally, the relationship between limb-selective activations and visual field maps extends to the dorsal stream where a posterior IPS activation overlaps V7. Overall, our measurements demonstrate a series of LOTC limb-selective activations that 1) have separate anatomical and functional boundaries, 2) overlap distinct visual field maps, and 3) illustrate differential position properties. These findings indicate that category selectivity

  19. Three-dimensional P-wave velocity structure of Mt. Etna, Italy

    USGS Publications Warehouse

    Villasenor, A.; Benz, H.M.; Filippi, L.; De Luca, G.; Scarpa, R.; Patane, G.; Vinciguerra, S.

    1998-01-01

    The three-dimensional P-wave velocity structure of Mt. Etna is determined to depths of 15 km by tomographic inversion of first arrival times from local earthquakes recorded by a network of 29 permanent and temporary seismographs. Results show a near-vertical low-velocity zone that extends from beneath the central craters to a depth of 10 km. This low-velocity region is coincident with a band of steeply-dipping seismicity, suggesting a magmatic conduit that feeds the summit eruptions. The most prominent structure is an approximately 8-km-diameter high-velocity body located between 2 and 12 km depth below the southeast flank of the volcano. This high-velocity body is interpreted as a remnant mafic intrusion that is an important structural feature influencing both volcanism and east flank slope stability and faulting.

  20. Exploring the Llaima Volcano Using Receiver Functions

    NASA Astrophysics Data System (ADS)

    Bishop, J. W.; Biryol, C.; Lees, J. M.

    2016-12-01

    The Llaima volcano in Chile is one of the most active volcanos in the Southern Andes, erupting at least 50 times since 1640. To understand the eruption dynamics behind these frequent paroxysms, it is important to identify the depth and extent of the magma chamber beneath the volcano. Furthermore, it is also important to identify structural controls on the magma storage regions and volcanic plumbing system, such as fault and fracture zones. To probe these questions, a dense, 26 station broadband seismic array was deployed around the Llaima volcano for 3 months (January to March, 2015). Additionally, broadband seismic data from 7 stations in the nearby Observatorio Volcanológico de Los Andes del Sur (OVDAS) seismic network was also obtained for this period. Teleseismic receiver functions were calculated from this combined data using an iterative deconvolution technique. Receiver function stacks (both H-K and CCP) yield seismic images of the deep structure beneath the volcano. Initial results depict two low velocity layers at approximately 4km and 12km. Furthermore, Moho calculations are 5-8 km deeper than expected from regional models, but a shallow ( 40 km) region is detected beneath the volcano peak. A large high Vp/Vs ratio anomaly (Vp/Vs > 0.185) is discernable to the east of the main peak of the volcano.

  1. Monitoring Mount Baker Volcano

    USGS Publications Warehouse

    Malone, S.D.; Frank, D.

    1976-01-01

    Hisotrically active volcanoes in the conterminous United States are restricted to the Cascade Range and extend to the Cascade Range and extend from Mount Baker near the Canadian border to Lassen Peak in northern California. Since 1800 A.D, most eruptive activity has been on a relatively small scale and has not caused loss of life or significant property damage. However, future  volcanism predictably will have more serious effects because of greatly increased use of land near volcanoes during the present century. (See "Appraising Volcanic Hazards of the Cascade Range of the Northwestern United States," Earthquake Inf. Bull., Sept.-Oct. 1974.) The recognition an impending eruption is highly important in order to minimize the potential hazard to people and property. Thus, a substantial increase in hydrothermal activity at Mount Baker in March 1975 ( see "Mount Baker Heating Up," July-Aug. 1975 issue) was regarded as a possible first signal that an eruption might occur, and an intensive monitoring program was undertaken. 

  2. Constraints on the geomorphological evolution of the nested summit craters of Láscar volcano from high spatio-temporal resolution TerraSAR-X interferometry

    NASA Astrophysics Data System (ADS)

    Richter, Nicole; Salzer, Jacqueline Tema; de Zeeuw-van Dalfsen, Elske; Perissin, Daniele; Walter, Thomas R.

    2018-03-01

    Small-scale geomorphological changes that are associated with the formation, development, and activity of volcanic craters and eruptive vents are often challenging to characterize, as they may occur slowly over time, can be spatially localized, and difficult, or dangerous, to access. Using high-spatial and high-temporal resolution synthetic aperture radar (SAR) imagery collected by the German TerraSAR-X (TSX) satellite in SpotLight mode in combination with precise topographic data as derived from Pléiades-1A satellite data, we investigate the surface deformation within the nested summit crater system of Láscar volcano, Chile, the most active volcano of the central Andes. Our aim is to better understand the structural evolution of the three craters that comprise this system, to assess their physical state and dynamic behavior, and to link this to eruptive activity and associated hazards. Using multi-temporal SAR interferometry (MT-InSAR) from ascending and descending orbital geometries, we retrieve the vertical and east-west components of the displacement field. This time series indicates constant rates of subsidence and asymmetric horizontal displacements of all summit craters between June 2012 and July 2014, as well as between January 2015 and March 2017. The vertical and horizontal movements that we observe in the central crater are particularly complex and cannot be explained by any single crater formation mechanism; rather, we suggest that short-term activities superimposed on a combination of ongoing crater evolution processes, including gravitational slumping, cooling and compaction of eruption products, as well as possible piston-like subsidence, are responsible for the small-scale geomorphological changes apparent in our data. Our results demonstrate how high-temporal resolution synthetic aperture radar interferometry (InSAR) time series can add constraints on the geomorphological evolution and structural dynamics of active crater and vent systems at

  3. The critical role of volcano monitoring in risk reduction

    USGS Publications Warehouse

    Tilling, R.I.

    2008-01-01

    Data from volcano-monitoring studies constitute the only scientifically valid basis for short-term forecasts of a future eruption, or of possible changes during an ongoing eruption. Thus, in any effective hazards-mitigation program, a basic strategy in reducing volcano risk is the initiation or augmentation of volcano monitoring at historically active volcanoes and also at geologically young, but presently dormant, volcanoes with potential for reactivation. Beginning with the 1980s, substantial progress in volcano-monitoring techniques and networks - ground-based as well space-based - has been achieved. Although some geochemical monitoring techniques (e.g., remote measurement of volcanic gas emissions) are being increasingly applied and show considerable promise, seismic and geodetic methods to date remain the techniques of choice and are the most widely used. Availability of comprehensive volcano-monitoring data was a decisive factor in the successful scientific and governmental responses to the reawakening of Mount St. Helens (Washington, USA) in 1980 and, more recently, to the powerful explosive eruptions at Mount Pinatubo (Luzon, Philippines) in 1991. However, even with the ever-improving state-ofthe-art in volcano monitoring and predictive capability, the Mount St. Helens and Pinatubo case histories unfortunately still represent the exceptions, rather than the rule, in successfully forecasting the most likely outcome of volcano unrest.

  4. Geologic map of Medicine Lake volcano, northern California

    USGS Publications Warehouse

    Donnelly-Nolan, Julie M.

    2011-01-01

    Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover more than 2,000 km2 east of the main axis of the Cascade Range in northern California. Across the Cascade Range axis to the west-southwest is Mount Shasta, its towering volcanic neighbor, whose stratocone shape contrasts with the broad shield shape of Medicine Lake volcano. Hidden in the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of Medicine Lake volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 8,000 ft (2,440 m). The maximum extent of lavas from this half-million-year-old volcano is about 80 km north-south by 45 km east-west. In postglacial time, 17 eruptions have added approximately 7.5 km3 to its total estimated volume of 600 km3, and it is considered to be the largest by volume among volcanoes of the Cascades arc. The volcano has erupted nine times in the past 5,200 years, a rate more frequent than has been documented at all other Cascades arc volcanoes except Mount St. Helens.

  5. Mount Meager Volcano, Canada: a Case Study for Landslides on Glaciated Volcanoes

    NASA Astrophysics Data System (ADS)

    Roberti, G. L.; Ward, B. C.; van Wyk de Vries, B.; Falorni, G.; Perotti, L.; Clague, J. J.

    2015-12-01

    Mount Meager is a strato-volcano massif in the Northern Cascade Volcanic Arc (Canada) that erupted in 2350 BP, the most recent in Canada. To study the stability of the Massif an international research project between France ( Blaise Pascal University), Italy (University of Turin) and Canada (Simon Fraser University) and private companies (TRE - sensing the planet) has been created. A complex history of glacial loading and unloading, combined with weak, hydrothermally altered rocks has resulted in a long record of catastrophic landslides. The most recent, in 2010 is the third largest (50 x 106 m3) historical landslide in Canada. Mount Meager is a perfect natural laboratory for gravity and topographic processes such as landslide activity, permafrost and glacial dynamics, erosion, alteration and uplift on volcanoes. Research is aided by a rich archive of aerial photos of the Massif (1940s up to 2006): complete coverage approximately every 10 years. This data set has been processed and multi-temporal, high resolution Orthophoto and DSMs (Digital Surface Models) have been produced. On these digital products, with the support on field work, glacial retreat and landslide activity have been tracked and mapped. This has allowed for the inventory of unstable areas, the identification of lava flows and domes, and the general improvement on the geologic knowledge of the massif. InSAR data have been used to monitor the deformation of the pre-2010 failure slope. It will also be used to monitor other unstable slopes that potentially can evolve to catastrophic collapses of up to 1 km3 in volume, endangering local communities downstream the volcano. Mount Meager is definitively an exceptional site for studying the dynamics of a glaciated, uplifted volcano. The methodologies proposed can be applied to other volcanic areas with high erosion rates such as Alaska, Cascades, and the Andes.

  6. Bi-directional volcano-earthquake interaction at Mauna Loa Volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Walter, T. R.; Amelung, F.

    2004-12-01

    At Mauna Loa volcano, Hawaii, large-magnitude earthquakes occur mostly at the west flank (Kona area), at the southeast flank (Hilea area), and at the east flank (Kaoiki area). Eruptions at Mauna Loa occur mostly at the summit region and along fissures at the southwest rift zone (SWRZ), or at the northeast rift zone (NERZ). Although historic earthquakes and eruptions at these zones appear to correlate in space and time, the mechanisms and implications of an eruption-earthquake interaction was not cleared. Our analysis of available factual data reveals the highly statistical significance of eruption-earthquake pairs, with a random probability of 5-to-15 percent. We clarify this correlation with the help of elastic stress-field models, where (i) we simulate earthquakes and calculate the resulting normal stress change at volcanic active zones of Mauna Loa, and (ii) we simulate intrusions in Mauna Loa and calculate the Coulomb stress change at the active fault zones. Our models suggest that Hilea earthquakes encourage dike intrusion in the SWRZ, Kona earthquakes encourage dike intrusion at the summit and in the SWRZ, and Kaoiki earthquakes encourage dike intrusion in the NERZ. Moreover, a dike in the SWRZ encourages earthquakes in the Hilea and Kona areas. A dike in the NERZ may encourage and discourage earthquakes in the Hilea and Kaoiki areas. The modeled stress change patterns coincide remarkably with the patterns of several historic eruption-earthquake pairs, clarifying the mechanisms of bi-directional volcano-earthquake interaction for Mauna Loa. The results imply that at Mauna Loa volcanic activity influences the timing and location of earthquakes, and that earthquakes influence the timing, location and the volume of eruptions. In combination with near real-time geodetic and seismic monitoring, these findings may improve volcano-tectonic risk assessment.

  7. Geochemical processes governing the compositional features of the crater fumarolic field at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Liotta, Marcello; Paonita, Antonio; Caracausi, Antonio; Martelli, Mauro; Rizzo, Andrea; Favara, Rocco

    2010-05-01

    Mt Etna is one of the most-active volcanoes in the world. It is characterized by major eruptions, frequent Strombolian activity, and ash emissions. The volcano summit consists of the central crater of Voragine surrounded by the three active cones of the North-East Crater, Bocca Nuova, and the South-East Crater. They are characterized by very fractured and unstable edges. Under these conditions most of the fractures represent preferential degassing pathways for volcanic fluids, so that the main fumarolic fields develop in such fractured areas. The geochemistry of the fumaroles at the summit area of Mt. Etna was investigated. Fumarolic samples were collected between June 2008 and August 2009. Gas samples were usually collected as 'dry gas' and analyzed for the concentrations of He, H2, O2, N2, CO, CH4, and CO2. Fumarolic gases were also sampled a few times using the classical Giggenbach bottles and Giggenbach-type bottles filled with ammonia and silver nitrate in order to determine the SO2/H2S ratio. In addition a novel method was employed in order to sample fumaroles characterized by high content of atmospheric gases. Two types of fumaroles were identified: low-temperature fumaroles, which are dominated by CO2 with minor amounts of SO2 and H2S, and negligible halogen contents, and high-temperature fumaroles, which are strongly air-contaminated and characterized by appreciable amounts of volcanogenic carbon, sulfur, and chlorine. Our data clearly indicate that secondary processes modify the composition of the fluids once they leave the magma body. A model based on thermodynamic data is proposed to explore such postmagmatic processes. We computed the equilibrium composition of magmatic gases that cool starting from magmatic temperatures under several pressure conditions. The model, which uses Etnean plume geochemistry as starting composition of fluids exsolved from magma, shows that SO2 and H2S control the redox conditions of the gas mixture during the cooling, until

  8. Three-dimensional resistivity structure of Furnas volcano (Azores archipelago, Portugal) revealed by magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Kiyan, Duygu; Hogg, Colin; Rath, Volker; Byrdina, Svetlana; Vandemeulebrouck, Jean; Revil, Andre; Silva, Catarina; Viveiros, Fatima; Ferreira, Teresa; Carmo, Rita

    2017-04-01

    The Furnas volcano is the eastern-most of the three active central volcanoes of Sao Miguel Island. The main caldera formed about 30 ka BP, followed by a younger eruption at 10-12 ka BP, which is responsible for the steep topography of more than 200 m in the target area. It contains several very young eruptive centers, and a shallow caldera lake. Tectonic features of varying directions have been identified in the caldera and its vicinity (Carmo et al., 2015). In the northern part of the caldera, containing the fumarole field of Caldeiras das Furnas, a detailed map of surface CO2 emissions was recently made available (Viveiros et al., 2010). Following a pilot survey of 13 AudioMagnetoTelluric soundings (AMT) and Electrical Resistivity Tomography (ERT) data collected along two profiles in the eastern part of Furnas caldera in 2015, a second campaign was completed in June 2016, yielding a total of 39 separate soundings including 15 broad-band magnetotelluric (MT) soundings to image the electrical conductivity of the subsurface. The data quality achieved by both techniques is very good, and initial results indicate a general correlation between regions of elevated conductivity at depth and the mapped surface CO2 emissions, suggesting that they may both be caused by the presence hydrothermal fluids. Dimensionality and directionality analysis using the WALDIM (Marti et al., 2009) approach in conjunction with Phase Tensor (Caldwell et al., 2004) indicate that the geo-electrical structure needs to be inverted in 3-D. Indicators of directionality derived from the analysis follow the general geological, fault dominated structural trend of NE-SW of Sao Miguel Island. A quantitative analysis of the potential influence of the Atlantic Ocean indicates that MT data up to 1 second period can be used in inversions with confidence without including the ocean. The 3-D inversions thus have been performed including only high-resolution topography and the Furnas lake bathymetry data

  9. Recent Seismicity in the Ceboruco Volcano, Western Mexico

    NASA Astrophysics Data System (ADS)

    Nunez, D.; Chávez-Méndez, M. I.; Nuñez-Cornu, F. J.; Sandoval, J. M.; Rodriguez-Ayala, N. A.; Trejo-Gomez, E.

    2017-12-01

    The Ceboruco volcano is the largest (2280 m.a.s.l) of several volcanoes along the Tepic-Zacoalco rift zone in Nayarit state (Mexico). During the last 1000 years, this volcano had effusive-explosive episodes with eight eruptions providing an average of one eruption each 125 years. Since the last eruption occurred in 1870, 147 years ago, a new eruption likelihood is really high and dangerous due to nearby population centers, important roads and lifelines that traverse the volcano's slopes. This hazards indicates the importance of monitoring the seismicity associated with the Ceboruco volcano whose ongoing activity is evidenced by fumaroles and earthquakes. During 2003 and 2008, this region was registered by just one Lennartz Marslite seismograph featuring a Lennartz Le3D sensor (1 Hz) [Rodríguez Uribe et al. (2013)] where they observed that seismicity rates and stresses appear to be increasing indicating higher levels of activity within the volcano. Until July 2017, a semi-permanent network with three Taurus (Nanometrics) and one Q330 Quanterra (Kinemetrics) digitizers with Lennartz 3Dlite sensors of 1 Hz natural frequency was registering in the area. In this study, we present the most recent seismicity obtained by the semi-permanent network and a temporary network of 21 Obsidians 4X and 8X (Kinemetrics) covering an area of 16 km x 16 km with one station every 2.5-3 km recording from November 2016 to July 2017.

  10. Operational Monitoring of Volcanoes Using Keyhole Markup Language

    NASA Astrophysics Data System (ADS)

    Dehn, J.; Bailey, J. E.; Webley, P.

    2007-12-01

    Volcanoes are some of the most geologically powerful, dynamic, visually appealing structures on the Earth's landscape. Volcanic eruptions are hard to predict, difficult to quantify and impossible to prevent, making effective monitoring a difficult proposition. In Alaska, volcanoes are an intrinsic part of the culture, with over 100 volcanoes and volcanic fields that have been active in historic time monitored by the Alaska Volcano Observatory (AVO). Observations and research are performed using a suite of methods and tools in the fields of remote sensing, seismology, geodesy and geology, producing large volumes of geospatial data. Keyhole Markup Language (KML) offers a context in which these different, and in the past disparate, data can be displayed simultaneously. Dynamic links keep these data current, allowing it to be used in an operational capacity. KML is used to display information from the aviation color codes and activity alert levels for volcanoes to locations of thermal anomalies, earthquake locations and ash plume modeling. The dynamic refresh and time primitive are used to display volcano webcam and satellite image overlays in near real-time. In addition a virtual globe browser using KML, such as Google Earth, provides an interface to further information using the hyperlink, rich- text and flash-embedding abilities supported within object description balloons. By merging these data sets in an easy to use interface, a virtual globe browser provides a better tool for scientists and emergency managers alike to mitigate volcanic crises.

  11. Understanding cyclic seismicity and ground deformation patterns at volcanoes: Intriguing lessons from Tungurahua volcano, Ecuador

    NASA Astrophysics Data System (ADS)

    Neuberg, Jürgen W.; Collinson, Amy S. D.; Mothes, Patricia A.; Ruiz, Mario C.; Aguaiza, Santiago

    2018-01-01

    Cyclic seismicity and ground deformation patterns are observed on many volcanoes worldwide where seismic swarms and the tilt of the volcanic flanks provide sensitive tools to assess the state of volcanic activity. Ground deformation at active volcanoes is often interpreted as pressure changes in a magmatic reservoir, and tilt is simply translated accordingly into inflation and deflation of such a reservoir. Tilt data recorded by an instrument in the summit area of Tungurahua volcano in Ecuador, however, show an intriguing and unexpected behaviour on several occasions: prior to a Vulcanian explosion when a pressurisation of the system would be expected, the tilt signal declines significantly, hence indicating depressurisation. At the same time, seismicity increases drastically. Envisaging that such a pattern could carry the potential to forecast Vulcanian explosions on Tungurahua, we use numerical modelling and reproduce the observed tilt patterns in both space and time. We demonstrate that the tilt signal can be more easily explained as caused by shear stress due to viscous flow resistance, rather than by pressurisation of the magmatic plumbing system. In general, our numerical models prove that if magma shear viscosity and ascent rate are high enough, the resulting shear stress is sufficient to generate a tilt signal as observed on Tungurahua. Furthermore, we address the interdependence of tilt and seismicity through shear stress partitioning and suggest that a joint interpretation of tilt and seismicity can shed new light on the eruption potential of silicic volcanoes.

  12. An Admittance Survey of Large Volcanoes on Venus: Implications for Volcano Growth

    NASA Technical Reports Server (NTRS)

    Brian, A. W.; Smrekar, S. E.; Stofan, E. R.

    2004-01-01

    Estimates of the thickness of the venusian crust and elastic lithosphere are important in determining the rheological and thermal properties of Venus. These estimates offer insights into what conditions are needed for certain features, such as large volcanoes and coronae, to form. Lithospheric properties for much of the large volcano population on Venus are not well known. Previous studies of elastic thickness (Te) have concentrated on individual or small groups of edifices, or have used volcano models and fixed values of Te to match with observations of volcano morphologies. In addition, previous studies use different methods to estimate lithospheric parameters meaning it is difficult to compare their results. Following recent global studies of the admittance signatures exhibited by the venusian corona population, we performed a similar survey into large volcanoes in an effort to determine the range of lithospheric parameters shown by these features. This survey of the entire large volcano population used the same method throughout so that all estimates could be directly compared. By analysing a large number of edifices and comparing our results to observations of their morphology and models of volcano formation, we can help determine the controlling parameters that govern volcano growth on Venus.

  13. A model of diffuse degassing at three subduction-related volcanoes

    NASA Astrophysics Data System (ADS)

    Williams-Jones, Glyn; Stix, John; Heiligmann, Martin; Charland, Anne; Sherwood Lollar, Barbara; Arner, N.; Garzón, Gustavo V.; Barquero, Jorge; Fernandez, Erik

    Radon, CO2 and δ13C in soil gas were measured at three active subduction-related stratovolcanoes (Arenal and Poás, Costa Rica; Galeras, Colombia). In general, Rn, CO2 and δ13C values are higher on the lower flanks of the volcanoes, except near fumaroles in the active craters. The upper flanks of these volcanoes have low Rn concentrations and light δ13C values. These observations suggest that diffuse degassing of magmatic gas on the upper flanks of these volcanoes is negligible and that more magmatic degassing occurs on the lower flanks where major faults and greater fracturing in the older lavas can channel magmatic gases to the surface. These results are in contrast to findings for Mount Etna where a broad halo of magmatic CO2 has been postulated to exist over much of the edifice. Differences in radon levels among the three volcanoes studied here may result from differences in age, the degree of fracturing and faulting, regional structures or the level of hydrothermal activity. Volcanoes, such as those studied here, act as plugs in the continental crust, focusing magmatic degassing towards crater fumaroles, faults and the fractured lower flanks.

  14. Genome sequence of two members of the chloroaromatic-degrading MT community: Pseudomonas reinekei MT1 and Achromobacter xylosoxidans MT3.

    PubMed

    Gutierrez-Urrutia, Izabook; Miossec, Matthieu J; Valenzuela, Sandro L; Meneses, Claudio; Dos Santos, Vitor A P Martins; Castro-Nallar, Eduardo; Poblete-Castro, Ignacio

    2018-06-10

    We describe the genome sequence of Pseudomonas reinekei MT1 and Achromobacter xylosoxidans MT3, the most abundant members of a bacterial community capable of degrading chloroaromatic compounds. The MT1 genome contains open reading frames encoding enzymes responsible for the catabolism of chlorosalicylate, methylsalicylate, chlorophenols, phenol, benzoate, p-coumarate, phenylalanine, and phenylacetate. On the other hand, the MT3 strain genome possesses no ORFs to metabolize chlorosalicylates; instead the bacterium is capable of metabolizing nitro-phenolic and phenolic compounds, which can be used as the only carbon and energy source by MT3. We also confirmed that MT3 displays the genetic machinery for the metabolism of chlorocathecols and chloromuconates, where the latter are toxic compounds secreted by MT1 when degrading chlorosalicylates. Altogether, this work will advance our fundamental understanding of bacterial interactions. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2005

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Estes, Steve; McNutt, Stephen R.

    2006-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at historically active volcanoes in Alaska since 1988 (Figure 1). The primary objectives of the seismic program are the real-time seismic monitoring of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog presents calculated earthquake hypocenters and seismic phase arrival data, and details changes in the seismic monitoring program for the period January 1 through December 31, 2005.The AVO seismograph network was used to monitor the seismic activity at thirty-two volcanoes within Alaska in 2005 (Figure 1). The network was augmented by two new subnetworks to monitor the Semisopochnoi Island volcanoes and Little Sitkin Volcano. Seismicity at these volcanoes was still being studied at the end of 2005 and has not yet been added to the list of permanently monitored volcanoes in the AVO weekly update. Following an extended period of monitoring to determine the background seismicity at the Mount Peulik, Ukinrek Maars, and Korovin Volcano, formal monitoring of these volcanoes began in 2005. AVO located 9,012 earthquakes in 2005.Monitoring highlights in 2005 include: (1) seismicity at Mount Spurr remaining above background, starting in February 2004, through the end of the year and into 2006; (2) an increase in seismicity at Augustine Volcano starting in May 2005, and continuing through the end of the year into 2006; (3) volcanic tremor and seismicity related to low-level strombolian activity at Mount Veniaminof in January to March and September; and (4) a seismic swarm at Tanaga Volcano in October and November.This catalog includes: (1) descriptions and locations of seismic instrumentation deployed in the field in 2005; (2) a

  16. Mantle fault zone beneath Kilauea Volcano, Hawaii.

    PubMed

    Wolfe, Cecily J; Okubo, Paul G; Shearer, Peter M

    2003-04-18

    Relocations and focal mechanism analyses of deep earthquakes (>/=13 kilometers) at Kilauea volcano demonstrate that seismicity is focused on an active fault zone at 30-kilometer depth, with seaward slip on a low-angle plane, and other smaller, distinct fault zones. The earthquakes we have analyzed predominantly reflect tectonic faulting in the brittle lithosphere rather than magma movement associated with volcanic activity. The tectonic earthquakes may be induced on preexisting faults by stresses of magmatic origin, although background stresses from volcano loading and lithospheric flexure may also contribute.

  17. Mantle fault zone beneath Kilauea Volcano, Hawaii

    USGS Publications Warehouse

    Wolfe, C.J.; Okubo, P.G.; Shearer, P.M.

    2003-01-01

    Relocations and focal mechanism analyses of deep earthquakes (???13 kilometers) at Kilauea volcano demonstrate that seismicity is focused on an active fault zone at 30-kilometer depth, with seaward slip on a low-angle plane, and other smaller, distinct fault zones. The earthquakes we have analyzed predominantly reflect tectonic faulting in the brittle lithosphere rather than magma movement associated with volcanic activity. The tectonic earthquakes may be induced on preexisting faults by stresses of magmatic origin, although background stresses from volcano loading and lithospheric flexure may also contribute.

  18. Initiative for the creation of an integrated infrastructure of European Volcano Observatories

    NASA Astrophysics Data System (ADS)

    Puglisi, G.; Bachelery, P.; Ferreira, T. J. L.; Vogfjörd, K. S.

    2012-04-01

    Active volcanic areas in Europe constitute a direct threat to millions of European citizens. The recent Eyjafjallajökull eruption also demonstrated that indirect effects of volcanic activity can present a threat to the economy and the lives of hundreds of million of people living in the whole continental area even in the case of activity of volcanoes with sporadic eruptions. Furthermore, due to the wide political distribution of the European territories, major activities of "European" volcanoes may have a worldwide impact (e.g. on the North Atlantic Ocean, West Indies included, and the Indian Ocean). Our ability to understand volcanic unrest and forecast eruptions depends on the capability of both the monitoring systems to effectively detect the signals generated by the magma rising and on the scientific knowledge necessary to unambiguously interpret these signals. Monitoring of volcanoes is the main focus of volcano observatories, which are Research Infrastructures in the ESFRI vision, because they represent the basic resource for researches in volcanology. In addition, their facilities are needed for the design, implementation and testing of new monitoring techniques. Volcano observatories produce a large amount of monitoring data and represent extraordinary and multidisciplinary laboratories for carrying out innovative joint research. The current distribution of volcano observatories in Europe and their technological state of the art is heterogeneous because of different types of volcanoes, different social requirements, operational structures and scientific background in the different volcanic areas, so that, in some active volcanic areas, observatories are lacking or poorly instrumented. Moreover, as the recent crisis of the ash in the skies over Europe confirms, the assessment of the volcanic hazard cannot be limited to the immediate areas surrounding active volcanoes. The whole European Community would therefore benefit from the creation of a network of

  19. Volcano-earthquake interaction at Mauna Loa volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Walter, Thomas R.; Amelung, Falk

    2006-05-01

    The activity at Mauna Loa volcano, Hawaii, is characterized by eruptive fissures that propagate into the Southwest Rift Zone (SWRZ) or into the Northeast Rift Zone (NERZ) and by large earthquakes at the basal decollement fault. In this paper we examine the historic eruption and earthquake catalogues, and we test the hypothesis that the events are interconnected in time and space. Earthquakes in the Kaoiki area occur in sequence with eruptions from the NERZ, and earthquakes in the Kona and Hilea areas occur in sequence with eruptions from the SWRZ. Using three-dimensional numerical models, we demonstrate that elastic stress transfer can explain the observed volcano-earthquake interaction. We examine stress changes due to typical intrusions and earthquakes. We find that intrusions change the Coulomb failure stress along the decollement fault so that NERZ intrusions encourage Kaoiki earthquakes and SWRZ intrusions encourage Kona and Hilea earthquakes. On the other hand, earthquakes decompress the magma chamber and unclamp part of the Mauna Loa rift zone, i.e., Kaoiki earthquakes encourage NERZ intrusions, whereas Kona and Hilea earthquakes encourage SWRZ intrusions. We discuss how changes of the static stress field affect the occurrence of earthquakes as well as the occurrence, location, and volume of dikes and of associated eruptions and also the lava composition and fumarolic activity.

  20. Lava lake activity at the summit of Kīlauea Volcano in 2016

    USGS Publications Warehouse

    Patrick, Matthew R.; Orr, Tim R.; Swanson, Donald A.; Elias, Tamar; Shiro, Brian

    2018-04-10

    The ongoing summit eruption at Kīlauea Volcano, Hawai‘i, began in March 2008 with the formation of the Overlook crater, within Halema‘uma‘u Crater. As of late 2016, the Overlook crater contained a large, persistently active lava lake (250 × 190 meters). The accessibility of the lake allows frequent direct observations, and a robust geophysical monitoring network closely tracks subtle changes at the summit. These conditions present one of the best opportunities worldwide for understanding persistent lava lake behavior and the geophysical signals associated with open-vent basaltic eruptions. In this report, we provide a descriptive and visual summary of lava lake activity during 2016, a year consisting of continuous lava lake activity. The lake surface was composed of large black crustal plates separated by narrow incandescent spreading zones. The dominant motion of the surface was normally from north to south, but spattering produced transient disruptions to this steady motion. Spattering in the lake was common, consisting of one or more sites on the lake margin. The Overlook crater was continuously modified by the deposition of spatter (often as a thin veneer) on the crater walls, with frequent collapses of this adhered lava into the lake. Larger collapses, involving lithic material from the crater walls, triggered several small explosive events that deposited bombs and lapilli around the Halema‘uma‘u Crater rim, but these did not threaten public areas. The lava lake level varied over several tens of meters, controlled primarily by changes in summit magma reservoir pressure (in part driven by magma supply rates) and secondarily by fluctuations in spattering and gas release from the lake (commonly involving gas pistoning). The lake emitted a persistent gas plume, normally averaging 1,000–8,000 metric tons per day (t/d) of sulfur dioxide (SO2), as well as a constant fallout of small juvenile and lithic particles, including Pele’s hair and tears. The

  1. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1, 2000 through December 31, 2001

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Estes, Steve; Moran, Seth C.; Paskievitch, John; McNutt, Stephen R.

    2002-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at potentially active volcanoes in Alaska since 1988 (Power and others, 1993; Jolly and others, 1996; Jolly and others, 2001). The primary objectives of this program are the seismic surveillance of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog reflects the status and evolution of the seismic monitoring program, and presents the basic seismic data for the time period January 1, 2000, through December 31, 2001. For an interpretation of these data and previously recorded data, the reader should refer to several recent articles on volcano related seismicity on Alaskan volcanoes in Appendix G.The AVO seismic network was used to monitor twenty-three volcanoes in real time in 2000-2001. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai Volcanic Group (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Great Sitkin Volcano, and Kanaga Volcano (Figure 1). AVO located 1551 and 1428 earthquakes in 2000 and 2001, respectively, on and around these volcanoes.Highlights of the catalog period (Table 1) include: volcanogenic seismic swarms at Shishaldin Volcano between January and February 2000 and between May and June 2000; an eruption at Mount Cleveland between February and May 2001; episodes of possible tremor at Makushin Volcano starting March 2001 and continuing through 2001, and two earthquake swarms at Great Sitkin Volcano in 2001.This catalog includes: (1) earthquake origin times

  2. Long-term changes in explosive and effusive behaviour at andesitic arc volcanoes: Chronostratigraphy of the Centre Hills Volcano, Montserrat

    NASA Astrophysics Data System (ADS)

    Coussens, Maya; Cassidy, Michael; Watt, Sebastian F. L.; Jutzeler, Martin; Talling, Peter J.; Barfod, Dan; Gernon, Thomas M.; Taylor, Rex; Hatter, Stuart J.; Palmer, Martin R.; Montserrat Volcano Observatory

    2017-03-01

    Volcanism on Montserrat (Lesser Antilles arc) has migrated southwards since the formation of the Silver Hills 2.5 Ma, and has formed three successively active volcanic centres. The Centre Hills volcano was the focus of volcanism from 1-0.4 Ma, before activity commenced at the currently active Soufrière Hills volcano. The history of activity at these two volcanoes provides an opportunity to investigate the pattern of volcano behaviour on an andesitic arc island over the lifetime of individual volcanoes. Here, we describe the pyroclastic stratigraphy of subaerial exposures around central Montserrat; identifying 11 thick (> 1 m) pumiceous units derived from sustained explosive eruptions of Centre Hills from 0.8-0.4 Ma. Over 10 other, less well- exposed pumiceous units have also been identified. The pumice-rich units are interbedded with andesite lava breccias derived from effusive, dome-forming eruptions of Centre Hills. The stratigraphy indicates that large (up to magnitude 5) explosive eruptions occurred throughout the history of Centre Hills, alongside effusive activity. This behaviour at Centre Hills contrasts with Soufrière Hills, where deposits from sustained explosive eruptions are much less common and restricted to early stages of activity at the volcano, from 175-130 ka. Subsequent eruptions at Soufriere Hills have been dominated by andesitic effusive eruptions. The bulk composition, petrography and mineral chemistry of volcanic rocks from Centre Hills and Soufrière Hills are similar throughout the history of both volcanoes, except for occasional, transient departures to different magma compositions, which mark shifts in vent location or dominant eruption style. For example, the final recorded eruption of Centre Hills, before the initiation of activity at Soufrière Hills, was more silicic than any other identified eruption on Montserrat; and the basaltic South Soufrière Hills episode marked the transition to the current stage of predominantly effusive

  3. Syrian Volcano

    NASA Image and Video Library

    2006-07-23

    This MOC image shows a small volcano in the Syria Planum region of Mars. Today, the lava flows that compose this small volcano are nearly hidden by a mantle of rough-textured, perhaps somewhat cemented, dust

  4. State of the hydrothermal activity of Soufrière of Guadeloupe volcano inferred by VLF surveys

    NASA Astrophysics Data System (ADS)

    Zlotnicki, J.; Vargemezis, G.; Mille, A.; Bruère, F.; Hammouya, G.

    2006-04-01

    La Soufrière (1467 m) is the active island arc volcano of Guadeloupe Island in the Lesser Antilles arc. Its historical eruptions are more or less violent phreatic outbursts the last of which, in 1976-1977, led to the evacuation of nearly 70 000 persons. The subsurface structure of the volcano consists of calderas, craters, and avalanche amphitheatres nested within the composite pile of eruptive products. Since the last magmatic eruption, dated ca. 1440 AD, the four phreatic eruptions have developed radial fractures on Soufrière dome favouring the development of a huge active hydrothermal system emphasized by a tropical environment. After the eruptions, the thermal state and the stable ground water flow are completely disorganised during several years during which the slow mineralization of rocks is becoming again preponderant. Sealing of fractures and decay of rocks permeability act as a cap for upward thermal transfers. Therefore Soufrière dome operates as a valve, resealing the hydrothermal system underlying the volcano thus providing over pressurization that could lead to the next phreatic eruption. In 1992 new small seismic swarms have appeared. Several of them are recorded every year while the emission of acid gas slowly increases. In order to recognise the superficial electrical resistive and conductive zones (less than 100 m depth) as well as the cavities on Soufrière volcano, we have made Very Low Frequency (VLF) surveys in 2000. Electrical conductive zones are clearly associated with major radial faults starting from the summit in which the hydrothermal activity takes place. In the continuation of these active hydrothermal fractures hot springs are located down slope. Conversely some of the resistive zones are associated with inactive clayed and sealed or opened faults. The distribution of the conductive zones allows detailing the state of the superficial part of the hydrothermal system of La Soufrière. The distribution of vertical clayed zones

  5. Sub-crustal seismic activity beneath Klyuchevskoy Volcano

    NASA Astrophysics Data System (ADS)

    Carr, M. J.; Droznina, S.; Levin, V. L.; Senyukov, S.

    2013-12-01

    Seismic activity is extremely vigorous beneath the Klyuchevskoy Volcanic Group (KVG). The unique aspect is the distribution in depth. In addition to upper-crustal seismicity, earthquakes take place at depths in excess of 20 km. Similar observations are known in other volcanic regions, however the KVG is unique in both the number of earthquakes and that they occur continuously. Most other instances of deep seismicity beneath volcanoes appear to be episodic or transient. Digital recording of seismic signals started at the KVG in early 2000s.The dense local network reliably locates earthquakes as small as ML~1. We selected records of 20 earthquakes located at depths over 20 km. Selection was based on the quality of the routine locations and the visual clarity of the records. Arrivals of P and S waves were re-picked, and hypocentral parameters re-established. Newl locations fell within the ranges outlined by historical seismicity, confirming the existence of two distinct seismically active regions. A shallower zone is at ~20 km depth, and all hypocenters are to the northeast of KVG, in a region between KVG and Shiveluch volcano. A deeper zone is at ~30 km, and all hypocenters cluster directly beneath the edifice of the Kyuchevskoy volcano. Examination of individual records shows that earthquakes in both zones are tectonic, with well-defined P and S waves - another distinction of the deep seismicity beneath KVG. While the upper seismic zone is unquestionably within the crust, the provenance of the deeper earthquakes is enigmatic. The crustal structure beneath KVG is highly complex, with no agreed-upon definition of the crust-mantle boundary. Rather, a range of values, from under 30 to over 40 km, exists in the literature. Similarly, a range of velocity structures has been reported. Teleseismic receiver functions (RFs) provide a way to position the earthquakes with respect to the crust-mantle boundary. We compare the differential travel times of S and P waves from deep

  6. Iceland Volcano

    Atmospheric Science Data Center

    2013-04-23

    article title:  Eyjafjallajökull, Iceland, Volcano Ash Cloud     View larger ... Europe and captured this image of the Eyjafjallajökull Volcano ash cloud as it continued to drift over the continent. Unlike other ...

  7. Measuring Gases Using Drones at Turrialba Volcano, Costa Rica

    NASA Astrophysics Data System (ADS)

    Stix, J.; Alan, A., Jr.; Corrales, E.; D'Arcy, F.; de Moor, M. J.; Diaz, J. A.

    2016-12-01

    We are currently developing a series of drones and associated instrumentation to study Turrialba volcano in Costa Rica. This volcano has shown increasing activity during the last 20 years, and the volcano is currently in a state of heightened unrest as exemplified by recent explosive activity in May-August 2016. The eruptive activity has made the summit area inaccessible to normal gas monitoring activities, prompting development of new techniques to measure gas compositions. We have been using two drones, a DJI Spreading Wings S1000 octocopter and a Turbo Ace Matrix-i quadcopter, to airlift a series of instruments to measure volcanic gases in the plume of the volcano. These instruments comprise optical and electrochemical sensors to measure CO2, SO2, and H2S concentrations which are considered the most significant species to help forecast explosive eruptions and determine the relative proportions of magmatic and hydrothermal components in the volcanic gas. Additionally, cameras and sensors to measure air temperature, relative humidity, atmospheric pressure, and GPS location are included in the package to provide meteorological and geo-referenced information to complement the concentration data and provide a better picture of the volcano from a remote location. The integrated payloads weigh 1-2 kg, which can typically be flown by the drones in 10-20 minutes at altitudes of 2000-4000 meters. Preliminary tests at Turrialba in May 2016 have been very encouraging, and we are in the process of refining both the drones and the instrumentation packages for future flights. Our broader goals are to map gases in detail with the drones in order to make flux measurements of each species, and to apply this approach at other volcanoes.

  8. Efficient inversion of volcano deformation based on finite element models : An application to Kilauea volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Charco, María; González, Pablo J.; Galán del Sastre, Pedro

    2017-04-01

    The Kilauea volcano (Hawaii, USA) is one of the most active volcanoes world-wide and therefore one of the better monitored volcanoes around the world. Its complex system provides a unique opportunity to investigate the dynamics of magma transport and supply. Geodetic techniques, as Interferometric Synthetic Aperture Radar (InSAR) are being extensively used to monitor ground deformation at volcanic areas. The quantitative interpretation of such surface ground deformation measurements using geodetic data requires both, physical modelling to simulate the observed signals and inversion approaches to estimate the magmatic source parameters. Here, we use synthetic aperture radar data from Sentinel-1 radar interferometry satellite mission to image volcano deformation sources during the inflation along Kilauea's Southwest Rift Zone in April-May 2015. We propose a Finite Element Model (FEM) for the calculation of Green functions in a mechanically heterogeneous domain. The key aspect of the methodology lies in applying the reciprocity relationship of the Green functions between the station and the source for efficient numerical inversions. The search for the best-fitting magmatic (point) source(s) is generally conducted for an array of 3-D locations extending below a predefined volume region. However, our approach allows to reduce the total number of Green functions to the number of the observation points by using the, above mentioned, reciprocity relationship. This new methodology is able to accurately represent magmatic processes using physical models capable of simulating volcano deformation in non-uniform material properties distribution domains, which eventually will lead to better description of the status of the volcano.

  9. Mauna Loa--history, hazards and risk of living with the world's largest volcano

    USGS Publications Warehouse

    Trusdell, Frank A.

    2012-01-01

    Mauna Loa on the Island Hawaiʻi is the world’s largest volcano. People residing on its flanks face many hazards that come with living on or near an active volcano, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and local tsunami (giant seawaves). The County of Hawaiʻi (Island of Hawaiʻi) is the fastest growing County in the State of Hawaii. Its expanding population and increasing development mean that risk from volcano hazards will continue to grow. U.S. Geological Survey (USGS) scientists at the Hawaiian Volcano Observatory (HVO) closely monitor and study Mauna Loa Volcano to enable timely warning of hazardous activity and help protect lives and property.

  10. A wireless sensor network for monitoring volcano-seismic signals

    NASA Astrophysics Data System (ADS)

    Lopes Pereira, R.; Trindade, J.; Gonçalves, F.; Suresh, L.; Barbosa, D.; Vazão, T.

    2014-12-01

    Monitoring of volcanic activity is important for learning about the properties of each volcano and for providing early warning systems to the population. Monitoring equipment can be expensive, and thus the degree of monitoring varies from volcano to volcano and from country to country, with many volcanoes not being monitored at all. This paper describes the development of a wireless sensor network (WSN) capable of collecting geophysical measurements on remote active volcanoes. Our main goals were to create a flexible, easy-to-deploy and easy-to-maintain, adaptable, low-cost WSN for temporary or permanent monitoring of seismic tremor. The WSN enables the easy installation of a sensor array in an area of tens of thousands of m2, allowing the location of the magma movements causing the seismic tremor to be calculated. This WSN can be used by recording data locally for later analysis or by continuously transmitting it in real time to a remote laboratory for real-time analyses. We present a set of tests that validate different aspects of our WSN, including a deployment on a suspended bridge for measuring its vibration.

  11. Real-Time Data Received from Mount Erebus Volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Aster, Richard; McIntosh, William; Kyle, Philip; Esser, Richard; Bartel, Beth Ann; Dunbar, Nelia; Johns, Bjorn; Johnson, Jeffrey B.; Karstens, Richard; Kurnik, Chuck; McGowan, Murray; McNamara, Sara; Meertens, Chuck; Pauley, Bruce; Richmond, Matt; Ruiz, Mario

    2004-03-01

    Internal and eruptive volcano processes involve complex interactions of multi-phase fluids with the solid Earth and the atmosphere, and produce diverse geochemical, visible, thermal, elastic, and anelastic effects. Multidisciplinary experimental agendas are increasingly being employed to meet the challenge of understanding active volcanoes and their hazards [e.g., Ripepe et al., 2002; Wallace et al., 2003]. Mount Erebus is a large (3794 m) stratovolcano that forms the centerpiece of Ross Island, Antarctica, the site of the principal U.S. (McMurdo) and New Zealand (Scott) Antarctic bases. With an elevation of 3794 m and a volume of ~1670 km3, Erebus offers exceptional opportunities for extended study of volcano processes because of its persistent, low-level, strombolian activity (Volcano Explosivity Index 0-1) and exposed summit magma reservoir (manifested as a long-lived phonolitic lava lake). Key scientific questions include linking conduit processes to near-field deformations [e.g., Aster et al., 2003], explosion physics [e.g., Johnson et al., 2003], magmatic differentiation and residence [e.g., Kyle et al., 1992], and effects on Antarctic atmospheric and ice geochemistry [e.g., Zreda-Gostynska et al., 1997]. The close proximity of Erebus (35 km) to McMurdo, and its characteristic dry, windy, cold, and high-elevation Antarctic environment, make the volcano a convenient test bed for the general development of volcano surveillance and other instrumentation under extreme conditions.

  12. Rainwater chemistry at a high-altitude station, Mt. Lulin, Taiwan: Comparison with a background station, Mt. Fuji

    NASA Astrophysics Data System (ADS)

    Wai, Ka Ming; Lin, Neng-Huei; Wang, Sheng-Hsiang; Dokiya, Yukiko

    2008-03-01

    Samples of rainwater were collected at a high-altitude site in east Asia between April 2003 and May 2005. The volume weighted mean pH value for the whole sampling period was 5.12, approaching that of typical natural water. Non-sea-salt (nss) SO42- and NH4+ were the most abundant anion and cation, respectively, both existing mostly in the form of (NH4)2SO4. Chloride was excessive in most of the samples. The signature of biomass burning in south and Southeast Asia was evident in the Mt. Lulin samples. Concentrations of chemical species were found to be elevated in the spring months, owing to the emissions from south/Southeast Asia and peak biomass burning activities and frequent dust storms (in the Indian Thar Desert). In the summer and fall seasons our samples are mainly influenced by marine air masses. The episodic species concentrations measured at the summit of Mt. Fuji during the spring were due to the influence of volcanic emissions from Miyake-Jima. Tropical cyclones (TC) over the western Pacific region and deep convections play important roles in the transport of boundary layer pollutants to the free troposphere, although their influence is not frequently detected at Mt. Lulin and Mt. Fuji. The rainwater chemistry at Mt. Lulin and Mt. Fuji were examined together with the aerosol chemistry obtained from the TRACE-P and ACE-Asia campaigns. The analysis of the Mt. Lulin data set demonstrates its background characteristics of the rainwater chemistry in east Asia.

  13. Nyiragonga Volcano

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image of the Nyiragonga volcano eruption in the Congo was acquired on January 28, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters about 50 to 300 feet ), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    Image: A river of molten rock poured from the Nyiragongo volcano in the Congo on January 18, 2002, a day after it erupted, killing dozens, swallowing buildings and forcing hundreds of thousands to flee the town of Goma. The flow continued into Lake Kivu. The lave flows are depicted in red on the image indicating they are still hot. Two of them flowed south form the volcano's summit and went through the town of Goma. Another flow can be seen at the top of the image, flowing towards the northwest. One of Africa's most notable volcanoes, Nyiragongo contained an active lava lake in its deep summit crater that drained catastrophically through its outer flanks in 1977. Extremely fluid, fast-moving lava flows draining from the summit lava lake in 1977 killed 50 to 100 people, and several villages were destroyed. The image covers an area of 21 x 24 km and combines a thermal band in red, and two infrared bands in green and blue.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the

  14. The activity of the Colima volcano and morphological changes in the summit between 2004 and 2013

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Camarena Garcia, M. A.

    2013-05-01

    Colima Volcano, located in the West of the Volcanic Mexican Belt (19° 30.696 N, 103° 37.026 W), has shown a new cycle of explosive activity beginning May 30 1999, and reaching its maximum in March-April of 2005 and January 2013. In the 2005 the explosive activity increased gradually, having the largest event on May 23, when a new dome was created. Hours later this dome was destroyed by a strong explosion, forming an ash column 5.6 km high with subsequent pyroclastic flows that reached a distance of 4.2 km flowing along the ravines of the South sector. On May 30 the most intense explosion in 1999 occurred, when the plume reached heights in excess of 4.4 km above the crater, and pyroclastic flows were created. On the same year in July two explosive events occurred of characteristics similar to those in May. These constant explosions caused continuous morphological changes in the summit, the most significant being the collapse of the North and South walls of the crater, in the first week of June of 2005, and the creation of a new crater in July. In 2006 the most significant explosive activity took place during April, May and July, when the eruptive columns reached heights of more than 1500 meters above the crater, occasionally forming small pyroclastic flows. In May of 2007 morphological changes were observed in the summit. Among them a crater explosion on the East side, a dome was formed on the West side, with 20 m in high and 50 m in diameter. Since the end of 2008 to December of 2012 the volcano remained calm, with a dome diameter of 220 m and height of 60 m, in January 2013 three explosions occurred, destroying the dome and throwing a volume of 1.5 million cubic meters. The eruptive column reached a height of 3000 above the crater. It reported light ashfall to the NE to 100 km away from the volcano. The explosive events continue to date, but they have diminished in size and intensity. This activity was similar to the one observed in 1902-1903 and reported by

  15. Seismic image of a CO2 reservoir beneath a seismically active volcano

    USGS Publications Warehouse

    Julian, B.R.; Pitt, A.M.; Foulger, G.R.

    1998-01-01

    Mammoth Mountain is a seismically active volcano 200 000 to 50 000 years old, situated on the southwestern rim of Long Valley caldera, California. Since 1989 it has shown evidence of unrest in the form of earthquake swarms (Hill et al. 1990), volcanic 'long-period' earthquakes (Pitt and Hill 1994), increased output of magmatic 3He (Sorey et al. 1993) and the emission of about 500 tonnes day-1 of CO2 (Farrar et al. 1995; Hill 1996; M. Sorey, personal communication, 1997) which has killed trees and poses a threat to human safety. Local-earthquake tomography shows that in mid-1989 areas of subsequent tree-kill were underlain by extensive regions where the ratio of the compressional and shear elastic-wave speeds Vp/VS was about 9% lower than in the surrounding rocks. Theory (Mavko and Mukerji 1995), experiment (Ito, DeVilbiss and Nur 1979) and experience at other geothermal/volcanic areas (Julian et al. 1996) and at petroleum reservoirs (Harris et al. 1996) indicate that Vp/VS is sensitive to pore-fluid compressibility, through its effect on Vp. The observed Vp/VS anomaly is probably caused directly by CO2, and seismic Vp/VS tomography is thus a promising tool for monitoring gas concentration and movement in volcanoes, which may in turn be related to volcanic activity.

  16. Radial anisotropy ambient noise tomography of volcanoes

    NASA Astrophysics Data System (ADS)

    Mordret, Aurélien; Rivet, Diane; Shapiro, Nikolai; Jaxybulatov, Kairly; Landès, Matthieu; Koulakov, Ivan; Sens-Schönfelder, Christoph

    2016-04-01

    The use of ambient seismic noise allows us to perform surface-wave tomography of targets which could hardly be imaged by other means. The frequencies involved (~ 0.5 - 20 s), somewhere in between active seismic and regular teleseismic frequency band, make possible the high resolution imaging of intermediate-size targets like volcanic edifices. Moreover, the joint inversion of Rayleigh and Love waves dispersion curves extracted from noise correlations allows us to invert for crustal radial anisotropy. We present here the two first studies of radial anisotropy on volcanoes by showing results from Lake Toba Caldera, a super-volcano in Indonesia, and from Piton de la Fournaise volcano, a hot-spot effusive volcano on the Réunion Island (Indian Ocean). We will see how radial anisotropy can be used to infer the main fabric within a magmatic system and, consequently, its dominant type of intrusion.

  17. Use of SAR data to study active volcanoes in Alaska

    USGS Publications Warehouse

    Dean, K.G.; Engle, K.; Lu, Z.; Eichelberger, J.; Near, T.; Doukas, M.

    1996-01-01

    Synthetic Aperture Radar (SAR) data of the Westdahl, Veniaminof, and Novarupta volcanoes in the Aleutian Arc of Alaska were analysed to investigate recent surface volcanic processes. These studies support ongoing monitoring and research by the Alaska Volcano Observatory (AVO) in the North Pacific Ocean Region. Landforms and possible crustal deformation before, during, or after eruptions were detected and analysed using data from the European Remote Sensing Satellites (ERS), the Japanese Earth Resources Satellite (JERS) and the US Seasat platforms. Field observations collected by scientists from the AVO were used to verify the results from the analysis of SAR data.

  18. A large hydrothermal reservoir beneath Taal Volcano (Philippines) revealed by magnetotelluric observations and its implications to the volcanic activity.

    PubMed

    Alanis, Paul K B; Yamaya, Yusuke; Takeuchi, Akihiro; Sasai, Yoichi; Okada, Yoshihiro; Nagao, Toshiyasu

    2013-01-01

    Taal Volcano is one of the most active volcanoes in the Philippines. The magnetotelluric 3D forward analyses indicate the existence of a large high resistivity anomaly (∼100 Ω·m) with a volume of at least 3 km×3 km×3 km, which is capped by a conductive layer (∼10 Ω·m), beneath the Main Crater. This high resistivity anomaly is hypothesized to be a large hydrothermal reservoir, consisting of the aggregate of interconnected cracks in rigid and dense host rocks, which are filled with hydrothermal fluids coming from a magma batch below the reservoir. The hydrothermal fluids are considered partly in gas phase and liquid phase. The presence of such a large hydrothermal reservoir and the stagnant magma below may have influences on the volcano's activity. Two possibilities are presented. First, the 30 January 1911 explosion event was a magmatic hydrothermal eruption rather than a base-surge associated with a phreato-magmatic eruption. Second, the earlier proposed four eruption series may be better interpreted by two cycles, each consisting of series of summit and flank eruptions.

  19. Seismic structure beneath Mt Vesuvius from receiver function analysis and local earthquakes tomography: evidences for location and geometry of the magma chamber

    NASA Astrophysics Data System (ADS)

    Agostinetti, N. Piana; Chiarabba, C.

    2008-12-01

    The recognition and localization of magmatic fluids are pre-requisites for evaluating the volcano hazard of the highly urbanized area of Mt Vesuvius. Here we show evidence and constraints for the volumetric estimation of magmatic fluids underneath this sleeping volcano. We use Receiver Functions for teleseismic data recorded at a temporary broad-band station installed on the volcano to constrain the S-wave velocity structure in the crust. Receiver Functions are analysed and inverted using the Neighbourhood Algorithm approach. The 1-D S-velocity profile is jointly interpreted and discussed with a new Vp and Vp/Vs image obtained by applying double difference tomographic techniques to local earthquakes. Seismologic data define the geometry of an axial, cylindrical high Vp, high Vs body consisting of a shallow solidified materials, probably the remnants of the caldera, and ultramafic rocks paving the crustal magma chamber. Between these two anomalies, we find a small region where the shear wave velocity drops, revealing the presence of magma at relatively shallow depths. The volume of fluids (30 km3) is sufficient to contribute future explosive eruptions.

  20. Volcan Baru: Eruptive History and Volcano-Hazards Assessment

    USGS Publications Warehouse

    Sherrod, David R.; Vallance, James W.; Tapia Espinosa, Arkin; McGeehin, John P.

    2008-01-01

    Volcan Baru is a potentially active volcano in western Panama, about 35 km east of the Costa Rican border. The volcano has had four eruptive episodes during the past 1,600 years, including its most recent eruption about 400?500 years ago. Several other eruptions occurred in the prior 10,000 years. Several seismic swarms in the 20th century and a recent swarm in 2006 serve as reminders of a restless tectonic terrane. Given this history, Volcan Baru likely will erupt again in the near or distant future, following some premonitory period of seismic activity and subtle ground deformation that may last for days or months. Future eruptions will likely be similar to past eruptions?explosive and dangerous to those living on the volcano?s flanks. Outlying towns and cities could endure several years of disruption in the wake of renewed volcanic activity. Described in this open-file report are reconnaissance mapping and stratigraphic studies, radiocarbon dating, lahar-inundation modeling, and hazard-analysis maps. Existing data have been compiled and included to make this report as comprehensive as possible. The report is prepared in coooperation with National Secretariat for Science, Technology and Innovation (SENACYT) of the Republic of Panama and the U.S. Agency for International Development (USAID).

  1. Applications of geophysical methods to volcano monitoring

    USGS Publications Warehouse

    Wynn, Jeff; Dzurisin, Daniel; Finn, Carol A.; Kauahikaua, James P.; Lahusen, Richard G.

    2006-01-01

    The array of geophysical technologies used in volcano hazards studies - some developed originally only for volcano monitoring - ranges from satellite remote sensing including InSAR to leveling and EDM surveys, campaign and telemetered GPS networks, electronic tiltmeters and strainmeters, airborne magnetic and electromagnetic surveys, short-period and broadband seismic monitoring, even microphones tuned for infrasound. They include virtually every method used in resource exploration except large-scale seismic reflection. By “geophysical ” we include both active and passive methods as well as geodetic technologies. Volcano monitoring incorporates telemetry to handle high-bandwith cameras and broadband seismometers. Critical geophysical targets include the flux of magma in shallow reservoir and lava-tube systems, changes in active hydrothermal systems, volcanic edifice stability, and lahars. Since the eruption of Mount St. Helens in Washington State in 1980, and the eruption at Pu’u O’o in Hawai’i beginning in 1983 and still continuing, dramatic advances have occurred in monitoring technology such as “crisis GIS” and lahar modeling, InSAR interferograms, as well as gas emission geochemistry sampling, and hazards mapping and eruption predictions. The on-going eruption of Mount St. Helens has led to new monitoring technologies, including advances in broadband Wi-Fi and satellite telemetry as well as new instrumentation. Assessment of the gap between adequate monitoring and threat at the 169 potentially dangerous Holocene volcanoes shows where populations are dangerously exposed to volcanic catastrophes in the United States and its territories . This paper focuses primarily on Hawai’ian volcanoes and the northern Pacific and Cascades volcanoes. The US Geological Survey, the US National Park System, and the University of Utah cooperate in a program to monitor the huge Yellowstone volcanic system, and a separate observatory monitors the restive Long Valley

  2. Volcano hazards program in the United States

    USGS Publications Warehouse

    Tilling, R.I.; Bailey, R.A.

    1985-01-01

    Volcano monitoring and volcanic-hazards studies have received greatly increased attention in the United States in the past few years. Before 1980, the Volcanic Hazards Program was primarily focused on the active volcanoes of Kilauea and Mauna Loa, Hawaii, which have been monitored continuously since 1912 by the Hawaiian Volcano Observatory. After the reawakening and catastrophic eruption of Mount St. Helens in 1980, the program was substantially expanded as the government and general public became aware of the potential for eruptions and associated hazards within the conterminous United States. Integrated components of the expanded program include: volcanic-hazards assessment; volcano monitoring; fundamental research; and, in concert with federal, state, and local authorities, emergency-response planning. In 1980 the David A. Johnston Cascades Volcano Observatory was established in Vancouver, Washington, to systematically monitor the continuing activity of Mount St. Helens, and to acquire baseline data for monitoring the other, presently quiescent, but potentially dangerous Cascade volcanoes in the Pacific Northwest. Since June 1980, all of the eruptions of Mount St. Helens have been predicted successfully on the basis of seismic and geodetic monitoring. The largest volcanic eruptions, but the least probable statistically, that pose a threat to western conterminous United States are those from the large Pleistocene-Holocene volcanic systems, such as Long Valley caldera (California) and Yellowstone caldera (Wyoming), which are underlain by large magma chambers still potentially capable of producing catastrophic caldera-forming eruptions. In order to become better prepared for possible future hazards associated with such historically unpecedented events, detailed studies of these, and similar, large volcanic systems should be intensified to gain better insight into caldera-forming processes and to recognize, if possible, the precursors of caldera-forming eruptions

  3. Afro-alpine forest cover change on Mt. Guna (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Birhanu, Adugnaw; Frankl, Amaury; Jacob, Miro; Lanckriet, Sil; Hendrickx, Hanne; Nyssen, Jan

    2016-04-01

    High mountain forests, such as the afro-alpine Erica arborea L. forests in Ethiopia, are very important for the livelihood of local communities, in relation to their impacts on the water balance of mountain ecosystems and surrounding agricultural areas. On volcanoes, the dominance of volcanic tuffs on the slopes, as well as that of gelifracts near the top further enhances infiltration, making it recharge areas. Earlier forest cover change studies in the Ethiopian highlands mainly deal with the lower vegetation belts. In this study, 3.37 km² on the western slopes of Mount Guna (one of the dozens of Miocene shield volcanoes that exist on top of the Ethiopian plateau) was mapped. The slope has an elevation between 3200 at its base and 4113 m a.s.l. at the peak. The present forest cover was recorded from high-resolution georeferenced satellite imagery from Google Maps and field data (2015), while historical forest cover was studied from georeferenced aerial photographs of 1982. In addition, key informant interviews were conducted to identify the trend of forest cover change and management practices. Whereas burning of the Erica forest for sake of land clearance (a typical practice on all Ethiopian mountains until the 1980s) most strikingly took place for three consecutive days in 1975, large-scale deforestation resulting from agricultural expansion and livestock pressure continued thereafter. However, between 2000 and 2014, due to active involvement of local and governmental institutions there was a slight regeneration of the vegetation and the Erica forest. Protection and regeneration of the forest was particularly efficient after it was given into custody of an orthodox church established in 1999 at the lower side of the forest. Overall, the study revealed that human and livestock pressures are the strongest drivers of deforestation. Furthermore, the study indicated that integrating the actions of local and governmental institutions is key for the protection of the

  4. Evidence for magma convection to shallow depths during quiescent degassing of Mt. Etna

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Mike, Burton; Giovanni, Salerno Giuseppe

    2015-04-01

    Mt. Etna, Italy, is one of the most intensely studied persistently active volcanoes in the world, and represents an important resource for volcanologists to better understand volcanic processes through quantitative empirical observations. Here we present the integrated results of open-path Fourier transform infrared (OP-FTIR) measurements of relative amounts of SO2, HCl and HF within the volcanic plume produced during quiescent degassing, and SO2 fluxes measured with an automatic network of scanning ultraviolet spectrometers in the period 2007-2009. The objective of this investigation is to better understand the magma dynamics which control gas release at this volcano, allowing a deeper insight into the interpretation of gas composition data in general for volcanology. During 2007-2009, SO2/HCl and SO2/HF molar ratios measured with solar OP-FTIR showed a progressive increase during an eruptive events which began on May 13th 2008, and some peaks related to 2007 activity at the Southeast crater (SEC). The cumulative amounts of SO2 and HCl emitted by Mt. Etna indicate that between eruptions over brief periods of time these two gases may be uncoupled, over longer periods they behave in a close-to-bulk degassing manner, such that the totality of gas released is that which would be expected based on original and final volatile contents measured using petrological analyses of eruptive products. Conversely, during the low-intensity but long-lived effusive eruption from May 2008 to July 2009 a dramatic departure from bulk degassing behaviour was observed, with halogen fluxes dropping significantly relative to SO2 flux. These measurements therefore provide compelling evidence that it is the shallow storage of magma at Etna (~10-20 MPa) which produces the majority of the observed halogen flux between eruptions. These observations allow us to propose a qualitative interpretative model for variations in SO2, HCl, HF amounts. We propose that a decreasing in the observed SO2

  5. Analysis of the fractal dimension of volcano geomorphology through Synthetic Aperture Radar (SAR) amplitude images acquired in C and X band.

    NASA Astrophysics Data System (ADS)

    Pepe, S.; Di Martino, G.; Iodice, A.; Manzo, M.; Pepe, A.; Riccio, D.; Ruello, G.; Sansosti, E.; Tizzani, P.; Zinno, I.

    2012-04-01

    In the last two decades several aspects relevant to volcanic activity have been analyzed in terms of fractal parameters that effectively describe natural objects geometry. More specifically, these researches have been aimed at the identification of (1) the power laws that governed the magma fragmentation processes, (2) the energy of explosive eruptions, and (3) the distribution of the associated earthquakes. In this paper, the study of volcano morphology via satellite images is dealt with; in particular, we use the complete forward model developed by some of the authors (Di Martino et al., 2012) that links the stochastic characterization of amplitude Synthetic Aperture Radar (SAR) images to the fractal dimension of the imaged surfaces, modelled via fractional Brownian motion (fBm) processes. Based on the inversion of such a model, a SAR image post-processing has been implemented (Di Martino et al., 2010), that allows retrieving the fractal dimension of the observed surfaces, dictating the distribution of the roughness over different spatial scales. The fractal dimension of volcanic structures has been related to the specific nature of materials and to the effects of active geodynamic processes. Hence, the possibility to estimate the fractal dimension from a single amplitude-only SAR image is of fundamental importance for the characterization of volcano structures and, moreover, can be very helpful for monitoring and crisis management activities in case of eruptions and other similar natural hazards. The implemented SAR image processing performs the extraction of the point-by-point fractal dimension of the scene observed by the sensor, providing - as an output product - the map of the fractal dimension of the area of interest. In this work, such an analysis is performed on Cosmo-SkyMed, ERS-1/2 and ENVISAT images relevant to active stratovolcanoes in different geodynamic contexts, such as Mt. Somma-Vesuvio, Mt. Etna, Vulcano and Stromboli in Southern Italy, Shinmoe

  6. Establishment, test and evaluation of a prototype volcano surveillance system

    NASA Technical Reports Server (NTRS)

    Ward, P. L.; Eaton, J. P.; Endo, E.; Harlow, D.; Marquez, D.; Allen, R.

    1973-01-01

    A volcano-surveillance system utilizing 23 multilevel earthquake counters and 6 biaxial borehole tiltmeters is being installed and tested on 15 volcanoes in 4 States and 4 foreign countries. The purpose of this system is to give early warning when apparently dormant volcanoes are becoming active. The data are relayed through the ERTS-Data Collection System to Menlo Park for analysis. Installation was completed in 1972 on the volcanoes St. Augustine and Iliamna in Alaska, Kilauea in Hawaii, Baker, Rainier and St. Helens in Washington, Lassen in California, and at a site near Reykjavik, Iceland. Installation continues and should be completed in April 1973 on the volcanoes Santiaguito, Fuego, Agua and Pacaya in Guatemala, Izalco in El Salvador and San Cristobal, Telica and Cerro Negro in Nicaragua.

  7. Multiphase modelling of mud volcanoes

    NASA Astrophysics Data System (ADS)

    Colucci, Simone; de'Michieli Vitturi, Mattia; Clarke, Amanda B.

    2015-04-01

    Mud volcanism is a worldwide phenomenon, classically considered as the surface expression of piercement structures rooted in deep-seated over-pressured sediments in compressional tectonic settings. The release of fluids at mud volcanoes during repeated explosive episodes has been documented at numerous sites and the outflows resemble the eruption of basaltic magma. As magma, the material erupted from a mud volcano becomes more fluid and degasses while rising and decompressing. The release of those gases from mud volcanism is estimated to be a significant contributor both to fluid flux from the lithosphere to the hydrosphere, and to the atmospheric budget of some greenhouse gases, particularly methane. For these reasons, we simulated the fluid dynamics of mud volcanoes using a newly-developed compressible multiphase and multidimensional transient solver in the OpenFOAM framework, taking into account the multicomponent nature (CH4, CO2, H2O) of the fluid mixture, the gas exsolution during the ascent and the associated changes in the constitutive properties of the phases. The numerical model has been tested with conditions representative of the LUSI, a mud volcano that has been erupting since May 2006 in the densely populated Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industry, farmland, and over 10,000 homes. The activity of LUSI mud volcano has been well documented (Vanderkluysen et al., 2014) and here we present a comparison of observed gas fluxes and mud extrusion rates with the outcomes of numerical simulations. Vanderkluysen, L.; Burton, M. R.; Clarke, A. B.; Hartnett, H. E. & Smekens, J.-F. Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia) Geochem. Geophys. Geosyst., Wiley-Blackwell, 2014, 15, 2932-2946

  8. Volcanoes: observations and impact

    USGS Publications Warehouse

    Thurber, Clifford; Prejean, Stephanie G.

    2012-01-01

    Volcanoes are critical geologic hazards that challenge our ability to make long-term forecasts of their eruptive behaviors. They also have direct and indirect impacts on human lives and society. As is the case with many geologic phenomena, the time scales over which volcanoes evolve greatly exceed that of a human lifetime. On the other hand, the time scale over which a volcano can move from inactivity to eruption can be rather short: months, weeks, days, and even hours. Thus, scientific study and monitoring of volcanoes is essential to mitigate risk. There are thousands of volcanoes on Earth, and it is impractical to study and implement ground-based monitoring at them all. Fortunately, there are other effective means for volcano monitoring, including increasing capabilities for satellite-based technologies.

  9. Pathogenic role of mtDNA duplications in mitochondrial diseases associated with mtDNA deletions.

    PubMed

    Odoardi, Francesca; Rana, Michele; Broccolini, Aldobrando; Mirabella, Massimiliano; Modoni, Anna; D'Amico, Adele; Papacci, Manuela; Tonali, Pietro; Servidei, Serenella; Silvestri, Gabriella

    2003-04-30

    We estimated the frequency of multiple mtDNA rearrangements by Southern blot in 32 patients affected by mitochondrial disorders associated with single deletions in order to assess genotype-phenotype correlations and elucidate the pathogenic significance of mtDNA duplications. Muscle in situ hybridization studies were performed in patients showing mtDNA duplications at Southern blot. We found multiple rearrangements in 12/32 (37.5%) patients; in particular, mtDNA duplications were detected in 4/4 Kearns-Sayre syndrome (KSS), in 1 Pearson's syndrome, in 1/3 encephalomyopathies with progressive external ophthalmoplegia (PEO), and in 2/23 PEO. In situ studies documented an exclusive accumulation of deleted mtDNAs in cytochrome c oxidase negative fibers of patients with mtDNA duplications. The presence of mtDNA duplications significantly correlated with onset of symptoms before age 15 and occurrence of clinical multisystem involvement. Analysis of biochemical data documented a predominant reduction of complex III in patients without duplications compared to patients with mtDNA duplications. Our data indicate that multiple mtDNA rearrangements are detectable in a considerable proportion of patients with single deletions and that mtDNA duplications do not cause any oxidative impairment. They more likely play a pathogenic role in the determination of clinical expression of mitochondrial diseases associated with single mtDNA deletions, possibly generating deleted mtDNAs in embryonic tissues by homologous recombination. Copyright 2003 Wiley-Liss, Inc.

  10. Volcano hazards in the Three Sisters region, Oregon

    USGS Publications Warehouse

    Scott, William E.; Iverson, R.M.; Schilling, S.P.; Fisher, B.J.

    2001-01-01

    Three Sisters is one of three potentially active volcanic centers that lie close to rapidly growing communities and resort areas in Central Oregon. Two types of volcanoes exist in the Three Sisters region and each poses distinct hazards to people and property. South Sister, Middle Sister, and Broken Top, major composite volcanoes clustered near the center of the region, have erupted repeatedly over tens of thousands of years and may erupt explosively in the future. In contrast, mafic volcanoes, which range from small cinder cones to large shield volcanoes like North Sister and Belknap Crater, are typically short-lived (weeks to centuries) and erupt less explosively than do composite volcanoes. Hundreds of mafic volcanoes scattered through the Three Sisters region are part of a much longer zone along the High Cascades of Oregon in which birth of new mafic volcanoes is possible. This report describes the types of hazardous events that can occur in the Three Sisters region and the accompanying volcano-hazard-zonation map outlines areas that could be at risk from such events. Hazardous events include landslides from the steep flanks of large volcanoes and floods, which need not be triggered by eruptions, as well as eruption-triggered events such as fallout of tephra (volcanic ash) and lava flows. A proximal hazard zone roughly 20 kilometers (12 miles) in diameter surrounding the Three Sisters and Broken Top could be affected within minutes of the onset of an eruption or large landslide. Distal hazard zones that follow river valleys downstream from the Three Sisters and Broken Top could be inundated by lahars (rapid flows of water-laden rock and mud) generated either by melting of snow and ice during eruptions or by large landslides. Slow-moving lava flows could issue from new mafic volcanoes almost anywhere within the region. Fallout of tephra from eruption clouds can affect areas hundreds of kilometers (miles) downwind, so eruptions at volcanoes elsewhere in the

  11. Acoustic scattering from mud volcanoes and carbonate mounds.

    PubMed

    Holland, Charles W; Weber, Thomas C; Etiope, Giuseppe

    2006-12-01

    Submarine mud volcanoes occur in many parts of the world's oceans and form an aperture for gas and fluidized mud emission from within the earth's crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering 10-15 dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or particulates (emitted) in the water column, (3) the carbonate bio-construction covering the mud volcano edifice. The experimental evidence, including visual, acoustic, and nonacoustic sensors, rules out the second hypothesis (at least during the observation time) and suggests that, for this particular mud volcano the dominant mechanism is associated with carbonate chimneys on the mud volcano. In terms of scattering levels, target strengths of 4-14 dB were observed from 800 to 3600 Hz for a monostatic geometry with grazing angles of 3-5 degrees. Similar target strengths were measured for vertically bistatic paths with incident and scattered grazing angles of 3-5 degrees and 33-50 degrees, respectively.

  12. Seismic structures beneath Popocatepetl (Mexico) and Gorely (Kamchatka) volcanoes derived from passive tomography studies

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Pavel; Koulakov, Ivan

    2014-05-01

    A number of active volcanoes are observed in different parts of the world, and they attract great interest of scientists. Comparing their characteristics helps in understanding the origin and mechanisms of their activity. One of the most effective methods for studying the deep structure beneath volcanoes is passive source seismic tomography. In this study we present results of tomographic inversions for two active volcanoes located in different parts of the world: Popocatepetl (Mexico) and Gorely (Kamchatka, Russia). In the past century both volcanoes were actively erupted that explains great interest to their detailed investigations. In both cases we made the full data analysis starting from picking the arrival times from local events. In the case of the Popocatepetl study, a temporary seismological network was deployed by GFZ for the period from December 1999 to July 2000. Note that during this period there were a very few events recorded inside the volcano. Most of recorded earthquakes occurred in surrounding areas and they probably have the tectonic nature. We performed a special analysis to ground the efficiency of using these data for studying seismic structure beneath the network installed on the volcano. The tomographic inversion was performed using the LOTOS code by Koulakov (2009). Beneath the Popocatepetl volcano we have found a zone of strong anti-correlation between P- and S-velocities that leaded to high values of Vp/Vs ratio. Similar features were found for some other volcanoes in previous studies. We interpret these anomalies as zones of high content of fluids and melts that are related to active magma sources. For the case of Gorely volcano we used the data of a temporary network just deployed in summer 2013 by our team from IPGG, Novosibirsk. Luckily, during the field works, the volcano started to manifest strong seismic activity. In this period, 100 - 200 volcanic events occurred daily. We collected the continuous seismic records from 20 stations

  13. Stratigraphy of Late Pleistocene-Holocene pyroclastic deposits of Tacana Volcano, Mexico-Guatemala

    NASA Astrophysics Data System (ADS)

    Macias, J. L.; Arce, J. L.; Garcia-Palomo, A.; Mora, J. C.; Saucedo, R.; Hughes, S.; Scolamacchia, T.

    2005-12-01

    Tacana volcano (4,060 masl), the highest peak of the Tacana Volcanic Complex, is an acitve volcano located on the Mexico-Guatemala border. Tacana resumed phreatic activity in 1950 and again in 1986. After this last event, the volcano became the locus of attention of authorities and local scientists began to study the complex. Tacana's stratigraphic record has been studied using radiocarbon dating and these indicate that the volcano has been very active in the past producing at least 12 explosive eruptions during the last 40 ka years as follow: a) Four partial dome destruction events with the generation of block-and-ash flow deposits at 40, 28, <26, and 16 ka. b) Four small-volume phreatomagmatic events that emplaced dilute density currents at 10.6, 7.5, 6, and 2.5 ka. c) Four eruptions that emplaced pumice-rich fall deposits, three of them widely dispersed towards the NE flank of the volcano in Guatemala and dated at ~32, <24 and <14 ka, and finally a 0.8 ka fall deposit restricted to the crater vicinity that might represent the youngest magmatic eruption of the volcano. Although refining of these stratigraphic sequence is still underway, the eruptive chronology of Tacana volcano cleary indicates that explosive eruptions producing plinian fall and pyroclastic density currents have taken place every 1 to 8 ka years. This record constrasts with the small phreatic eruptions that occur 1-2 per century. So, this indicates that Tacana volcano is more active than previously considered and these results must be considered for future researches on hazards maps and mitigation.

  14. A Volcano Exploration Project Pu`u `O`o (VEPP) Exercise: Is Kilauea in Volcanic Unrest? (Invited)

    NASA Astrophysics Data System (ADS)

    Schwartz, S. Y.

    2010-12-01

    Volcanic activity captures the interest and imagination of students at all stages in their education. Analysis of real data collected on active volcanoes can further serve to engage students in higher-level inquiry into the complicated physical processes associated with volcanic eruptions. This exercise takes advantage of both student fascination with volcanoes and the recognized benefits of incorporating real, internet-accessible data to achieve its goals of enabling students to: 1) navigate a scientific website; 2) describe the physical events that produce volcano monitoring data; 3) identify patterns in geophysical time-series and distinguish anomalies preceding and synchronous with eruptive events; 4) compare and contrast geophysical time series and 5) integrate diverse data sets to assess the eruptive state of Kilauea volcano. All data come from the VEPP website (vepp.wr.usgs.gov) which provides background information on the historic activity and volcano monitoring methods as well as near-real time volcano monitoring data from the Pu`u `O`o eruptive vent on Kilauea Volcano. This exercise, designed for geology majors, has students initially work individually to acquire basic skills with volcano monitoring data interpretation and then together in a jigsaw activity to unravel the events leading up to and culminating in the July 2007 volcanic episode. Based on patterns established prior to the July 2007 event, students examine real-time volcano monitoring data to evaluate the present activity level of Kilauea volcano. This exercise will be used for the first time in an upper division Geologic Hazards class in fall 2010 and lessons learned including an exercise assessment will be presented.

  15. International Collaboration on Building Local Technical Capacities for Monitoring Volcanic Activity at Pacaya Volcano, Guatemala.

    NASA Astrophysics Data System (ADS)

    Escobar-Wolf, R. P.; Chigna, G.; Morales, H.; Waite, G. P.; Oommen, T.; Lechner, H. N.

    2015-12-01

    Pacaya volcano is a frequently active and potentially dangerous volcano situated in the Guatemalan volcanic arc. It is also a National Park and a major touristic attraction, constituting an important economic resource for local municipality and the nearby communities. Recent eruptions have caused fatalities and extensive damage to nearby communities, highlighting the need for risk management and loss reduction from the volcanic activity. Volcanic monitoring at Pacaya is done by the Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH), instrumentally through one short period seismic station, and visually by the Parque Nacional Volcan de Pacaya y Laguna de Calderas (PNVPLC) personnel. We carry out a project to increase the local technical capacities for monitoring volcanic activity at Pacaya. Funding for the project comes from the Society of Exploration Geophysicists through the Geoscientists Without Borders program. Three seismic and continuous GPS stations will be installed at locations within 5 km from the main vent at Pacaya, and one webcam will aid in the visual monitoring tasks. Local educational and outreach components of the project include technical workshops on data monitoring use, and short thesis projects with the San Carlos University in Guatemala. A small permanent exhibit at the PNVPLC museum or visitor center, focusing on the volcano's history, hazards and resources, will also be established as part of the project. The strategy to involve a diverse group of local collaborators in Guatemala aims to increase the chances for long term sustainability of the project, and relies not only on transferring technology but also the "know-how" to make that technology useful. Although not a primary research project, it builds on a relationship of years of joint research projects at Pacaya between the participants, and could be a model of how to increase the broader impacts of such long term collaboration partnerships.

  16. Calcio-carbonatite melts and metasomatism in the mantle beneath Mt. Vulture (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Rosatelli, Gianluigi; Wall, Frances; Stoppa, Francesco

    2007-12-01

    At Mt. Vulture volcano (Basilicata, Italy) calcite globules (5-150 μm) are hosted by silicate glass pools or veins cross-cutting amphibole-bearing, or more common spinel-bearing mantle xenoliths and xenocrysts. The carbonate globules are rounded or elongated and are composed of a mosaic of 2-20 μm crystals, with varying optical orientation. These features are consistent with formation from a quenched calciocarbonatite melt. Where in contact with carbonate amphibole has reacted to form fassaitic pyroxene. Some of these globules contain liquid/gaseous CO 2 bubbles and sulphide inclusions, and are pierced by quench microphenocrysts of silicate phases. The carbonate composition varies from calcite to Mg-calcite (3.8-5.0 wt.% MgO) both within the carbonate globules and from globule to globule. Trace element contents of the carbonate, determined by LAICPMS, are similar to those of carbonatites worldwide including ΣREE up to 123 ppm. The Sr-Nd isotope ratios of the xenolith carbonate are similar to the extrusive carbonatite and silicate rocks of Mt. Vulture testifying to derivation from the same mantle source. Formation of immiscibile silicate-carbonatite liquids within mantle xenoliths occurred via disequilibrium immiscibility during their exhumation.

  17. Can North Korean Nuclear Explosions Stir Baekdu (Changbai) Volcano to be Erupted?

    NASA Astrophysics Data System (ADS)

    Hong, T. K.; Choi, E.; Park, S.; Shin, J. S.

    2015-12-01

    Potential volcanic eruption in Mt. Baekdu (Changbai) hasbeen a long-lasting concern in the far-eastern Asia.There were several explosive eruptions historically. Themost recent eruption was made in 1903. The eruption in969 is believed to be the most violent with volcanicexplosivity index of 7. The volcano is located in ~130 kmaway from the North Korean nuclear explosion test sitewhere three moderate-size nuclear explosions withmagnitudes of 4.3, 4.7 and 5.1 were conducted in 2006,2009 and 2013. There is increasing concern that a largenuclear explosion may trigger volcanic eruption. Seismicwaveforms are subtle to vary with the crustal structure.The strong ground motions generated by a potential largenuclear explosion are difficult to be simulated forvolcanic regions where complex crustal structures areexpected. We calculate the ground motions by hypotheticallarge nuclear explosions using a nuclear-explosion sourcemodel and the seismic waveforms of prior nuclearexplosions. The validity of the method is examined bycomparing the observed and quasi-synthetic seismicwaveforms of prior nuclear explosions. The peak groundaccelerations (PGA) around the volcano are estimated froma PGA attenuation equation that was determined based onseismic waveforms from natural earthquakes. Thehorizontal and vertical PGAs by an M7.0 undergroundnuclear explosion are expected to reach 0.14 and 0.11m/s2 at the volcano, inducing a dynamic stress in themagma chamber. The induced pressure change in the magmachamber is verified by numerical modeling of dynamicstress changes.

  18. ALS-based hummock size-distance relationship assessment of Mt Shasta debris avalanche deposit, Northern California, USA

    NASA Astrophysics Data System (ADS)

    Tortini, Riccardo; Carn, Simon; van Wyk de Vries, Benjamin

    2015-04-01

    The failure of destabilized volcano flanks is a likely occurrence during the lifetime of a stratovolcano, generating large debris avalanches and drastically changing landforms around volcanoes. The significant hazards associated with these events in the Cascade range were demonstrated, for example, by the collapse of Mt St Helens (WA), which triggered its devastating explosive eruption in 1980. The rapid modification of the landforms due to these events makes it difficult to estimate the magnitude of prehistoric avalanches. However, the widespread preservation of hummocks along the course of rockslide-debris avalanches is highly significant for understanding the physical characteristics of these landslides. Mt Shasta is a 4,317 m high, snow-capped, steep-sloped stratovolcano located in Northern California. The current edifice began forming on the remnants of an ancestral Mt Shasta that collapsed ~300-380k years ago producing one of the largest debris avalanches known on Earth. The debris avalanche deposit (DAD) covers a surface of ~450 km2 across the Shasta valley, with an estimated volume of ~26 km3. We analyze ALS data on hummocks from the prehistoric Shasta valley DAD in northern California (USA) to derive the relationship between hummock size and distance from landslide source, and interpret the geomorphic significance of the intercept and slope coefficients of the observed functional relationships. Given the limited extent of the ALS survey (i.e. 40 km2), the high-resolution dataset is used for validation of the morphological parameters extracted from freely available, broader coverage DTMs such as the National Elevation Dataset (NED). The ALS dataset also permits the identification of subtle topographic features not apparent in the field or in coarser resolution datasets, including a previously unmapped fault, of crucial importance for both seismic and volcanic hazard assessment in volcanic areas. We present evidence from the Shasta DAD of neotectonic

  19. Contribution of space platforms to a ground and airborne remote-sensing programme over active Italian volcanoes

    NASA Technical Reports Server (NTRS)

    Cassinis, R.; Lechi, G. M.; Tonelli, A. M.

    1974-01-01

    ERTS-1 imagery of the volcanic areas of southern Italy was used primarily for the evaluation of space platform capabilties in the domains of regional geology, soil and rock-type classification and, more generally, to study the environment of active volcanoes. The test sites were selected and equipped primarily to monitor thermal emission, but ground truth data was also collected in other domains (reflectance of rocks, soils and vegetation). The test areas were overflown with a two channel thermal scanner, while a thermo camera was used on the ground to monitor the hot spots. The primary goal of this survey was to plot the changes in thermal emission with time in the framework of a research program for the surveillance of active volcanoes. However, another task was an evaluation of emissivity changes by comparing the outputs of the two thermal channels. These results were compared with the reflectance changes observed on multispectral ERTS-1 imagery.

  20. Volcano and earthquake hazards in the Crater Lake region, Oregon

    USGS Publications Warehouse

    Bacon, Charles R.; Mastin, Larry G.; Scott, Kevin M.; Nathenson, Manuel

    1997-01-01

    Crater Lake lies in a basin, or caldera, formed by collapse of the Cascade volcano known as Mount Mazama during a violent, climactic eruption about 7,700 years ago. This event dramatically changed the character of the volcano so that many potential types of future events have no precedent there. This potentially active volcanic center is contained within Crater Lake National Park, visited by 500,000 people per year, and is adjacent to the main transportation corridor east of the Cascade Range. Because a lake is now present within the most likely site of future volcanic activity, many of the hazards at Crater Lake are different from those at most other Cascade volcanoes. Also significant are many faults near Crater Lake that clearly have been active in the recent past. These faults, and historic seismicity, indicate that damaging earthquakes can occur there in the future. This report describes the various types of volcano and earthquake hazards in the Crater Lake area, estimates of the likelihood of future events, recommendations for mitigation, and a map of hazard zones. The main conclusions are summarized below.