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Sample records for active mud volcanoes

  1. Mud volcanoes on Mars?

    NASA Technical Reports Server (NTRS)

    Komar, Paul D.

    1991-01-01

    The term mud volcano is applied to a variety of landforms having in common a formation by extrusion of mud from beneath the ground. Although mud is the principal solid material that issues from a mud volcano, there are many examples where clasts up to boulder size are found, sometimes thrown high into the air during an eruption. Other characteristics of mud volcanoes (on Earth) are discussed. The possible presence of mud volcanoes, which are common and widespread on Earth, on Mars is considered.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. High-resolution seismic structure analysis of an active submarine mud volcano area off SW Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Hsiao-Shan; Hsu, Shu-Kun; Tsai, Wan-Lin; Tsai, Ching-Hui; Lin, Shin-Yi; Chen, Song-Chuen

    2015-04-01

    In order to better understand the subsurface structure related to an active mud volcano MV1 and to understand their relationship with gas hydrate/cold seep formation, we conducted deep-towed side-scan sonar (SSS), sub-bottom profiler (SBP), multibeam echo sounding (MBES), and multi-channel reflection seismic (MCS) surveys off SW Taiwan from 2009 to 2011. As shown in the high-resolution sub-bottom profiler and EK500 sonar data, the detailed structures reveal more gas seeps and gas flares in the study area. In addition, the survey profiles show several submarine landslides occurred near the thrust faults. Based on the MCS results, we can find that the MV1 is located on top of a mud diapiric structure. It indicates that the MV1 has the same source as the associated mud diapir. The blanking of the seismic signal may indicate the conduit for the upward migration of the gas (methane or CO2). Therefore, we suggest that the submarine mud volcano could be due to a deep source of mud compressed by the tectonic convergence. Fluids and argillaceous materials have thus migrated upward along structural faults and reach the seafloor. The gas-charged sediments or gas seeps in sediments thus make the seafloor instable and may trigger submarine landslides.

  8. 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.

  9. Mud Volcanoes Formation And Occurrence

    NASA Astrophysics Data System (ADS)

    Guliyev, I. S.

    2007-12-01

    Mud volcanoes are natural phenomena, which occur throughout the globe. They are found at a greater or lesser scale in Azerbaijan, Turkmenistan, Georgia, on the Kerch and Taman peninsulas, on Sakhalin Island, in West Kuban, Italy, Romania, Iran, Pakistan, India, Burma, China, Japan, Indonesia, Malaysia, New Zealand, Mexico, Colombia, Trinidad and Tobago, Venezuela and Ecuador. Mud volcanoes are most well-developed in Eastern Azerbaijan, where more than 30% of all the volcanoes in the world are concentrated. More than 300 mud volcanoes have already been recognized here onshore or offshore, 220 of which lie within an area of 16,000 km2. Many of these mud volcanoes are particularly large (up to 400 m high). The volcanoes of the South Caspian form permanent or temporary islands, and numerous submarine banks. Many hypotheses have been developed regarding the origin of mud volcanoes. Some of those hypotheses will be examined in the present paper. Model of spontaneous excitation-decompaction (proposed by Ivanov and Guliev, 1988, 2002). It is supposed that one of major factors of the movement of sedimentary masses and formation of hydrocarbon deposits are phase transitions in sedimentary basin. At phase transitions there are abnormal changes of physical and chemical parameters of rocks. Abnormal (high and negative) pressure takes place. This process is called as excitation of the underground environment with periodicity from several tens to several hundreds, or thousand years. The relationship between mud volcanism and the generation of hydrocarbons, particularly methane, is considered to be a critical factor in mud volcano formation. At high flow rates the gas and sediment develops into a pseudo-liquid state and as flow increases the mass reaches the "so-called hover velocity" where mass transport begins. The mass of fluid moves as a quasi-uniform viscous mass through the sediment pile in a piston like manner until expelled from the surface as a "catastrophic eruption

  10. 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.

  11. Distribution and characters of the mud diapirs and mud volcanoes off southwest Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Song-Chuen; Hsu, Shu-Kun; Wang, Yunshuen; Chung, San-Hsiung; Chen, Po-Chun; Tsai, Ching-Hui; Liu, Char-Shine; Lin, Hsiao-Shan; Lee, Yuan-Wei

    2014-10-01

    In order to identify the mud diapirs and mud volcanoes off SW Taiwan, we have examined ∼1500 km long MCS profiles and related marine geophysical data. Our results show ten quasi-linear mud diapirs, oriented NNE-SSW to N-S directions. Thirteen mud volcanoes are identified from the multibeam bathymetric data. These mud volcanoes generally occur on tops of the diapiric structures. Moreover, the active mud flow tracks out of mud volcanoes MV1, MV3 and MV6 are observed through the high backscatter intensity stripes on the sidescan sonar images. The heights of the cone-shaped mud volcanoes range from 65 m to 345 m, and the diameters at base from 680 m to 4100 m. These mud volcanoes have abrupt slopes between 5.3° and 13.6°, implying the mudflow is active and highly viscous. In contrast, the flat crests of mud volcanoes are due to relative lower-viscosity flows. The larger cone-shaped mud volcanoes located at deeper water depths could be related to a longer eruption history. The formation of mud diapirs and volcanoes in the study area are ascribed to the overpressure in sedimentary layers, compressional tectonic forces and gas-bearing fluids. Especially, the gas-bearing fluid plays an important role in enhancing the intrusion after the diapirism as a large amount of gas expulsions is observed. The morphology of the upper Kaoping Slope is mainly controlled by mud diapiric intrusions.

  12. Volcano acoustic activity associated with the eruption of Mt. Usu, 2000 - Mud-pool Strombolian -

    NASA Astrophysics Data System (ADS)

    Aoyama, H.; Oshima, H.; Maekawa, T.

    2001-12-01

    There was intense acoustic activity associated with the eruption of Mount Usu, which began on March 31, 2000. Repeating phreatic explosions generated many isolated infrasonic signals, which were observed at plural acoustic stations. During the periods when acoustic activity was high, infrasonic pulses as many as 200 were identified every 10 minutes. Source location of infrasonic signals could be well identified from the records of the low frequency microphone network. Two active craters, Nishiyama craterlets and Konpirayama craterlets, are clearly distinguished by sound source determination analysis though distance between them is around 1 km. To investigate the transition of acoustic activity from April to June, 2000, we contrive a method to detect arrival and amplitude of infrasonic signals automatically. The number of automatically identified infrasonic signals exceeds 1.46 million during three months. It seems that there is a good correlation between acoustic activity and seismic signal amplitude. Patterns of acoustic activity and infrasonic pulse shapes observed at Usu volcano are very similar to those of observed at Stromboli volcano, Italy. We name the acoustic activity accompanied with phreatic explosion that scatters a lot of clods `mud-pool Strombolian type'. Phreatic explosion excites not only infrasonic pulse but also seismic signal observed before the arrival of infrasonic pulse. Existence of Rayleigh wave phase with large amplitude suggests that the seismic wave is excited at a shallow part.

  13. Plumbing System Dynamics Of Mud Volcanoes (Azerbaijan)

    NASA Astrophysics Data System (ADS)

    Mazzini, A.; Svensen, H.; Planke, S.; Akhmanov, G. G.; Guliyev, I.; Johansen, H.; Fallick, T.

    2006-12-01

    Piercement structures, such as mud volcanoes, are common in many sedimentary basins. A number of issues need to be addressed in order to get a better understanding of the mechanism driving the formation of such features and the controlling their activity. These relate to processes in the source region, in the conduit zone, and the hydrology of the seepage stage between eruption events. Seepage activity of dormant mud volcanoes can provide important insight about the subsurface plumbing system and the origin of the fluids/mud breccia expelled. A comprehensive field study was carried out on six onshore mud volcanoes in Azerbaijan. Field observations reveal that seepage of fluids and mud breccia occurs with different dynamics at closely spaced sites forming diverse features such as gryphons, pools and salsa lakes. An extensive set of analyses was conducted on fluids seeping at different locations on the six structures. Geochemical analyses show that seeping gas has a general mixed thermogenic-biogenic signature. Reverse correlation between δ 13C in CH 4 and CO 2 supports the hypothesis of shallow chambers located at different depths where biogenic methane is produced. Deep reservoirs reveal the presence of thermogenic gas that rising mixes with shallow biogenic methane. Water geochemical analyses reveal a wide range of salinities (900-42000 ppm) that correlate with mud content in the water. Large pools show highest salinity as opposite as high gryphons where denser mud is erupted. Coupled water 18O and D stable isotopes demonstrate that there is no contribution of meteoric water in the seeping fluids. Denser (clast-rich) mud breccia and consistently higher δ 18O water isotope are commonly recorded at gryphon sites. This suggests deeper roots for gryphons. Results reveal the presence of an interconnected and intricate plumbing system consisting of branched conduits and chambers that develop in the near subsurface of the crater.

  14. Active mud volcanoes on the continental slope of the Canadian Beaufort Sea

    NASA Astrophysics Data System (ADS)

    Paull, C. K.; Dallimore, S. R.; Caress, D. W.; Gwiazda, R.; Melling, H.; Riedel, M.; Jin, Y. K.; Hong, J. K.; Kim, Y.-G.; Graves, D.; Sherman, A.; Lundsten, E.; Anderson, K.; Lundsten, L.; Villinger, H.; Kopf, A.; Johnson, S. B.; Hughes Clarke, J.; Blasco, S.; Conway, K.; Neelands, P.; Thomas, H.; Côté, M.

    2015-09-01

    Morphologic features, 600-1100 m across and elevated up to 30 m above the surrounding seafloor, interpreted to be mud volcanoes were investigated on the continental slope in the Beaufort Sea in the Canadian Arctic. Sediment cores, detailed mapping with an autonomous underwater vehicle, and exploration with a remotely operated vehicle show that these are young and actively forming features experiencing ongoing eruptions. Biogenic methane and low-chloride, sodium-bicarbonate-rich waters are extruded with warm sediment that accumulates to form cones and low-relief circular plateaus. The chemical and isotopic compositions of the ascending water indicate that a mixture of meteoric water, seawater, and water from clay dehydration has played a significant role in the evolution of these fluids. The venting methane supports extensive siboglinid tubeworms communities and forms some gas hydrates within the near seafloor. We believe that these are the first documented living chemosynthetic biological communities in the continental slope of the western Arctic Ocean.

  15. Fossil Foraminifera from four active mud volcanoes in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Kohl, Barry; Roberts, Harry H.

    1994-06-01

    Samples were collected for foraminiferal studies by the Johnson Sea-Link I and II manned submersibles on the Louisiana continental slope. This paper documents that the mud, extruded onto the sea floor from depth by four mud volcanoes, ranges in age from Miocene to Pleistocene based on studies of the planktonic foraminiferal fauna. The vents are in water depths ranging from 300 to 690 m located in Garden Banks Block 382, Green Canyon Blocks 143 and 272, and Mississippi Canyon Block 929. Two mud volcanoes in GB 382 and MC 929 also have rich fossil foraminiferal microfaunas. We suggest that the extrusion of fossil sediments onto the sea floor during the Quaternary is a reasonable explanation for frequent occurrences of displaced fossil microfaunas encountered at depth in wells drilling on the flanks of salt diapirs in the slope environment. Results of this study have important implications for age dating subsurface sediments in bathyal locations.

  16. Organic geochemical signatures controlling methane outgassing at active mud volcanoes in the Canadian Beaufort Sea

    NASA Astrophysics Data System (ADS)

    DongHun, Lee; YoungKeun, Jin; JungHyun, Kim; Heldge, Niemann; JongKu, Gal; BoHyung, Choi

    2016-04-01

    Based on the water column acoustic anomalies related to active methane (CH4) venting, numerous active Mud Volcanoes (MVs) were recently identified at ~282, ~420, and ~740 m water depths on the continental slope of the Canadian Beaufort Sea (Paull et al., 2015). While geophysical aspects such as the multibeam bathymetric mapping are thoroughly investigated, biogeochemical processes controlling outgassing CH4 at the active MVs are not well constrained. Here, we investigated three sediment cores from the active MVs and one sediment core from a non-methane influenced reference site recovered during the ARA-05C expedition with the R/V ARAON in 2014. We analyzed lipid biomarkers and their stable carbon isotopic values (δ13C) in order to determine key biogeochemical processes involved in CH4 cycling in the MV sediments. Downcore CH4 and sulphate (SO42-) concentration measurements revealed a distinct sulfate-methane transition zone (SMTZ) at the shallow sections of the cores (15 - 45 cm below seafloor (cm bsf) at 282 m MV, 420 m MV, and 740 m MV). The most abundant diagnostic lipid biomarkers in the SMTZ were sn-2-hydroxyarchaeol (-94‰) and archaeol (-66‰) with the sn-2-hydroxyarchaeol: archaeol ratio of 1.1 to 5, indicating the presence of ANME-2 or -3. However, we also found substantial amounts of monocyclic biphytane-1 (BP-1, -118‰), which is rather indicative for ANME-1. Nevertheless, the concentration of sn-2-hydroxyarchaeol was 2-fold higher than any other archaeal lipids, suggesting a predominant ANME-2 or -3 rather than ANME-1 as a driving force for the anaerobic methane oxidation (AOM) in these systems. We will further investigate the microbial community at the active MVs using nucleic acid (RNA and DNA) sequence analyses in near future. Our study provides first biogeochemical data set of the active MVs in the Canadian Beaufort Sea, which helps to better understand CH4 cycling mediated in these systems. Reference Paull, C.K., et al. (2015), Active mud

  17. 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.

  18. Active sulfur cycling by diverse mesophilic and thermophilic microorganisms in terrestrial mud volcanoes of Azerbaijan.

    PubMed

    Green-Saxena, A; Feyzullayev, A; Hubert, C R J; Kallmeyer, J; Krueger, M; Sauer, P; Schulz, H-M; Orphan, V J

    2012-12-01

    Terrestrial mud volcanoes (TMVs) represent geochemically diverse habitats with varying sulfur sources and yet sulfur cycling in these environments remains largely unexplored. Here we characterized the sulfur-metabolizing microorganisms and activity in four TMVs in Azerbaijan. A combination of geochemical analyses, biological rate measurements and molecular diversity surveys (targeting metabolic genes aprA and dsrA and SSU ribosomal RNA) supported the presence of active sulfur-oxidizing and sulfate-reducing guilds in all four TMVs across a range of physiochemical conditions, with diversity of these guilds being unique to each TMV. The TMVs varied in potential sulfate reduction rates (SRR) by up to four orders of magnitude with highest SRR observed in sediments where in situ sulfate concentrations were highest. Maximum temperatures at which SRR were measured was 60°C in two TMVs. Corresponding with these trends in SRR, members of the potentially thermophilic, spore-forming, Desulfotomaculum were detected in these TMVs by targeted 16S rRNA analysis. Additional sulfate-reducing bacterial lineages included members of the Desulfobacteraceae and Desulfobulbaceae detected by aprA and dsrA analyses and likely contributing to the mesophilic SRR measured. Phylotypes affiliated with sulfide-oxidizing Gamma- and Betaproteobacteria were abundant in aprA libraries from low sulfate TMVs, while the highest sulfate TMV harboured 16S rRNA phylotypes associated with sulfur-oxidizing Epsilonproteobacteria. Altogether, the biogeochemical and microbiological data indicate these unique terrestrial habitats support diverse active sulfur-cycling microorganisms reflecting the in situ geochemical environment.

  19. The diversity of mud volcanoes in the landscape of Azerbaijan

    NASA Astrophysics Data System (ADS)

    Rashidov, Tofig

    2014-05-01

    on surface, often of plane-conical shape, rising for 5 to 400 m and more over the country (for example, mud volcano Toragay, 400 m height). The base diameter is from 100 m to 3-4 km and more. Like the magmatic ones, the mud volcanoes are crowned with crater of convex-plane or deeply-seated shape. In Azerbaijan there are all types of mud volcanoes: active, extinct, buried, submarine, island, abundantly oil seeping. According to their morphology they are defined into cone-shaped, dome-shaped, ridge-shaped, plateau-shaped. The crater shapes are also various: conical, convex-plane, shield-shaped, deeply-seated, caldera-like. The most complete morphological classification was given in "Atlas of mud volcanoes of Azerbaijan" (Yakubov et al., 1971). Recently (Aliyev Ad. et al., 2003) it was proposed a quite new morphological classification of mud volcanoes of Azerbaijan. For the first time the mud volcanic manifestations had been defined. Volcanoes are ranged according to morphological signs, crater shape and type of activity.

  20. Mud Volcanoes as Exploration Targets on Mars

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Oehler, Dorothy Z.

    2010-01-01

    Tens of thousands of high-albedo mounds occur across the southern part of the Acidalia impact basin on Mars. These structures have geologic, physical, mineralogic, and morphologic characteristics consistent with an origin from a sedimentary process similar to terrestrial mud volcanism. The potential for mud volcanism in the Northern Plains of Mars has been recognized for some time, with candidate mud volcanoes reported from Utopia, Isidis, northern Borealis, Scandia, and the Chryse-Acidalia region. We have proposed that the profusion of mounds in Acidalia is a consequence of this basin's unique geologic setting as the depocenter for the tune fraction of sediments delivered by the outflow channels from the highlands.

  1. Seafloor distribution and last glacial to postglacial activity of mud volcanoes on the Calabrian accretionary prism, Ionian Sea

    NASA Astrophysics Data System (ADS)

    Ceramicola, Silvia; Praeg, Daniel; Cova, Andrea; Accettella, Daniela; Zecchin, Massimo

    2014-06-01

    Mud volcanoes (MVs) are abundant along the eastern Mediterranean subduction zones, recording mud breccia extrusion over long timescales (106 years), but to date relatively few have been recognised in the northern Ionian Sea on the Calabrian accretionary prism (CAP). In the present study, the seafloor distribution and recent activity of MVs is investigated across a 35,600 km2 sector of the CAP using a regional acoustic dataset (multibeam bathymetric and backscatter imagery, integrated with subbottom profiles) locally ground-truthed by sediment cores. A total of 54 MVs are identified across water depths of 150-2,750 m using up to four geophysical criteria: distinctive morphology, high backscatter, unstratified subbottom facies and, in one case, a hydroacoustic flare. Fourteen MVs are identified from 3-4 criteria, of which five have been previously proven by cores containing mud breccia beneath up to 1.6 m of hemipelagic sediments (Madonna dello Ionio MVs 1-3, Pythagoras MV and the newly named Sartori MV), while nine others are identified for the first time (Athena, Catanzaro, Cerere, Diana, Giunone, Minerva, `right foot', Venere 1 and 2). Forty other as yet unnamed MVs are inferred from 1-2 geophysical criteria (three from distinctive morphology alone). All but one possible MV lie on the inner plateau of the CAP, landwards of the Calabrian Escarpment in a zone up to 120 km wide that includes the inner pre-Messinian wedge and the fore-arc basins, where they are interpreted to record the ascent from depth of overpressured fluids that interacted with tectonic structures and with evaporitic or shale seals within the fore-arc basins. The rise of fluids may have been triggered by post-Messinian out-of-sequence tectonism that affected the entire pre-Messinian prism, but Plio-Quaternary sedimentation rates and depositional styles support the inference that significant mud volcanism has taken place only on the inner plateau. Sedimentation rates across the CAP applied to a 12

  2. Biogeochemical interactions among the arsenic, iron, humic substances, and microbes in mud volcanoes in southern Taiwan.

    PubMed

    Liu, Chia-Chuan; Maity, Jyoti Prakash; Jean, Jiin-Shuh; Sracek, Ondra; Kar, Sandeep; Li, Zhaohui; Bundschuh, Jochen; Chen, Chien-Yen; Lu, Hsueh-Yu

    2011-01-01

    Fluid and mud samples collected from Hsiaokunshui (HKS), Wushanting (WST), Yenshuikeng (YSK), Kunshuiping (KSP), Liyushan (LYS), and Sinyangnyuhu (SYNH) mud volcanoes of southwestern Taiwan were characterized for major ions, humic substances (HS) and trace elements concentrations. The relationship between the release of arsenic (As) and activities of sulfate-reducing bacteria has been assessed to understand relevant geochemical processes in the mud volcanoes. Arsenic (0.02-0.06 mg/L) and humic substances (4.13 × 10(-4) to 1.64 × 10(-3) mM) in the fluids of mud volcanoes showed a positive correlation (r = 0.99, p < 0.05) except in Liyushan mud volcano. Arsenic and iron in mud sediments formed two separate groups i) high As, but low Fe in HKS, WST, and SYNH; and ii) low As, but high Fe in the YSK, KSP, and LYS mud volcanoes. The Eh(S.H.E.) values of the mud volcano liquids were characterized by mild to strongly reducing conditions. The HKS, SYNH, and WST mud volcanoes (near the Chishan Fault) belongs to strong reducing environment (-33 to -116 mV), whereas the LYS, YSK, and KSP mud volcanoes located near the coastal plain are under mild reducing environment (-11 to 172 mV). At low Eh values mud volcanoes, saturation index (SI) values of poorly crystalline phases such as amorphous ferric hydroxide indicate understaturation, whereas saturation is reached in relatively high Eh(S.H.E.) values mud volcanoes. Arsenic contents in sediments are low, presumably due to its release to fluids (As/Fe ratio in YSK, KSP, and LYS sediment: 4.86 × 10(-4)-6.20 × 10(-4)). At low Eh(S.H.E.) values (mild to strong reducing environment), arsenic may co-precipitate with sulfides as a consequence of sulfate reduction (As/Fe ratios in WST, HKS, and SYNH sediments: 0.42-0.69).

  3. Episodic massive mud eruptions from submarine mud volcanoes examined through topographical signatures

    NASA Astrophysics Data System (ADS)

    Kioka, Arata; Ashi, Juichiro

    2015-10-01

    The role of mud volcanism on subsurface fluid migration and material cycling has long been debated. Here we compile the heights and radii of offshore mud volcanoes and estimate a mean volume of episodic massive mud eruptions based on previous studies into granular flows. The volume is estimated as a function of the ratio of height to basal radius of the mud volcano's body under reasonable assumptions of the sizes of the mud conduit. Nearly all known offshore mud volcanoes are found to be polygenetic with the mean individual eruption volume of the pie-type mud volcano being several orders of magnitude larger than that of the cone type. The frequent occurrence of pie-type mud volcanoes in accretionary margins characterized by high-sediment influx is explained by their efficiency in the transport of large amounts of fluidized sediments from deep depths to the seafloor.

  4. Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz

    PubMed Central

    Coelho, Francisco J. R. C.; Louvado, António; Domingues, Patrícia M.; Cleary, Daniel F. R.; Ferreira, Marina; Almeida, Adelaide; Cunha, Marina R.; Cunha, Ângela; Gomes, Newton C. M.

    2016-01-01

    The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults. PMID:27762306

  5. Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Coelho, Francisco J. R. C.; Louvado, António; Domingues, Patrícia M.; Cleary, Daniel F. R.; Ferreira, Marina; Almeida, Adelaide; Cunha, Marina R.; Cunha, Ângela; Gomes, Newton C. M.

    2016-10-01

    The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults.

  6. Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz.

    PubMed

    Coelho, Francisco J R C; Louvado, António; Domingues, Patrícia M; Cleary, Daniel F R; Ferreira, Marina; Almeida, Adelaide; Cunha, Marina R; Cunha, Ângela; Gomes, Newton C M

    2016-10-20

    The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults.

  7. Geochemical characterization of the Nirano Mud Volcano Field

    NASA Astrophysics Data System (ADS)

    Sciarra, Alessandra; Cantucci, Barbara; Ricci, Tullio; Conventi, Marzia

    2016-04-01

    Mud volcanoes, among fluid venting structures, are the most important phenomena related to natural seepage from the Earth's surface. The occurrence of mud volcanoes is controlled by several factors, such as tectonic activity and continuous hydrocarbon accumulation in a reservoir. Mud volcanoes in Italy occur along the external compressive margin of the Apennine chain. These mud volcanoes are usually small and unspectacular, when compared to other world examples. They rarely exhibit the periodic explosions, which is often related to important seismic activity. The Nirano Mud Volcano Field (NMVF) is located in the western sector of the Modena Apennine margin (Italy), which belongs to the Northern Apennines. The NMVF occurs over the crest of a thrust anticline associated with the main Pede-Apennine thrust and represents a good example of an onshore relationship between a mud volcano caldera structure and active thrust deformation, even if the fluid pathways are still not well understood at depth. The mud volcanoes are distributed along an area of about 10 ha, inside of the wider Natural Reserve, and are situated at the bottom of a wide sub-circular depression. The NMVF is currently formed by four main vents composed of a number of individual active cones (or gryphons) defining structural alignments trending ENE-WSW. A geochemical soil gas survey of 230 CO2 and CH4 fluxes and 150 CO2, CH4, Rn, He, H2 concentration measurements has been carried out inside the NMVF. Moreover, the fluid emissions from 4 active cones located in different sectors of NMVF have been sampled for chemical and isotopical analysis of water and free gas. The distribution of pathfinder elements as 222Rn, He e H2 has been studied in order to identify potential faults and/or fractures related to preferential migration pathways and the possible interactions between reservoir and surface. Soil gas data highlight two zones characterized by higher values, localized in the WSW and ENE of the NMVF area. In

  8. Mineralogy And Geochemistry Of Mud From Andaman Mud Volcanoes And Its Potential As A Hydrocarbon Source

    NASA Astrophysics Data System (ADS)

    Datta, S.; Bhattacharyya, C. R.

    2007-12-01

    Mud volcanoes are a common feature, reported by several workers, in the Baratang Island of Middle Andamans, India. The association of methane gas and adsorbed hydrocarbons in the mud has been cited well by scientists working in Andamans and also by others working on other eruption areas around the world. Our intended work centres around delineating the nature of such mud volcanoes in the above terrain, their chemical composition with special reference to the clay minerals formed under this sedimentary volcanism environment and exploiting such volcanic deposits towards potential hydrocarbon reserves (if any). The analysis so far suggests that, at any instant of time, gas vents at variable rates in different gas channels at the same site, and that the compositional differences in these vent gases are nearly as large as can be produced by hydrate crystallization. Our hypothesis is compatible with geologic generalizations that venting evolves from fast (mud volcano), to intermediate (hydrate crystallization), to slow (carbonate precipitation) if venting organized into more discrete vents with time. The most realistic agent that explains the observed effects is a rapid local emission of mud and/or water. Powder XRD of bulk mud samples enable identification of the complete suite of minerals, in addition to the clay minerals. Variability in modal mineralogy is tracked using Rietveld Method of crystal structure refinement. In addition, micro- XRD of sample cores in situ provide mineral identification as well as textural information such as grain size and distribution (e.g. fine-grained polycrystalline versus larger crystals) as well as preferred orientation (e.g. due to flow layering or strain). Stable isotopes of the separated clay minerals (smectite- and illite-rich extruded mud) from the mud volcanoes will be utilized towards the knowledge of nature of volcanism in the Andaman areas. The most likely mechanism believed is re-hydration of shales by both hydrocarbons and a

  9. Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments

    PubMed Central

    Hosein, Riad; Haque, Shirin; Beckles, Denise M.

    2014-01-01

    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region. PMID:25370529

  10. Mud volcanoes of trinidad as astrobiological analogs for martian environments.

    PubMed

    Hosein, Riad; Haque, Shirin; Beckles, Denise M

    2014-10-13

    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil's Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  11. Eruption of a deep-sea mud volcano triggers rapid sediment movement.

    PubMed

    Feseker, Tomas; Boetius, Antje; Wenzhöfer, Frank; Blandin, Jerome; Olu, Karine; Yoerger, Dana R; Camilli, Richard; German, Christopher R; de Beer, Dirk

    2014-11-11

    Submarine mud volcanoes are important sources of methane to the water column. However, the temporal variability of their mud and methane emissions is unknown. Methane emissions were previously proposed to result from a dynamic equilibrium between upward migration and consumption at the seabed by methane-consuming microbes. Here we show non-steady-state situations of vigorous mud movement that are revealed through variations in fluid flow, seabed temperature and seafloor bathymetry. Time series data for pressure, temperature, pH and seafloor photography were collected over 431 days using a benthic observatory at the active Håkon Mosby Mud Volcano. We documented 25 pulses of hot subsurface fluids, accompanied by eruptions that changed the landscape of the mud volcano. Four major events triggered rapid sediment uplift of more than a metre in height, substantial lateral flow of muds at average velocities of 0.4 m per day, and significant emissions of methane and CO₂ from the seafloor.

  12. Microtremor study of Gunung Anyar mud volcano, Surabaya, East Java

    NASA Astrophysics Data System (ADS)

    Syaifuddin, Firman; Bahri, Ayi Syaeful; Lestari, Wien; Pandu, Juan

    2016-05-01

    The existence of mud volcano system in East Java is known from the ancient period, especially in Surabaya. Gunung Anyar mud volcano is one of the mud volcano system manifestation was appeared close to the residence. Because of this phenomenon we have to learn about the impact of this mud volcano manifestation to the neighbourhood. The microtremor study was conducted to evaluate the possible influence effect of the mud volcano to the environment and get more information about the subsurface condition in this area. Microtremor is one of the geophysical methods which measure the natural tremor or vibration of the earth, the dominant frequency of the tremor represent thickness of the soft sediment layer overlay above the bed rock or harder rock layer beneath our feet. In this study 90 stations was measured to record the natural tremor. The result from this study shows the direct influenced area of this small mud volcano system is close to 50m from the centre of the mud volcano and bed rock of this area is range between 66 to 140 meter.

  13. Spring Deposits and Mud Volcanoes on Mars

    NASA Astrophysics Data System (ADS)

    Allen, C. C.; Oehler, D. Z.; Baker, D. M.

    2008-12-01

    We report evidence for spring deposits in Vernal Crater, Arabia Terra. The Vernal structures are low mounds, each approximately 250 m by 500 m in extent, with terraced flanks, apical depressions, river-like channels, concentric fractures, and elliptical tonal anomalies. All of these features are common in terrestrial springs such as the Dalhousie complex in Australia. The structures occur in an apparent unit of interdune, water-laid sediment and are associated with evidence of subsurface fluid flow in sets of aligned outcrops. The Vernal springs may be part of a larger complex of spring deposits and lineations, suggesting that fluid flow in this region was relatively extensive. The structures in Vernal Crater are coated with a thin layer of dust, which prevents mineral identification from orbit. In an attempt to find evidence for additional spring mounds, we conducted a survey of nearly 2,000 locations for which CRISM spectral images are available. We used CRISM data to identify dust-free, hydrated areas and HiRISE, CTX, and MOC images to evaluate morphology. This study covered all longitudes and latitudes from 50N to 70S, except near Tharsis where data were analyzed south of 15S. No location exhibited morphological features that closely resembled those in Vernal Crater, suggesting that these putative spring mounds are not common in the highlands of Mars. Our search led us to concentrate on a dust-free area, centered at 41.8N, 332.5E in Acidalia Planitia where Farrand et al. (2005) identified features resembling spring mounds or mud volcanoes. Tanaka et al. (2005) mapped this region as part of the Early Amazonian Vastitas Borealis Unit, interpreted as reworked sediments from outflow channels and highland sources. We mapped over 20 high-albedo pitted domes in the area covered by one HiRISE frame, with dome diameters ranging from 350 m to 1 km. Nearby, similar domes have measured heights ranging from 36 to 65 m. The dome material is darker in THEMIS nighttime IR than

  14. Hydrothermal activity and carbon-dioxide discharge at Shrub and upper Klawasi mud volcanoes, Wrangell Mountains, Alaska

    USGS Publications Warehouse

    Sorey, Michael L.; Werner, Cindy; McGimsey, Robert G.; Evans, William C.

    2000-01-01

    Shrub mud volcano, one of three mud volcanoes of the Klawasi group in the Copper River Basin, Alaska, has been discharging warm mud and water and CO2?rich gas since 1996. A field visit to Shrub in June 1999 found the general level of hot-spring discharge to be similar, but somewhat more widespread, than in the previous two years. Evidence of recent animal and vegetation deaths from CO2 exposure were confined to localized areas around various gas and fluid vents. Maximum fluid temperatures in each of three main discharge areas, ranging from 48-54?C, were equal to or higher than those measured in the two previous years; such temperatures are significantly higher than those observed intermittently over the past 30 years. At Upper Klawasi mud volcano, measured temperatures of 23-26?C and estimated rates of gas and water discharge in the summit crater lake were also similar to those observed in the previous two years. Gas discharging at Shrub and Upper Klawasi is composed of over 98% CO2 and minor amounts of meteoric gases (N2, O2, Ar) and gases partly of deeper origin (CH4 and He). The rate of CO2 discharge from spring vents and pools at Shrub is estimated to be ~10 metric tonnes per day. This discharge, together with measured concentrations of bicarbonate, suggest that a total CO2 upflow from depth of 20-40 metric tonnes per day at Shrub.Measurements were made of diffuse degassing rates from soil at one ~300 m2 area near the summit of Shrub that included vegetation kill suggestive of high CO2 concentrations in the root zone. Most of measured gas flow rates in this area were significantly higher than background values, and a CO2 concentration of 26 percent was measured at a depth of 10 cm where the gas flow rate was highest. Although additional measurements of diffuse gas flow were made elsewhere at Shrub, no other areas of vegetation kill related to diffuse degassing and high soil-gas CO2 concentrations could be seen from the air.Chemical and isotopic compositions of

  15. THE "MUD VOLCANO," A STINKY THERMAL FEATURE ON THE GRAND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    THE "MUD VOLCANO," A STINKY THERMAL FEATURE ON THE GRAND LOOP ROAD. ACIDIC HOT SPRINGS HAVE REDUCED THE UNDERLYING LAVA TO A FINE CLAY, PRODUCING AN AREA OF BOILING MUD. THE ODOR OF ROTTEN EGGS IS FROM HYDROGEN SULFIDE GAS. - Grand Loop Road, Forming circuit between Mammoth Hot Springs, Norris Junction, Madison Junction, Old Faithful, Mammoth, Park County, WY

  16. Volcanic Environments Monitoring by Drones Mud Volcano Case Study

    NASA Astrophysics Data System (ADS)

    Amici, S.; Turci, M.; Giulietti, F.; Giammanco, S.; Buongiorno, M. F.; La Spina, A.; Spampinato, L.

    2013-08-01

    Volcanic activity has often affected human life both at large and at small scale. For example, the 2010 Eyjafjallajokull eruption caused severe economic damage at continental scale due to its strong effect on air traffic. At a local scale, ash fall and lava flow emission can cause harm and disruption. Understanding precursory signals to volcanic eruptions is still an open and tricky challenge: seismic tremor and gas emissions, for example, are related to upcoming eruptive activity but the mechanisms are not yet completely understood. Furthermore, information related to gases emission mostly comes from the summit crater area of a volcano, which is usually hard to investigate with required accuracy. Although many regulation problems are still on the discussion table, an increasing interest in the application of cutting-edge technology like unmanned flying systems is growing up. In this sense, INGV (Istituto Nazionale di Geofisica e Vulcanologia) started to investigate the possibility to use unmanned air vehicles for volcanic environment application already in 2004. A flight both in visual- and radio-controlled mode was carried out on Stromboli volcano as feasibility test. In this work we present the preliminary results of a test performed by INGV in collaboration with the University of Bologna (aerospace division) by using a multi-rotor aircraft in a hexacopter configuration. Thermal camera observations and flying tests have been realised over a mud volcano located on its SW flank of Mt. Etna and whose activity proved to be related to early stages of magma accumulation within the volcano.

  17. Microbial methane turnover at mud volcanoes of the Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Niemann, H.; Duarte, J.; Hensen, C.; Omoregie, E.; Magalhães, V. H.; Elvert, M.; Pinheiro, L. M.; Kopf, A.; Boetius, A.

    2006-11-01

    The Gulf of Cadiz is a tectonically active area of the European continental margin and characterised by a high abundance of mud volcanoes, diapirs, pockmarks and carbonate chimneys. During the R/V SONNE expedition "GAP-Gibraltar Arc Processes (SO-175)" in December 2003, several mud volcanoes were surveyed for gas seepage and associated microbial methane turnover. Pore water analyses and methane oxidation measurements on sediment cores recovered from the centres of the mud volcanoes Captain Arutyunov, Bonjardim, Ginsburg, Gemini and a newly discovered, mud volcano-like structure called "No Name" show that thermogenic methane and associated higher hydrocarbons rising from deeper sediment strata are completely consumed within the seabed. The presence of a distinct sulphate-methane transition zone (SMT) overlapping with high sulphide concentrations suggests that methane oxidation is mediated under anaerobic conditions with sulphate as the electron acceptor. Anaerobic oxidation of methane (AOM) and sulphate reduction (SR) rates show maxima at the SMT, which was found between 20 and 200 cm below seafloor at the different mud volcanoes. In comparison to other methane seeps, AOM activity (<383 mmol m -2 year -1) and diffusive methane fluxes (<321 mmol m -2 year -1) in mud volcano sediments of the Gulf of Cadiz are low to mid range. Corresponding lipid biomarker and 16S rDNA clone library analysis give evidence that AOM is mediated by a mixed community of anaerobic methanotrophic archaea and associated sulphate reducing bacteria (SRB) in the studied mud volcanoes. Little is known about the variability of methane fluxes in this environment. Carbonate crusts littering the seafloor of mud volcanoes in the northern part of the Gulf of Cadiz had strongly 13C-depleted lipid signatures indicative of higher seepage activities in the past. However, actual seafloor video observations showed only scarce traces of methane seepage and associated biological processes at the seafloor. No

  18. Mud Volcanoes - Analogs to Martian Cones and Domes (by the Thousands!)

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Oehler, Dorothy

    2010-01-01

    Mud volcanoes are mounds formed by low temperature slurries of gas, liquid, sediments and rock that erupt to the surface from depths of meters to kilometers. They are common on Earth, with estimates of thousands onshore and tens of thousands offshore. Mud volcanoes occur in basins with rapidly-deposited accumulations of fine-grained sediments. Such settings are ideal for concentration and preservation of organic materials, and mud volcanoes typically occur in sedimentary basins that are rich in organic biosignatures. Domes and cones, cited as possible mud volcanoes by previous authors, are common on the northern plains of Mars. Our analysis of selected regions in southern Acidalia Planitia has revealed over 18,000 such features, and we estimate that more than 40,000 occur across the area. These domes and cones strongly resemble terrestrial mud volcanoes in size, shape, morphology, associated flow structures and geologic setting. Geologic and mineralogic arguments rule out alternative formation mechanisms involving lava, ice and impacts. We are studying terrestrial mud volcanoes from onshore and submarine locations. The largest concentration of onshore features is in Azerbaijan, near the western edge of the Caspian Sea. These features are typically hundreds of meters to several kilometers in diameter, and tens to hundreds of meters in height. Satellite images show spatial densities of 20 to 40 eruptive centers per 1000 square km. Many of the features remain active, and fresh mud flows as long as several kilometers are common. A large field of submarine mud volcanoes is located in the Gulf of Cadiz, off the Atlantic coasts of Morocco and Spain. High-resolution sonar bathymetry reveals numerous km-scale mud volcanoes, hundreds of meters in height. Seismic profiles demonstrate that the mud erupts from depths of several hundred meters. These submarine mud volcanoes are the closest morphologic analogs yet found to the features in Acidalia Planitia. We are also conducting

  19. Mud Volcanoes - Analogs to Martian Cones and Domes (by the thousands !)

    NASA Astrophysics Data System (ADS)

    Allen, C.; Oehler, D.

    2010-12-01

    Mud volcanoes are mounds formed by low temperature slurries of gas, liquid, sediments and rock that erupt to the surface from depths of meters to kilometers. They are common on Earth, with estimates of thousands onshore and tens of thousands offshore. Mud volcanoes occur in basins with rapidly-deposited accumulations of fine-grained sediments. Such settings are ideal for concentration and preservation of organic materials, and mud volcanoes typically occur in sedimentary basins that are rich in organic biosignatures. Domes and cones, cited as possible mud volcanoes by previous authors, are common on the northern plains of Mars. Our analysis of selected regions in southern Acidalia Planitia has revealed over 18,000 such features, and we estimate that more than 40,000 occur across the area. These domes and cones strongly resemble terrestrial mud volcanoes in size, shape, morphology, associated flow structures and geologic setting. Geologic and mineralogic arguments rule out alternative formation mechanisms involving lava, ice and impacts. We are studying terrestrial mud volcanoes from onshore and submarine locations. The largest concentration of onshore features is in Azerbaijan, near the western edge of the Caspian Sea. These features are typically hundreds of meters to several kilometers in diameter, and tens to hundreds of meters in height. Satellite images show spatial densities of 20 to 40 eruptive centers per 1000 km2. Many of the features remain active, and fresh mud flows as long as several kilometers are common. A large field of submarine mud volcanoes is located in the Gulf of Cadiz, off the Atlantic coasts of Morocco and Spain. High-resolution sonar bathymetry reveals numerous km-scale mud volcanoes, hundreds of meters in height. Seismic profiles demonstrate that the mud erupts from depths of several hundred meters. These submarine mud volcanoes are the closest morphologic analogs yet found to the features in Acidalia Planitia. We are also conducting

  20. Mud volcanoes discovered near the Crommelin South Crater, Mars

    NASA Astrophysics Data System (ADS)

    Pondrelli, M.; Rossi, A.; Ori, G. G.; Praeg, D.; Ceramicola, S.

    2010-12-01

    We report the first detection of mud volcanoes in the equatorial highlands of Mars, in the Arabia Terra region within an unnamed crater located immediately south of the Crommelin crater, herein referred to as ‘Crommelin South’ crater. Mud volcanoes are recognized on the crater floor as hundreds of isolated or coalescing sub-conical mounds, with heights estimated at up to several tens of metres. The mounds include simple forms with sub-elliptical plan-forms typically 100-300 m in diameter, in places coalescing to form composite mounds up to 500 m in diameter. More than 50% of the mounds show subcircular depressions at the apex indicating locations of vents. The mounds are all associated with a distinctive sediment facies that includes clasts up to boulder size, which we interpret as the first deposits of mud volcanic breccia to be recognized on Mars. The larger clasts are sub-angular to angular and include bright features that appear to be derived from bright layers within the surrounding Layered Deposits. The mudbreccia facies is observed to stratigraphically overlie the Layered Deposits and, which infill this part of the crater in thicknesses estimated at up to 300 m. The distribution of the mud volcanoes is closely related to impact-related faults and fractures, which represent probable pathways for subsurface fluid migration. The Crommelin South mud volcanoes are comparable in form and deposits texture to terrestrial mud volcanoes, which are typically composed of matrix-supported mud breccias (including clasts up to metric or decametric size) derived from multiple stratigraphic levels as a response to the upward migration of overpressured fluids from depths of kilometers. The presence of bright clasts in the Crommelin South mud breccias is consistent with their extrusion in response to the upward migration of fluids through the relatively thin crater-fill from overpressured sources in underlying crustal materials, probably along long-lived pathways provided

  1. Studies of the composition of hydrocarbon components of the Yuzhno-Sakhalinsk and Pugachevo mud volcanoes

    NASA Astrophysics Data System (ADS)

    Polonik, N. S.; Shakirov, R. B.; Sorochinskaya, A. V.; Obzhirov, A. I.

    2015-05-01

    This report considers the results of studies of the composition of hydrocarbon components of the Yuzhno-Sakhalinsk and Pugachevo mud volcanoes (Sakhalin Island). The similarity in the chemical composition of hydrocarbons of these volcanoes was revealed, as was the variation in the ratios of hydrocarbon components under seismic activation. Two maxima of hydrocarbon concentrations were shown, and basically the marine genesis of the initial organic matter was substantiated. A possible interpretation of the obtained dada is presented.

  2. Gas hydrate accumulation at the Hakon Mosby Mud Volcano

    USGS Publications Warehouse

    Ginsburg, G.D.; Milkov, A.V.; Soloviev, V.A.; Egorov, A.V.; Cherkashev, G.A.; Vogt, P.R.; Crane, K.; Lorenson, T.D.; Khutorskoy, M.D.

    1999-01-01

    Gas hydrate (GH) accumulation is characterized and modeled for the Hakon Mosby mud volcano, ca. 1.5 km across, located on the Norway-Barents-Svalbard margin. Pore water chemical and isotopic results based on shallow sediment cores as well as geothermal and geomorphological data suggest that the GH accumulation is of a concentric pattern controlled by and formed essentially from the ascending mud volcano fluid. The gas hydrate content of sediment peaks at 25% by volume, averaging about 1.2% throughout the accumulation. The amount of hydrate methane is estimated at ca. 108 m3 STP, which could account for about 1-10% of the gas that has escaped from the volcano since its origin.

  3. Eruption of a deep-sea mud volcano triggers rapid sediment movement

    PubMed Central

    Feseker, Tomas; Boetius, Antje; Wenzhöfer, Frank; Blandin, Jerome; Olu, Karine; Yoerger, Dana R.; Camilli, Richard; German, Christopher R.; de Beer, Dirk

    2014-01-01

    Submarine mud volcanoes are important sources of methane to the water column. However, the temporal variability of their mud and methane emissions is unknown. Methane emissions were previously proposed to result from a dynamic equilibrium between upward migration and consumption at the seabed by methane-consuming microbes. Here we show non-steady-state situations of vigorous mud movement that are revealed through variations in fluid flow, seabed temperature and seafloor bathymetry. Time series data for pressure, temperature, pH and seafloor photography were collected over 431 days using a benthic observatory at the active Håkon Mosby Mud Volcano. We documented 25 pulses of hot subsurface fluids, accompanied by eruptions that changed the landscape of the mud volcano. Four major events triggered rapid sediment uplift of more than a metre in height, substantial lateral flow of muds at average velocities of 0.4 m per day, and significant emissions of methane and CO2 from the seafloor. PMID:25384354

  4. Tracking hydrothermal feature changes in response to seismicity and deformation at Mud Volcano thermal area, Yellowstone

    NASA Astrophysics Data System (ADS)

    Diefenbach, A. K.; Hurwitz, S.; Murphy, F.; Evans, W.

    2013-12-01

    The Mud Volcano thermal area in Yellowstone National Park comprises many hydrothermal features including fumaroles, mudpots, springs, and thermal pools. Observations of hydrothermal changes have been made for decades in the Mud Volcano thermal area, and include reports of significant changes (the appearance of new features, increased water levels in pools, vigor of activity, and tree mortality) following an earthquake swarm in 1978 that took place beneath the area. However, no quantitative method to map and measure surface feature changes through time has been applied. We present an analysis of aerial photographs from 1954 to present to track temporal changes in the boundaries between vegetated and thermally barren areas, as well as location, extent, color, clarity, and runoff patterns of hydrothermal features within the Mud Volcano thermal area. This study attempts to provide a detailed, long-term (>50 year) inventory of hydrothermal features and change detection at Mud Volcano thermal area that can be used to identify changes in hydrothermal activity in response to seismicity, uplift and subsidence episodes of the adjacent Sour Creek resurgent dome, or other potential causes.

  5. Near-specular acoustic scattering from a buried submarine mud volcano.

    PubMed

    Gerig, Anthony L; Holland, Charles W

    2007-12-01

    Submarine mud volcanoes are objects that form on the seafloor due to the emission of gas and fluidized sediment from the Earth's interior. They vary widely in size, can be exposed or buried, and are of interest to the underwater acoustics community as potential sources of active sonar clutter. Coincident seismic reflection data and low frequency bistatic scattering data were gathered from one such buried mud volcano located in the Straits of Sicily. The bistatic data were generated using a pulsed piston source and a 64-element horizontal array, both towed over the top of the volcano. The purpose of this work was to appropriately model low frequency scattering from the volcano using the bistatic returns, seismic bathymetry, and knowledge of the general geoacoustic properties of the area's seabed to guide understanding and model development. Ray theory, with some approximations, was used to model acoustic propagation through overlying layers. Due to the volcano's size, scattering was modeled using geometric acoustics and a simple representation of volcano shape. Modeled bistatic data compared relatively well with experimental data, although some features remain unexplained. Results of an inversion for the volcano's reflection coefficient indicate that it may be acoustically softer than expected.

  6. Gravity anomalies of the active mud diapirs off southwest Taiwan

    NASA Astrophysics Data System (ADS)

    Doo, Wen-Bin; Hsu, Shu-Kun; Lo, Chung-Liang; Chen, Song-Chuen; Tsai, Ching-Hui; Lin, Jing-Yi; Huang, Yuan-Ping; Huang, Yin-Sheng; Chiu, Shye-Donq; Ma, Yu-Fang

    2015-12-01

    Overpressure and buoyant effect of underlying sediments are generally used to account for the upward motion or formation of submarine mud volcanoes and mud diapirs. In this study, we process and interpret the gravity anomalies associated with the active mud diapirs off SW Taiwan. Geologically, the mud diapirs are just formed and are still very active, thus we can better understand the initial process of the mud diapirs formation through the gravity analysis. Our results show that the density contrasts of the submarine mud diapirs with respect to the surroundings are generally positive. Because the study area is in a tectonically compressive regime and the gas plume venting from the submarine mud volcanoes is very active, we thus infer that mechanically the mud diapirs off SW Taiwan have been formed mainly due to the tectonic compression on the underlying sediments of high pore-fluid pressure, instead of the buoyancy of the buried sediments. The overpressured sediments and fluid are compressed and pushed upwards to pierce the overlying sediments and form the more compacted mud diapirs. The relatively denser material of the mud diapirs probably constrains the flowing courses of the submarine canyons off SW Taiwan, especially for the upper reaches of the Kaoping and Fangliao submarine canyons.

  7. Mud volcano venting induced gas hydrate formation at the upper slope accretionary wedge, offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Saulwood; Tseng, Yi-Ting; Cheng, Wan-Yen; Chou, Cheng-Tien; Chen, NeiChen; Hsieh, I.-Chih

    2016-04-01

    TsanYao Mud Volcano (TYMV) is the largest mud volcano cone in the Hengchun Mud Volcano Group (HCMVG), located at the upper slope of the accrretionary wedge, southwest of Taiwan. The region is under active tectonic activity with the Philippine Plate, moving northwestward at a rate of ~8 cm/year. This region also receives huge quantity of suspended particle load of ~100 mT/year at present time from adjacent small rivers of the Island of Taiwan. Large loads of suspended sediments influx become a major source of organic carbon and later gas and other hydrocarbon. Gas and fluid in the mud volcano are actively venting from deep to the sea floor on the upper slope of the accretionary wedge. In order to understand venting on the HCMVG, echo sounder, towcam and coring were carried out. Pore water sulfate, chloride, potassium, calcium, stable isotope O-18, gas compositions, dissolved sulfide were analysed. The HCMVG consists of 12 volcano cones of different sizes. Large quantity of gas and fluid are venting directly from deep to the TYMV structure high, as well as 50+ other vents as appeared as flares on the echo sounder. Some flares are reaching to the atmosphere and likely a source of green house gases to the atmosphere. Venting fluids include gas bubbles, suspended particle, mud, and breccia. Breccia size could reach more than 12 cm in diameter. Circular bands in different color appeared around the cone may represent stages of vent eruptions. Compositions of vent gas include methane, ethane and propane. High proportions of ethane and propane in the vent gas demonstrated that source of gas are thermogenic in origin. Patchy authigenic carbonate, bacterial mats, bivalves, tube worms and other chemosynthesis organisms were supported by venting gas AOM process near the sea floor. Pore water chloride concentrations show distinct variation pattern from center cone to the side of the volcano, with low in the center and high away from the cone. Pore water with higher than seawater

  8. Results of study of deep underground structure of mud volcanoes in North-Western Caucasus by means of geological and geophysical methods

    NASA Astrophysics Data System (ADS)

    Sobissevitch, A. L.; Gorbatikov, A. V.; Ovsuychenko, A. N.; Sobissevitch, L. E.; Stepanova, M. Yu.; Morev, B. A.

    2009-04-01

    Results of complementary geological and geophysical studies of mud volcanic phenomena in North-Western Caucasus (Taman mud volcanic province) are presented. New technology for passive subsurface sounding of the Earth's crust has been originally developed at the Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Patented since 2005, this technology represents the new kind of seismic survey based on specific features of propagation of the Rayleigh waves. It uses natural background microseismic noise as a sounding signal. By using the method of low-frequency microseismic sounding in the course of field works carried out in 2006 - 2008, there have been obtained three vertical cross-sections for the two mud volcanoes down to the depth of 25 km. For the two different mud volcanoes their deep subsurface structure has been revealed and discussed. The Gora Karabetova mud volcano is one of the most active mud volcanoes in the Taman peninsula with primarily explosive behaviour while the Shugo mud volcano's activity pattern is different, explosive events are rare and both types of phenomena may be explained by the configuration of their feeding systems, tectonic position and deep pathways of migration of fluids. Complementary interpretation of raw data sets delivered form geophysical and geological surveys allows considering principal differences of origin and mechanisms of mud volcanic activity for the Shugo and the Gora Karabetova mud volcanoes.

  9. The "Mud-volcanoes route" (Emilia Apennines, northern Italy)

    NASA Astrophysics Data System (ADS)

    Coratza, Paola; Castaldini, Doriano

    2016-04-01

    In the present paper the "Mud-volcanoes route" (MVR), an itinerary unfolds across the districts of Viano, Sassuolo, Fiorano Modenese and Maranello, in which part of the Emilia mud volcanoes fields are located, is presented. The Mud-volanoes route represents an emotional journey that connects places and excellences through the geological phenomenon of mud volcanoes, known with the local name "Salse". The Mud Volcanoes are created by the surfacing of salt water and mud mixed with gaseous and liquid hydrocarbons along faults and fractures of the ground. The name "Salsa"- from Latin salsus - results from the"salt" content of these muddy waters, ancient heritage of the sea that about a million years ago was occupying the current Po Plain. The "Salse" may take the shape of a cone or a level-pool according to the density of the mud. The Salse of Nirano, in the district of Fiorano Modenese, is one of the most important in Italy and among the most complex in Europe. Less extensive but equally charming and spectacular, are the "Salse" located in the districts of Maranello (locality Puianello), Sassuolo (locality Montegibbio) and Viano (locality Casola Querciola and Regnano). These fascinating lunar landscapes have always attracted the interest of researchers and tourist.The presence on the MVR territory of ancient settlements, Roman furnaces and mansions, fortification systems and castles, besides historic and rural buildings, proves the lasting bond between this land and its men. In these places, where the culture of good food has become a resource, we can find wine cellars, dairy farms and Balsamic vinegar factories that enable us to appreciate unique worldwide products. This land gave also birth to some personalities who created unique worldwide famous values, such as the myth of the Ferrrari, the ceramic industry and the mechatronics. The MVR is represented in a leaflet containing, short explanation, photos and a map in which are located areas with mud volcanoes, castles

  10. Origin of fluids and eruption dynamics at LUSI mud volcano (East Java, Indonesia)

    NASA Astrophysics Data System (ADS)

    Vanderkluysen, L.; Hartnett, H. E.; Clarke, A. B.; Burton, M. R.

    2013-12-01

    The LUSI mud volcano near Sidoarjo in East Java (Indonesia) has been erupting mud, water and gases since May 2006. It is the most recent manifestation of mud volcanism in the Sunda back-arc region, part of a larger cluster of a dozen mud volcanoes scattered across East Java and Madura. LUSI discharged as much as 180,000 cubic meters of mud per day at the peak of its activity, destroyed thousands of homes, and displaced tens of thousands of people. The erupted fluids are a mixture of water, clays, and other minerals at near-boiling temperatures, accompanied by the bursting of gas bubbles on average every 1-3 minutes, which trigger mud fountains ~20 m in height. We have taken a multi-disciplinary approach to assess both the fluid provenance and eruption behavior at this complex and evolving mud volcano, by using a combination of absorption infrared spectrometry of the gases, X-Ray diffraction of the solid fraction, major and trace element analyses of solids and dissolved ions in liquids, and isotopic analyses of separated water (D/H and 87Sr/86Sr). Similar analyses of other regional fluid sources (hot springs, surface waters, sea water, and relict mud volcanoes) were also carried out for comparison. From open path FTIR measurements, we determine that the gases released during explosions at LUSI consist of 98% water vapor, 1.5% carbon dioxide, and 0.5% methane, with corresponding fluxes of 2,300 t/yr of CH4, 30,000 t/yr of CO2 and 800,000 t/yr of water vapor. The methane flux is two orders of magnitude larger than estimates for any other single mud volcano on Earth. By comparing the mineral composition of solids present in the mud to rock outcrops of the local stratigraphy, the solids can be traced with some certainty to the blue-gray clays of the Upper Kalibeng formation, found 1600-1800 m beneath the LUSI main vent. However, the water content and chemical composition of the liquid phase are more difficult to interpret. The LUSI fluids are compositionally distinct

  11. Observations and Rock Analyses in a Kumano Mud Volcano in Nankai Accretionary Prism

    NASA Astrophysics Data System (ADS)

    Morita, S.; Aoike, K.; Sawada, T.; Ashi, J.; Gulick, S. P.; Flemings, P. B.; Kuramoto, S.; Saito, S.; Mikada, H.; Kinoshita, M.

    2002-12-01

    Kumano Basin is a forearc basin on the eastern Nankai Accretionary Prism off southwest Japan. Recent bathymetric survey showed existence of small knolls in the Kumano Basin. Submersible and ROV dives, sidescan sonar and deep-towed camera investigations revealed so far that at least five of the small knolls are mud volcanoes erupted on the Kumano Basin floor. In June and August, 2002, Dive 677 and 681 by submersible SHINKAI 6500 (YK02-02: R/V Yokosuka) and Dive 267 by ROV KAIKO (KR02-10: R/V Kairei) were performed in one of the mud volcanoes, Kumano Knoll No.4, which is 100 m high and 800 m in diameter at the foot of the knoll. The knoll has a plateau of about 300 m diameter on the top, which shows bumpy surface where there are waves, steps and craters of several meters in diameter. The craters imply active or dead cold seeps and are occasionally accompanied by Calyptogena colonies. The plateau is mostly covered with mud. Rock gravels and boulders were observed mainly on outer slope of the knoll. Sidescan sonar and subbottom profiler data by KAIKO system show marked contrasts in sonic reflectivity and penetration between the Kumano Knoll No.4 and the Kumano Basin floor. The high sonic reflectivity and the low penetration on the knoll indicate that main body of the knoll is composed of clastic ejecta as a mud volcano. On the Kumano Knoll No.4, the dives obtained semi-consolidated mudstone, mud breccia, and biotite arkose sandstone. Chronological analysis on nannofossil indicates the sedimentary rocks are in the late Early Miocene through the Middle Miocene. According to this age and geological information on land, it is likely that the sedimentary rocks on the knoll were originally deposited at the beginning of formation of the Kumano Basin. Porosity of these sedimentary rocks is very low (< 18 %). Some mud breccias contain calcite veins that cut the angular mud gravels. These features lead to finding processes until when the sedimentary rocks reached to the seafloor

  12. XRF geochemistry of Maya mud volcano (SAGAS 08 cruise Alboran Sea)

    NASA Astrophysics Data System (ADS)

    Rodríguez Germade, Isabel; Fátima López Rodríguez, Carmen; Rubio, Belén.; Comas, Menchu; Rey, Daniel; Vilas, Federico; Álvarez, Paula

    2010-05-01

    Mud ascent as the result of active diapirism and mud volcanoes on the seafloor are common features in the Alboran Sea. It is thought that these have been developed during a compressional tectonic setting that produced folding and wrench tectonics throughout the basin. During the TTR 17 cruise of the R/V Professor Logachev (2008), several new and previously discovered mud volcanoes and structure mounds were sampled in the southwest sector of Alboran Basin. Most of the investigated mud volcanic deposits, such as Melilla and Maya structures, were covered by a thick drape of hemipelagic mud, suggesting that volcanoes are currently inactive. The aim of this paper is to demonstrate the ability of high-resolution XRF core scanning based geochemical depth profiles to discriminate between mud volcanoes, mounds and hemipelagic sediments, and also to show high resolution geochemical profiles of the core 419G from Maya mud volcano. For our purpose U-channels were subsampled from the centre of half-split gravity cores. High-resolution XRF data of 28 major and trace elements were acquired for each core on an Itrax Core Scanner at the University of Vigo by using Mo and Cr lamps. The acquisition was performed with in this case a 300 µm resolution and provided about 100,000 data point (i.e. XRF spectra), for each meter of core. We used carbon dating to estimate the age of the Maya mud volcano sediments. We also used a scanning electron microscope to do microanalysis and to study mineralogy. The results show that down-core high resolution XRF scanner based geochemical profiles represented a good and quick screening tool for identifying authigenic methane-related carbonate-rich layers that may represent paleo-indicators for ancient methane seepage. Sedimentary Sr/Ca and Mg/Ca ratios have also been explored to infer the presence of authigenic aragonite (Sr-rich) and Mg-rich carbonate phases (high-Mg calcite, dolomite). The coexistence of methane anaerobic oxidation process and

  13. Archaeal populations in hypersaline sediments underlying orange microbial mats in the Napoli mud volcano.

    PubMed

    Lazar, Cassandre Sara; L'haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-05-01

    Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the "active" archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the anaerobic methanotrophic Archaea (ANME) of the ANME-1, ANME-2a, and ANME-2c groups, suggesting that AOM occurred in these sediment layers. Enrichment cultures showed the presence of viable marine methylotrophic Methanococcoides in shallow sediment layers. Thus, the archaeal community diversity seems to show that active methane cycling took place in the hypersaline microbial mat-associated sediments of the Napoli mud volcano.

  14. Violent Gas Venting on the Heng-Chun Mud Volcano, South China Sea Active Continental Margin offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, S.; Cheng, W. Y.; Tseng, Y. T.; Chen, N. C.; Hsieh, I. C.; Yang, T. F.

    2014-12-01

    Accumulation of methane as gas hydrate under the sea floor has been considered a major trap for both thermal and biogenic gas in marine environment. Aided by rapid AOM process near the sea floor, fraction of methane escaping the sea floor has been considered at minuscule. However, most studies focused mainly on deepwater gas hydrate systems where gas hydrate remain relatively stable. We have studied methane seeps on the active margin offshore Taiwan, where rapid tectonic activities occur. Our intention is to evaluate the scale and condition of gas seeps in the tectonic active region. Towcam, coring, heat probe, chirp, multibeam bathymetric mapping and echo sounding were conducted at the study areas. Our results showed that gas is violently venting at the active margin, not only through sediments, but also through overlying sea water, directly into the atmosphere. Similar ventings, but, not in this scale, have also been identified previously in the nearby region. High concentrations of methane as well as traces of propane were found in sediments and in waters with flares. In conjunction, abundant chemosynthetic community, life mussel, clams, tube worms, bacterial mats together with high concentrations of dissolve sulfide, large authigenic carbonate buildups were also found. Our results indicate that methane could be another major green house gas in the shallow water active margin region.

  15. Boron-rich mud volcanoes of the Black Sea region: modern analogues to ancient sea-floor tourmalinites associated with Sullivan-type Pb-Zn deposits?

    USGS Publications Warehouse

    Slack, J.F.; Turner, R.J.W.; Ware, P.L.G.

    1998-01-01

    Large submarine mud volcanoes in the abyssal part of the Black Sea south of the Crimean Peninsula are similar in many respects to synsedimentary mud volcanoes in the Mesoproterozoic Belt-Purcell basin. One of the Belt-Purcell mud volcanoes directly underlies the giant Sullivan Pb-Zn-Ag deposit in southeastern British Columbia. Footwall rocks to the Sullivan deposit comprise variably tourmalinized siltstone, conglomerate, and related fragmental rock; local thin pyrrhotite-rich and spessartine-quartz beds are interpreted as Fe and Fe-Mn exhalites, respectively. Analogous Fe- and Mn-rich sediments occur near the abyssal Black Sea mud volcanoes. Massive pyrite crusts and associated carbonate chimneys discovered in relatively shallow waters (~200 m depth) west of the Crimean Peninsula indicate an active sea-floor-hydrothermal system. Subaerial mud volcanoes on the Kerch and Taman Peninsulas (~100 km north of the abyssal mud volcanoes) contain saline thermal waters that locally have very high B contents (to 915 mg/L). These data suggest that tourmalinites might be forming in or near submarine Black Sea mud volcanoes, where potential may also exist for Sullivan-type Pb-Zn mineralization.

  16. Organic chemical composition of mud from the LUSI mud volcano, Sidoarjo, East Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Rosenbauer, R. J.; Campbell, P.; Lam, A.

    2009-12-01

    Sidoarjo, East Java, Indonesia is the site of LUSI, a terrestrial mud volcano that has been erupting since May 29, 2006. In response to a U.S. Department of State request, the U.S. Geological Survey has been assisting the Indonesian Government to describe the geological and geochemical aspects and potential health risk of the mud eruption. We report here on the organic chemical composition of the mud. Organic chemical analyses were carried out by gas chromatography/mass spectroscopy following organic extraction by microwave-assisted solvent extraction and compound fractionation by adsorption chromatography. There is a petroliferous component in the mud that is fresh, immature, and nonbiodegraded. There is a complete suite of n-alkanes with a bell-shaped pattern typical of fresh petroleum with a Cmax around C20. The alkane content ranges from 0.12 to 1.01 mg/kg dry mud. The presence of certain hopanes (i.e. 17 α,21β(H)-30-norhopane and 17α,21β(H)-hopane) is also indicative of the presence of oil. The proportions of other biomarker compounds (pristane/phytane = 2.4) and the dominance of the C27 sterane (5α(H),14α(H),17α(H)-chlolestane) suggest that oil formed under oxic conditions and has a likely coastal marine or terrigenous source. The presence of oleanane indicates a Cretaceous or younger age for the petrogenic material. These geochemical parameters are consistent with Indonesian oil derived from Tertiary marlstone source rocks that contained kerogen deposited under oxic conditions, probably the upper Miocene Klasafet Formation. Polycyclic aromatic hydrocarbons (PAHs) are present and range in content from 0.1 to 2.2 mg/kg dry mud. The low molecular weight (LMW) PAHs, in particular, naphthalene and methyl-naphthalene are dominant except for perylene which is ubiquitous in the environment. The presence of both parent and higher homologue PAHs indicate a petrogenic rather than combustion source. PAHs are known carcinogens but toxicity data in sediments are

  17. Tectonic control on the distribution of onshore mud volcanoes in parts of the Upper Benue Trough, northeastern Nigeria.

    NASA Astrophysics Data System (ADS)

    Musa, Ojochenemi K.; Kurowska, Ewa E.; Schoeneich, Krzysztof; Alagbe, Solomon A.; Ayok, Jeremiah

    2016-06-01

    Onshore mud volcanoes are rare geological phenomena, which in Nigeria were reported for the first time few years ago in the Upper Benue Trough. In this study a detail geological mapping of the area of mud volcanoes occurrence was carried out, with the primary aim of defining their relationship, if any, to the structural geology there. The systematic field reconnaissance included field observations of the structural features, as well as analysis of the location and distribution of the onshore mud volcanoes, marking their locations on the topographic and geological maps, analysis of the aerial photographs and satellite images. The study area covered the central part of the Upper Benue Trough where the onshore mud volcanoes were found. The study area is the part of a sedimentary basin comprising Cretaceous clastic rocks that have been deformed intensively by a network of faults often embedded in the underlying Precambrian basement. This network of faults underwent a rejuvenation period from the Aptian to the Palaeocene. The most prominent tectonic structure in the study area is the NE - SW trending Kaltungo Fault Zone, however, there are other minor faults with N - S and NW - SE trends. This study shows that the mud volcanoes found in the study area are usually located near or within fault zones, within the outcropping Upper Cretaceous Yolde Formation and Upper Bima Sandstone, both of which were deformed by the Kaltungo faults, as well as by other minor faults. Worldwide, incidences of onshore mud volcano formation are usually attributed to areas of tectonic activity, rapid sedimentation or hydrocarbon occurrence. In this study, the interpretation of the field observations and mapping results, combined with information on the structural evolution of the study area and seismic pattern (very scarce), have led to the conclusion that the location of onshore mud volcanoes in the Upper Benue Trough, being located along the fault zones, is structurally controlled. The close

  18. The geological and geochemical study of the mud volcanoes of Azerbaijan

    SciTech Connect

    Guliyev, I.A.; Aliyev, A.A.; Rahmanov, R.R.

    1995-08-01

    Azerbaijan is a classic region for the study of mud volcanism. Of the 700 mud volcanoes known in the world, 220 are in Azerbaijan. These are of great interest, not least in relation to oil and gas exploration since they give information on subsurface sediments beyond the reach of drilling. Mud volcanoes are clearly visible on satellite images. They are confined to structural lineaments and associated fractures. Changes in the morphology of some mud volcanoes post-eruption can be detected from a series of images pre-dating and post-dating eruptions. Mud volcanoes are notable for gradients of temperature that are by an order of magnitude or a factor of 102 greater than the temperature gradients established elsewhere. The gases of mud volcanoes consist mainly of methane (95-100%). There are small amounts of C{sub 2-6}, CO{sub 2}, N{sub 2}, He and Ar. The isotopic composition of carbon (ICC) within the methane varies from -61.29. to -35.W{close_quotes} which is isotopically heavier than the methane from producing fields. The ICC of the CO{sub 2} has a very wide range (from -49.6% to +23.1%), indicating several sources of its formation. The isotopically superheavy CO{sub 2} (+5%) is especially interesting. Oils from mud volcanoes are typically severely biodegraded. Their ICC ranges from -24.76% to -28.2%. A relationship between {partial_derivative}{sup l3}C of oils and ages of accumulations has been established. Waters of mud volcanoes are lightly mineralised, containing chiefly bicarbonates and sodium. The hydrogen composition of the water is abnormally heavy. Ejected rocks from mud volcanoes range in age from Cretaceous - Pliocene. Their study suggests that deeply buried reservoirs maintain good poroperm characteristics because of relatively little catagenesis.

  19. Mud Volcanoes from the Beaufort Sea to the South China Sea

    NASA Astrophysics Data System (ADS)

    Lundsten, E. M.; Paull, C. K.; Caress, D. W.; Dallimore, S.; Melling, H.; Liu, C. S.; Anderson, K.; Gwiazda, R.

    2015-12-01

    The detailed morphology of five submarine mud volcanoes were surveyed using an Autonomous Underwater Vehicle (AUV) developed at the Monterey Bay Aquarium Research Institute. Mud volcanoes are constructional features built by extrusion of gas, subsurface fluids and fine-grained sediment. Two surveys covering four submarine mud volcanoes were conducted on the CCGS Sir Wilfred Laurier in the Beaufort Sea in the Canadian Arctic. A survey of one mud volcano was conducted on the Taiwanese Ocean Research V in the South China Sea, SE of Taiwan. The AUV carried a multibeam sonar, a 1-6 kHz chirp sub-bottom profiler, and a110 kHz sidescan, and obtained overlapping multibeam bathymetric coverage at a vertical resolution of 0.15 m with a horizontal footprint of 0.9 m and chirp seismic-reflection profiles with a vertical resolution of 0.11 m. Mud volcanoes were either flat topped or conical. The conical mud volcano off Taiwan had a diameter of ~2 km and 10° side slopes; the conical feature in the Beaufort Sea had a diameter of ~1.5 km and 4° side slopes. The sides of the conical mud volcanoes were smooth, suggesting they were formed by sediment flows that emanate from a vent on their crests. The flanks of the conical mud volcanoes characteristically had very low acoustic reflectivity, but one single high reflectivity trail from the crest of the Beaufort Sea mud volcano indicates a recent flow. Three mud volcanoes in the Beaufort Sea formed circular, flat-topped plateaus that are up to ~1.1 km in diameter and elevated up to 30 m from the surrounding seafloor. The fine scale morphology and reflectivity on these plateaus show low relief, concentric, and ovoid circles that appear to be mud boils probably associated with eruptive events of varying ages at shifting vent sites. The different mud volcano shapes are attributed to variations in the viscosity of the erupting sediment slurries and may represent a sequential morphology, which is altered by shifts in venting position over

  20. 3D Subsoil Model of the San Biagio `Salinelle' Mud Volcanoes (Belpasso, Sicily) derived from Geophysical Surveys

    NASA Astrophysics Data System (ADS)

    Imposa, S.; Grassi, S.; De Guidi, G.; Battaglia, F.; Lanaia, G.; Scudero, S.

    2016-11-01

    Mud volcanoes are common in active mountain fronts. At Mt. Etna, located just between the Apennine front in Sicily and its foredeep, there are some manifestations of mud volcanism in the lower border of the volcanic edifice. The activity of these mud volcanoes is characterized by persistent emission of muddy water mixed with salts, which rises to the surface due to the gas pressure in the subsoil. The San Biagio Salinelle is one of the three mud volcano fields located around the Paternò eruptive monogenic apparatus; this old volcanic structure was one of the first subaerial volcanic manifestations that formed in the pre-Etnean phase. It is not fully clear whether and how the activity of the mud fields is connected with the volcanic activity of Mt. Etna. Noninvasive geophysical surveys were carried out in the area of the active cone of the San Biagio Salinelle, in order to identify the probable ascent path of the emitted products. Seismic ambient noise records were collected at the nodes of a specially designed grid and, subsequently, the V s values were obtained from an active seismic survey. A digital elevation model (DEM) of the area was obtained by a topographic survey, carried out with the GNSS technique (global navigation satellite system), in real-time kinematic mode. The DEM and the topographic benchmark installed will represent the reference surface for future periodic monitoring of the ongoing deformation in the area. Our results provide an accurate and detailed 3D subsurface model showing the shallower feeding system of the investigated mud volcano.

  1. Characterization of a deep-sea microbial mat from an active cold seep at the Milano mud volcano in the Eastern Mediterranean Sea.

    PubMed

    Heijs, Sander K; Damsté, Jaap S Sinninghe; Forney, Larry J

    2005-09-01

    A white, filamentous microbial mat at the Milano mud volcano in the Eastern Mediterranean Sea was sampled during the Medinaut cruise of the R/V Nadir in 1998. The composition of the mat community was characterized using a combination of phylogenetic and lipid biomarker methods. The mat sample was filtered through 0.2 and 5-microm filters to coarsely separate unicellular and filamentous bacteria. Analyses of 16S rRNA gene sequences amplified from the total community DNA from these fractions showed that similar archaeal populations were present in both fractions. However, the bacterial populations in the fractions differed from one another, and were more diverse than the archaeal ones. Lipid analysis showed that bacteria were the dominant members of the mat microbial community and the relatively low delta(13)C carbon isotope values of bulk bacterial lipids suggested the occurrence of methane- and sulfide-based chemo(auto)trophy. Consistent with this, the bacterial populations in the fractions were related to Alpha-, Gamma- and Epsilonproteobacteria, most of which were chemoautotrophic bacteria that utilize hydrogen sulfide (or reduced sulfur compounds) and/or methane. The most common archaeal 16S rRNA gene sequences were related to those of previously identified Archaea capable of anaerobic methane oxidation. Although the filamentous organisms observed in the mat were not conclusively identified, our results indicated that the Eastern Mediterranean deep-sea microbial mat community might be sustained on a combination of methane- and sulfide-driven chemotrophy.

  2. Differential InSAR Monitoring of the Lampur Sidoarjo Mud Volcano (Java, Indonesia) Using ALOS PALSAR Imagery

    NASA Astrophysics Data System (ADS)

    Thomas, Adam; Holley, Rachel; Burren, Richard; Meikle, Chris; Shilston, David

    2010-03-01

    The Lampur Sidoarjo mud volcano (Java, Indonesia), colloquially called LUSI, first appeared in May 2006. Its cause, whether the result of natural or anthropogenic activities (or a combination of both), is still being debated within the academic, engineering and political communities.The mud volcano expels up to 150,000 m3 of mud per day; and over time, this large volume of mud has had a major environmental and economic impact on the region. The mud flow from LUSI has now covered 6 km2 to depths some tens of metres, displacing approximately 30,000 residents; and continues to threaten local communities, businesses and industry. With such a large volume of mud being expelled each day it is inevitable (as with onshore oil and gas production fields) that there will be some ground surface movement and instability issues at the mud source (the main vent), and in the vicinity of the mud volcano footprint.Due to the dynamic ground surface conditions, engineers and academics alike have found it difficult to reliably monitor ground surface movements within the effected region using conventional surveying techniques. Consequently, engineers responsible for the risk assessment of ground surface instabilities within the proximity of LUSI have called upon the use of satellite interferometry to continually monitor the hazard.The Advanced Land Observing Satellite (ALOS), launched on 24th January 2006, carries onboard an L- band Synthetic Aperture Radar (SAR) instrument called PALSAR (Phased Array type L-band Synthetic Aperture Radar). In contrast to established C-band (5.6cm wavelength) SAR instruments onboard ERS-1 & -2, Envisat, Radarsat-1, and the recently launched Radarsat-2 satellite, PALSAR's (L-band/23.8cm wavelength) instrument presents a number of advantages, including the ability to map larger-scale ground motions, over relatively short timeframes, in tropical environments, without suffering as significantly from signal decorrelation associated with C-band imagery

  3. Viral infections stimulate the metabolism and shape prokaryotic assemblages in submarine mud volcanoes.

    PubMed

    Corinaldesi, Cinzia; Dell'Anno, Antonio; Danovaro, Roberto

    2012-06-01

    Mud volcanoes are geological structures in the oceans that have key roles in the functioning of the global ecosystem. Information on the dynamics of benthic viruses and their interactions with prokaryotes in mud volcano ecosystems is still completely lacking. We investigated the impact of viral infection on the mortality and assemblage structure of benthic prokaryotes of five mud volcanoes in the Mediterranean Sea. Mud volcano sediments promote high rates of viral production (1.65-7.89 × 10(9) viruses g(-1) d(-1)), viral-induced prokaryotic mortality (VIPM) (33% cells killed per day) and heterotrophic prokaryotic production (3.0-8.3 μgC g(-1) d(-1)) when compared with sediments outside the mud volcano area. The viral shunt (that is, the microbial biomass converted into dissolved organic matter as a result of viral infection, and thus diverted away from higher trophic levels) provides 49 mgC m(-2) d(-1), thus fuelling the metabolism of uninfected prokaryotes and contributing to the total C budget. Bacteria are the dominant components of prokaryotic assemblages in surface sediments of mud volcanoes, whereas archaea dominate the subsurface sediment layers. Multivariate multiple regression analyses show that prokaryotic assemblage composition is not only dependant on the geochemical features and processes of mud volcano ecosystems but also on synergistic interactions between bottom-up (that is, trophic resources) and top-down (that is, VIPM) controlling factors. Overall, these findings highlight the significant role of the viral shunt in sustaining the metabolism of prokaryotes and shaping their assemblage structure in mud volcano sediments, and they provide new clues for our understanding of the functioning of cold-seep ecosystems.

  4. Long-range acoustic scattering from a shallow-water mud-volcano cluster.

    PubMed

    Holland, Charles W; Preston, John R; Abraham, Douglas A

    2007-10-01

    Analysis of reverberation measurements in the Straits of Sicily shows high intensity, discrete, scattered returns 10-20 dB above background reverberation. These returns are due to scattering from mud volcanoes. The reverberation from the mud volcanoes at ranges of 15-22 km is reasonably consistent over these spatial scales (i.e., kilometers) and temporal scales of several hours; measurements separated by 4 years are also similar. Statistical characterization indicates that the reverberation associated with a mud-volcano cluster is strongly non-Rayleigh and that the reverberation can be characterized by a single (shape) parameter, roughly independent of frequency. The non-Rayleigh statistics, with a concomitant increase in the probability of false alarm, indicate that mud volcanoes are a likely source of clutter. Mean target strengths were estimated at 1-11 dB over 160-1400 Hz and are consistent with target strengths measured during a different year at short (direct-path) ranges. Accumulated evidence points to small (order 10 m diameter and several meters high) carbonate chimneys on the mud-volcano edifice as the scattering mechanism as opposed to the edifice itself or scattering from gas bubbles in the water column. Thus, the results represent acoustic scattering from mud volcanoes in a quiescent state.

  5. Linking geochemical processes in mud volcanoes with arsenic mobilization driven by organic matter.

    PubMed

    Liu, Chia-Chuan; Kar, Sandeep; Jean, Jiin-Shuh; Wang, Chung-Ho; Lee, Yao-Chang; Sracek, Ondra; Li, Zhaohui; Bundschuh, Jochen; Yang, Huai-Jen; Chen, Chien-Yen

    2013-11-15

    The present study deals with geochemical characterization of mud fluids and sediments collected from Kunshuiping (KSP), Liyushan (LYS), Wushanting (WST), Sinyangnyuhu (SYNH), Hsiaokunshui (HKS) and Yenshuikeng (YSK) mud volcanoes in southwestern Taiwan. Chemical constituents (cations, anions, trace elements, organic carbon, humic acid, and stable isotopes) in both fluids and mud were analyzed to investigate the geochemical processes and spatial variability among the mud volcanoes under consideration. Analytical results suggested that the anoxic mud volcanic fluids are highly saline, implying connate water as the probable source. The isotopic signature indicated that δ(18)O-rich fluids may be associated with silicate and carbonate mineral released through water-rock interaction, along with dehydration of clay minerals. Considerable amounts of arsenic in mud irrespective of fluid composition suggested possible release through biogeochemical processes in the subsurface environment. Sequential extraction of As from the mud indicated that As was mostly present in organic and sulphidic phases, and adsorbed on amorphous Mn oxyhydroxides. Volcanic mud and fluids are rich in organic matter (in terms of organic carbon), and the presence of humic acid in mud has implications for the binding of arsenic. Functional groups of humic acid also showed variable sources of organic matter among the mud volcanoes being examined. Because arsenate concentration in the mud fluids was found to be independent from geochemical factors, it was considered that organic matter may induce arsenic mobilization through an adsorption/desorption mechanism with humic substances under reducing conditions. Organic matter therefore plays a significant role in the mobility of arsenic in mud volcanoes.

  6. Mud volcanoes in central Italy: Subsoil characterization through a multidisciplinary approach

    NASA Astrophysics Data System (ADS)

    Rainone, M. L.; Rusi, S.; Torrese, P.

    2015-04-01

    Mud volcanoes are common geological phenomenons observed worldwide as in Italy. They are well described in the scientific literature for their morphological, tectonic and hydrogeological features. They represent not only a relevant geological and geomorphological interest but also not negligible elements of hazard and risk associated with the presence of soft and pliable sediments and with the possible unexpected emission of gas and mud. Therefore, the understanding of their structure and hydrogeological circuits in the subsurface is an important key to define hazard and risk conditions in the adjacent areas. This paper deals with a multidisciplinary study including geophysical and hydrochemical surveys undertaken at the Pineto (central Italy) mud volcano site to achieve an interpretative conceptual model explaining the shallow upward migration of deep mud fluids. Shallow electrical and seismic imaging of the mud volcano was obtained using two dimensional and three dimensional (2D-3D) electrical resistivity tomography and 2D reflection seismic surveys. The hydrochemical properties of the rising fluids were assessed by means of seasonal measurements of the chemical-physical parameters, the concentrations of major ions, and some natural isotopes. This mud volcano or mud lump appears as a dome of about 15 × 10 m in size. The height of the crater is 2 m approximately, while the diameter of the crater is 2.5 m. Emission of fluids and solids (cold brine, mud, gas) occurs from this crater. Upper Pliocene-lower Pleistocene foredeep pelitic deposits (over-compacted clays with silty-sandy levels) overlain by clayey-silty deposits crop out in the area. The survey results seem to reveal that the uprising of deep fluids does not occur exactly below the mud volcano at present. Instead, a high conductivity body is present within a fractured zone in the pelitic deposits at 60 m approximately to the ENE. The probable occurrence of a high permeability layer approximately between 20

  7. Methane-related microbial processes and metabolic stratification in a terrestrial mud volcano, southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Cheng, T.; Lin, L.; Wang, P.; Chu, P.; Wu, J.

    2009-12-01

    Mud volcanoes are distinct geological features with fluid, sediment and hydrocarbon-enriched gas mixtures emitted from deep sedimentary environments. Without microbial attenuation in the water column, methane emission to atmosphere from terrestrial mud volcanoes constitutes a significant proportion to the global methane inventory. Microorganisms mediating methane transformation would be particularly enriched in such environments. Their activity, distribution, and diversity involved remain not well-constrained. At Shin-Yan-Ny-Hu Mud Volcanoes (SYNHMV) of southwestern Taiwan, we performed series of measurements and analyses on the pore water and eruptive water samples using geochemical and molecular approaches, in order to determine microbial processes and community assemblages responsible for methane transformation. Geochemical measurements indicated that sulfate depletion was companied with methane increase as the depth increased. Dissolved inorganic carbon (DIC) more depleted in 13C was observed at the depth of sulfate-methane transition zone (SMT, at ~12cm depth) than at other depth intervals. These characteristics of methane, sulfate, and DIC isotope profiles and the presence of ANME-1 sequences showed a high similarity with those of marine sediments, indicating the existence of active anaerobic oxidation of methane (AOM). From bottom to top, the increasing δ13C values of methane with the greatest value occurring in the eruptive surface water suggests methanogenesis and/or methane oxidation over the entire depth range. The contribution of microbial methane could be supported by molecular data of which methanogen-related archaea distributed throughout the entire depths, and the community structures were characterized by Methanosarcinales dominating at shallow depths and Methanomicrobiales dominating in deep sediments. The affinities and activities to substrate addition for methanogenesis appeared to be depth-dependent. Bacterial sequences affiliated with methane

  8. Preliminary Analytical Results for a Mud Sample Collected from the LUSI Mud Volcano, Sidoarjo, East Java, Indonesia

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Casadevall, Thomas J.; Wibowo, Handoko T.; Rosenbauer, Robert J.; Johnson, Craig A.; Breit, George N.; Lowers, Heather; Wolf, Ruth E.; Hageman, Philip L.; Goldstein, Harland L.; Anthony, Michael W.; Berry, Cyrus J.; Fey, David L.; Meeker, Gregory P.; Morman, Suzette A.

    2008-01-01

    On May 29, 2006, mud and gases began erupting unexpectedly from a vent 150 meters away from a hydrocarbon exploration well near Sidoarjo, East Java, Indonesia. The eruption, called the LUSI (Lumpur 'mud'-Sidoarjo) mud volcano, has continued since then at rates as high as 160,000 m3 per day. At the request of the United States Department of State, the U.S. Geological Survey (USGS) has been providing technical assistance to the Indonesian Government on the geological and geochemical aspects of the mud eruption. This report presents initial characterization results of a sample of the mud collected on September 22, 2007, as well as inerpretive findings based on the analytical results. The focus is on characteristics of the mud sample (including the solid and water components of the mud) that may be of potential environmental or human health concern. Characteristics that provide insights into the possible origins of the mud and its contained solids and waters have also been evaluated.

  9. Uplift revealed by LASER scanner surveys in Murono mud volcano, Niigata Prefecture, Japan, and estimation of its source

    NASA Astrophysics Data System (ADS)

    Takahashi, A.; Fukuda, Y.; Kusumoto, S.

    2014-12-01

    Since mud volcanoes spew out pressurized material, such as natural gas, oil, mud including water from a deeper ground, the activities of the mud volcanoes are good indicators of the stress conditions/orientations as well as the tectonic controls. The Murono mud volcano area located in Tokamachi City, Niigata prefecture, Japan, is one of the active ground deforming areas associated with mud, natural gas, oil and water eruptions. This area is famous because rapid ground deformation events were recorded corresponding to neighboring large earthquakes. For instance, associated with Naganoken-Hokubu Earthquake (Mw. 6.7) which occurred in 2011, the area recorded a sudden large uplift of about 50 cm. In order to reveal the source mechanism of the mud volcano, Toyama University has been conducting successive leveling surveys at 61 benchmarks. They revealed that the same area of the rapid uplift of 2011 has been still uplifting, even the amount of the uplift is much smaller (20 mm/yr). However, the source of the uplift could not be well identified due to the low spatial resolutions. Therefore, in order to obtain a high resolution land deformation pattern, we have conducted laser scanning surveys two times in June and October 2013, using TOPCON Imaging Station IS-301, which can obtain 3D point cloud data by the automatic laser scanning mode without reflector. The surface deformations obtained by comparing the June and October datasets indicate clear uplifts where the sudden uplift occurred. Since the uplift area show a clear concentric pattern, we estimated the source of the uplift assuming a Mogi source model. The obtained source parameters are, depth=14[m], Volume=14[m3], assuming the Poisson's ratio of 0.25. Then the calculated uplift at the nearest benchmark also shows good agreement with the uplift obtained by the leveling survey. The current uplift is much smaller than the 2011 uplift. Nevertheless both sources could be the same, because the areas of the uplifts are

  10. Methane Hydrate Recovered From A Mud Volcano in Santa Monica Basin, Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Normark, W. R.; Hein, J. R.; Powell, C. L.; Lorenson, T. D.; Lee, H. J.; Edwards, B. D.

    2003-12-01

    In July 2003, a short (2.1 m) piston core from the summit of a mud volcano recovered methane hydrate at a water depth of 813 m in Santa Monica Basin. The discovery core penetrated into in the hydrate as evidenced by chunks of ice and violent degassing of the core section between 162 and 212 cm depth. The core consists of shell hash and carbonate clasts (to 7-cm long) in silty mud. The methanogenic carbonates are of two types: massive, recrystallized nodular masses with an outer mm-thick sugary patina and a bivalve coquina with carbonate cement. Living clams including the genus Vesicomya, commonly found at cold-seep sites elsewhere, were recovered from the top of the core. Further sampling attempts using piston, gravity, and box corers, all of which were obtained within 15 m of the discovery core, recovered olive-brown silty mud with variable amounts of whole and fragmented bivalve shells and methanogenic carbonate fragments characteristic of cold-seep environments. Gases collected in cores adjacent to the discovery core contain elevated amounts of methane and trace amounts of heavier hydrocarbon gases, indicating some component from thermogenic sources. Hydrogen sulfide was also detected in these sediment samples. Vertical channels in one core may have served as fluid pathways. The existence of hydrate at such a shallow depth in the sediment was unexpected, however, the presence of Vesicomya and hydrogen sulfide indicate that the mud volcano is a site of active methane venting. The mud volcano, which is about 24 km west-southwest of Redondo Beach, is about 300 m in diameter at the base. No internal structure is resolved on either high resolution deep-tow boomer or single-channel air-gun profiles, most likely as a result of the gas content and sediment deformation. The diapiric structure has ascended through well-bedded sediment on the lower slope of the basin, producing as much as 30 m of bathymetric relief. It is located in an area where strike-slip motion along

  11. Aerobic and anaerobic methane oxidation in terrestrial mud volcanoes in the Northern Apennines

    NASA Astrophysics Data System (ADS)

    Wrede, C.; Brady, S.; Rockstroh, S.; Dreier, A.; Kokoschka, S.; Heinzelmann, S. M.; Heller, C.; Reitner, J.; Taviani, M.; Daniel, R.; Hoppert, M.

    2012-07-01

    Methane oxidizing prokaryotes are ubiquitous in oxic and anoxic habitats wherever C1-compounds are present. Thus, methane saturated mud volcano fluids should be a preferred habitat of methane consuming prokaryotes, using the readily available electron donors. In order to understand the relevance of methane as a carbon and energy source in mud volcano communities, we investigate the diversity of prokaryotic organisms involved in oxidation of methane in fluid samples from the Salse di Nirano mud volcano field situated in the Northern Apennines. Cell counts were at approximately 0.7 × 106 microbial cells/ml. A fraction of the microbial biomass was identified as ANME (anaerobic methanotroph) archaea by fluorescence in situ hybridization (FISH) analysis. They are associated in densely colonized flakes, of some tens of μm in diameter, embedded in a hyaline matrix. Diversity analysis based on the 16S rDNA genes, retrieved from amplified and cloned environmental DNA, revealed a high proportion of archaea, involved in anaerobic oxidation of methane (AOM). Aerobic methane-oxidizing proteobacteria could be highly enriched from mud volcano fluids, indicating the presence of aerobic methanotrophic bacteria, which may contribute to methane oxidation, whenever oxygen is readily available. The results imply that biofilms, dominated by ANME archaea, colonize parts of the mud volcano venting system.

  12. Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia)

    NASA Astrophysics Data System (ADS)

    Vanderkluysen, Loïc; Burton, Michael R.; Clarke, Amanda B.; Hartnett, Hilairy E.; Smekens, Jean-François

    2014-07-01

    LUSI mud volcano 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. Mud extrusion rates of 180,000 m3 d-1 were measured in the first few months of the eruption, decreasing to a loosely documented <20,000 m3 d-1 in 2012. The last few years of activity have been characterized by periodic short-lived eruptive bursts. In May and October 2011, we documented this activity using high-resolution time-lapse photography, open-path FTIR, and thermal infrared imagery. Gases (98% water vapor, 1.5% carbon dioxide, 0.5% methane) were periodically released by the bursting of bubbles approximately 3 m in diameter which triggered mud fountains to ˜10 m and gas plumes to hundreds of meters above the vent. During periods of quiescence (1-3 min), no appreciable gas seepage occurred. We estimate that LUSI releases approximately 2300 t yr-1 of methane, 30,000 t yr-1 of CO2, and 800,000 t yr-1 of water vapor. Gas bubble nucleation depths are >4000 m for methane and approximately 600 m for carbon dioxide; however, the mass fractions of these gases are insufficient to explain the observed dynamics. Rather, the primary driver of the cyclic bubble-bursting activity is decompressional boiling of water, which initiates a few tens of meters below the surface, setting up slug flow in the upper conduit. Our measured gas flux and conceptual model lead to a corresponding upper-bound estimate for the mud-water mass flux of 105 m3 d-1.

  13. Discovery of ferromanganese hydrocarbon-related nodules associated with the Meknes mud volcano (Western Moroccan margin)

    NASA Astrophysics Data System (ADS)

    González, F. J.; Somoza, L.; Medialdea, T.; León, R.; Torres, T.; Ortiz, J. E.; Martín-Rubí, J. A.

    2012-04-01

    A suite of ferromanganese nodules were sampled during the MVSEIS-2008 cruise aboard of the R/V Hespérides in the flanks of Meknes mud volcano (Moroccan margin, NE Central Atlantic). The nodules were collected at water depths between 750-850 m within a seabed area characterized by high acoustic backscatter values. Debris of cold water corals and hydrocarbon-derived authigenic carbonate crusts were sampled at same time. The nodules show tabular morphology, up to 20 cm in maximum diameter and 2 kg of weight, brown-reddish external color and they are internally composed by a concentric to complex arrangement of laminae. The results of X-ray diffraction analysis show that these ferromanganese nodules are essentially composed of goethite and lepidocrocite, being Mn-oxides, silicates (quartz and clay minerals) and carbonates (calcite, dolomite and siderite) accessory to occasional minerals. All the samples display micritic to micro-sparitic mosaic under the petrographic microscope which forms massive, laminated or dendritic-mottled textures. The nodules show a high abundance of Fe, minor Mn and low contents of trace metals and REEs. Mature hydrocarbons, as n-alkanes derived from marine bacterial activity, and phenanthrene have been detected in all the ferromanganese nodules analyzed. These nodules display analogous characteristics (textural, mineralogical and geochemical) to the nodules studied by González et al (2009) in the carbonate mud-mounds in the Gulf of Cadiz, offshore Iberian margin. In this way, the same preliminary genetic model proposed for these nodules might be applicable to those find in the Meknes mud volcano. Therefore, the anaerobic oxidation of hydrocarbon-rich fluids within the mud-breccia sediments in the flanks of Meknes mud volcano would induce the formation of early diagenetic Fe-(Mn) carbonate nodules. Thus, the nodules were later exhumed by the erosive action of sea bottom currents generating the replacement of ferromanganese carbonates by Fe

  14. Periodic gas release from the LUSI mud volcano (East Java, Indonesia)

    NASA Astrophysics Data System (ADS)

    Vanderkluysen, L.; Burton, M. R.; Clarke, A. B.; Hartnett, H. E.; Smekens, J.

    2012-12-01

    The LUSI mud volcano has been erupting since May 2006 in a densely populated district of the Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industries, farmlands, and 10,000 homes. Peak mud extrusion rates of 180,000 m3/d were measured in the first few months of the eruption, which have decreased to <20,000 m3/d in 2012. Mud volcanoes often release fluids in a pulsating fashion, with periodic timescales ranging from minutes to days, and LUSI is no exception. These oscillations, common in natural systems of multi-phase fluid flow, are thought to result from some combination of complex feedback mechanisms between conduit and source geometry, fluid compressibility, viscosity and density, changes in lithostatic stresses, reservoir pressure, fluid phases or vent conditions. Crisis management workers and local residents reported observations of pulsating eruptive cycles lasting a few hours during the first two years of the eruption, and possibly beyond. Since that time, activity has shifted to individual transient eruptions recurring at intervals of a few minutes. In May and October of 2011, we documented the periodic explosive release of fluids at LUSI using a combination of high-resolution time-lapse photography, continuous webcam, open path FTIR, and thermal infrared imagery. The mud, consisting of approximately 70% water, is erupted at temperatures close to boiling. Gases are periodically released by the bursting of bubbles approximately 3 m in diameter, triggering mud fountains ~20 m in height. No appreciable gas seepage was detected in the quiescent intervals between bubble bursts. Absorption spectrometry in the infrared spectrum reveals that the gas released during explosions consists of 98.5% water vapor, 1% carbon dioxide, and 0.3% methane. On rare occasions, minor amounts of ammonia were also detected. Using simplified plume geometries based on observations, we estimate that LUSI releases approximately 1,500 T

  15. Sedimentology and geochemistry of mud volcanoes in the Anaximander Mountain Region from the Eastern Mediterranean Sea.

    PubMed

    Talas, Ezgi; Duman, Muhammet; Küçüksezgin, Filiz; Brennan, Michael L; Raineault, Nicole A

    2015-06-15

    Investigations carried out on surface sediments collected from the Anaximander mud volcanoes in the Eastern Mediterranean Sea to determine sedimentary and geochemical properties. The sediment grain size distribution and geochemical contents were determined by grain size analysis, organic carbon, carbonate contents and element analysis. The results of element contents were compared to background levels of Earth's crust. The factors that affect element distribution in sediments were calculated by the nine push core samples taken from the surface of mud volcanoes by the E/V Nautilus. The grain size of the samples varies from sand to sandy silt. Enrichment and Contamination factor analysis showed that these analyses can also be used to evaluate of deep sea environmental and source parameters. It is concluded that the biological and cold seep effects are the main drivers of surface sediment characteristics from the Anaximander mud volcanoes.

  16. Ten Years of Monitoring the Eruption of Shrub Mud Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    McGimsey, R. G.; Evans, W. C.; Bergfeld, D.; McCarthy, S. H.; Hagstrum, J. T.

    2007-12-01

    Shrub mud volcano, one of three in the Klawasi group on the eastern flank of Mount Drum volcano in the Wrangell volcanic field of eastern Alaska, has been erupting warm, saline mud and CO2-rich gas continuously since at least the summer of 1997, following 40 years of repose. The initial eruption in early summer of 1997, documented by Richter and others (1998), involved violent fountaining of mud, up to 6-8 m high, from nearly a dozen vents located near the summit, and quiet effusion from vents located about mid-way down the north flank of the 100-m-high cone. Guided by topography, early emissions of copious amounts of CO2 gas flowed in narrow streams through brushy foliage leaving behind stripes of brown, dead vegetation along the flow paths. The hazard posed by the CO2 emissions was evident from dead birds and mammals found near the vents. Initial surveys of the activity in 1997 recorded water temperatures up to 46°C. A survey in 1999 by Sorey and others (2000) found numerous active vents-many in different locations than those two years earlier-a maximum water temperature of 54°C, and an estimated total discharge of warm water of 50 l/s. Measured CO2 emissions were extrapolated to a discharge rate of 6-12 tonnes/day. The highest water temperature recorded was 57.3°C in 2000, with temperatures gradually declining since. From year to year, we found that eruptive activity migrated amongst clusters of vents, some new and some continuing from 1997. Between the summer of 2003 and the spring of 2004, the system changed dramatically when a large collapse pit formed a few tens of meters from the main summit vents and all previously active vents became inactive. This water-filled circular pit measured 28 m in diameter, up to 9 m deep, and encompassed an area that had previously been unaffected by the eruptive activity. In July 2004, water temperature and discharge at the outlet channel was 37.2°C and 9.4 l/s, respectively. The total CO2 discharge from the roiling pool

  17. Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

    NASA Astrophysics Data System (ADS)

    López-Rodríguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruíz, F.; Comas, M.

    2014-06-01

    Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocentre containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, anaerobic oxidation of methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n alkane distributions and n alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S+22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotrophic archaea (irregular isoprenoids and dialkyl glycerol diethers) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected glycerol dialkyl glycerol tetraethers, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggests that no recent active methane seepage

  18. New data on the material composition of mud volcano products on Kerch Peninsula

    NASA Astrophysics Data System (ADS)

    Ershov, V. V.; Levin, B. V.

    2016-11-01

    The results of recent studies of the isotope and chemical composition of the waters and breccias that erupted from mud volcanoes of Kerch Peninsula are presented. It was found that the waters of the volcanoes considered were characterized by low salinity, a chloride-hydrocarbonate-sodium composition, and an increased 18O content. The breccias were enriched in organic matter and some microelements (Li, Se, Hg, etc.). As for petrogenic elements, depletion of Ca in the breccias is noted.

  19. Intermediate sulfur oxidation state compounds in the euxinic surface sediments of the Dvurechenskii mud volcano (Black Sea)

    NASA Astrophysics Data System (ADS)

    Lichtschlag, Anna; Kamyshny, Alexey; Ferdelman, Timothy G.; deBeer, Dirk

    2013-03-01

    The deep Black Sea is known to be depleted in electron-acceptors for sulfide oxidation. This study on depth distributions of sulfur species (S(II), S(0), Sn2-, SO32-, SO32-, SO42-) in the Dvurechenskii mud volcano, a cold seep situated in the permanently anoxic eastern Black Sea basin (Sorokin Trough, 2060 m water depth), showed remarkable concentrations of sulfide oxidation products. Sulfite concentrations of up to 11 μmol L-1, thiosulfate concentrations of up to 22 μmol L-1, zero-valent sulfur concentrations of up to 150 μmol L-1 and up to five polysulfide species were measured in the upper 20 cm of the sediment. Electron-acceptors found to be available in the Dvurechenskii mud volcano (DMV) for the oxidation of hydrogen sulfide to sulfide oxidation intermediates are iron-minerals, and probably also reactive manganese phases. Up to 60 μmol g-1 of reactive iron-minerals and up to 170 μmol L-1 dissolved iron was present in the central summit with the highest fluid upflow and fresh mud outflow. Thus, the source for the oxidative power in the DMV are reactive iron phases extruded with the mud from an ancient source in the deeply buried sediments, leading to the formation of various sulfur intermediates in comparably high concentrations. Another possible source of sulfide oxidation intermediates in DMV sediments could be the formation of zero-valent sulfur by sulfate dependent anaerobic microbial oxidation of methane followed by disproportionation of zero-valent sulfur. Sulfide oxidation intermediates, which are produced by these processes, do not reach thermodynamic equilibrium with rhombic sulfur, especially close to the active center of the DMV due to a short equilibration time. Thus, mud volcano sediments, such as in the DMV, can provide oxidizing niches even in a highly reduced environment like the abyssal part of the Black Sea.

  20. Diversity and spatial distribution of prokaryotic communities along a sediment vertical profile of a deep-sea mud volcano.

    PubMed

    Pachiadaki, Maria G; Kallionaki, Argyri; Dählmann, Anke; De Lange, Gert J; Kormas, Konstantinos Ar

    2011-10-01

    We investigated the top 30-cm sediment prokaryotic community structure in 5-cm spatial resolution, at an active site of the Amsterdam mud volcano, East Mediterranean Sea, based on the 16S rRNA gene diversity. A total of 339 and 526 sequences were retrieved, corresponding to 25 and 213 unique (≥98% similarity) phylotypes of Archaea and Bacteria, respectively, in all depths. The Shannon-Wiener diversity index H was higher for Bacteria (1.92-4.03) than for Archaea (0.99-1.91) and varied differently between the two groups. Archaea were dominated by anaerobic methanotrophs ANME-1, -2 and -3 groups and were related to phylotypes involved in anaerobic oxidation of methane from similar habitats. The much more complex Bacteria community consisted of 20 phylogenetic groups at the phylum/candidate division level. Proteobacteria, in particular δ-Proteobacteria, was the dominant group. In most sediment layers, the dominant phylotypes of both the Archaea and Bacteria communities were found in neighbouring layers, suggesting some overlap in species richness. The similarity of certain prokaryotic communities was also depicted by using four different similarity indices. The direct comparison of the retrieved phylotypes with those from the Kazan mud volcano of the same field revealed that 40.0% of the Archaea and 16.9% of the Bacteria phylotypes are common between the two systems. The majority of these phylotypes are closely related to phylotypes originating from other mud volcanoes, implying a degree of endemicity in these systems.

  1. Microbial processes and communities in sediment samples along a transect across the Lusi mud volcano, Indonesia

    NASA Astrophysics Data System (ADS)

    Krueger, Martin; Straaten, Nontje; Mazzini, Adriano

    2015-04-01

    The Lusi eruption represents one of the largest ongoing sedimentary hosted geothermal systems. This eruption started in 2006 following to a 6.3 M earthquake that stroke Java Island. Since then it has been spewing boiling mud from a central crater with peaks reaching 180.000 m3 per day. Today an area of about 8 km2 is covered by locally dried mud breccia where a network of hundreds of satellite seeping pools is active. Numerous investigations focused on the study of offshore microbial colonies that commonly thrive at offshore methane seeps and mud volcanoes, however very little has been done for onshore seeping structures. Lusi represents a unique opportunity to complete a comprehensive study of onshore microbial communities fed by the seepage of CH4 and CO2 as well as of heavier liquid hydrocarbons originating from several km below the surface. We conducted a sampling campaign at the Lusi site collecting samples of fresh mud close to the erupting crater using a remote controlled drone. In addition we completed a transect towards outer parts of the crater to collect older, weathered samples for comparison. In all samples active microorganisms were present. The highest activities for CO2 and CH4 production as well as for CH4 oxidation and hydrocarbon degradation were observed in medium-age mud samples collected roughly in the middle of the transect. Rates for aerobic methane oxidation were high, as was the potential of the microbial communities to degrade hydrocarbons (oils, alkanes, BTEX tested). The data suggests a transition of microbial populations from an anaerobic, hydrocarbon-driven metabolism in fresher samples from center or from small seeps to more generalistic, aerobic microbial communities in older, more consolidated sediments. Currently, the microbial communities in the different sediment samples are analyzed using quantitative PCR and T-RFLP combined with MiSeq sequencing. This study represents an initial step to better understand onshore seepage

  2. Rootless Cone? Pingo? or Mud Volcano? in Central Elysium Planitia, Mars

    NASA Astrophysics Data System (ADS)

    Noguchi, R.; Kurita, K.

    2011-03-01

    It is possible that Mars has experienced recent (~100 Ma) magmatism. In central Elysium Planitia, the identification of cone-like landforms are discussed: rootless cones, pingos, or mud volcanos. From their morphology, the landforms are thought to be rootless cones.

  3. Results of SO222; Pore fluid chemistry of the Kumano Basin mud volcanoes, Japan

    NASA Astrophysics Data System (ADS)

    Tryon, M. D.; Kopf, A.; Madison, M. J.

    2012-12-01

    The primary hypotheses driving the MeMo Project at the mud volcanoes of the Kumano Basin, arcward of the NanTroSEIZE IODP drilling transect, are: 1) Much, if not most, of the chemically bound water released from depths corresponding to the transition from aseismic to seismogenic behavior are being transported via the subduction factory's intermediate loop, i.e., upwards through the wedge via faults and the fractured upper plate, and 2), the Kumano Basin mud volcanoes tap these fluids and may provide insights on fluid genesis and pathways within the Nankai forearc. During RV Sonne cruise SO222 (Jun-Jul 2012) we collected 600+ pore fluid samples from 6 MeBo drill cores (up to 35 mbsf) and 39 gravity cores (up to 8 mbsf). With few exceptions, the cores from mud volcanoes indicate two trends of fluid freshening with depth; a shallow freshening trend and a deeper freshening trend. Our initial thoughts on this is that the large amount of shallow freshening in the gravity cores is due to gas hydrate dissociation during core recovery and processing, and the deeper freshening trend may be due to advection of fluids influence by mineral dehydration at great depth. At this point, the fluids have just arrived back at the lab and further analyses are about to begin. We will report here on the initial results and present preliminary thoughts on the genesis of the fluids being emitted at the mud volcanoes.

  4. Mud Volcanoes in the Martian Lowlands: Potential Windows to Fluid-Rich Samples from Depth

    NASA Technical Reports Server (NTRS)

    Oehler, Dorothy Z.; Allen, Carlton C.

    2009-01-01

    The regional setting of the Chryse-Acidalia area augurs well for a fluid-rich subsurface, accumulation of diverse rock types reflecting the wide catchment area, astrobiological prospectivity, and mud volcanism. This latter provides a mechanism for transporting samples from relatively great depth to the surface. Since mud volcanoes are not associated with extreme heat or shock pressures, materials they transport to the surface are likely to be relatively unaltered; thus such materials could contain interpretable remnants of potential martian life (e.g., organic chemical biomarkers, mineral biosignatures, or structural remains) as well as unmetamorphosed rock samples. None of the previous landings on Mars was located in an area with features identified as potential mud volcanoes (Fig. 3), but some of these features may offer targets for future missions aimed at sampling deep fluid-rich strata with potential habitable zones.

  5. Microbial communities imposed by different geochemical contexts in Sicilian mud volcanoes

    NASA Astrophysics Data System (ADS)

    Wang, Pei-Ling; Chiu, Yi-Ping; Lin, Li-Hung; Italiano, Francesco

    2016-04-01

    were relatively depleted in solutes (with chloride concentrations ranging about 40% of seawater). Transition of methane abundances indicative of methane consumption could be equivocally identified. Cell abundances were high, varying between 108 - 109 cells g-1 with anaerobic methanotrophs ranging around 107 cells g-1. Communities were primarily composed of Halobacteriales, ANME, Delta-Proteobacteria, Bacteroidetes, and Chloroflexi. The dominant OTUs were related to uncultured DHVEG-6, ANME-2, sulfate reducers and S/Fe reducers. A small fraction of sequences related to aerobic methanotrophs and methanogens were recovered from samples near surface and at depth, respectively. Overall, our results combined with previous studies conducted elsewhere demonstrate that anaerobic methanotrophy and methanogenesis were prevalent in terrestrial mud volcanoes characterized by low salinity and high methane. Their in situ activities and interactions with other metabolisms would be vital in determining the quantity of methane produced within sediments and released into the atmosphere. Moreover, aerobic heterotrophy and sulfur oxidation dominated over other metabolisms in mud volcanoes fed with fluids potentially circulating through evaporites and low-methane volcanic gases. The effectiveness of biological methane filtration is therefore strongly controlled by geochemical contexts imposed by geological frameworks.

  6. Microbiological investigation of methane- and hydrocarbon-discharging mud volcanoes in the Carpathian Mountains, Romania.

    PubMed

    Alain, Karine; Holler, Thomas; Musat, Florin; Elvert, Marcus; Treude, Tina; Krüger, Martin

    2006-04-01

    Paclele Mici is a terrestrial mud volcano field located in the Carpathian Mountains (Romania), where thermal alteration of sedimentary organic compounds leads to methane, higher hydrocarbons and other petroleum compounds that are continuously released into the environment. The hydrocarbons represent potential substrates for microorganisms. We studied lipid biomarkers, stable isotope ratios, the effect of substrate (methane, other organic compounds) addition and 16S rRNA genes to gain insights into the hitherto unknown microbial community at this site. Quantitative real-time polymerase chain reaction analysis demonstrated that bacteria were much more abundant than archaea. Phylogenetic analyses of 16S rDNA clone sequences indicated the presence of bacterial and archaeal lineages generally associated with the methane cycle (methanogens, aerobic and anaerobic methanotrophs), the sulfur cycle (sulfate reducers), and groups linked to the anaerobic degradation of alkanes or aromatic hydrocarbons. The presence of sulfate reducers, methanogens and methanotrophs in this habitat was also confirmed by concurrent surveys of lipid biomarkers and their isotopic signatures. Incubation experiments with several common and complex substrates revealed the potential of the indigenous microbial community for sulfate reduction, methanogenesis and aerobic methanotrophy. Additionally, consistently to the detection of methane-oxidizing archaea (ANME) and 13C-depleted archaeal lipids, a weak but significant activity of anaerobic methane oxidation was measured by radiotracer techniques and in vitro. This survey is the first to report the presence and activity of ANME in a terrestrial environment.

  7. Mud volcanoes and evaporite seismites in a tidal flat of northern Kuwait—implications for fluid flow in sabkhas of the Persian (Arabian) Gulf

    NASA Astrophysics Data System (ADS)

    Duane, Michael J.; Reinink-Smith, Linda; Eastoe, Christopher; Al-Mishwat, Ali T.

    2015-06-01

    This paper reports the first interpretative field map and stable isotope geochemistry of an exhumed Miocene inlier with conical mud volcanoes in a Persian (Arabian) Gulf salt flat (sabkha). In Kuwait, the siliciclastic low-heat flow margin of the northern gulf sector produced sedimentary conditions with numerous multilayered, unstable density gradients that were highly susceptible to recording liquefaction effects. The geotechnical characteristics of the sabkhas and the effects of local seismic activity resulted in ideal conditions in marginal sediments of Kuwait Bay, well suited for the development of deformation features. Three-dimensional, pseudo-biohermal exposures exhibit ellipsoidal pillows with craters separated by fluidized channels of chaotic orientation. The size and morphology of these structures together with co-genetic mud volcanoes are strongly influenced by sedimentary factors such as density gradients and tectonic events such as localized seismic activity, which caused mixing of fluids. Diapirs emerged concurrently with syn-sedimentary deformation, and the mud injection responded to episodic seismic activity. Interpretation based on previously published reflux models such as evaporative pumping and seawater flooding of coastal sabkhas is not applicable in this case. Rather, a model of focused ascent of brine initiated by episodic seismicity is proposed. Swarms of mud volcanoes represent new abiotic sedimentary features in sabkhas, but the per-ascensum nature of the fluid offers some comparisons to siliceous hot-water vents in south-eastern Brazil.

  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. Mud volcano field seaward of the Barbados Accretionary Complex: A deep-towed side scan sonar survey

    NASA Astrophysics Data System (ADS)

    Henry, Pierre; Le Pichon, Xavier; Lallemant, Siegfried; Foucher, Jean-Paul; Westbrook, Graham; Hobart, Michael

    1990-06-01

    A 30 km2 diapiric field has been identified near 13°50'N up to 12 km seaward of the deformation front of the Barbados accretionary complex. Using a deep-towed side scan sonar with a 3.5-kHz profiler, we identified 31 different diapiric structures. Based on seismic stratigraphy, we show that this field has been active for 200,000 years and that it is a transient feature triggered by the seaward propagation of the high pore fluid pressure associated with the décollement beneath the accretionary complex. Both basement and décollement in this area are anomalously shallow due to the presence of a N110° basement ridge. The height of the diapirs above seafloor does not exceed 40-50 m and can be related to the pressure head of the mud below the décollement. Two types of structures are identified: mud volcanoes and massively emplaced diapirs and ridges on the one hand, enigmatic circular very flat mud pies and conical mounds on the other hand. The second type of structures has steeper slopes and appears to be associated with very active venting, as confirmed by a submersible exploration reported in a companion paper (Le Pichon et al., this issue (b)). The venting results in the formation of a stiff carbonate crust and of large subsiding basins around the mud pies. Continuous active fluid expulsion through these structures indicates that an efficient piping system still connects them to the zone of anomalously high pore pressure below the protodécollement.

  10. Active submarine volcano sampled

    USGS Publications Warehouse

    Taylor, B.

    1983-01-01

    On June 4, 1982, two full dredge hauls of fresh lava were recovered from the upper flanks of Kavachi submarine volcano, Solomon Islands, in the western Pacific Ocean, from the water depths of 1,200 and 2,700 feet. the shallower dredge site was within 0.5 mile of the active submarine vent shown at the surface by an area of slick water, probably caused by gas emissions. Kavachi is a composite stratovolcano that has been observed to erupt every year or two for at least the last 30 years (see photographs). An island formed in 1952, 1961, 1965, and 1978; but, in each case, it rapidly eroded below sea level. The latest eruption was observed by Solair pilots during the several weeks up to and including May 18, 1982. 

  11. 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.

  12. A long-term monitoring of resistivity variation at the Wushangting mud volcano site in Southwestern Taiwan

    NASA Astrophysics Data System (ADS)

    Chang, P.; Chen, L.

    2007-12-01

    We used a two-dimensional (2D) time-lapse electrical resistivity method in monitoring the activities of mud volcanoes. The mud volcano is a geomorphic feature formed by gases and fluid gushing through fault fissures at the mudstone area. The extensively eruption of fluid in mud volcanoes in the Yanchao area of southwestern Taiwan reveals the activities of the active Chishan Fault. However, there are no direct evidence showing the relationships between erupted gas volumes and fault activities. Through the time-lapse resistivity monitoring in the area, we hope to provide useful information to evaluate the fault activities. Our in-field monitoring site is located at the Wushangting Preservation Zone, which are on the Chishan Fault line in Yanchao. The measuring period is from July 2006 to May 2007, measuring frequency is once a week in the first month and is decreased to about once a month in the following months. The average resistivity at the research site is between 3.36 to 9.43 Ohm-m. During the period, the major changes of resistivity are located between the surface and a depth of 3-m. On December 26th, 2006, three earthquakes occurred as high as 6.7, 6.4, 5.2 at the Richter scale outside the sea of PingTung county, about 100 km southwest from the monitoring site. After the earthquakes, the resistivity is found to be raised up 2 to 5 Ohm-m between the surface and a depth of 3-m. There are a lot of reasons that may cause the changes of resistivity, for example, the temperature, the humidity, the earthquake activities and its subsequent influence, i.e., gas or fluid emission from the subsurface. After examine the weather records during the monitoring period, we suggest that the decrease of resitivity in the monitoring site is most likely to be the subsequent influence of the earthquake activities. Currently, we are continuing the resistivity monitoring surveys and hope to provide more data in order to be compared with the previous observation records.

  13. Evidence of episodic long-lived eruptions in the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes, Gulf of Cádiz

    NASA Astrophysics Data System (ADS)

    Toyos, María H.; Medialdea, Teresa; León, Ricardo; Somoza, Luis; González, Francisco Javier; Meléndez, Nieves

    2016-06-01

    High-resolution single channel and multichannel seismic reflection profiles and multibeam bathymetric and backscatter data collected during several cruises over the period 1999 to 2007 have enabled characterising not only the seabed morphology but also the subsurface structural elements of the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes (MVs) in the Gulf of Cádiz at 1,050-1,250 m water depth. These MVs vary strongly in morphology and size. The data reveal elongated cone-shaped edifices, rimmed depressions, and scarps interpreted as flank failures developed by collapse, faulting, compaction and gravitational processes. MV architecture is characterised by both extrusive and intrusive complexes, comprising stacked edifices (including seabed cones and up to four buried bicones) underlain by chaotic vertical zones and downward-tapering cones suggesting feeder systems. These intrusive structures represent the upper layer of the feeder system linking the fluid mud sources with the constructional edifices. The overall architecture is interpreted to be the result of successive events of mud extrusion and outbuilding alternating with periods of dormancy. Each mud extrusion phase is connected with the development of an edifice, represented by a seabed cone or a buried bicone. In all four MVs, the stacked edifices and the intrusive complexes penetrate Late Miocene-Quaternary units and are rooted in the Gulf of Cádiz wedge emplaced during the late Tortonian. Major phases of mud extrusion and outbuilding took place since the Late Pliocene, even though in the Yuma and Jesús Baraza MVs mud volcanism started in the Late Miocene shortly after the emplacement of the Gulf of Cádiz wedge. This study shows that fluid venting in the eastern sector of the Gulf of Cádiz promoted the outbuilding of large long-lived mud volcanoes active since the Late Miocene, and which have been reactivated repeatedly until recent times.

  14. Sources of mud volcano fluids in the Gulf of Cadiz—indications for hydrothermal imprint

    NASA Astrophysics Data System (ADS)

    Hensen, Christian; Nuzzo, Marianne; Hornibrook, Edward; Pinheiro, Luis M.; Bock, Barbara; Magalhães, Vitor H.; Brückmann, Warner

    2007-03-01

    Mud volcanism in the Gulf of Cadiz occurs over a large area extending from the shelf to more than 3500 m water depth and is triggered by compressional stress along the European-African plate boundary, affecting a deeply faulted sedimentary sequence of locally more than 5 km thickness. The investigation of six active sites shows that mud volcano (MV) fluids, on average, are highly enriched in CH 4, Li, B, and Sr and depleted in Mg, K, and Br. The purity of the fluids is largely controlled by the intensity of upward directed flow. Flow rates could be constrained by numerical modelling and vary between <0.05 and 15 cm yr -1. Application of δD-δ 18O systematics identifies clay mineral dehydration, most likely within Mesozoic and Tertiary shales and marls, as the major source of fluids. Hence, Cl and Na in the pore fluids are mostly depleted below seawater values, following a general trend of dilution. However, deviations from this trend occur and are likely caused by the dissolution of halite in evaporitic deposits. Other secondary processes overprinting the original fluid composition may occur along the flow path, such as dissolution of anhydrite or gypsum and/or the formation of calcite and dolomite. Different sources of fluids are also indicated by variations in 87Sr/ 86Sr, which range from 0.7086 to 0.7099 at the different sites. Dehydration may be induced primarily by overburden and tectonic compression; however, very high concentrations of Li and B, specifically at Captain Arutyunov MV (CAMV) indicate additional leaching at temperatures above 150 °C, which could be explained by the injection of hot fluids along deep penetrating, major E-W strike-slip fault systems. This hypothesis is supported by the occurrence of generally thermogenic, but significantly CH 4-enriched, light volatile hydrocarbon gases at CAMV which cannot be explained by shallow microbial methanogenesis. Li and Li/B ratios from different types of hot and cold vents are used to infer that high

  15. The origin and migration of mud volcano fluids in Taiwan: Evidence from hydrogen, oxygen, and strontium isotopic compositions

    NASA Astrophysics Data System (ADS)

    Chao, Hung-Chun; You, Chen-Feng; Liu, Hou-Chun; Chung, Chuan-Hsiung

    2013-08-01

    Mud volcanoes are important gateways for deep fluids to migrate upward and provide windows for studying fluid/sediment interaction at depth. Fluids emitted from 40 terrestrial mud volcanoes were collected in southern and eastern Taiwan to study their chemical compositions, including H, O and Sr isotopes (87Sr/86Sr and δ88/86Sr). Relative to seawater, the mud volcano fluids are depleted in Cl, Mg, SO42-, and δD and are elevated in B, Ba, Li, and δ18O, possibly due to water-rock interaction and clay dehydration (mainly smectite to illite transformation) in the source region. The distribution of Sr in mud volcano fluids shows patterns associated with their localities and geological settings. Most fluids have higher 87Sr/86S than seawater, indicating water-rock interaction at depth. The low Na, 87Sr/86S, and high Ca fluids emitted from eastern Taiwan imply intense interaction with igneous basement. Most fluids have higher Sr/Cl and lower δ88Sr than seawater except mud volcanoes in the northern Chu-kou Fault, which emit low Sr/Cl and extremely high δ88Sr (up to 0.82‰) fluids. We performed laboratory carbonate precipitation experiments that indicate that these high Sr isotope ratios are caused by co-precipitation of carbonates from high alkalinity fluids. Mud volcano fluids in Taiwan originate at depth and their chemical compositions are controlled by the host rock, degrees of water-rock interaction, and clay dehydration, but also are masked by retrograde progresses, such as carbonate precipitation during migration. Our results show that an approach combining water isotopes (δD and δ18O) and strontium isotopes (87Sr/86Sr and δ88/86Sr) provides a robust tool for tracing fluid sources and migration pathways in accretionary prisms.

  16. The use of rotational invariants for the interpretation of marine CSEM data with a case study from the North Alex mud volcano, West Nile Delta

    NASA Astrophysics Data System (ADS)

    Hölz, Sebastian; Swidinsky, Andrei; Sommer, Malte; Jegen, Marion; Bialas, Jörg

    2015-04-01

    Submarine mud volcanos at the seafloor are surface expressions of fluid flow systems within the seafloor. Since the electrical resistivity of the seafloor is mainly determined by the amount and characteristics of fluids contained within the sediment's pore space, electromagnetic methods offer a promising approach to gain insight into a mud volcano's internal resistivity structure. To investigate this structure, we conducted a controlled source electromagnetic experiment, which was novel in the sense that the source was deployed and operated with a remotely operated vehicle, which allowed for a flexible placement of the transmitter dipole with two polarization directions at each transmitter location. For the interpretation of the experiment, we have adapted the concept of rotational invariants from land-based electromagnetics to the marine case by considering the source normalized tensor of horizontal electric field components. We analyse the sensitivity of these rotational invariants in terms of 1-D models and measurement geometries and associated measurement errors, which resemble the experiment at the mud volcano. The analysis shows that any combination of rotational invariants has an improved parameter resolution as compared to the sensitivity of the pure radial or azimuthal component alone. For the data set, which was acquired at the `North Alex' mud volcano, we interpret rotational invariants in terms of 1-D inversions on a common midpoint grid. The resulting resistivity models show a general increase of resistivities with depth. The most prominent feature in the stitched 1-D sections is a lens-shaped interface, which can similarly be found in a section from seismic reflection data. Beneath this interface bulk resistivities frequently fall in a range between 2.0 and 2.5 Ωm towards the maximum penetration depths. We interpret the lens-shaped interface as the surface of a collapse structure, which was formed at the end of a phase of activity of an older mud

  17. Early Archean serpentine mud volcanoes at Isua, Greenland, as a niche for early life.

    PubMed

    Pons, Marie-Laure; Quitté, Ghylaine; Fujii, Toshiyuki; Rosing, Minik T; Reynard, Bruno; Moynier, Frederic; Douchet, Chantal; Albarède, Francis

    2011-10-25

    The Isua Supracrustal Belt, Greenland, of Early Archean age (3.81-3.70 Ga) represents the oldest crustal segment on Earth. Its complex lithology comprises an ophiolite-like unit and volcanic rocks reminiscent of boninites, which tie Isua supracrustals to an island arc environment. We here present zinc (Zn) isotope compositions measured on serpentinites and other rocks from the Isua supracrustal sequence and on serpentinites from modern ophiolites, midocean ridges, and the Mariana forearc. In stark contrast to modern midocean ridge and ophiolite serpentinites, Zn in Isua and Mariana serpentinites is markedly depleted in heavy isotopes with respect to the igneous average. Based on recent results of Zn isotope fractionation between coexisting species in solution, the Isua serpentinites were permeated by carbonate-rich, high-pH hydrothermal solutions at medium temperature (100-300 °C). Zinc isotopes therefore stand out as a pH meter for fossil hydrothermal solutions. The geochemical features of the Isua fluids resemble the interstitial fluids sampled in the mud volcano serpentinites of the Mariana forearc. The reduced character and the high pH inferred for these fluids make Archean serpentine mud volcanoes a particularly favorable setting for the early stabilization of amino acids.

  18. Origins of hydrocarbon gas seeping out from offshore mud volcanoes in the Nile delta

    NASA Astrophysics Data System (ADS)

    Prinzhofer, Alain; Deville, Eric

    2013-04-01

    This paper discusses the origin of gas seepages (free gas or dissolved gas in ground water or brine) sampled with the Nautile submarine during the Nautinil cruise at the seafloor of the deep water area of the Nile turbiditic system on different mud volcanoes and brine pools. Generally, the gas is wet and includes C1, C2, C3, iC4, nC4, CO2. These gas samples show no evidence of biodegradation which is not the case of the gas present in the deep hydrocarbon accumulations at depth. It indicates that the gas expelled by the mud volcanoes is not issued from direct leakages from deep gas fields. The collected gas samples mainly have a thermogenic origin and show different maturities. Some samples show very high maturities indicating that these seepages are sourced from great depths, below the Messinian salt. Moreover, the different chemical compositions of the gas samples reflect not only differences in maturity but also the fact that the gas finds its origin in different deep source rocks. Carbon dioxide has an organic signature and cannot result from carbonate decomposition or mantle fluids. The crustal-derived radiogenic isotopes show that the analyzed gas samples have suffered a fractionation processes after the production of the radiogenic isotopes, due either to oil occurrence at depth interacting with the flux of gas, and/or fractionation during the fluid migration.

  19. Sulfur Cycling in Mud Volcanoes Along the Crimean Peninsula, Black Sea

    NASA Astrophysics Data System (ADS)

    Lyons, T. W.; Werne, J. P.; Baas, M.; Stadnitskaya, A.

    2001-12-01

    Recent sediment sampling (Leg 1, TTR-11 Cruise, R/V Professor Logachev, July-August 2001) in the north-central Black Sea was undertaken to characterize bacterial sulfur cycling associated with the abundant hydrocarbon vents in the region and, more specifically, with the products and pathways of anaerobic methane oxidation. Gravity cores and box cores from proximal and distal locations relative to specific vents revealed a complex and spatially varying array of sediment types ranging from mud breccias and enigmatic, homogeneous mud flows along the flanks of the volcanoes to both coherent and disrupted sections of the classic Unit 1-2-3 late Pleistocene-Holocene sequence in the deep Black Sea. Gas hydrates and/or carbonate crusts were also recovered at many localities. In order to track the sulfur cycle and specifically link bacterially mediated oxidation-reduction reactions and mineral precipitation to methane cycling, a detailed characterization of pore-water and solid-phase constituents was initiated. These efforts are emphasizing the concentrations and S-isotope relationships of dissolved sulfate and sulfide, iron monosulfide and pyrite, and organic sulfur fractions. The oxygen isotope trend for dissolved sulfate will also be tracked. All of these analyses will benefit from high-resolution sampling across the subsurface maximum in bacterial sulfate reduction rate and the corresponding maximum in methane oxidation marking the interface between upward migration of methane and downward diffusion of seawater sulfate. Additional analyses include (1) quantification of the reactive Fe reservoir as it relates to sources and sinks in the S cycle and (2) collaborative microbiology with an emphasis on 16S rRNA PCR approaches and lipid biomarkers. Among other objectives, the goal of this research is to contrast the sulfur geochemical baseline that is well established for "typical" late Pleistocene-Holocene deposits of the abyssal Black Sea, including a recent model for the

  20. 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.

  1. Cold seep communities in the deep eastern Mediterranean Sea: composition, symbiosis and spatial distribution on mud volcanoes

    NASA Astrophysics Data System (ADS)

    Olu-Le Roy, Karine; Sibuet, Myriam; Fiala-Médioni, Aline; Gofas, Serge; Salas, Carmen; Mariotti, André; Foucher, Jean-Paul; Woodside, John

    2004-12-01

    Two mud volcano fields were explored during the French-Dutch MEDINAUT cruise (1998) with the submersible NAUTILE, one south of Crete along the Mediteranean Ridge at about 2000 m depth (Olimpi mud field) and the other south of Turkey between 1700 and 2000 m depth (Anaximander mud field) where high methane concentrations were measured. Chemosynthetic communities were observed and sampled on six mud volcanoes and along a fault scarp. The communities were dominated by bivalves of particularly small size, belonging to families commonly found at seeps (Mytilidae, Vesicomyidae, Thyasiridae) and to Lucinidae mostly encountered in littoral sulfide-rich sediments and at the shallowest seeps. Siboglinid polychaetes including a large vestimentiferan Lamellibrachia sp. were also associated. At least four bivalve species and one siboglinid are associated with symbiotic chemoautotrophic bacteria, as evidenced by Transmission Electronic Microscopy and isotopic ratio measurements. Among the bivalves, a mytilid harbors both methanotrophic and sulfide-oxidizing bacteria. Video spatial analysis of the community distribution on three volcanoes shows that dense bivalve shell accumulations (mainly lucinids) spread over large areas, from 10% to 38% of the explored areas (2500-15000 m 2) on the different volcanoes. Lamellibrachia sp. had different spatial distribution and variable density in the two mud volcano fields, apparently related with higher methane fluxes in the Anaximander volcanoes and maybe with the instability due to brines in the Olimpi area. The abundance and richness of the observed chemosynthetic fauna and the size of some of the species contrast with the poverty of the deep eastern Mediterranean. The presence of a specialized fauna, with some mollusk genera and species shared with other reduced environments of the Mediterranean, but not dominated by the large bivalves usually found at seeps, is discussed.

  2. The effects of the Yogyakarta earthquake at LUSI mud volcano, Indonesia

    NASA Astrophysics Data System (ADS)

    Lupi, M.; Saenger, E. H.; Fuchs, F.; Miller, S. A.

    2013-12-01

    The M6.3 Yogyakarta earthquake shook Central Java on May 27th, 2006. Forty seven hours later, hot mud outburst at the surface near Sidoarjo, approximately 250 km from the earthquake epicentre. The mud eruption continued and originated LUSI, the youngest mud volcanic system on earth. Since the beginning of the eruption, approximately 30,000 people lost their homes and 13 people died due to the mud flooding. The causes that initiated the eruption are still debated and are based on different geological observations. The earthquake-triggering hypothesis is supported by the evidence that at the time of the earthquake ongoing drilling operations experienced a loss of the drilling mud downhole. In addition, the eruption of the mud began only 47 hours after the Yogyakarta earthquake and the mud reached the surface at different locations aligned along the Watukosek fault, a strike-slip fault upon which LUSI resides. Moreover, the Yogyakarta earthquake also affected the volcanic activity of Mt. Semeru, located as far as Lusi from the epicentre of the earthquake. However, the drilling-triggering hypothesis points out that the earthquake was too far from LUSI for inducing relevant stress changes at depth and highlight how upwelling fluids that reached the surface first emerged only 200 m far from the drilling rig that was operative at the time. Hence, was LUSI triggered by the earthquake or by drilling operations? We conducted a seismic wave propagation study on a geological model based on vp, vs, and density values for the different lithologies and seismic profiles of the crust beneath LUSI. Our analysis shows compelling evidence for the effects produced by the passage of seismic waves through the geological formations and highlights the importance of the overall geological structure that focused and reflected incoming seismic energy.

  3. Modelling the impact of Siboglinids on the biogeochemistry of the Captain Arutyunov mud volcano (Gulf of Cadiz)

    NASA Astrophysics Data System (ADS)

    Soetaert, K.; van Oevelen, D.; Sommer, S.

    2012-12-01

    A 2-Dimensional mathematical reaction-transport model was developed to study the impact of the mud-dwelling frenulate tubeworm Siboglinum sp. on the biogeochemistry of a~sediment (MUC15) at the Captain Arutyunov mud volcano (CAMV). By explicitly describing the worm in its surrounding sediment, we are able to make budgets of processes occurring in- or outside of the worm, and to quantify how different worm densities and biomasses affect the anaerobic oxidation of methane (AOM) and sulfide reoxidation (HSox). The model shows that, at the observed densities, the presence of a thin worm body is sufficient to keep the upper 10 cm of sediment well homogenised with respect to dissolved substances, in agreement with observations. By this "bio-ventilation" activity, the worm pushes the sulfate-methane transition (SMT) zone downward to the posterior end of its body, and simultaneously physically separates the sulfide produced during the anaerobic oxidation of methane from oxygen. While there is little scope for AOM to take place in the tubeworm's body, 70% of the sulfide that is produced by sulfate reduction processes or that is advected in the sediment is preferentially shunted via the organism where it is oxidised by endosymbionts providing the energy for the worm's growth. The process of sulfide reoxidation, occurring predominantly in the worm's body is thus very distinct from the anaerobic oxidation of methane, which is a diffuse process that takes place in the sediments in the methane-sulfate transition zone. We show how the sulfide oxidation process is affected by increasing densities and length of the frenulates, and by upward advection velocity. Our biogeochemical model is one of the first to describe tubeworms explicitly. It can be used to directly link biological and biogeochemical observations at seep sites, and to study the impacts of mud-dwelling frenulates on the sediment biogeochemistry under varying environmental conditions. Also, it provides a tool to

  4. Modelling the impact of Siboglinids on the biogeochemistry of the Captain Arutyunov mud volcano (Gulf of Cadiz)

    NASA Astrophysics Data System (ADS)

    Soetaert, K.; van Oevelen, D.; Sommer, S.

    2012-06-01

    A 2-Dimensional mathematical reaction-transport model was developed to study the impact of the mud-dwelling frenulate tubeworm Siboglinum sp. on the biogeochemistry of a sediment (MUC15) at the Captain Arutyunov mud volcano (CAMV). By explicitly describing the worm in its surrounding sediment, we are able to make budgets of processes occurring in- or outside of the worm, and to quantify how different worm densities and biomasses affect the anaerobic oxidation of methane (AOM) and sulfide reoxidation (HSox). The model shows that, at the observed densities, the presence of a thin worm body is sufficient to keep the upper 10 cm of sediment well homogenized with respect to dissolved substances, in agreement with observations. By this "bio-ventilation" activity, the worm pushes the sulfate-methane transition (SMT) zone downward to the posterior end of its body, and simultaneously physically separates the sulfide produced during the anaerobic oxidation of methane from oxygen. While there is little scope for the AOM to take place in the tubeworm's body, 70% of the sulfide that is produced by sulfate reduction processes or that is advected in the sediment is preferentially shunted via the organism where it is oxidised by endosymbionts providing the energy for the worm's growth. The process of sulfide reoxidation, occurring predominantly in the worm's body is thus very distinct from the anaerobic oxidation of methane, which is a diffuse process that takes place in the sediments in the methane-sulfate transition zone. We show how the sulfide oxidation process is affected by increasing densities and length of the frenulates, and by upward advection velocity. Our biogeochemical model is one of the first to describe tubeworms explicitly. It can be used to directly link biological and biogeochemical observations at seep sites, and to study the impacts of mud-dwelling frenulates on the sediment biogeochemistry under varying environmental conditions. Also, it provides a tool to

  5. Multiple visions of Indonesia's mud volcano: understanding representations of disaster across discursive settings.

    PubMed

    Drake, Phillip

    2016-04-01

    The Lapindo mudflow is one of the most controversial disasters in Indonesian history. Despite its unique biophysical features, most consider the mudflow a social disaster as scientific conflicts about its main trigger have evolved into legal disputes over accountability and rights. This paper examines this 'trigger debate', the stakes of scientific contention and the broader social and natural dynamics that shape the terms of this debate. A Latourian impulse drives this analysis, which aims to improve both understandings of--and responses to--complex disasters. This paper also notes that the stakes of representation extend to constructions of its stakeholders, especially to victims. As socionatural disasters become an increasingly common feature of the contemporary world, from mud volcanoes to extreme weather events caused by global warming, it is more important than ever to understand the dynamics of representing disasters and stakeholders.

  6. Aquipuribacter nitratireducens sp. nov., isolated from a soil sample of a mud volcano.

    PubMed

    Srinivas, T N R; Anil Kumar, P; Tank, M; Sunil, B; Poorna, Manasa; Zareena, Begum; Shivaji, S

    2015-08-01

    A novel Gram-stain-positive, coccoid, non-motile bacterium, designated strain AMV4T, was isolated from a soil sample collected from a mud volcano located in the Andaman Islands, India. The colony was pale orange. Strain AMV4T was positive for oxidase, aesculinase, lysine decarboxylase and ornithine decarboxylase activities and negative for amylase, catalase, cellulase, protease, urease and lipase activities. 16S rRNA gene sequence analysis indicated that strain AMV4T was a member of the order Actinomycetales and was closely related to Aquipuribacter hungaricus with a sequence similarity of 97.13% (pairwise alignment). Phylogenetic analyses showed that strain AMV4T clustered with Aquipuribacter hungaricus and was distantly related to the other genera of the family Intrasporangiaceae. DNA-DNA hybridization between strains AMV4T and Aquipuribacter hungaricus IV-75T showed a relatedness of 28%. The predominant cellular fatty acids were iso-C15 : 0 (6.9%), anteiso-C15 : 0 (25.3%), C16 : 0 (12.9%), anteiso-C16 : 0 (5.6%), C18 : 1ω9c (19.8%) and C18 : 3ω6,9,12c (9.1%). The diagnostic diamino acid in the cell-wall peptidoglycan of strain AMV4T was meso-diaminopimelic acid. Strain AMV4T contained MK-10(H4) as the predominant respiratory quinone. The polar lipids consisted of phosphatidylglycerol, one unidentified glycolipid, two unidentified phospholipids and five unidentified lipids. The DNA G+C content of strain AMV4T was 74.3 mol%. Based on data from this taxonomic study using a polyphasic approach, it is proposed that strain AMV4T represents a novel species of the genus Aquipuribacter, with the suggested name Aquipuribacter nitratireducens sp. nov. The type strain is AMV4T ( = CCUG 58430T = DSM 22863T = NBRC 107137T).

  7. Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Jiangxin; Song, Haibin; Guan, Yongxian; Yang, Shengxiong; Pinheiro, Luis M.; Bai, Yang; Liu, Boran; Geng, Minghui

    2015-12-01

    factors of gravity sliding/slumping, fluid escape activity and sandbodies intrusion. Seismic data suggest that the mud volcanoes have likely undergone two episodes of evolution, which include a widespread drastic formation of mud volcanoes with dome-like structures, a wide range of seepage occurrences and the formation of complex sediments in the first stage, and the appearance of pockmarks, conical mud volcanoes (groups), and the formation of deformed, filled or broken buried complex sediments by continuous fluid flow processes during stage 2, in the Pliocene and the Quaternary. Pockmark gullies are extensively found along the slope, due to the interaction of slope failure and fluid escape processes. The Cenozoic sedimentary cover is thin in the Northern Zhongjiannan basin, which evolved from a Late Cretaceous or Palaeogene-Oligocene rift to the Neogene-Quaternary post-rift thermal subsidence, and therefore intense deep thermogenic fluid flow can easily affect the soft Cenozoic sediments, produce complex sediment deformation, and form numerous fluid flow structures at the seafloor, in particular pockmarks and mud volcanoes that dominantly emerged during the period of post-rift thermal subsidence and neotectonic movement since ca. 5.5 Ma.

  8. Distribution and geological control of mud volcanoes and other fluid/free gas seepage features in the Mediterranean Sea and nearby Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Mascle, Jean; Mary, Flore; Praeg, Daniel; Brosolo, Laetitia; Camera, Laurent; Ceramicola, Silvia; Dupré, Stéphanie

    2014-06-01

    Existing knowledge on the distribution of mud volcanoes (MVs) and other significant fluid/free gas-venting features (mud cones, mud pies, mud-brine pools, mud carbonate cones, gas chimneys and, in some cases, pockmark fields) discovered on the seafloor of the Mediterranean Sea and in the nearby Gulf of Cadiz has been compiled using regional geophysical information (including multibeam coverage of most deepwater areas). The resulting dataset comprises both features proven from geological sampling, or in situ observations, and many previously unrecognized MVs inferred from geophysical evidence. The synthesis reveals that MVs clearly have non-random distributions that correspond to two main geodynamic settings: (1) the vast majority occur along the various tectono-sedimentary accretionary wedges of the Africa-Eurasia subduction zone, particularly in the central and eastern Mediterranean basins (external Calabrian Arc, Mediterranean Ridge, Florence Rise) but also along its westernmost boundary in the Gulf of Cadiz; (2) other MVs characterize thick depocentres along parts of the Mesozoic passive continental margins that border Africa from eastern Tunisia to the Levantine coasts, particularly off Egypt and, locally, within some areas of the western Mediterranean back-arc basins. Meaningfully accounting for MV distribution necessitates evidence of overpressured fluids and mud-rich layers. In addition, cross-correlations between MVs and other GIS-based data, such as maps of the Messinian evaporite basins and/or active (or recently active) tectonic trends, stress the importance of assessing geological control in terms of the presence, or not, of thick seals and potential conduits. It is contended that new MV discoveries may be expected in the study region, particularly along the southern Ionian Sea continental margins.

  9. Application of terrestrial laser scanning for detection of ground surface deformation in small mud volcano (Murono, Japan)

    NASA Astrophysics Data System (ADS)

    Hayakawa, Yuichi S.; Kusumoto, Shigekazu; Matta, Nobuhisa

    2016-07-01

    We perform terrestrial laser scanning (TLS) to detect changes in surface morphology of a mud volcano in Murono, north-central Japan. The study site underwent significant deformation by a strong earthquake in 2011, and the surface deformation has continued in the following years. The point cloud datasets were obtained by TLS at three different times in 2011, 2013 and 2014. Those point clouds were aligned by cloud-based registration, which minimizes the closest point distance of point clouds of unchanged ground features, and the TLS-based point cloud data appear to be suitable for detecting centimeter-order deformations in the central domain of the mud volcano, as well as for measurements of topographic features including cracks of paved ground surface. The spatial patterns and accumulative amount of the vertical deformation during 2011-2014 captured by TLS correspond well with those previously reported based on point-based leveling surveys, supporting the validity of TLS survey.

  10. Development of a machine learning technique for automatic analysis of seafloor image data: Case example, Pogonophora coverage at mud volcanoes

    NASA Astrophysics Data System (ADS)

    Lüdtke, A.; Jerosch, K.; Herzog, O.; Schlüter, M.

    2012-02-01

    Digital image processing provides powerful tools for fast and precise analysis of large image data sets in marine and geoscientific applications. Because of the increasing volume of georeferenced image and video data acquired by underwater platforms such as remotely operated vehicles, means of automatic analysis of the acquired image data are required. A new and fast-developing application is the combination of video imagery and mosaicking techniques for seafloor habitat mapping. In this article we introduce an approach to fully automatic detection and quantification of Pogonophora coverage in seafloor video mosaics from mud volcanoes. The automatic recognition is based on textural image features extracted from the raw image data and classification using machine learning techniques. Classification rates of up to 98.86% were achieved on the training data. The approach was extensively validated on a data set of more than 4000 seafloor video mosaics from the Håkon Mosby Mud Volcano.

  11. Black Sea mud volcanoes and their relation to the search for methane gas hydrates and environmental security

    NASA Astrophysics Data System (ADS)

    Shnyukov, Evgeny; Yanko-Hombach, Valentina; Motnenko, Irena

    2016-04-01

    As of today, the number of known offshore mud volcanoes in the Black Sea is 68. The areas possessing the greatest abundance include the northern part of the Black Sea (Sorokin trough, Tuapsinskaya trough, Shatskiy arch) and the Kerch downfold (the area south of the Kerch peninsula). An intensive study of mud volcanoes has been performed in the course of on-shore and off-shore expeditions carried out by Ukrainian scientists since 1990. They brought to light new geological, geophysical, and geochemical data on the properties of mud volcanoes by (1) high resolution hydro-acoustic, seismic-acoustic, and gravity methods, (2) geothermal observations of the thermal regime of the water and uppermost sediments, (3) gravity core sampling of bottom deposits, (4) dredges and buckets, and (5) study of these samples by lithological, geochemical, paleontological, and biological methods. Methane gas hydrates have been recovered in about 28 localities largely associated with mud volcanoes below 600-700 m water depth, which suggests their close genetic relationships. Age of the sediments hosting methane gas hydrates as well as their lithological properties (e.g., grain-size) vary significantly. Relatively coarse-grained sediments make better hydrate reservoirs than fine-grained sediments. The area of the Black Sea suitable for gas hydrate formation is estimated at 288,100 km2, representing about 68% of the total Black Sea, or almost 91% of the deep-water basin; the volume of gas hydrates has been set at 4.8 km3 corresponding to 0.1-11012 m3 of free methane. A peculiar morphological structure of the sea bottom - conical hills (anticlinals) with low geostatic pressure and subsidence in their central part - provide a target in the search for underwater mud volcanoes. Our data show that such structures are formed by mud breccia and rock debris that are brought to the surface by methane flows, which escape along tectonic ruptures from the deep part of the lithosphere located beneath a

  12. 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…

  13. Draft Genome Sequence of Lutibaculum baratangense Strain AMV1T, Isolated from a Mud Volcano in Andamans, India.

    PubMed

    Singh, Aditya; Sreenivas, Ara; Sathyanarayana Reddy, Gundlapally; Pinnaka, Anil Kumar; Shivaji, Sisinthy

    2014-07-24

    The 4.3-Mb genome of Lutibaculum baratangense strain AMV1(T), isolated from a soil sample collected from a mud volcano in Andamans, India, is reported. The draft genome of strain Lutibaculum baratangense AMV1(T) consists of 4,300,776 bp with a G+C content of 66.93 mol% and 4,198 predicted coding regions, including 56 RNAs.

  14. Stratified Community Responses to Methane and Sulfate Supplies in Mud Volcano Deposits: Insights from an In Vitro Experiment

    PubMed Central

    Zhang, Yu; Maignien, Lois; Stadnitskaia, Alina; Boeckx, Pascal; Xiao, Xiang; Boon, Nico

    2014-01-01

    Numerous studies on marine prokaryotic communities have postulated that a process of anaerobic oxidation of methane (AOM) coupled with sulfate reduction (SR) is the main methane sink in the world's oceans. AOM has also been reported in the deep biosphere. But the responses of the primary microbial players in eliciting changes in geochemical environments, specifically in methane and sulfate supplies, have yet to be fully elucidated. Marine mud volcanoes (MVs) expel a complex fluid mixture of which methane is the primary component, forming an environment in which AOM is a common phenomenon. In this context, we attempted to identify how the prokaryotic community would respond to changes in methane and sulfate intensities, which often occur in MV environments in the form of eruptions, diffusions or seepage. We applied an integrated approach, including (i) biochemical surveys of pore water originated from MV, (ii) in vitro incubation of mud breccia, and (iii) prokaryotic community structure analysis. Two distinct AOM regions were clearly detected. One is related to the sulfate methane transition zone (SMTZ) at depth of 30–55 cm below the sea floor (bsf); the second is at 165–205 cm bsf with ten times higher rates of AOM and SR. This finding contrasts with the sulfide concentrations in pore waters and supports the suggestion that potential AOM activity below the SMTZ might be an important methane sink that is largely ignored or underestimated in oceanic methane budget calculations. Moreover, the incubation conditions below the SMTZ favor the growth of methanotrophic archaeal group ANME-2 compared to ANME-1, and promote the rapid growth and high diversity of bacterial communities. These incubation conditions also promote the increase of richness in bacterial communities. Our results provide direct evidence of the mechanisms by which deep AOM processes can affect carbon cycling in the deep biosphere and global methane biochemistry. PMID:25393146

  15. Hot and Cold: Complex Biochemical Processes in a Mud Volcano Setting on the Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Bordoloi, S.; Aharon, P.; Pape, T.

    2006-12-01

    Hydrocarbon seeps on the Gulf of Mexico (GOM) seafloor are conventionally defined as "cold", being characterized by hydrocarbon-rich fluid emissions at ambient sea floor temperature, mineralization of gas hydrates, precipitation of carbonates depleted in 13C, association with chemosynthetic fauna (mussel beds, tube worms etc.) and dominance of microbial processes fueled by venting hydrocarbons within the sediments. Analyses of carbonate phases, pore-fluids and biomarkers from cores (length~25cm) taken by ALVIN from an active mud volcano on the northern Gulf of Mexico slope (GC-272, 27°41`25"; 91°32`28") point towards a vent setting far more complex than sites previously investigated. We argue that the mud volcano setting in GC-272 is distinguished by episodes of cold methane venting when gas hydrates are forming in the sediment pore spaces (visually confirmed) alternating with periodic hot venting of warm brines (formation fluids) advected on the sea floor. We support our argument with the evidence that follows. Scalenohedral calcite crystals (1-2 mm in size) scattered within the sediment exhibit unusually negative δ18O values (down to -6‰ PDB) and δ13C values ranging from -2 ‰ to - 20‰ PDB. Temperature calculations based on the δ18O composition of the calcites and coexisting pore fluids yield a fluid temperature of ~45°C which is far higher than the recorded bottom water temperatures of ~8°C at a depth of 680 m. Pore fluid Na/Cl ratios (0.92-1.2) confirm the mixing of cold GOM bottom waters (Na/Cl=0.82) with advecting hot brines (Na/Cl=~1.0) resulting in a brine fluid at 45°C. The δ13C of the calcites is isotopically heavier by comparison with typical seep carbonates from the GOM suggesting a mixed carbon source consisting of pore fluid DIC, brine DIC and bottom seawater DIC. Hence the scalenohedral calcites are the product of hot venting episodes and are precipitated within the sediments from calcite-saturated pore-fluids (SI= ~5). Biomarker assays

  16. Chemosynthetic bacteria found in bivalve species from mud volcanoes of the Gulf of Cadiz.

    PubMed

    Rodrigues, Clara F; Webster, Gordon; Cunha, Marina R; Duperron, Sébastien; Weightman, Andrew J

    2010-09-01

    As in other cold seeps, the dominant bivalves in mud volcanoes (MV) from the Gulf of Cadiz are macrofauna belonging to the families Solemyidae (Acharax sp., Petrasma sp.), Lucinidae (Lucinoma sp.), Thyasiridae (Thyasira vulcolutre) and Mytilidae (Bathymodiolus mauritanicus). The delta(13)C values measured in solemyid, lucinid and thyasirid specimens support the hypothesis of thiotrophic nutrition, whereas isotopic signatures of B. mauritanicus suggest methanotrophic nutrition. The indication by stable isotope analysis that chemosynthetic bacteria make a substantial contribution to the nutrition of the bivalves led us to investigate their associated bacteria and their phylogenetic relationships based on comparative 16S rRNA gene sequence analysis. PCR-denaturing gradient gel electrophoresis analysis and cloning of bacterial 16S rRNA-encoding genes confirmed the presence of sulfide-oxidizing symbionts within gill tissues of many of the studied specimens. Phylogenetic analysis of bacterial 16S rRNA gene sequences demonstrated that most bacteria were related to known sulfide-oxidizing endosymbionts found in other deep-sea chemosynthetic environments, with the co-occurrence of methane-oxidizing symbionts in Bathymodiolus specimens. This study confirms the presence of several chemosynthetic bivalves in the Gulf of Cadiz and further highlights the importance of sulfide- and methane-oxidizing symbionts in the trophic ecology of macrobenthic communities in MV.

  17. Hydrocarbon Potential of the Offshore Akçakoca Region: Mud Volcano, Gas Hydrate and Shallow Gas Indications on Acoustic Data

    NASA Astrophysics Data System (ADS)

    Özel, Özkan; Mert Küçük, Hilmi; Atgin, Orhan; Dondurur, Derman; Çifçi, Günay

    2015-04-01

    The Black Sea is a large marginal sea located within complex folded chains of the Alpine system, represented by the Balkanides-Pontides belt to the south, and by the Caucasus and Crimea Mountains to the north and northwest. The Black Sea sediments are rich in calcite and organic carbon, the latter showing a high degree of preservation due to anoxia in the waters below 100-150 m. The Black Sea is one of the richest waters having immense gas and gas hydrate accumulations. Shelf and slopes with high sedimentation rates is considered as methane sources and gas seeps are observed around the basin. The study area is located offshore Akçakoca gas well which produces dry gas of 570.000 m3/day from reverse-fault anticline reservoir of Eocene age. The area also has the Kozlu structure far offshore, which has gas accumulations, gas chimneys and possible mud volcanoes. In 2012, a total of 1150 km high resolution multichannel seismic reflection (MCS), very high resolution Chirp sub-bottom profiler and multibeam bathymetry datasets were collected offshore of Akçakoca and Zonguldak in the Western Black Sea continental slope. The dataset were combined with the acoustic data from R/V Poseidon cruise in 2004 which included multibeam bathymetry, deep-towed side scan sonar and gravity coring on the Kozlu High. Bathymetric data shows that the shelf break is located at approx. 120 m water depths and continental slope extends between 120 to 1800 m water depths including 30 degree of maximum dip. In addtion, continental slope is dissected by several canyons and canyon systems with smaller scale gullies. Preliminary analysis of the seismic data shows the shallow gas anomalies of the continental rise area and a mud volcano offshore of Akçakoca has been discovered at approx. 1490 m water depth. Diameter of the new discovered mud volcano is approx. 250 m. The southern part of the mud volcano has several gas chimneys reaching to the seabed, which are possibly actively degassing. Gas plumes

  18. Quantitative Approach To Seamount Volumes And Eruption Rates For Serpentinite Mud Volcanoes

    NASA Astrophysics Data System (ADS)

    Fedenczuk, T.; Fryer, P.

    2008-12-01

    Serpentinite mud volcanoes in the Mariana forearc are formed by the hydration of mantle peridotite with slab- derived fluids. We calculated the volumes of five seamounts (Pacman, Celestial, Conical, Turquoise, and Big Blue Seamounts) using bathymetric, and (where available) multi-channel seismic reflection data. We interpolated the underlying pre-emplacent surfaces of each seamount using three methods (kriging, harmonic, and multiquadratic radial function), and three estimation techniques to define the pre-eruption seafloor surface beneath the seamounts (perimeter outline, wide area grid, and a geologically interpreted subsurface). We compared the percent difference between each. The interpolation methods produced volume results that differ as follows: 1.9% between kriging and the multiquadratic radial function, 3.6% between kriging and the harmonic function, and 3.8% between multiquadratic radial and the harmonic function. The techniques for determining the subsurface had larger percent differences as follows: 22% between the wide area grid and the geologic interpretation, 20% between geologic interpretation and the perimeter technique, and 18% between wide area grid and the perimeter technique. Based on linear regression results with a high R2, we conclude that there is a strong correlation between the results provided by all three methods. Based on the similarity of all of the regression slopes and their proximity to 1, we can conclude that no method will consistently over- or underestimate the volumes. The geologic interpretation technique should be used when subsurface data (seismic, drill cores, etc.) is available, or when workers have a strong geologic understanding and/or experience in the area. The other two techniques (perimeter and wide area grid) may be useful for large scale comparison studies that include many tens or hundreds of seamounts (or other features), where time constraints and a need for a systematic and repeatable approach is required, or

  19. Methanoculleus sediminis sp. nov., a methanogen from sediments near a submarine mud volcano.

    PubMed

    Chen, Sheng-Chung; Chen, Mei-Fei; Lai, Mei-Chin; Weng, Chieh-Yin; Wu, Sue-Yao; Lin, Saulwood; Yang, Tsanyao F; Chen, Po-Chun

    2015-07-01

    A mesophilic, hydrogenotrophic methanogen, strain S3Fa(T), was isolated from sediments collected by Ocean Researcher I cruise ORI-934 in 2010 near the submarine mud volcano MV4 located at the upper slope of south-west Taiwan. The methanogenic substrates utilized by strain S3Fa(T) were formate and H2/CO2 but not acetate, secondary alcohols, methylamines, methanol or ethanol. Cells of strain S3Fa(T) were non-motile, irregular cocci, 0.5-1.0 μm in diameter. The surface-layer protein showed an Mr of 128,000.The optimum growth conditions were 37 °C, pH 7.1 and 0.17 M NaCl. The DNA G+C content of the genome of strain S3Fa(T) was 62.3 mol%. Phylogenetic analysis revealed that strain S3Fa(T) was most closely related to Methanoculleus marisnigri JR1(T) (99.3% 16S rRNA gene sequence similarity). Genome relatedness between strain S3Fa(T) and Methanoculleus marisnigri JR1(T) was computed using both genome-to-genome distance analysis (GGDA) and average nucleotide identity (ANI) with values of 46.3-55.5% and 93.08%, respectively. Based on morphological, phenotypic, phylogenetic and genomic relatedness data, it is evident that strain S3Fa(T) represents a novel species of the genus Methanoculleus, for which the name Methanoculleus sediminis sp. nov. is proposed. The type strain is S3Fa(T) ( = BCRC AR10044(T) = DSM 29354(T)).

  20. Long-term in situ monitoring at Dashgil mud volcano, Azerbaijan: a link between seismicity, pore-pressure transients and methane emission

    NASA Astrophysics Data System (ADS)

    Kopf, Achim; Delisle, Georg; Faber, Eckhard; Panahi, Behrouz; Aliyev, Chingiz S.; Guliyev, Ibrahim

    2010-10-01

    Mud volcanism is a global phenomenon usually associated with compressional tectonics that favour extrusion of fluid- and clay mineral-rich sediment both on land and offshore. Methane, the dominant gas phase, is emitted at variable rates during and after emplacement of the mud domes. In case of continental mud volcanoes, the gas is directly released into the atmosphere, thereby contributing to global warming. Azerbaijan is one of the countries with one of the highest abundances of mud domes globally. One of the most prominent mud volcanoes, Dashgil, has been chosen for a case study because of its historic record of violent eruptions, continued activity, and well-documented regional geology in the Caucasus orogenic wedge adjacent to the Caspian Sea. Since 2003, gas flux has quantitatively measured at one of the two crater lakes and is characterized by valve-type behaviour and episodically violent degassing. In 2007, the large crater lake was additionally equipped with methane fluxmeters as well as an in situ pore-pressure probe into the conduit. Our data are complemented by regional seismicity, and exhibit the following results: (1) there seems to be a significant correlation between changes in pore pressure in the conduit feeding the main crater lake and the rate of gas escape; (2) changes in gas-flux rate appear to be independent of local seismicity, in particular since no larger EQs have been recorded since 2003; (3) despite discontinuous monitoring owing to technical failures, we observe an overall increase in methane emission with time; (4) nearby earthquake activity (

  1. Lipid composition and microbial diversity of carbonate crusts and mud volcano deposits in the sorokin trough, ne black sea

    NASA Astrophysics Data System (ADS)

    Stadnitskaia, A.; Abbas, B.; Baas, M.; Coolen, M.; Muyzer, G.; van Weering, T.; Ivanov, M.; Sinninghe Damsté, J.

    2003-04-01

    In order to identify prokaryotes involved in AOM, a combination of lipid biomarker analysis, compound-specific carbon isotopic measurements, and 16S rRNA gene sequences was used. Four methane-related carbonate crusts, pelagic sediments and mud volcanic deposits were collected from Odessa, NIOZ and Kazakov mud volcanoes investigated during the 11th Training Through Research expedition (2001) in the Sorokin Trough, NE Black Sea. Strongly depleted archaeal and bacterial SR lipids directly indicate an incorporation of methane-derived carbon into their biomass. Chemotaxonomic and isotopic data suggest that microbial diversities involved in AOM are different among examined carbonates and sediments. This was complementary confirmed by denaturing gradient gel electrophoresis (DGGE) using specific primers for archaea and bacteria. Evidently, this study has implications for identifying additional microbial assemblages involved in AOM subsequently inducing precipitation of carbonates in a various gas-venting environments.

  2. Flux rates and sulfur isotopic composition of pore fluids from three mud volcanoes in the northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Gilhooly, W. P.; Ruppel, C. D.; Dickens, G. R.; Berg, P.; Macko, S. A.

    2010-12-01

    Chloride and sulfate pore water analyses were performed on a total of 29 piston and gravity cores collected along center to flank transects across 3 mud volcanoes, which were located on the Louisiana continental slope in Garden Banks (GB425), Green Canyon (CG185), and Mississippi Canyon (MC852). All three sites are known areas of oil and gas discharge. In addition, seepage at GC185 and GB425 supports highly developed chemosynthetic communities, whereas no known communities have been observed at MC852. Comparison of pore water chemistry (sulfur concentrations and sulfur isotope compositions) among these 3 sites provides initial insight about fluid migration processes and advection rates and about the connection between fluid flux and the establishment of chemosynthetic communities. Pore water advection velocities were calculated from chloride profiles using a steady-state one dimensional advection-diffusion model. In general, chloride concentrations increased with depth to more than four times seawater concentrations. Incidences of pore water freshening are likely associated with hydrate dissociation. Chloride profiles show characteristic concave-up shapes at the center of each mud volcano and concave-down shapes along the flanks, a pattern that we previously interpreted and modeled (doi:10.1029/2004GL021909; doi:10.1111/j.1468-8123.2007.00191.x) in terms of seawater recharge-discharge. The depth of the sulfate-methane interface (SMI) shoals toward the center of the mud volcanoes, indicating potentially rapid anaerobic methane oxidation in these areas. Where the SMI is shallow, pore water sulfide S-isotope values are correspondingly elevated (~ +10 ‰) relative to seawater sulfate (δ34S = +21‰) and presumably represent near-quantitative reduction of pore water sulfate at GB425 and MC852. There is no such pattern at GC185. Such differences potentially reflect advection rates, the ages of the fluids, timing of fluid efflux, and differences in their chemistry.

  3. Ultramafic clasts from the South Chamorro serpentine mud volcano reveal a polyphase serpentinization history of the Mariana forearc mantle

    NASA Astrophysics Data System (ADS)

    Kahl, Wolf-Achim; Jöns, Niels; Bach, Wolfgang; Klein, Frieder; Alt, Jeffrey C.

    2015-06-01

    Serpentine seamounts located on the outer half of the pervasively fractured Mariana forearc provide an excellent window into the forearc devolatilization processes, which can strongly influence the cycling of volatiles and trace elements in subduction zones. Serpentinized ultramafic clasts recovered from an active mud volcano in the Mariana forearc reveal microstructures, mineral assemblages and compositions that are indicative of a complex polyphase alteration history. Petrologic phase relations and oxygen isotopes suggest that ultramafic clasts were serpentinized at temperatures below 200 °C. Several successive serpentinization events represented by different vein generations with distinct trace element contents can be recognized. Measured in situ Rb/Cs ratios are fairly uniform ranging between 1 and 10, which is consistent with Cs mobilization from sediments at lower temperatures and lends further credence to the low-temperature conditions proposed in models of the thermal structure in forearc settings. Late veins show lower fluid mobile element (FME) concentrations than early veins, suggesting a decreasing influence of fluid discharge from the subducting slab on the composition of the serpentinizing fluids. The continuous microfabric and mineral chemical evolution observed in the ultramafic clasts may have implications as to the origin and nature of the serpentinizing fluids. We hypothesize that opal and smectite dehydration produce quartz-saturated fluids with high FME contents and Rb/Cs between 1 and 4 that cause the early pervasive serpentinization. The partially serpentinized material may then be eroded from the basal plane of the suprasubduction mantle wedge. Serpentinization continued but the interacting fluids did not carry a pronounced sedimentary signature, either because FMEs were no longer released from the slab, or due to an en route loss of FMEs. Late chrysotile veins that document the increased access of fluids in a now fluid-dominated regime are

  4. The effect of strong salinity and temperature gradients on transport processes and the formation of bathyal authigenic gypsum at a marine mud volcano

    NASA Astrophysics Data System (ADS)

    Haffert, L.; Haeckel, M.

    2012-04-01

    A thermodynamic activity model (Pitzer approach) applicable to extreme environmental pTS-conditions (up to 1000 bar, 200 ° C and 6 M NaCl) coupled to an extensive mineral database has been developed. The advantage of this code over existing ones, such as Phreeqc, Wateq, Minteq, is the additional integration of a comprehensive pressure correction, as well as the flexibility on the choice of input datasets, allowing fine-tuning of the model according the relevant pTS range. An example of the successful application of the model is the interpretation of near-surface pore water profiles from the Mercator mud volcano in the Gulf of Cadiz. These profiles are intriguing for two reasons. First, they are characterised by a strong salinity gradient in the upper 1-2 mbsf created by the mixing of upward advecting hypersaline (halite and gypsum saturated, S=360) mud volcano fluids and seawater (S=35) and, second, the pore water profiles encompass various types of authigenic gypsum (CaSO4·2H2O) and anhydrite (CaSO4) crystals, which usually form only in evaporitic environments. It was found that while high Ca and SO4 concentrations from dissolution of an underlying diapir provide gypsum saturated fluids, the occurrence of supersaturation and thus authigenic gypsum (or anhydrite) precipitation is only possible through the reduction of temperature. In addition to the strong temperature control, the salinity has an important impact on the resultant composition of the precipitating CaSO4 minerals. Increasing salinity significantly lowers the activity of water, thereby raising the gypsum-anhydrite transition zone from >1 km to about 500 m sediment depth at the MMV and during heat pulses (> 30 ° C) even to within a few metres below the seafloor. Another effect of the strong salinity gradient is its influence on the diffusive transport of solutes. When comparing the activity and concentration profiles of dissolved species at the Mercator mud volcano, it becomes obvious that here the

  5. Draft Genome Sequence of Methanoculleus sediminis S3FaT, a Hydrogenotrophic Methanogen Isolated from a Submarine Mud Volcano in Taiwan.

    PubMed

    Chen, Sheng-Chung; Chen, Mei-Fei; Weng, Chieh-Yin; Lai, Mei-Chin; Wu, Sue-Yao

    2016-04-21

    Here, we announce the genome sequence of ITALIC! Methanoculleus sediminisS3Fa(T)(DSM 29354(T)), a strict anaerobic methanoarchaeon, which was isolated from sediments near the submarine mud volcano MV4 located offshore in southwestern Taiwan. The 2.49-Mb genome consists of 2,459 predicted genes, 3 rRNAs, 48 tRNAs, and 1 ncRNA. The sequence of this novel strain may provide more information for species delineation and the roles that this strain plays in the unique marine mud volcano habitat.

  6. Long-term in situ monitoring at Dashgil mud volcano, Azerbaijan: A link between seismicity, pore pressure transients and methane emission

    NASA Astrophysics Data System (ADS)

    Lange, M.; Kopf, A.; Delisle, G.; Faber, E.; Panahi, B.; Aliyev, C.; Guliyev, I.

    2009-12-01

    Mud volcanism is a global phenomenon usually associated with compressional tectonics that favour extrusion of fluid- and clay mineral-rich sediment both on land and offshore. Methane, the dominant gas phase, is emitted at variable rates during and after emplacement of the mud domes. In case of continental mud volcanoes, the gas is directly released into the atmosphere, thereby contributing to global warming. Azerbaijan is one of the countries with one of the highest abundances of mud domes globally. One of the most prominent mud volcanoes, Dashgil, has been chosen for a case study because of its historic record of violent eruptions, continued activity, and well-documented regional geology in the Caucasus orogenic wedge adjacent to the Caspian Sea. Since 2003, gas flux has quantitatively measured at one of the two crater lakes and is characterized by valve-type behaviour and episodically violent degassing. In 2007, the large crater-lake was additionally equipped with methane fluxmeters as well as an in situ pore pressure probe into the conduit. Our data are complemented by regional seismicity, and exhibit the following results: (1) There seems to be a significant correlation between changes in pore pressure in the conduit feeding the main crater lake and the rate of gas escape; (2) Changes in gas flux rate appear to be independent of local seismicity, in particular since no larger EQs have been recorded since 2003; (3) Despite discontinuous monitoring owing to technical failures, we observe an overall increase in methane emission with time; (4) Nearby earthquake activity (< M4.6) can be correlated with pore pressure transients recorded by the piezometer, which reach up to 2.4 kPa compared to the pre-seismic value; (5) From time to time, there are strong lake level fluctuations decoupled from precipitation or evaporation, which are explained by subbottom hydraulic communication between the two crater lakes and adjacent gryphons. The wealth of observations leads us to

  7. Origin and evolution of fluids from mud volcanoes in the Barbados accretionary complex

    NASA Astrophysics Data System (ADS)

    Godon, Arnaud; Jendrzejewski, Nathalie; Castrec-Rouelle, Maryse; Dia, Aline; Pineau, Françoise; Boulègue, Jacques; Javoy, Marc

    2004-05-01

    A large collection of fluids (54 interstitial fluids and four expelled fluids) were sampled at the Manon site, at the outer edge of the Barbados accretionary complex. These warm fluids (up to 20°C) are expelled by sub-marine (5000 mbsl) mud volcanoes consisting of diapirs (unchanneled flow) and diatremes (channeled). Chlorine stable isotope ratios of these fluids were measured by IRMS with a reproducibility of ± 0.05‰ (1σ) versus SMOC (Standard Mean Ocean Chloride). A large range of δ 37Cl between -5.3‰ and +0.1‰ is observed. Data from each volcanic structure describe a mixing between seawater and a low-δ 37Cl fluid. The whole set of data is interpreted as the result of a mixing between two deep components and seawater. The two deep fluids are chemically distinct (e.g., in Ca, Mg, K, Li, Sr and Br contents and Br/Cl ratio). They display low and significantly different 87Sr/ 86Sr ratios (0.707790 and 0.707892, respectively) and δ 37Cl values (-4.51 and -5.24‰, respectively). Physicochemical processes such as mineralogical transformation, diffusion, compaction or ion filtration are known to fractionate chlorine stable isotopes and can produce fluids with negative δ 37Cl values. Ion filtration due to sediment compaction appears to be the more likely process to explain the negative δ 37Cl values observed at the Manon site. A model for the generation of these signatures is proposed where a residual negative δ 37Cl fluid reservoir is created at the bottom of the prism or the sediment pile. Further compaction/fracturing and/or dewatering of the slab may flush out these fluids and focus them towards the décollement zone. Mixing between the fluids and ultimately with seawater and water released during gas hydrate destabilizations may explain the data set within the individual cores and between the different structures.

  8. Hydrological regulations, land use and a mud volcano affecting the sediment and carbon load of the tropical Brantas River, Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Jennerjahn, Tim; Jänen, Ingo

    2014-05-01

    Intensive human uses of the coastal zone and increasing extreme events are more and more endangering the integrity of coastal ecosystems during the Anthropocene. This is of particular importance in SE Asia where large parts of the population live in the coastal zone and economically depend on its resources. Intensive tectonic activity in the circum-Pacific 'Ring of fire' exposes the region to extreme natural events like volcano eruptions, earthquakes and occasionally following tsunamis. The Indonesian island of Java is a prime example in this respect because of its location on an active continental margin and a population density >1,000 inhabitants km-2. Its second largest river, the Brantas, empties into the shallow Madura Strait through two major branches, the Wonokromo and the Porong, the latter being responsible for 80 % of the discharge. Major land use in the catchment is agriculture (61 %) and the hydrology and sediment load of the river is regulated by 8 large dams and numerous weirs. The estuarine lowlands in the prograding delta were once covered by mangroves which were to a large extent replaced by aquaculture ponds. The eruption of a mud volcano near the Porong in 2006 added another factor affecting the amount and composition of the dissolved and particulate river loads. Concentrations of total suspended sediments (TSM) and particulate organic carbon (POC) displayed large seasonal variations in the Brantas before its diversion into the Porong and the Wonokromo as well as in the latter two with maxima during the wet season (Nov-April). High concentrations in the Porong during both seasons were mainly due to the constantly high input from the mud volcano. Favourable weathering conditions and agriculture as the predominant land use are responsible for high erosion rates of 4-14 mm yr-1 in the catchment. The 8 major dams and numerous weirs built between the 1970s and the 1990s retain a large amount of that sediment leading to an overall low sediment yield of

  9. 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.

  10. A novel, mat-forming Thiomargarita population associated with a sulfidic fluid flow from a deep-sea mud volcano.

    PubMed

    Girnth, Anne-Christin; Grünke, Stefanie; Lichtschlag, Anna; Felden, Janine; Knittel, Katrin; Wenzhöfer, Frank; de Beer, Dirk; Boetius, Antje

    2011-02-01

    A mat-forming population of the giant sulfur bacterium Thiomargarita was discovered at the flank of the mud volcano Amon on the Nile Deep Sea Fan in the Eastern Mediterranean Sea. All cells were of a spherical and vacuolated phenotype and internally stored globules of elemental sulfur. With a diameter of 24-65 µm, Thiomargarita cells from the Eastern Mediterranean were substantially smaller than cells of previously described populations. A 16S rRNA gene fragment was amplified and could be assigned to the Thiomargarita-resembling cells by fluorescence in situ hybridization. This sequence is monophyletic with published Thiomargarita sequences but sequence similarities are only about 94%, indicating a distinct diversification. In the investigated habitat, highly dynamic conditions favour Thiomargarita species over other sulfur-oxidizing bacteria. In contrast to Thiomargarita namibiensis populations, which rely on periodic resuspension from sulfidic sediment into the oxygenated water column, Thiomargarita cells at the Amon mud volcano seem to remain stationary at the sediment surface while environmental conditions change around them due to periodic brine flow.

  11. High diversity of frenulates (Polychaeta: Siboglinidae) in the Gulf of Cadiz mud volcanoes: A DNA taxonomy analysis

    NASA Astrophysics Data System (ADS)

    Hilário, A.; Johnson, S. B.; Cunha, M. R.; Vrijenhoek, R. C.

    2010-01-01

    Frenulates are the most poorly known members of the family Siboglinidae (Polychaeta: Canalipalpata). These thread-like worms occur in reducing marine sediments worldwide, but they are often overlooked in benthic samples or too poorly preserved for adequate taxonomic evaluations. We report on a remarkable diversity of frenulates that were recently sampled from 13 mud volcanoes (350-3902 m deep) in the Gulf of Cadiz, off southern Iberia. Sampled with benthic coring devices, the bodies of these long tubiculous worms were often broken or incomplete, making them difficult to identify morphologically. Consequently, we employed DNA taxonomic methods to assess their diversity. Mitochondrial cytochrome- c-oxidase subunit 1 ( COI) sequences distinguished 15 evolutionary lineages inhabiting the Gulf of Cadiz. Only four of the lineages could be assigned to currently recognized Atlantic species; the remaining 11 may be new to science. This remarkable diversity of frenulates in a small geographical region is unprecedented and is hypothesized to result from environmental heterogeneity associated with the bathymetric and geochemical settings of these mud volcanoes.

  12. Microbial diversity in Frenulata (Siboglinidae, Polychaeta) species from mud volcanoes in the Gulf of Cadiz (NE Atlantic).

    PubMed

    Rodrigues, Clara F; Hilário, Ana; Cunha, Marina R; Weightman, Andrew J; Webster, Gordon

    2011-06-01

    Frenulates are a group of gutless marine annelids belonging to the Siboglinidae that are nutritionally dependent upon endosymbiotic bacteria. We have characterized the bacteria associated with several frenulate species from mud volcanoes in the Gulf of Cadiz by PCR-DGGE of bacterial 16S rRNA genes, coupled with analysis of 16S rRNA gene libraries. In addition to the primary symbiont, bacterial consortia (microflora) were found in all species analysed. Phylogenetic analyses indicate that the primary symbiont in most cases belongs to the Gammaproteobacteria and were related to thiotrophic and methanotrophic symbionts from other marine invertebrates, whereas members of the microflora were related to multiple bacterial phyla. This is the first molecular evidence of methanotrophic bacteria in at least one frenulate species. In addition, the occurrence of the same bacterial phylotype in different Frenulata species, from different depths and mud volcanoes suggests that there is no selection for specific symbionts and corroborates environmental acquisition as previously proposed for this group of siboglinids.

  13. The relationship between mud volcanoes, petroleum migration and accretionary prisms: Lessons from the Caucasus, the Australian margin and Venezuela

    SciTech Connect

    Ware, P.

    1996-08-01

    Mud volcanoes have been widely documented in areas of overpressure where explosive expansion of trapped methane has occurred during argillokinesis. In an area with high sedimentation rate, such as the Gulf of Mexico, there may be no time for fine-grained sediment to de-water before being covered by impermeable material. In an accretionary wedge this process is complicated by overthrusting of off-scraped material which increases the overburden pressure and provides many more avenues for the migration of fluids through the system. In some cases, such as is seen in the Caribbean, the fluids may escape directly to the surface (or seabottom) through high permeability beds. When this happens there may be no diapirism. In other cases, such as in Venezuela, the forearc may be the site of rapid, laterally-derived, sedimentation, and fluids from the overthrusted rocks may be forced to escape through several kilometers of recent deltaic sediments. Since these fluids may include petroleum, this has obvious exploration potential. If there are no suitable reservoir rocks, such as in Timor, there may be no commercial accumulations. However, many giant fields are associated, world-wide, with mud volcanoes, such as those in Azerbaijan.

  14. Macrofaunal assemblages from mud volcanoes in the Gulf of Cadiz: abundance, biodiversity and diversity partitioning across spatial scales

    NASA Astrophysics Data System (ADS)

    Cunha, M. R.; Rodrigues, C. F.; Génio, L.; Hilário, A.; Ravara, A.; Pfannkuche, O.

    2013-04-01

    The Gulf of Cadiz is an extensive seepage area in the south Iberian margin (NE Atlantic) encompassing over 40 mud volcanoes (MVs) at depths ranging from 200 to 4000 m. The area has a long geologic history and a central biogeographic location with a complex circulation ensuring oceanographic connectivity with the Mediterranean Sea, equatorial and North Atlantic regions. The geodynamics of the region promotes a notorious diversity in the seep regime despite the relatively low fluxes of hydrocarbon-rich gases. We analyse quantitative samples taken during the cruises TTR14, TTR15 and MSM01-03 in seven mud volcanoes grouped into Shallow MVs (Mercator: 350 m, Kidd: 500 m, Meknès: 700 m) and Deep MVs (Captain Arutyunov: 1300 m, Carlos Ribeiro: 2200 m, Bonjardim: 3000 m, Porto: 3900 m) and two additional Reference sites (ca. 550 m). Macrofauna (retained by a 500 μm sieve) was identified to species level whenever possible. The samples yielded modest abundances (70-1567 individuals per 0.25 m2), but the local and regional number of species is among the highest ever reported for cold seeps. Among the 366 recorded species, 22 were symbiont-hosting bivalves (Thyasiridae, Vesicomyidae, Solemyidae) and tubeworms (Siboglinidae). The multivariate analyses supported the significant differences between Shallow and Deep MVs: The environmental conditions at the Shallow MVs make them highly permeable to the penetration of background fauna leading to high diversity of the attendant assemblages (H': 2.92-3.94; ES(100): 28.3-45.0; J': 0.685-0.881). The Deep MV assemblages showed, in general, contrasting features but were more heterogeneous (H': 1.41-3.06; ES(100): 10.5-30.5; J': 0.340-0.852) and often dominated by one or more siboglinid species. The rarefaction curves confirmed the differences in biodiversity of Deep and Shallow MVs as well as the convergence of the latter to the Reference sites. The Bray-Curtis dissimilarity demonstrated the high β-diversity of the assemblages

  15. Macrofaunal assemblages from mud volcanoes in the Gulf of Cadiz: abundance, biodiversity and diversity partitioning across spatial scales

    NASA Astrophysics Data System (ADS)

    Cunha, M. R.; Rodrigues, C. F.; Génio, L.; Hilário, A.; Ravara, A.; Pfannkuche, O.

    2012-12-01

    The Gulf of Cadiz is an extensive seepage area in the South Iberian Margin (NE Atlantic) encompassing over 40 mud volcanoes (MVs) at depths ranging from 200 to 4000 m. The area has a long geologic history and a central biogeographic location with a complex circulation assuring oceanographic connectivity with the Mediterranean Sea, Equatorial and Northern Atlantic regions. The geodynamics of the region promotes a notorious diversity in the seep regime despite the relatively low fluxes of hydrocarbon-rich gases. We analyse quantitative samples taken during the cruises TTR14, TTR15 and MSM01-03 in seven mud volcanoes grouped into Shallow MVs (Mercator: 350 m, Kidd: 500 m, Meknès: 700 m) and Deep MVs (Captain Arutyunov: 1300 m, Carlos Ribeiro: 2200 m, Bonjardim: 3000 m, Porto: 3900 m) and two additional reference sites (ca. 550 m). Macrofauna (retained by a 500 μm sieve) was identified to species level whenever possible. The samples yielded modest abundances (70-1567 ind. per 0.25 m2) but a number of species among the highest ever reported for cold seeps. Among the 366 recorded species, 22 were symbiont-hosting bivalves (Thyasiridae, Vesicomyidae, Solemyidae) and tubeworms (Siboglinidae). The multivariate analyses indicated significant differences between Shallow and Deep MVs: The environmental conditions at the Shallow MVs makes them highly permeable to the penetration of background fauna leading to high diversity of the attendant assemblages (H': 2.92-3.94; ES(100): 28.3-45.0; J': 0.685-0.881). The Deep MVs showed, in general, contrasting features but were more heterogeneous (H': 1.41-3.06; ES(100): 10.5-30.5; J': 0.340-0.852) and often dominated by one or more siboglinid species. The rarefaction curves confirmed the differences in biodiversity of Deep and Shallow MVs as well as the approximation of the latter to the reference sites. The Bray-Curtis dissimilarity demonstrated the high β-diversity of the assemblages, especially in pairwise comparisons involving

  16. Character of seismic motion at a location of a gas hydrate-bearing mud volcano on the SW Barents Sea margin

    NASA Astrophysics Data System (ADS)

    Franek, Peter; Mienert, Jürgen; Buenz, Stefan; Géli, Louis

    2014-08-01

    The Håkon Mosby mud volcano (HMMV) at 1270 m water depth on the SW Barents Sea slope has been intensively studied since its discovery in 1989. A variety of sensors monitored morphological, hydrological, geochemical, and biological parameters in the HMMV area. An ocean bottom seismometer deployment allowed us to register seismic motion for 2 years, from October 2008 to October 2010. The analysis of seismic records documents two types of seismic signals. The first type are harmonic tremors with frequency peaks around 4-5 and 8-10 Hz that occur in swarms. Their origin could be from fluid flow circulation or resonant vibrations of gas bubbles or from delayed movement of fluid-rich sediments in the conduit or in a deeper pseudo-mud chamber of the HMMV. Because swarms occur with a periodicity of ~ 6 h, tide-related effects are suspected to influence the mechanism originating the tremors. The second type of signals are regional earthquakes that were in 15 cases recognized in seismic records. The activity of harmonic tremors was not significantly affected by earthquakes.

  17. Active tectonics and mud diapirism in the Gulf of Squillace (Crotone Basin, Calabrian Arc, Italy)

    NASA Astrophysics Data System (ADS)

    Artoni, A.; Capozzi, R.; Lorenzini, S.; Oppo, D.; Polonia, A.; Torelli, L.

    2009-04-01

    The Calabrian arc is a prominent accretionary prism in the Mediterranean sea that contains alpine metamorphic rocks and connects the southern Apennine chain of Calabria, to the north, with the Maghrebian chain of Sicily, to the southwest. Recent active deformation inside the prism is testified by the earthquakes records and by submarine mud volcanism. The latter, not yet well defined within the accretionary prism, is generally associated to deeper active tectonic structures. In order to unravel the relationships between mud volcanoes and deeper deformations a study has been carried out in the Gulf of Squillace, located in the central portion of the backstop zone of the Calabrian arc and inside the Crotone basin. The deeper tectono-stratigraphic frame has been defined by using 10 well logs, 330 kms of public seismic reflection lines and three CROP seismic lines (the project for deep crust of Italy) recently processed with prestack depth migration. The study has been carried out within the Italian PRIN 2006 Project: "Tectonic and Sedimentation in the Accretionary Complex at the Front of the Calabrian Arc (Ionian Sea)". Three major tectonic units could be distinguished; from the top to the bottom, they are: 1) a metamorphic basement nappe (Alpine/Calabrian units); 2) a complex and east-verging Apenninic-Maghrebian prism, that can be subdivided in an outer prism sealed by middle Eocene(?)/Oligocene deposits and an inner prism sealed by middle/late Miocene deposits; 3) a deeper Mesozoic to Neogene relatively undeformed block interpreted as a thinned block of continental crust that preserves Mesozoic extensional fault. Subsurface mapping of Alpine/Calabrian and Apenninic-Maghrebian units show that their leading edges are oriented NNE-SSW and their tectonic stack was completed at least in the late Miocene; since then, WNW-ESE trending Catanzaro-Squillace transcurrent faults system and out-of-sequence thrusting started to locally reshape the backstop. The Cantanzaro

  18. Methanogenic calcite, 13C-depleted bivalve shells, and gas hydrate from a mud volcano offshore southern California

    USGS Publications Warehouse

    Hein, J.R.; Normark, W.R.; McIntyre, B.R.; Lorenson, T.D.; Powell, C.L.

    2006-01-01

    Methane and hydrogen sulfide vent from a cold seep above a shallowly buried methane hydrate in a mud volcano located 24 km offshore southern California in?? 800 m of water. Bivalves, authigenic calcite, and methane hydrate were recovered in a 2.1 m piston core. Aragonite shells of two bivalve species are unusually depleted in 13C (to -91??? ??13C), the most 13C-depleted shells of marine macrofauna yet discovered. Carbon isotopes for both living and dead specimens indicate that they used, in part, carbon derived from anaerobically oxidized methane to construct their shells. The ??13C values are highly variable, but most are within the range -12??? to -91???. This variability may be diagnostic for identifying cold-seep-hydrate systems in the geologic record. Authigenic calcite is abundant in the cores down to ???1.5 m subbottom, the top of the methane hydrate. The calcite is depleted in 13C (??13C = -46??? to -58???), indicating that carbon produced by anaerobically oxidized methane is the main source of the calcite. Methane sources include a geologic hydrocarbon reservoir from Miocene source rocks, and biogenic and thermogenic degradation of organic matter in basin sediments. Oxygen isotopes indicate that most calcite formed out of isotopic equilibrium with ambient bottom water, under the influence of gas hydrate dissociation and strong methane flux. High metal content in the mud volcano sediment indicates leaching of basement rocks by fluid circulating along an underlying fault, which also allows for a high flux of fossil methane. ?? 2006 Geological Society of America.

  19. Endosymbioses between bacteria and deep-sea siboglinid tubeworms from an Arctic Cold Seep (Haakon Mosby Mud Volcano, Barents Sea).

    PubMed

    Lösekann, Tina; Robador, Alberto; Niemann, Helge; Knittel, Katrin; Boetius, Antje; Dubilier, Nicole

    2008-12-01

    Siboglinid tubeworms do not have a mouth or gut and live in obligate associations with bacterial endosymbionts. Little is currently known about the phylogeny of frenulate and moniliferan siboglinids and their symbionts. In this study, we investigated the symbioses of two co-occurring siboglinid species from a methane emitting mud volcano in the Arctic Ocean (Haakon Mosby Mud Volcano, HMMV): Oligobrachia haakonmosbiensis (Frenulata) and Sclerolinum contortum (Monilifera). Comparative sequence analysis of the host-specific 18S and the symbiont-specific 16S rRNA genes of S. contortum showed that the close phylogenetic relationship of this host to vestimentiferan siboglinids was mirrored in the close relationship of its symbionts to the sulfur-oxidizing gammaproteobacterial symbionts of vestimentiferans. A similar congruence between host and symbiont phylogeny was observed in O. haakonmosbiensis: both this host and its symbionts were most closely related to the frenulate siboglinid O. mashikoi and its gammaproteobacterial symbiont. The symbiont sequences from O. haakonmosbiensis and O. mashikoi formed a clade unaffiliated with known methane- or sulfur-oxidizing bacteria. Fluorescence in situ hybridization indicated that the dominant bacterial phylotypes originated from endosymbionts residing inside the host trophosome. In both S. contortum and O. haakonmosbiensis, characteristic genes for autotrophy (cbbLM) and sulfur oxidation (aprA) were present, while genes diagnostic for methanotrophy were not detected. The molecular data suggest that both HMMV tubeworm species harbour chemoautotrophic sulfur-oxidizing symbionts. In S. contortum, average stable carbon isotope values of fatty acids and cholesterol of -43 per thousand were highly negative for a sulfur oxidizing symbiosis, but can be explained by a (13)C-depleted CO(2) source at HMMV. In O. haakonmosbiensis, stable carbon isotope values of fatty acids and cholesterol of -70 per thousand are difficult to reconcile with

  20. Motivations for muon radiography of active volcanoes

    NASA Astrophysics Data System (ADS)

    Macedonio, G.; Martini, M.

    2010-02-01

    Muon radiography represents an innovative tool for investigating the interior of active volcanoes. This method integrates the conventional geophysical techniques and provides an independent way to estimate the density of the volcano structure and reveal the presence of magma conduits. The experience from the pioneer experiments performed at Mt. Asama, Mt. West Iwate, and Showa-Shinzan (Japan) are very encouraging. Muon radiography could be applied, in principle, at any stratovolcano. Here we focus our attention on Vesuvius and Stromboli (Italy).

  1. Organic Geochemistry of Sediments, Interstitial Fluids and Light Volatile Hydrocarbon Gases from Giza and North Alex Mud Volcanoes, Western Nile Deep-Sea Fan

    NASA Astrophysics Data System (ADS)

    Nuzzo, Marianne; Elvert, Marcus; Heuer, Verena; Schmidt, Mark; Hinrichs, Kai-Uwe; Scholz, Florian; Reitz, Anja; Hensen, Christian

    2010-05-01

    The West Nile Delta Project is a multi-disciplinary research project lead at IFM-GEOMAR (Kiel, Germany) and funded by RWE-DEA (Hamburg, Germany). It aims at investigating the sources and transport mechanisms of fluids and hydrocarbon gases seeping at two mud volcanoes (MVs) of the western Nile Deep-Sea Fan: North Alex and Giza MVs, and at the long-term monitoring of the seepage activity at these sites [1,2]. A comparative study of the organic geochemistry of sediments, gases and fluids was carried out in order to constrain (i) the sources of fluids, mud and gases erupted at these cold seeps, and (ii) the microbial hydrocarbon-oxidation processes associated with the extrusion of mud and gases. The molecular and stable isotope composition of light volatile hydrocarbon gases stripped from pore fluids reveal a clear thermogenic origin at the less active Giza MV and at the active centre of N. Alex MV. However, they probably originate from different sources, as shown by the distinct 13C-CH4 values of ~ -45‰ and -37‰VPDB at North Alex and Giza MVs, respectively, while 2H-CH4 values are similar (~ -228‰VSMOW). Away from the centre at North Alex MV the gases have variable compositions and are mainly produced by Archaea microbes. The microbial production of CH4 is probably sustained by the high content of the mud breccia sediments in labile organic matter. Indeed Total Organic Carbon content values are high (~ 1 and 2%weight) in MV sediments from both sites as well as at the reference site away from Giza MV, suggesting a main shallow (Plio-Pleistocene) sedimentary source. Consistently, the sedimentary lipids contain high amounts of compounds typically issued from terrestrial plants such as -amyrin and nC26:0 to nC30:0 fatty acids & alkenols. The hypothesis that labile terrestrial organic matter sustains intense microbial activity in the mud volcano sediments is supported by the extreme enrichment of pore fluids in a suite of Volatile Fatty Acids, in particular

  2. Significance of Dynamic Pore Pressure Variations - Comparison of Observations on Mud Volcanoes on the Costa Rica Margin and in the Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Brueckmann, W.; Linke, P.; Pieper, M.; Hensen, C.; Tuerk, M.

    2006-12-01

    Research in the cooperative research center (SFB) 574 "Volatiles and Fluids in Subduction Zones" at the University Kiel focuses on volatile and fluid exchange processes at subduction zones. These have a significant impact on the long-term geochemical evolution of the hydrosphere and atmosphere. In the SFB 574 working area off Central America more than 120 mud volcanoes, mud diapirs and cold seeps have been identified and sampled. To better understand the internal dynamics of these structures and the temporal variability of fluid expulsion an in-situ tool for monitoring shallow pore pressure variations was devised. The tool (PWPL) monitors pore pressure variations along a 2m profile in the shallow subsurface using a stinger with 4 pressure ports. Positioned with a video-guided lander the stinger is gently pushed into the seafloor where it remains for several weeks or months in autonomous mode before being retrieved. While particular emphasis was placed on the convergent margin of Central America, mud volcanoes in other tectonic settings suitable for long-term observations of fluid flux are used for comparison. Here we will present data and interpretations from two mud volcanoes off Costa Rica and in the Gulf of Cadiz where we have conducted successful tests. Pore pressure data from short-term tests on Mound 11 on the continental slope off Costa Rica are compared with new results from a long-term (3-month) campaign on the Captain Arutjunov deep water mud volcano in the Gulf of Cadiz. Rates of fluid flow at both structures have been thoroughly characterized and quantified with geochemical methods providing a frame of reference for judging the significance of dynamic pore pressure variations.

  3. The Debris Flow of September 20, 2014, in Mud Creek, Mount Shasta Volcano, Northern California

    NASA Astrophysics Data System (ADS)

    De La Fuente, J. A.; Bachmann, S.; Courtney, A.; Meyers, N.; Mikulovsky, R.; Rust, B.; Coots, F.; Veich, D.

    2015-12-01

    The debris flow in Mud Creek on September 20, 2014 occurred during a warm spell at the end of an unusually long and hot summer. No precipitation was recorded during or immediately before the event, and it appears to have resulted from rapid glacial melt. It initiated on the toe of the Konwakiton Glacier, and immediately below it. The flow track was small in the upper parts (40 feet wide), but between 8,000 and 10,000 feet in elevation, it entrained a large volume of debris from the walls and bed of the deeply incised gorge and transported it down to the apex of the Mud Creek alluvial fan (4,800'). At that point, it overflowed the channel and deposited debris on top of older (1924) debris flow deposits, and the debris plugged a road culvert 24 feet wide and 12 feet high. A small fraction of the flow was diverted to a pre-existing overflow channel which parallels Mud Creek, about 1,000 feet to the west. The main debris flow traveled down Mud Creek, confined to the pre-existing channel, but locally got to within a foot or so of overflowing the banks. At elevation 3920', video was taken during the event by a private citizen and placed on YouTube. The video revealed that the flow matrix consisted of a slurry of water/clay/silt/sand/gravel, transporting boulders 1-6 feet in diameter along with the flow. Cobble-sized rock appears to be absent. Sieve analysis of the debris flow matrix material revealed a fining of particles in a downstream direction, as expected. The thickness of deposits on the fan generally decreased in a downstream direction. Deposits were 5-6 feet deep above the Mud Creek dam, which is at 4,800' elevation, and 4-5 feet deep at the dam itself. Further downstream, thicknesses decreased as follows: 3920'aqueduct crossing, 3-4 feet; 3620' Pilgrim Creek Road crossing, 2-3 feet; 3,520', 1-2 feet; 3,440' abandoned railroad grade, 1 foot. This event damaged roads, and future events could threaten life and property. There is a need to better understand local

  4. Water, ice and mud: Lahars and lahar hazards at ice- and snow-clad volcanoes

    USGS Publications Warehouse

    Waythomas, Christopher F.

    2014-01-01

    Large-volume lahars are significant hazards at ice and snow covered volcanoes. Hot eruptive products produced during explosive eruptions can generate a substantial volume of melt water that quickly evolves into highly mobile flows of ice, sediment and water. At present it is difficult to predict the size of lahars that can form at ice and snow covered volcanoes due to their complex flow character and behaviour. However, advances in experiments and numerical approaches are producing new conceptual models and new methods for hazard assessment. Eruption triggered lahars that are ice-dominated leave behind thin, almost unrecognizable sedimentary deposits, making them likely to be under-represented in the geological record.

  5. Ejected Sedimentary Rocks of Mud Volcanoes as Indicators of Depositional Environments and of Hydrocarbon Generation within the South Caspian Basin, Azerbaijan

    NASA Astrophysics Data System (ADS)

    Berner, U.; Scheeder, G.; Kus, J.; Köthe, A.; Movsumova, U.

    2009-04-01

    Mud volcanoes are prominent geological features of the South Caspian Basin of Azerbaijan, one of the oldest oil producing regions worldwide. The basin is characterized by extreme sedimentation rates, which lead to the accumulation of large volumes of Mesozoic and Cenozoic sediments. These mostly unconsolidated strata reach thicknesses of up to 20 km and overlay a continental basement in the onshore part. Tectonic forces control the occurrences of mud volcanoes in regions with over-pressured subsurface sediments as mud volcanoes are closely linked to fault systems. The mud volcanoes of Azerbaijan are a surface expression of vertical hydrocarbon migration and offer the chance to investigate the subsurface by means of ejected rocks transported to the surface. These rocks of Mesozoic and Cenozoic sedimentary sequences are potential indicators of the regional hydrocarbon generation. The mud of nineteen volcano cones contained numerous ejected rock fragments, which we use to identify environmental and depositional parameters of the sediments of the Caspian Basin. We also intended to estimate the depth range from which the mud was transported to the surface using organic geochemical parameters. Mircopalaeontological investigations (calcareous nannoplankton) have been performed on selected samples. These analyses suggest that the investigated sediments are of Late Cretaceous to Palaeogene ages and relate to the stratigraphic interval during which the main hydrocarbon source rocks of Azerbaijan have been deposited. Organic geochemical, organic petrographical and mircopalaeontological investigations have been performed on selected samples of nineteen mud volcanoes. Analyses total organic carbon and total sulphur were performed on an elemental analyzer. These analyses suggest that the sediments can be classified as anoxic marine deposits whereas only few are sediments of a lacustrine environment. Bulk source rock information were obtained from RockEval pyrolysis. Resulting

  6. Chemosymbiotic bivalves from the mud volcanoes of the Gulf of Cadiz, NE Atlantic, with descriptions of new species of Solemyidae, Lucinidae and Vesicomyidae

    PubMed Central

    Olive, Graham; Rodrigues, Clara F.; Cunha, Marina R.

    2011-01-01

    Abstract The chemosymbiotic bivalves collected from the mud volcanoes of the Gulf of Cadiz are reviewed. Of the thirteen species closely associated with chemosynthetic settings two Solemyidae, Solemya (Petrasma) elarraichensis sp. n. and Acharax gadirae sp. n., one Lucinidae, Lucinoma asapheus sp. n., and one Vesicomyidae, Isorropodon megadesmus sp. n. are described and compared to close relatives of their respective families. The biodiversity and distribution of the chemosymbiotic bivalves in the Gulf of Cadiz are discussed and compared to the available information from other cold seeps in the Eastern Atlantic and Mediterranean. Although there is considerable similarity at the genus level between seep/mud volcano fields in the Eastern Atlantic and Mediterranean, there is little overlap at the species level. This indicates a high degree of endemism within chemosymbiotic bivalve assemblages. PMID:21976991

  7. Chemosymbiotic bivalves from the mud volcanoes of the Gulf of Cadiz, NE Atlantic, with descriptions of new species of Solemyidae, Lucinidae and Vesicomyidae.

    PubMed

    Olive, Graham; Rodrigues, Clara F; Cunha, Marina R

    2011-01-01

    The chemosymbiotic bivalves collected from the mud volcanoes of the Gulf of Cadiz are reviewed. Of the thirteen species closely associated with chemosynthetic settings two Solemyidae, Solemya (Petrasma) elarraichensissp. n. and Acharax gadiraesp. n., one Lucinidae, Lucinoma asapheussp. n., and one Vesicomyidae, Isorropodon megadesmussp. n. are described and compared to close relatives of their respective families. The biodiversity and distribution of the chemosymbiotic bivalves in the Gulf of Cadiz are discussed and compared to the available information from other cold seeps in the Eastern Atlantic and Mediterranean. Although there is considerable similarity at the genus level between seep/mud volcano fields in the Eastern Atlantic and Mediterranean, there is little overlap at the species level. This indicates a high degree of endemism within chemosymbiotic bivalve assemblages.

  8. Volcanoes!

    USGS Publications Warehouse

    ,

    1997-01-01

    Volcanoes is an interdisciplinary set of materials for grades 4-8. Through the story of the 1980 eruption of Mount St. Helens, students will answer fundamental questions about volcanoes: "What is a volcano?" "Where do volcanoes occur and why?" "What are the effects of volcanoes on the Earth system?" "What are the risks and the benefits of living near volcanoes?" "Can scientists forecast volcanic eruptions?"

  9. Lipid Composition of methane-derived Carbonate Crusts and Sediments from Mud Volcanoes in the Sorokin Trough, NE Black Sea

    NASA Astrophysics Data System (ADS)

    Stadnitskaia, A.; Baas, M.; Hopmans, E.; van Weering, T.; Sinninghe Damsté, J.

    2003-04-01

    We investigated the distributions and d13C values of bacterial and archaeal lipids in four carbonate crusts and hosting sediments collected from three mud volcanoes in the Sorokin Trough during the 11th Training Through Research expedition in 2001. The lipid extract from carbonate crusts contains abundant archaeal and bacterial biomarkers such as pentamethylicosane (PMI), unsaturated PMIs, archaeol, hydroxyarchaeols (sn-2 and sn-3 isomers), diphytanyl glycerol diethers (DGDs). Hosting sediments also contain a diversity of bacterial and archaeal lipids, but their concentrations are significantly lower then those observed in the crusts. The stable isotopic signature of these compounds have established their biosynthesis by consortia of microorganisms performing anaerobic methanotrophy. Quantitatively, the most predominant group of archaeal core membrane lipids in the crusts and in the sediments is the glycerol dialkyl glycerol tetraethers (GDGTs). Besides, two carbonate crusts contained two archaeal core membrane macrocyclic diether lipids which have not been reported previously. These macrocyclic diethers are structurally related to GDGTs with one and two cyclopentane rings. Cyclopentane-bearing GDGTs are well known for different archaeal species thriving in different environments, while a macrocyclic diether was found only in the thermophilic methanogen Methanococcus jannaschi. Therefore, the molecular structure of novel macrocyclic DGDs unites ecologically contrasting archaeal groups. Strongly depleted carbon isotopic values of these diethers indicate that these diethers derived from archaea acting within anaerobic methane-oxidizing consortia in cold-water environments.

  10. First measurements of gas output from bubbling pools in a mud volcano at the periphery of Mt Etna (Italy): methodologies and implications for monitoring purposes

    NASA Astrophysics Data System (ADS)

    Federico, Cinzia; Giudice, Gaetano; Liuzzo, Marco; Pedone, Maria; Cosenza, Paolo; Riccobono, Giuseppe

    2014-05-01

    Gases and brines emitted in the southern sector of Mt Etna from mofettes, mud pools and mud volcanoes come from an hydrothermal reservoir hosted within the clayey formations of the sedimentary basement (Chiodini et al., 1996). The gas emitted consists mainly of CO2, with CH4, N2 and He as minor species. CO2 and He stable isotopes indicate a clear magmatic origin for these gases, and their compositional changes during either eruptive or rest periods closely parallel that of crater fumaroles (Paonita et al., 2012). Altough these manifestations are the most significant CO2 emitters outside the crater area, their mass output has never been measured. We present the first measurements of gas flux from several bubbling mud pools in a mud volcano located in the village of Paternò (Lon 14.89° Lat 37.57°), in the southern flank of the volcano. We performed gas measurements using a home-made apparatus, able to capture all the bubbles over an area of 0.4 m2. Over an area of about 7000 m2, we measured the flow rate of every single bubbling pool, providing that it had a minimum flux rate of 0.5 l/min. The maximum measured flow rate for a single pool was 15 l/min. A preliminary estimate of the total CO2 output over the whole mud volcano is in the order of few t/d. At the same time, we measured the chemical composition of emitted gases in various pools, characterised by different gas flow rates, to calculate the output of CO2 and verify the effect of eventual chemical fractionation processes upon gas chemistry. During the same campaign of direct measurements, we also used a commercial infrared laser unit (GasFinder 2.0 from Boreal Laser Ltd) for measurement of volcanic CO2 path-integrated concentrations along cross-sections of the atmospheric plumes in the area. The GasFinder was set as to measure CO2 concentrations at 1 Hz rate. During the field campaigns, the position of the GasFinder unit was sequentially moved so as to scan the plumes from different viewing directions and

  11. Plant growth promoting capability and genetic diversity of bacteria isolated from mud volcano and lime cave of Andaman and Nicobar Islands.

    PubMed

    Venkadesaperumal, Gopu; Amaresan, Natrajan; Kumar, Krishna

    2014-01-01

    Twenty four bacterial strains from four different regions of mud volcano and lime cave were isolated to estimate their diversity, plant growth promoting and biocontrol activities to use them as inoculant strains in the fields. An excellent antagonistic effect against four plant pathogens and plant growth promoting properties such as IAA production, HCN production, phosphate solubilization, siderophore production, starch hydrolysis and hydrolytic enzymes syntheses were identified in OM5 (Pantoea agglomerans) and EM9 (Exiguobacterium sp.) of 24 studied isolates. Seeds (Chili and tomato) inoculation with plant growth promoting strains resulted in increased percentage of seedling emergence, root length and plant weight. Results indicated that co-inoculation gave a more pronounced effects on seedling emergence, secondary root numbers, primary root length and stem length, while inoculation by alone isolate showed a lower effect. Our results suggest that the mixed inocula of OM5 and EM9 strains as biofertilizers could significantly increase the production of food crops in Andaman archipelago by means of sustainable and organic agricultural system.

  12. Plant growth promoting capability and genetic diversity of bacteria isolated from mud volcano and lime cave of Andaman and Nicobar Islands

    PubMed Central

    Venkadesaperumal, Gopu; Amaresan, Natrajan; Kumar, Krishna

    2014-01-01

    Twenty four bacterial strains from four different regions of mud volcano and lime cave were isolated to estimate their diversity, plant growth promoting and biocontrol activities to use them as inoculant strains in the fields. An excellent antagonistic effect against four plant pathogens and plant growth promoting properties such as IAA production, HCN production, phosphate solubilization, siderophore production, starch hydrolysis and hydrolytic enzymes syntheses were identified in OM5 (Pantoea agglomerans) and EM9 (Exiguobacterium sp.) of 24 studied isolates. Seeds (Chili and tomato) inoculation with plant growth promoting strains resulted in increased percentage of seedling emergence, root length and plant weight. Results indicated that co-inoculation gave a more pronounced effects on seedling emergence, secondary root numbers, primary root length and stem length, while inoculation by alone isolate showed a lower effect. Our results suggest that the mixed inocula of OM5 and EM9 strains as biofertilizers could significantly increase the production of food crops in Andaman archipelago by means of sustainable and organic agricultural system. PMID:25763031

  13. Isotopic composition of dissolved inorganic carbon in subsurface sediments of gas hydrate-bearing mud volcanoes, Lake Baikal: implications for methane and carbonate origin

    NASA Astrophysics Data System (ADS)

    Krylov, Alexey A.; Khlystov, Oleg M.; Hachikubo, Akihiro; Minami, Hirotsugu; Nunokawa, Yutaka; Shoji, Hitoshi; Zemskaya, Tamara I.; Naudts, Lieven; Pogodaeva, Tatyana V.; Kida, Masato; Kalmychkov, Gennady V.; Poort, Jeffrey

    2010-06-01

    We report on the isotopic composition of dissolved inorganic carbon (DIC) in pore-water samples recovered by gravity coring from near-bottom sediments at gas hydrate-bearing mud volcanoes/gas flares (Malenky, Peschanka, Peschanka 2, Goloustnoe, and Irkutsk) in the Southern Basin of Lake Baikal. The δ13C values of DIC become heavier with increasing subbottom depth, and vary between -9.5 and +21.4‰ PDB. Enrichment of DIC in 13C indicates active methane generation in anaerobic environments near the lake bottom. These data confirm our previous assumption that crystallization of carbonates (siderites) in subsurface sediments is a result of methane generation. Types of methanogenesis (microbial methyl-type fermentation versus CO2-reduction) were revealed by determining the offset of δ13C between dissolved CH4 and CO2, and also by using δ13C and δD values of dissolved methane present in the pore waters. Results show that both mechanisms are most likely responsible for methane generation at the investigated locations.

  14. Highly plastic behavior and fluidization of gouge; implications for fault and landslide mechanics and for the generation of mud volcanoes

    NASA Astrophysics Data System (ADS)

    Shimamoto, Toshihiko; Aoki, Kazuhiro; Seshimo, Kazuyoshi; Hu, Wei; Ma, Shengli; Yao, Lu; Xiong, Ran; Xiao, Yinke

    2016-04-01

    minimum of 0.02 when the initial pore water was greater than about 30 wt%. The landslide is moving slowly at velocities to ca. 1 cm/day on a very gentle slope with a dip angle of 1 to 3 degrees, corresponding to friction coefficients of 0.02 to 0.05. Our drained tests still could not fully reproduce this landslide and we plan to conduct undrained tests as the other extreme case. Highly plastic behavior of gouge with very low friction may lead to extreme weakening of faults with dehydration, and mud volcanoes may also be caused by dramatic weakening of granular materials with abundant water. Fluidization of gouge can be an important mechanism for ultra-low friction of faults and landslide slip zones with degassing reactions or with vaporization of dehydrated water at low normal stresses. We have just made a gouge sample cell with O-rings and a pore-pressure gauge to refine those preliminary experiment, by conducting undrained tests with controlled amount of pore water while monitoring pore pressure. Additional data will be reported on those materials and on fine sandstone from a mud volcano in the Nankai Trough.

  15. 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.

  16. Geochemistry, isotopic composition and origin of fluids emanating from mud volcanoes in the Copper River Basin, Alaska. Final report

    SciTech Connect

    Motyka, R.J.; Hawkins, D.B.; Poreda, R.J.; Jeffries, A.

    1986-05-01

    Two compositionally different groups of mud volcanoes exist in the Copper River Basin: the Tolsona group which discharges Na-Ca rich, HCO/sub 3/-SO/sub 4/ poor saline waters accompanied by small amounts of gas, composed predominately of CH/sub 4/ and N/sub 2/; and the Klawasi group which discharges Ca poor, Na-HCO/sub 3/ rich saline waters accompanied by enormous amounts of CO/sub 2/. The Tolsona-type water chemistry and isotopic composition could have been produced through the following processes: dilution of original interstitial seawaters with paleo-meteoric waters, possibly during a period of uplift in the mid-Cretaceous; loss of HCO/sub 3/ and SO/sub 4/ and modification of other constituent concentrations by shale-membrane filtration; further depletion of Mg, K, HCO/sub 3/, and SO/sub 4/, and enrichment in Ca and Sr through dolomitization, hydrolysis, and clay-forming processes; and leaching of B, I, Li, and SiO/sub 2/ from marine sediments. Compared to the Tolsona waters, the Klawasi waters are strongly enriched in Li, Na, K, Mg, HCO/sub 3/, SO/sub 4/, B, SiO/sub 2/ and delta/sup 18/O and strongly depleted in Ca, Sr and D. The Klawasi wates also contain high concentrations of arsenic (10 to 48 ppM). The differences in fluid chemistry between Klawasi and Tolsona can be explained as the result of the interaction of fluids derived from a magmatic intrusion and contact decarbonation of limestone beds underlying the Klawasi area with overlying Tolsona-type formation waters.

  17. Spatial variations of community structures and methane cycling across a transect of Lei-Gong-Hou mud volcanoes in eastern Taiwan

    PubMed Central

    Wang, Pei-Ling; Chiu, Yi-Ping; Cheng, Ting-Wen; Chang, Yung-Hsin; Tu, Wei-Xain; Lin, Li-Hung

    2014-01-01

    This study analyzed cored sediments retrieved from sites distributed across a transect of the Lei-Gong-Hou mud volcanoes in eastern Taiwan to uncover the spatial distributions of biogeochemical processes and community assemblages involved in methane cycling. The profiles of methane concentration and carbon isotopic composition revealed various orders of the predominance of specific methane-related metabolisms along depth. At a site proximal to the bubbling pool, the methanogenic zone was sandwiched by the anaerobic methanotrophic zones. For two sites distributed toward the topographic depression, the methanogenic zone overlaid the anaerobic methanotrophic zone. The predominance of anaerobic methanotrophy at specific depth intervals is supported by the enhanced copy numbers of the ANME-2a 16S rRNA gene and coincides with high dissolved Fe/Mn concentrations and copy numbers of the Desulfuromonas/Pelobacter 16S rRNA gene. Assemblages of 16S rRNA and mcrA genes revealed that methanogenesis was mediated by Methanococcoides and Methanosarcina. pmoA genes and a few 16S rRNA genes related to aerobic methanotrophs were detected in limited numbers of subsurface samples. While dissolved Fe/Mn signifies the presence of anaerobic metabolisms near the surface, the correlations between geochemical characteristics and gene abundances, and the absence of aerobic methanotrophs in top sediments suggest that anaerobic methanotrophy is potentially dependent on iron/manganese reduction and dominates over aerobic methanotrophy for the removal of methane produced in situ or from a deep source. Near-surface methanogenesis contributes to the methane emissions from mud platform. The alternating arrangements of methanogenic and methanotrophic zones at different sites suggest that the interactions between mud deposition, evaporation, oxidation and fluid transport modulate the assemblages of microbial communities and methane cycling in different compartments of terrestrial mud volcanoes. PMID

  18. Spatial variations of community structures and methane cycling across a transect of Lei-Gong-Hou mud volcanoes in eastern Taiwan.

    PubMed

    Wang, Pei-Ling; Chiu, Yi-Ping; Cheng, Ting-Wen; Chang, Yung-Hsin; Tu, Wei-Xain; Lin, Li-Hung

    2014-01-01

    This study analyzed cored sediments retrieved from sites distributed across a transect of the Lei-Gong-Hou mud volcanoes in eastern Taiwan to uncover the spatial distributions of biogeochemical processes and community assemblages involved in methane cycling. The profiles of methane concentration and carbon isotopic composition revealed various orders of the predominance of specific methane-related metabolisms along depth. At a site proximal to the bubbling pool, the methanogenic zone was sandwiched by the anaerobic methanotrophic zones. For two sites distributed toward the topographic depression, the methanogenic zone overlaid the anaerobic methanotrophic zone. The predominance of anaerobic methanotrophy at specific depth intervals is supported by the enhanced copy numbers of the ANME-2a 16S rRNA gene and coincides with high dissolved Fe/Mn concentrations and copy numbers of the Desulfuromonas/Pelobacter 16S rRNA gene. Assemblages of 16S rRNA and mcrA genes revealed that methanogenesis was mediated by Methanococcoides and Methanosarcina. pmoA genes and a few 16S rRNA genes related to aerobic methanotrophs were detected in limited numbers of subsurface samples. While dissolved Fe/Mn signifies the presence of anaerobic metabolisms near the surface, the correlations between geochemical characteristics and gene abundances, and the absence of aerobic methanotrophs in top sediments suggest that anaerobic methanotrophy is potentially dependent on iron/manganese reduction and dominates over aerobic methanotrophy for the removal of methane produced in situ or from a deep source. Near-surface methanogenesis contributes to the methane emissions from mud platform. The alternating arrangements of methanogenic and methanotrophic zones at different sites suggest that the interactions between mud deposition, evaporation, oxidation and fluid transport modulate the assemblages of microbial communities and methane cycling in different compartments of terrestrial mud volcanoes.

  19. 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)

  20. Volcanoes

    SciTech Connect

    Decker, R.W.; Decker, B.

    1989-01-01

    This book describes volcanoes although the authors say they are more to be experienced than described. This book poses more question than answers. The public has developed interest and awareness in volcanism since the first edition eight years ago, maybe because since the time 120 volcanoes have erupted. Of those, the more lethal eruptions were from volcanoes not included in the first edition's World's 101 Most Notorious Volcanoes.

  1. 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

  2. Monitoring and Characterizing the Geysering and Seismic Activity at the Lusi Mud Eruption Site, East Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Karyono, Karyono; Obermann, Anne; Mazzini, Adriano; Lupi, Matteo; Syafri, Ildrem; Abdurrokhim, Abdurrokhim; Masturyono, Masturyono; Hadi, Soffian

    2016-04-01

    The Lusi eruption began on May 29, 2006 in the northeast of Java Island, Indonesia, and to date is still active. Lusi is a newborn sedimentary-hosted hydrothermal system characterized by continuous expulsion of liquefied mud and breccias and geysering activity. Lusi is located upon the Watukosek fault system, a left lateral wrench system connecting the volcanic arc and the bakarc basin. This fault system is still periodically reactivated as shown by field data. In the framework of the Lusi Lab project (ERC grant n° 308126) we conducted several types of monitoring. Based on camera observations, we characterized the Lusi erupting activity by four main behaviors occurring cyclically: (1) Regular activity, which consists in the constant emission of water and mud breccias (i.e. viscous mud containing clay, silt, sand and clasts) associated with the constant expulsion of gas (mainly aqueous vapor with minor amounts of CO2 and CH4) (2) Geysering phase with intense bubbling, consisting in reduced vapor emission and more powerful bursting events that do not seem to have a regular pattern. (3) Geysering phase with intense vapor and degassing discharge and a typically dense plume that propagates up to 100 m height. (4) Quiescent phase marking the end of the geysering activity (and the observed cycle) with no gas emissions or bursts observed. To investigate the possible seismic activity beneath Lusi and the mechanisms controlling the Lusi pulsating behaviour, we deployed a network of 5 seismic stations and a HD camera around the Lusi crater. We characterize the observed types of seismic activity as tremor and volcano-tectonic events. Lusi tremor events occur in 5-10 Hz frequency band, while volcano tectonic events are abundant in the high frequencies range from 5 Hz until 25 Hz. We coupled the seismic monitoring with the images collected with the HD camera to study the correlation between the seismic tremor and the different phases of the geysering activity. Key words: Lusi

  3. Formation of mud volcanoes, giant polygons and chaotic terrains on Mars as the result of compaction and convection of altered pyroclastic deposits.

    NASA Astrophysics Data System (ADS)

    Lopez, Teodolina; Baratoux, David; Antoine, Raphaël; Rabinowicz, Michel; Le Deit, Laëtitia; Kurita, Key; D'Uston, Lionel

    2014-05-01

    Rheology of crustal material is a key parameter to understand surface morphology on solid planets. Detections of phyllosilicate-rich units on Mars, made by OMEGA and CRISM instruments, over a major part of the Southern Plains [1] and in some specific regions as ejectas and craters central peaks in the Northern Plains [2], suggest a widespread extend of phyllosicate-rich deposits. Analysis of recent experimental characterization of the rheology of phyllosilicates leads us to propose a link between several types of surface features on Mars and the hydrodynamic instabilities that may develop in such material. More precisely, we propose and argue that the formation of mud volcanoes, giant polygons and chaotic terrains results from the interplay of compaction, hydrothermal convection and plastic convection in thick phyllosilicate-rich units. Indeed, the compaction and hydrothermal convection that may develop in the 4° tilted sedimentary layers in Firsoff crater [3] would lead to the formation of a top light-layered deposit intruded by mud volcanoes. In the same way, compaction coupled with hydrothermal and plastic convection in the 2.5 km thick sediment cover of Utopia [4] and Acidalia Planitiae can explain the formation of the giant polygons and their associated set of mud volcanoes. Besides, strong plastic and hydrothermal convection coupled with compaction acting in the 5 km thick cover of Hydraotes Chaos would explain the formation of (i) the kilometre deep troughs separating the polygonal mesas recorded there, and (ii) the km large pitted mud cones paving these troughs. Finally, we obtain new insights into the sub-surface structure prevailing to the formation of outflow channels. Indeed, we propose the formation of a network of connected deconsolidated clays tubes would provide the necessary hydrological connectivity that eventually led to the major outflow events. [1] e.g. Ehlmann et al., 2013, Spa. Sci. Rev., 174 (1-4); [2] Carter et al., 2010, Science, 328

  4. Formation of Mud Volcanoes, Giant Polygons and Chaotic Terrains on Mars as the Result of Compaction and Convection of Thick Altered Pyroclastic Deposit

    NASA Astrophysics Data System (ADS)

    Lopez, T.; Baratoux, D.; Antoine, R.; Rabinowicz, M.; Le Deit, L.; Kurita, K.; D'Uston, L.

    2013-12-01

    Rheology of crustal material is a key parameter to understand surface morphology on solid planets. Detections of phyllosilicate-rich units on Mars, made by OMEGA and CRISM instruments, over a major part of the Southern Plains [1] and in some specific regions as ejectas and craters central peaks in the Northern Plains [2], suggest a widespread extend of phyllosicate-rich deposits. Analysis of recent experimental characterization of the rheology of phyllosilicates leads us to propose a link between several types of surface features on Mars and the hydrodynamic instabilities that may develop in such material. More precisely, we propose and argue that the formation of mud volcanoes, giant polygons and chaotic terrains results from the interplay of compaction, hydrothermal convection and plastic convection in thick phyllosilicate-rich units. Indeed, the compaction and hydrothermal convection that may develop in the 4° tilted sedimentary layers in Firsoff crater [3] would lead to the formation of a top light-layered deposit intruded by mud volcanoes. In the same way, compaction coupled with hydrothermal and plastic convection in the 2.5 km thick sediment cover of Utopia [4] and Acidalia Planitiae can explain the formation of the giant polygons and their associated set of mud volcanoes. Besides, strong plastic and hydrothermal convection coupled with compaction acting in the 5 km thick cover of Hydraotes Chaos would explain the formation of (i) the kilometre deep troughs separating the polygonal mesas recorded there, and (ii) the km large pitted mud cones paving these troughs. Finally, we obtain new insights into the sub-surface structure prevailing to the formation of outflow channels. Indeed, we propose the formation of a network of connected deconsolidated clays tubes would provide the necessary hydrological connectivity that eventually led to the major outflow events. [1] e.g. Ehlmann et al., 2013, Spa. Sci. Rev., 174 (1-4); [2] Carter et al., 2010, Science, 328

  5. Decarbonation of the Subducting Pacific Plate Triggered by the Lawsonite-to-Epidote Transition Beneath the Mariana Forearc Serpentinite Mud Volcanoes

    NASA Astrophysics Data System (ADS)

    Mottl, M. J.; McCollom, T. M.; Wheat, C. G.; Fryer, P.

    2008-12-01

    A band of serpentinite mud volcanoes in the outer half of the Mariana forearc provides a unique view into conditions, processes, and fluxes in the shallowest part of a subduction zone, to depths of ~25 km. These large mud volcanoes, up to 2 km high and 50 km across, are abundant along a 600-km swath from 13°47'N to 19°33'N and from 50 to 90 km behind the trench. They form when water generated by dehydration of the subducting Pacific Plate ascends into the overlying mantle of the Philippine Plate and converts it to serpentinite. This low-density rock then rises buoyantly along fractures and extrudes at the seafloor, usually as a point source, producing a mud volcano with a central conduit that is narrow relative to the diameter of the volcano. This conduit feeds flows of unconsolidated sedimentary serpentinite that comprise the bulk of the seamount and contain variably serpentinized clasts of harzburgite ranging in size from silt to boulders. The upwelling serpentinite brings up fragments of subducted ocean crust metamorphosed in the blueschist facies. Also rising up are the aqueous fluids generated during, and responsible for, this metamorphism and serpentinization, that exit the seafloor as springs on the summits of the mud volcanoes. Because depleted harzburgite is much simpler chemically and mineralogically than most igneous rocks, these upwelling pore waters retain a clear chemical signal of their deep metamorphic origin in spite of their long ascent. The ascending fluids are all fresher than seawater because of slab dehydration. Their chemistry varies abruptly with distance: near the trench, at 48-54 km, they have pH 10.7, much higher Ca and Sr than seawater and much lower alkalinity, sulfate, Na/Cl, K, Rb, and B. Farther from the trench, at 70 to 90 km, the waters have pH 12.5 and show the opposite trends relative to seawater for all of these species. Sulfate, Na/Cl, K, Rb, Cs, and B all increase regularly with distance from the trench, leached from the

  6. 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.

  7. GlobVolcano: Earth Observation Services for global monitoring of active volcanoes

    NASA Astrophysics Data System (ADS)

    Tampellini, L.; Ratti, R.; Borgström, S.; Seifert, F. M.; Solaro, G.

    2009-04-01

    The GlobVolcano project 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 Volcanological Observatories and other mandate users (Civil Protection, scientific communities of volcanoes) in their monitoring activities. The information service is assessed in close cooperation with the user organizations for different types of active 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. The following EO-based information services have been defined, harmonising the user requirements provided by a worldwide selection of user organizations. - Deformation Mapping - Surface Thermal Anomalies - Volcanic Gas Emission (SO2) - Volcanic Ash Tracking During the first phase of the project (completed in June 2008) a pre-operational information system has been designed, implemented and validated, involving a limited number of test areas and respective user organizations (i.e. Piton de la Fournaise in La Reunion Island, Karthala in Comore Islands, Stromboli, Volcano and Etna in Italy, Soufrière Hills in Montserrat Island, Colima in Mexico, Merapi in Indonesia). 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 regularly monitored and as many user organizations are involved and cooperating with the project team. Based on user requirements, the GlobVolcano Information System has been developed following system engineering rules and criteria, besides most recent interoperability standards for geospatial data. The GlobVolcano Information System includes two main elements: 1. The GlobVolcano Data Processing System, which consists of seven of EO data processing subsystems

  8. 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.

  9. 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

  10. Digital data set of volcano hazards for active Cascade Volcanos, Washington

    USGS Publications Warehouse

    Schilling, Steve P.

    1996-01-01

    Scientists at the Cascade Volcano Observatory have completed hazard assessments for the five active volcanos in Washington. The five studies included Mount Adams (Scott and others, 1995), Mount Baker (Gardner and others, 1995), Glacier Peak (Waitt and others, 1995), Mount Rainier (Hoblitt and others, 1995) and Mount St. Helens (Wolfe and Pierson, 1995). Twenty Geographic Information System (GIS) data sets have been created that represent the hazard information from the assessments. The twenty data sets have individual Open File part numbers and titles

  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. 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.

  13. 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.

  14. Volcanoes

    MedlinePlus

    ... hot gases and debris called pyroclastic flows. Some dangers from volcanoes can be predicted ahead of time ... for All Disasters Illnesses, injuries, carbon monoxide poisoning, animals & insects, food, water, cleanup, mold, environmental concerns, and ...

  15. 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.

  16. Seismic activity of Erebus volcano, antarctica

    NASA Astrophysics Data System (ADS)

    Kaminuma, Katsutada

    1987-11-01

    Mount Erebus is presently the only Antarctic volcano with sustained eruptive activity in the past few years. It is located on Ross Island and a convecting anorthoclase phonolite lava lake has occupied the summit crater of Mount Erebus from January 1973 to September 1984. A program to monitor the seismic activity of Mount Erebus named IMESS was started in December 1980 as an international cooperative program among Japan, the United States and New Zealand. A new volcanic episode began on 13 September, 1984 and continued until December. Our main observations from the seismic activity from 1982 1985 are as follows: (1) The average numbers of earthquakes which occurred around Mount Erebus in 1982, 1983 and January August 1984 were 64, 134 and 146 events per day, respectively. Several earthquake swarms occurred each year. (2) The averag number of earthquakes in 1985 is 23 events per day, with only one earthquake swarm. (3) A remarkable decrease of the background seismicity is recognized before and after the September 1984 activity. (4) Only a few earthquakes were located in the area surrounding Erebus mountain after the September 1984 activity. A magma reservoir is estimated to be located in the southwest area beneath the Erebus summit, based on the hypocenter distributions of earthquakes.

  17. Possible manifestations of underwater mud volcanoes based on results of sonar investigations in region of Taman Peninsula

    NASA Astrophysics Data System (ADS)

    Kaevitser, V. I.; Rimskii-Korsakov, N. A.; Smolyaninov, I. V.; Razmanov, V. M.; Krivtsov, A. P.

    2016-09-01

    This paper presents the results of three-dimensional acoustic seabed mapping in the region of the Taman Peninsula in the Black Sea using an interferometric side-scan sonar and an acoustic profiler. Mapping has revealed underwater objects identified as manifestations of underwater mud volcanism. Detailed analysis of sonar images of the relief and seabed profiles in the region of the objects has confirmed the original hypothesis.

  18. Actinomycetes from solitary wasp mud nest and swallow bird mud nest: isolation and screening for their antibacterial activity.

    PubMed

    Kumar, Vijay; Bharti, Alpana; Gupta, Vivek Kumar; Gusain, Omprakash; Bisht, Gajraj Singh

    2012-03-01

    The aim of this study was to isolate and screen actinomycetes from solitary wasp and swallow bird mud nests for antimicrobial activity. The actinomycetes were isolated from soil of nests of solitary wasp and swallow bird, and identified on the basis of morphological characteristics and molecular biological methods. A total of 109 actinomycetal isolates were obtained from 12 soil samples (6 from each habitat) using two media. The highest number of actinomycetes were recovered on Humic acid vitamin agar media (65.13%, n = 71) as compared to actinomycetes isolation agar media (34.86%, n = 38). The antimicrobial activity of actinomycetes isolates was determined using the agar plug method. Among 109 isolates, 51 isolates (46.78%) showed antibacterial activity by agar plug assay. The morphological and molecular characteristics confirmed that the most of active isolates in both sample belonged to the genus Streptomyces, the other potential genera like Streptosporangium, Actinomadura, Saccharopolyspora, Thermoactinomycetes and Nocardia were also recovered, but in a low frequency. The isolates designated as 8(1), BN-6, MN 2(6), MN 2(7) and MN 9(V) showed most promising activity against various drug resistant bacterial pathogens. It seems that the promising isolates from these unusual/unexplored habitats may prove to be an important step in development of drug for treating multi-drug resistant bacterial pathogens.

  19. Novel archaeal macrocyclic diether core membrane lipids in a methane-derived carbonate crust from a mud volcano in the Sorokin Trough, NE Black Sea

    PubMed Central

    Stadnitskaia, Alina; Baas, Marianne; Ivanov, Michael K.; Van Weering, Tjeerd C.E.; Sinninghe Damsté, Jaap S.

    2003-01-01

    A methane-derived carbonate crust was collected from the recently discovered NIOZ mud volcano in the Sorokin Trough, NE Black Sea during the 11th Training-through-Research cruise of the R/V Professor Logachev. Among several specific bacterial and archaeal membrane lipids present in this crust, two novel macrocyclic diphytanyl glycerol diethers, containing one or two cyclopentane rings, were detected. Their structures were tentatively identified based on the interpretation of mass spectra, comparison with previously reported mass spectral data, and a hydrogenation experiment. This macrocyclic type of archaeal core membrane diether lipid has so far been identified only in the deep-sea hydrothermal vent methanogen Methanococcus jannaschii. Here, we provide the first evidence that these macrocyclic diethers can also contain internal cyclopentane rings. The molecular structure of the novel diethers resembles that of dibiphytanyl tetraethers in which biphytane chains, containing one and two pentacyclic rings, also occur. Such tetraethers were abundant in the crust. Compound-specific isotope measurements revealed δ13C values of –104 to –111‰ for these new archaeal lipids, indicating that they are derived from methanotrophic archaea acting within anaerobic methane-oxidizing consortia, which subsequently induce authigenic carbonate formation. PMID:15803662

  20. 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.

  1. Determining the stress field in active volcanoes using focal mechanisms

    NASA Astrophysics Data System (ADS)

    Massa, Bruno; D'Auria, Luca; Cristiano, Elena; De Matteo, Ada

    2016-11-01

    Stress inversion of seismological datasets became an essential tool to retrieve the stress field of active tectonics and volcanic areas. In particular, in volcanic areas, it is able to put constrains on volcano-tectonics and in general in a better understanding of the volcano dynamics. During the last decades, a wide range of stress inversion techniques has been proposed, some of them specifically conceived to manage seismological datasets. A modern technique of stress inversion, the BRTM, has been applied to seismological datasets available at three different regions of active volcanism: Mt. Somma-Vesuvius (197 Fault Plane Solutions, FPSs), Campi Flegrei (217 FPSs) and Long Valley Caldera (38,000 FPSs). The key role of stress inversion techniques in the analysis of the volcano dynamics has been critically discussed. A particular emphasis was devoted to performances of the BRTM applied to volcanic areas.

  2. 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.

  3. 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.

  4. On the carcinogenic polycyclic aromatic hydrocarbon benzo(a)pyrene in volcano exhausts.

    PubMed

    Ilnitsky, A P; Belitsky, G A; Shabad, L M

    1976-05-01

    The content of benzo(a)pyrene in the juvenile ashes of the volcano Tyatya (Kunashir Island, Kuriles) and in the soil, vegetation and volcanic mud collected near volcanos in Kamchatka was studied. It was concluded that volcanic activity does not play a large role in forming the background level of this carcinogen in the human environment.

  5. 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, C. 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.

  6. Seismic Activity at Vailulu'u, Samoa's Youngest Volcano

    NASA Astrophysics Data System (ADS)

    Konter, J.; Staudigel, H.; Hart, S.

    2002-12-01

    Submarine volcanic systems, as a product of the Earth's mantle, play an essential role in the Earth's heat budget and in the interaction between the solid Earth and the hydrosphere and biosphere. Their eruptive and intrusive activity exerts an important control on these hydrothermal systems. In March 2000, we deployed an array of five ocean bottom hydrophones (OBH) on the summit region (625-995 m water depth) of Vailulu'u Volcano (14°12.9'S;169°03.5'W); this volcano represents the active end of the Samoan hotspot chain and is one of only a few well-studied intra-plate submarine volcanoes. We monitored seismic activity for up to 12 months at low sample rate (25 Hz), and for shorter times at a higher sample rate (125 Hz). We have begun to catalogue and locate a variety of acoustic events from this network. Ambient ocean noise was filtered out by a 4th-order Butterworth bandpass filter (2.3 - 10 Hz). We distinguish small local earthquakes from teleseismic activity, mostly identified by T- (acoustic) waves, by comparison with a nearby GSN station (AFI). Most of the detected events are T-phases from teleseismic earthquakes, characterized by their emergent coda and high frequency content (up to 30 Hz); the latter distinguishes them from low frequency emergent signals associated with the volcano (e.g. tremor). A second type of event is characterized by impulsive arrivals, with coda lasting a few seconds. The differences in arrival times between stations on the volcano are too small for these events to be T-waves; they are very likely to be local events, since the GSN station in Western Samoa (AFI) shows no arrivals close in time to these events. Preliminary locations show that these small events occur approximately once per day and are located within the volcano (the 95% confidence ellipse is similar to the size of the volcano, due to the small size of the OBH network). Several events are located relatively close to each other (within a km radius) just NW of the crater.

  7. Seismicity characteristics of a potentially active Quaternary volcano: The Tatun Volcano Group, northern Taiwan

    NASA Astrophysics Data System (ADS)

    Konstantinou, Konstantinos I.; Lin, Cheng-Horng; Liang, Wen-Tzong

    2007-02-01

    The Tatun Volcano Group (TVG) is located at the northern tip of Taiwan, near the capital Taipei and close to two nuclear power plants. Because of lack of any activity in historical times it has been classified as an extinct volcano, even though more recent studies suggest that TVG might have been active during the last 20 ka. In May 2003 a seismic monitoring project at the TVG area was initiated by deploying eight three-component seismic stations some of them equipped with both short-period and broadband sensors. During the 18 months observation period local seismicity mainly consisted of high frequency earthquakes either occurring as isolated events, or as a continuous sequence in the form of spasmodic bursts. Mixed and low frequency events were also present during the same period, even though they occurred only rarely. Arrival times from events with clear P-/S-wave phases were inverted in order to obtain a minimum 1D velocity model with station corrections. Probabilistic nonlinear earthquake locations were calculated for all these events using the newly derived velocity model. Most high frequency seismicity appeared to be concentrated near the areas of hydrothermal activity, forming tight clusters at depths shallower than 4 km. Relative locations, calculated using the double-difference method and utilising catalogue and cross-correlation differential traveltimes, showed insignificant differences when compared to the nonlinear probabilistic locations. In general, seismicity in the TVG area seems to be primarily driven by circulation of hydrothermal fluids as indicated by the occurrence of spasmodic bursts, mixed/low frequency events and a b-value (1.17 ± 0.1) higher than in any other part of Taiwan. These observations, that are similar to those reported in other dormant Quaternary volcanoes, indicate that a magma chamber may still exist beneath TVG and that a future eruption or period of unrest should not be considered unlikely.

  8. 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

    The GlobVolcano project (2007-2010) is part of the Data User Element programme of the European Space Agency (ESA). The project aims at demonstrating Earth Observation (EO) based integrated services to support the Volcano Observatories and other mandate users (e.g. Civil Protection) in their monitoring activities. 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. In a first phase, a complete information system has been designed, implemented and validated, involving a limited number of test areas and respective user organizations. In the currently on-going second phase, GlobVolcano is delivering pre-operational services over 15 volcanic sites located in three continents and as many user organizations are involved and cooperating with the project team. The set of GlobVolcano offered EO based information products is composed as follows: Deformation Mapping DInSAR (Differential Synthetic Aperture Radar Interferometry) has been used to study a wide range of surface displacements related to different phenomena (e.g. seismic faults, volcanoes, landslides) at a spatial resolution of less than 100 m and cm-level precision. Permanent Scatterers SAR Interferometry method (PSInSARTM) has been introduced by Politecnico of Milano as an advanced InSAR technique capable of measuring millimetre scale displacements of individual radar targets on the ground by using multi-temporal data-sets, estimating and removing the atmospheric components. Other techniques (e.g. CTM) have followed similar strategies and have shown promising results in different scenarios. Different processing approaches have been adopted, according to data availability, characteristic of the area and dynamic characteristics of the volcano. Conventional DInSAR: Colima (Mexico), Nyiragongo (Congo), Pico (Azores), Areanal (Costa Rica) PSInSARTM: Piton de la Fournaise (La Reunion Island

  9. Isotopic evidence ( 87Sr/ 86Sr, δ 7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Scholz, Florian; Hensen, Christian; Reitz, Anja; Romer, Rolf L.; Liebetrau, Volker; Meixner, Anette; Weise, Stephan M.; Haeckel, Matthias

    2009-09-01

    The chemical and isotopic composition of pore fluids is presented for five deep-rooted mud volcanoes aligned on a transect across the Gulf of Cadiz continental margin at water depths between 350 and 3860 m. Generally decreasing interstitial Li concentrations and 87Sr/ 86Sr ratios with increasing distance from shore are attributed to systematically changing fluid sources across the continental margin. Although highest Li concentrations at the near-shore mud volcanoes coincide with high salinities derived from dissolution of halite and late-stage evaporites, clayey, terrigenous sediments are identified as the ultimate Li source to all pore fluids investigated. Light δ 7Li values, partly close to those of hydrothermal vent fluids (δ 7Li: +11.9‰), indicate that Li has been mobilized during high-temperature fluid/sediment or fluid/rock interactions in the deep sub-surface. Intense leaching of terrigenous clay has led to radiogenic 87Sr/ 86Sr ratios (˜0.7106) in pore fluids of the near-shore mud volcanoes. In contrast, non-radiogenic 87Sr/ 86Sr ratios (˜0.7075) at the distal locations are attributed to admixing of a basement-derived fluid component, carrying an isotopic signature from interaction with the basaltic crust. This inference is substantiated by temperature constraints from Li isotope equilibrium calculations suggesting exchange processes at particularly high temperatures (>200 °C) for the least radiogenic pore fluids of the most distal location. Advective pore fluids in the off-shore reaches of the Gulf of Cadiz are influenced by successive exchange processes with both oceanic crust and terrigenous, fine-grained sediments, resulting in a chemical and isotopic signature similar to that of fluids in near-shore ridge flank hydrothermal systems. This suggests that deep-rooted mud volcanoes in the Gulf of Cadiz represent a fluid pathway intermediate between mid-ocean ridge hydrothermal vent and shallow, marginal cold seep. Due to the thicker sediment

  10. An active dealkalization of red mud with roasting and water leaching.

    PubMed

    Zhu, Xiaobo; Li, Wang; Guan, Xuemao

    2015-04-09

    The research has focused on the dealkalization of red mud after active roasting and water leaching, which is obtained from bauxite during alumina production. The main factors such as roasting temperature, roasting time, water leaching stage, leaching temperature, leaching reaction time and liquid to solid ratio were investigated. The mechanism of dealkalization was in-depth studied by using ICP-AES, XRD, TG-DSC, SEM-EDS and leaching kinetic. The results show that the dealkalization rate reached 82% under the condition of roasting temperature of 700 °C, roasting time of 30 min, four stage water leaching, liquid to solid ratio of 7 mL/g, leaching temperature of 90 °C and reaction time of 60 min. The diffraction peak of Na6CaAl6Si6(CO3)O24 · 2H2O in red mud was decreased during the active roasting process, whereas the mineral phases of NaOH · H2O and Na2Ca(CO3)2 were appeared. The content of alkali obviously decreased and the grade of other elements increased during the process of active roasting and water leaching, which was in favor of next application process of red mud. The water leaching was controlled by internal diffusion of SCM and the apparent activation energy was 22.63 kJ/mol.

  11. 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.

  12. Continuous gravity observations at active volcanoes through superconducting gravimeters

    NASA Astrophysics Data System (ADS)

    Carbone, Daniele; Greco, Filippo

    2016-04-01

    Continuous gravity measurements at active volcanoes are usually taken through spring gravimeters that are easily portable and do not require much power to work. However, intrinsic limitations dictate that, when used in continuous, these instruments do not provide high-quality data over periods longer than some days. Superconducting gravimeters (SG), that feature a superconducting sphere in a magnetic field as the proof mass, provide better-quality data than spring gravimeters, but are bigger and need mains electricity to work, implying that they cannot be installed close to the active structures of high volcanoes. An iGrav SG was installed on Mt. Etna (Italy) in September 2014 and has worked almost continuously since then. It was installed about 6km from the active craters in the summit zone of the volcano. Such distance is normally too much to observe gravity changes due to relatively fast (minutes to days) volcanic processes. Indeed, mass redistributions in the shallowest part of the plumbing system induce short-wavelength gravity anomalies, centered below the summit craters. Nevertheless, thanks to the high precision and long-term stability of SGs, it was possible to observe low-amplitude changes over a wide range of timescales (minutes to months), likely driven by volcanic activity. Plans are in place for the implementation of a mini-array of SGs at Etna.

  13. Deep structure and origin of active volcanoes in China

    NASA Astrophysics Data System (ADS)

    Zhao, D.

    2010-12-01

    Recent geophysical studies have provided important constraints on the deep structure and origin of the active intraplate volcanoes in Mainland China. Magmatism in the western Pacific arc and back-arc areas is caused by the corner flow in the mantle wedge and dehydration of the subducting slab (e.g., Zhao et al., 2009a), while the intraplate magmatism in China has different origins. The active volcanoes in Northeast China (such as the Changbai and Wudalianchi) are caused by hot upwelling in the big mantle wedge (BMW) above the stagnant slab in the mantle transition zone and deep slab dehydration as well (Zhao et al., 2009b). The Tengchong volcano in Southwest China is caused by a similar process in the BMW above the subducting Burma microplate (or Indian plate) (Lei et al., 2009a). The Hainan volcano in southernmost China is a hotspot fed by a lower-mantle plume which may be associated with the Pacific and Philippine Sea slabs' deep subduction in the east and Indian slab's deep subduction in the west down to the lower mantle (Lei et al., 2009b; Zhao, 2009). The stagnant slab finally collapses down to the bottom of the mantle, which can trigger the upwelling of hot mantle materials from the lower mantle to the shallow mantle beneath the subducting slabs and may cause the slab-plume interactions (Zhao, 2009). References Lei, J., D. Zhao, Y. Su, 2009a. Insight into the origin of the Tengchong intraplate volcano and seismotectonics in southwest China from local and teleseismic data. J. Geophys. Res. 114, B05302. Lei, J., D. Zhao, B. Steinberger et al., 2009b. New seismic constraints on the upper mantle structure of the Hainan plume. Phys. Earth Planet. Inter. 173, 33-50. Zhao, D., 2009. Multiscale seismic tomography and mantle dynamics. Gondwana Res. 15, 297-323. Zhao, D., Z. Wang, N. Umino, A. Hasegawa, 2009a. Mapping the mantle wedge and interplate thrust zone of the northeast Japan arc. Tectonophysics 467, 89-106. Zhao, D., Y. Tian, J. Lei, L. Liu, 2009b. Seismic

  14. 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

  15. 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.

  16. Kizimen Volcano, Kamchatka, Russia: 2010-2012 Eruptive Activity

    NASA Astrophysics Data System (ADS)

    Gordeev, E.; Droznin, V.; Malik, N.; Muravyev, Y.

    2012-12-01

    New eruptive activity at Kizimen Volcano began in October 2010 after 1.5 years of seismic build up. Two vents located at the summit of the volcano had been producing occasional steam-and-gas emissions with traces of ash until early December. Kizimen is located at a junction between Shapensky graben in the Central Kamchatka Depression and a horst of Tumrok Ridge. Kizimen is a 2376 m a.s.l. complex stratovolcano. The only single eruption reported in historic time occurred from December 1928 to January 1929. Little is known about the volcano; explosive activity was preceded by strong local earthquakes, and ashfalls were reported in neighboring settlements. During the period between eruptions the volcano was producing constant fumarolic activity, reported since 1825. During the cause of the current (2010-2012) eruption, the volcano produced several eruptive phases: moderate explosive activity was observed from December 10, 2010 to late February 2011 (ashfalls and descend of pyroclastic flows resulted in a large lahar traveling along the valley of the Poperechny Creek on December 13, 2010); from late February to mid-December the volcano produced an explosive-effusive phase (the lava flow descended eastern flank, while explosive activity has decreased), which resulted in strong explosions on December 14, 2011 accompanied by scores of pyroclastic flows of various thickness to the NE foot on the volcano. Since then, a constant growth of the large lava flow has been accompanied by strong steam-and-gas emissions from the summit crater. The erupted materials are tephra and deposits of pyroclastic and lava flows consisted of high-aluminous andesites and dacites of potassium-sodium series: SiO2 content varied from 61% in December 2010 to 65-68% in January-February 2011, and up to 62% in December 2011. Ashfalls area exceeded 100 km2 (the weight of erupted tephra > 107 tons), while the total area of pyroclastic flows was estimated to be 15.5 km2 (V= 0.16 km3). Until late May 2012

  17. Underwater observations of active lava flows from Kilauea volcano, Hawaii

    USGS Publications Warehouse

    Tribble, G.W.

    1991-01-01

    Underwater observation of active submarine lava flows from Kilauea volcano, Hawaii, in March-June 1989 revealed both pillow lava and highly channelized lava streams flowing down a steep and unconsolidated lava delta. The channelized streams were 0.7-1.5 m across and moved at rates of 1-3 m/s. The estimated flux of a stream was 0.7 m3/s. Jets of hydrothermal water and gas bubbles were associated with the volcanic activity. The rapidly moving channelized lava streams represent a previously undescribed aspect of submarine volcanism. -Author

  18. Study of Seismic Activity at Ceboruco Volcano, Mexico

    NASA Astrophysics Data System (ADS)

    Nunez-Cornu, F. J.; Escudero, C. R.; Rodríguez Ayala, N. A.; Suarez-Plascencia, C.

    2013-12-01

    Many societies and their economies endure the disastrous consequences of destructive volcanic eruptions. The Ceboruco stratovolcano (2,280 m.a.s.l.) is located in Nayarit, Mexico, at the west of the Mexican volcanic belt and towards the Sierra de San Pedro southeast, which is a key communication point for coast of Jalisco and Nayarit and the northwest of Mexico. It last eruptive activity was in 1875, and during the following five years it presents superficial activity such as vapor emissions, ash falls and riodacitic composition lava flows along the southeast side. Although surface activity has been restricted to fumaroles near the summit, Ceboruco exhibits regular seismic unrest characterized by both low frequency seismic events and volcano-tectonic earthquakes. From March 2003 until July 2008 a three-component short-period seismograph Marslite station with a Lennartz 3D (1Hz) was deployed in the south flank (CEBN) and within 2 km from the summit to monitoring the seismic activity at the volcano. The LF seismicity recorded was classified using waveform characteristics and digital analysis. We obtained four groups: impulsive arrivals, extended coda, bobbin form, and wave package amplitude modulation earthquakes. The extended coda is the group with more earthquakes and present durations of 50 seconds. Using the moving particle technique, we read the P and S wave arrival times and estimate azimuth arrivals. A P-wave velocity of 3.0 km/s was used to locate the earthquakes, most of the hypocenters are below the volcanic edifice within a circular perimeter of 5 km of radius and its depths are calculated relative to the CEBN elevation as follows. The impulsive arrivals earthquakes present hypocenters between 0 and 1 km while the other groups between 0 and 4 km. Results suggest fluid activity inside the volcanic building that could be related to fumes on the volcano. We conclude that the Ceboruco volcano is active. Therefore, it should be continuously monitored due to the

  19. 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.

  20. 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

  1. Mud Volcanism in the South East Caspian, Gorgon Plane, Iran

    NASA Astrophysics Data System (ADS)

    Mazzini, A.; Poludetkina, E. N.; Mehrabi, B.; Krueger, M.; Inguaggiato, S.; Etiope, G.

    2014-12-01

    Although numerous studies have been completed on the Western Caspian side (e.g. mainly Azerbaijan), very little is known about the hydrocarbon plumbing system of the deepest and southernmost basin. This region has great potentials for hydrocarbon exploration and the study of mud volcanoes located here represents the opportunity to access to an open window to better understand the stratigraphy and the mechanisms ongoing at great depth as well as the origin and signature of the seeping fluids. Three so far unexplored mud volcano structures (Sofikam, Gharniarigh, and Naftliche) have been mapped and sampled in the Golestan region in the south eastern Caspian Sea. All the structures have negative morphology (i.e. "pockmark like") with caldera collapse. A multidisciplinary workflow of analyses is being conducted including gas and water geochemistry, incubation of microbial colonies, petrography of the seeping mud and erupted mud breccia clasts. Sofikam consists of 5 distinct pools up to 4-5 m in diameter that forms an E-W oriented alignment. All of the pools display vigorous seepage of fluids and are either water- or denser mud-dominated. Gharniarigh is a large mud volcano up to ~600 m in diameter with a bulging island in the internal part of the crater where eroded gryphons ridges witness a palaeo vigorous activity. The outskirts of the "island" are almost entirely flooded with water and/or covered with salt crusts in the summer. Here are distributed several small water and gas seeps. Naftliche (~400 m wide) is filled with water with a main seep in the centre of the lake. Preliminary gas geochemistry indicates the seepage of methane-dominated gas in all structures with additional small portions of ethane and propane as well as iC4 in Gharniarigh and Naftliche. All samples collected for microbial colonies incubation reveal strong activity with CO2 production under aerobic and anaerobic conditions as well as production of biogenic methane. In particular, samples from

  2. 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.

  3. International Global Atmospheric Chemistry Programme global emissions inventory activity: Sulfur emissions from volcanoes, current status

    SciTech Connect

    Benkovitz, C.M.

    1995-07-01

    Sulfur emissions from volcanoes are located in areas of volcanic activity, are extremely variable in time, and can be released anywhere from ground level to the stratosphere. Previous estimates of global sulfur emissions from all sources by various authors have included estimates for emissions from volcanic activity. In general, these global estimates of sulfur emissions from volcanoes are given as global totals for an ``average`` year. A project has been initiated at Brookhaven National Laboratory to compile inventories of sulfur emissions from volcanoes. In order to complement the GEIA inventories of anthropogenic sulfur emissions, which represent conditions circa specific years, sulfur emissions from volcanoes are being estimated for the years 1985 and 1990.

  4. 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.

  5. Evidence of the activity of dissimilatory sulfate-reducing prokaryotes in nonsulfidogenic tropical mobile muds.

    PubMed

    Madrid, Vanessa M; Aller, Robert C; Aller, Josephine Y; Chistoserdov, Andrei Y

    2006-08-01

    In spite of the nonsulfidic conditions and abundant reactive iron(III) commonly found in mobile tropical deltaic muds, genes encoding dissimilatory sulfite reductase (dsr) were successfully amplified from the upper approximately 1 m of coastal deposits sampled along French Guiana and in the Gulf of Papua. The dsr sequences retrieved were highly diverse, were generally represented in both study regions and fell into six large phylogenetic groupings: Deltaproteobacteria, Thermodesulfovibrio groups, Firmicutes and three groups without known cultured representatives. The spatial and temporal distribution of dsr sequences strongly supports the contention that the sulfate-reducing prokaryote communities in mobile mud environments are cosmopolitan and stable over a period of years. The decrease in the (35)SO(4) (2-) tracer demonstrates that, despite abundant reactive sedimentary iron(III) ( approximately 350-400 mumol g(-1)), the sulfate-reducing prokaryotes present are active, with the highest levels of sulfide being generated in the upper zones of the cores (0-30 cm). Both the time course of the (35)S-sulfide tracer activity and the lack of reduced sulfur in sediments demonstrate virtually complete anaerobic loss of solid phase sulfides. We propose a pathway of organic matter oxidation involving at least 5-25% of the remineralized carbon, wherein sulfide produced by sulfate-reducing prokaryotes is cyclically oxidized biotically or abiotically by metal oxides.

  6. Quantitative measurements of active Ionian volcanoes in Galileo NIMS data

    NASA Astrophysics Data System (ADS)

    Saballett, Sebastian; Rathbun, Julie A.; Lopes, Rosaly M. C.; Spencer, John R.

    2016-10-01

    Io is the most volcanically active body in our solar system. The spatial distribution of volcanoes a planetary body's surface gives clues into its basic inner workings (i.e., plate tectonics on earth). Tidal heating is the major contributor to active surface geology in the outer solar system, and yet its mechanism is not completely understood. Io's volcanoes are the clearest signature of tidal heating and measurements of the total heat output and how it varies in space and time are useful constraints on tidal heating. Hamilton et al. (2013) showed through a nearest neighbor analysis that Io's hotspots are globally random, but regionally uniform near the equator. Lopes-Gautier et al. (1999) compared the locations of hotspots detected by NIMS to the spatial variation of heat flow predicted by two end-member tidal heating models. They found that the distribution of hotspots is more consistent with tidal heating occurring in asthenosphere rather than the mantle. Hamilton et al. (2013) demonstrate that clustering of hotspots also supports a dominant role for asthenosphere heating. These studies were unable to account for the relative brightness of the hotspots. Furthermore, studies of the temporal variability of Ionian volcanoes have yielded substantial insight into their nature. The Galileo Near Infrared Mapping Spectrometer (NIMS) gave us a large dataset from which to observe active volcanic activity. NIMS made well over 100 observations of Io over an approximately 10-year time frame. With wavelengths spanning from 0.7 to 5.2 microns, it is ideally suited to measure blackbody radiation from surfaces with temperatures over 300 K. Here, we report on our effort to determine the activity level of each hotspot observed in the NIMS data. We decide to use 3.5 micron brightness as a proxy for activity level because it will be easy to compare to, and incorporate, ground-based observations. We fit a 1-temperature blackbody to spectra in each grating position and averaged the

  7. 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.

  8. 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).

  9. Linking subsurface to surface degassing at active volcanoes: A thermodynamic model with applications to Erebus volcano

    NASA Astrophysics Data System (ADS)

    Iacovino, Kayla

    2015-12-01

    Volcanic plumbing systems are the pathways through which volatiles are exchanged between the deep Earth and the atmosphere. The interplay of a multitude of processes occurring at various depths in the system dictates the composition and quantity of gas eventually erupted through volcanic vents. Here, a model is presented as a framework for interpreting surface volcanic gas measurements in terms of subsurface degassing processes occurring throughout a volcanic plumbing system. The model considers all possible sources of fluid from multiple depths, including degassing of dissolved volatiles during crystallization and/or decompression as recorded in melt inclusions plus any co-existing fluid phase present in a magma reservoir. The former is achieved by differencing melt inclusion volatile contents between groups of melt inclusions saturated at discrete depths. The latter is calculated using a thermodynamic model, which computes the composition of a C-O-H-S fluid in equilibrium with a melt given a minimum of five thermodynamic parameters commonly known for natural systems (T, P, fO2, either fH2 or one parameter for H2O, and either fS2 or one parameter for CO2). The calculated fluids are thermodynamically decompressed and run through a mixing model, which finds all possible mixtures of subsurface fluid that match the chemistry of surface gas within ±2.0 mol%. The method is applied to Mount Erebus (Antarctica), an active, intraplate volcano whose gas emissions, which emanate from an active phonolitic lava lake, have been well quantified by FTIR, UV spectroscopy, and multi-gas sensors over the last several decades. In addition, a well-characterized suite of lavas and melt inclusions, and petrological interpretations thereof, represent a wealth of knowledge about the shallow, intermediate, and deep parts of the Erebus plumbing system. The model has been used to calculate the compositions of seven C-O-H-S fluids that originate from four distinct regions within the Erebus

  10. Ground-based observations of time variability in multiple active volcanoes on Io

    NASA Astrophysics Data System (ADS)

    Rathbun, Julie A.; Spencer, John R.

    2010-10-01

    Since before the beginning of the Galileo spacecraft's Jupiter orbital tour, we have observed Io from the ground using NASA's Infrared Telescope Facility (IRTF). We obtained images of Io in reflected sunlight and in-eclipse at 2.3, 3.5, and 4.8 μm. In addition, we have measured the 3.5 μm brightness of an eclipsed Io as it is occulted by Jupiter. These lightcurves enable us to measure the brightness and one-dimensional location of active volcanoes on the surface. During the Galileo era, two volcanoes were observed to be regularly active: Loki and either Kanehekili and/or Janus. At least 12 other active volcanoes were observed for shorter periods of time, including one distinguishable in images that include reflected sunlight. These data can be used to compare volcano types and test volcano eruption models, such as the lava lake model for Loki.

  11. Shallow S wave attenuation and actively degassing magma beneath Taal Volcano, Philippines

    NASA Astrophysics Data System (ADS)

    Kumagai, Hiroyuki; Lacson, Rudy; Maeda, Yuta; Figueroa, Melquiades S.; Yamashina, Tadashi

    2014-10-01

    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 real-time broadband seismic network was recently deployed and has detected volcano-tectonic events beneath Taal. Our source location analysis of these volcano-tectonic events, using onset arrival times and high-frequency seismic amplitudes, points to the existence of a region of strong attenuation near the ground surface beneath the east flank of Volcano Island in Taal Lake. 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. These features strongly suggest that the high-attenuation region represents an actively degassing magma body near the surface that has existed for more than 20 years.

  12. The recent seismo-volcanic activity at Deception Island volcano

    NASA Astrophysics Data System (ADS)

    Ibáñez, Jesús M.; Almendros, Javier; Carmona, Enrique; Martínez-Arévalo, Carmen; Abril, Miguel

    2003-06-01

    This paper reviews the recent seismic studies carried out at Deception Island, South Shetland Islands, Antarctica, which was monitored by the Argentinean and Spanish Antarctic Programs since 1986. Several types of seismic network have been deployed temporarily during each Antarctic summer. These networks have consisted of a variety of instruments, including radio-telemetered stations, autonomous digital seismic stations, broadband seismometers, and seismic arrays. We have identified two main types of seismic signals generated by the volcano, namely pure seismo-volcanic signals, such as volcanic tremor and long-period (LP) events, and volcano-tectonic (VT) earthquakes. Their temporal distributions are far from homogeneous. Volcanic tremors and LP events usually occur in seismic swarms lasting from a few hours to some days. The number of LP events in these swarms is highly variable, from a background level of less than 30/day to a peak activity of about 100 events/h. The occurrence of VT earthquakes is even more irregular. Most VT earthquakes at Deception Island have been recorded during two intense seismic crises, in 1992 and 1999, respectively. Some of these VT earthquakes were large enough to be felt by researchers working on the island. Analyses of both types of seismic events have allowed us to derive source locations, establish seismic source models, analyze seismic attenuation, calculate the energy and stress drop of the seismic sources, and relate the occurrence of seismicity to the volcanic activity. Pure seismo-volcanic signals are modelled as the consequence of hydrothermal interactions between a shallow aquifer and deeper hot materials, resulting in the resonance of fluid-filled fractures. VT earthquakes constitute the brittle response to changes in the distribution of stress in the volcanic edifice. The two VT seismic series are probably related to uplift episodes due to deep injections of magma that did not reach the surface. This evidence, however

  13. Evolution of Deformation Studies on Active Hawaiian Volcanoes

    USGS Publications Warehouse

    Decker, Robert; 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

  14. Recent Seismic and Geodetic Activity at Multiple Volcanoes in the Ecuadorean Andes

    NASA Astrophysics Data System (ADS)

    Hernandez, S.; Ruiz, M. C.; McCausland, W. A.; Prejean, S. G.; Mothes, P. A.; Bell, A. F.; Hidalgo, S.; Barrington, C.; Yepez, M.; Aguaiza, S.; Plain, M.

    2015-12-01

    The state of volcanic activity often fluctuates between periods of repose and unrest. The transition time between a period of repose and unrest, or vice versa for an open system, can occur within a matter of hours or days. Because of this short time scale, real-time seismic and geodetic (e.g. tiltmeter, GPS) monitoring networks are crucial for characterizing the state of activity of a volcano. In the Ecuadorean Andes, 5 volcanoes demonstrate long-term (Tungurahua, Reventador, and Guagua Pichincha) or recently reactivated (Cotopaxi, Chiles-Cerro Negro) seismic and geodetic activity. The Instituto Geofisico regularly characterizes volcano seismicity into long period, very long period, volcano-tectonic, and tremor events. Significant recent changes at these volcanoes include: rigorous reactivation of glacier-capped Cotopaxi, drumbeat seismicity absent a dome extrusion at Tungurahua, and regularly reoccurring (~7 day recurrence interval), shallow seismic swarms at Guagua Pichincha. These volcanoes locate along both the Western and Eastern Cordillera of the Ecuadorean Andes and, where data are available, manifest important variations in chemical composition, daily gas flux, and surficial deformation. We summarize the long-term geophysical parameters measured at each volcano and place recent changes in each parameter in a larger magmatic and hydrothermal context. All of the studied volcanoes present significant societal hazards to local and regional communities.

  15. Sangay volcano, Ecuador: structural development, present activity and petrology

    NASA Astrophysics Data System (ADS)

    Monzier, Michel; Robin, Claude; Samaniego, Pablo; Hall, Minard L.; Cotten, Jo; Mothes, Patricia; Arnaud, Nicolas

    1999-05-01

    Sangay (5230 m), the southernmost active volcano of the Andean Northern Volcanic Zone (NVZ), sits ˜130 km above a >32-Ma-old slab, close to a major tear that separates two distinct subducting oceanic crusts. Southwards, Quaternary volcanism is absent along a 1600-km-long segment of the Andes. Three successive edifices of decreasing volume have formed the Sangay volcanic complex during the last 500 ka. Two former cones (Sangay I and II) have been largely destroyed by sector collapses that resulted in large debris avalanches that flowed out upon the Amazon plain. Sangay III, being constructed within the last avalanche amphitheater, has been active at least since 14 ka BP. Only the largest eruptions with unusually high Plinian columns are likely to represent a major hazard for the inhabited areas located 30 to 100 km west of the volcano. However, given the volcano's relief and unbuttressed eastern side, a future collapse must be considered, that would seriously affect an area of present-day colonization in the Amazon plain, ˜30 km east of the summit. Andesites greatly predominate at Sangay, there being few dacites and basalts. In order to explain the unusual characteristics of the Sangay suite—highest content of incompatible elements (except Y and HREE) of any NVZ suite, low Y and HREE values in the andesites and dacites, and high Nb/La of the only basalt found—a preliminary five-step model is proposed: (1) an enriched mantle (in comparison with an MORB source), or maybe a variably enriched mantle, at the site of the Sangay, prior to Quaternary volcanism; (2) metasomatism of this mantle by important volumes of slab-derived fluids enriched in soluble incompatible elements, due to the subduction of major oceanic fracture zones; (3) partial melting of this metasomatized mantle and generation of primitive basaltic melts with Nb/La values typical of the NVZ, which are parental to the entire Sangay suite but apparently never reach the surface and subordinate

  16. 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.

  17. Identifying hazard parameter to develop quantitative and dynamic hazard map of an active volcano in Indonesia

    NASA Astrophysics Data System (ADS)

    Suminar, Wulan; Saepuloh, Asep; Meilano, Irwan

    2016-05-01

    Analysis of hazard assessment to active volcanoes is crucial for risk management. The hazard map of volcano provides information to decision makers and communities before, during, and after volcanic crisis. The rapid and accurate hazard assessment, especially to an active volcano is necessary to be developed for better mitigation on the time of volcanic crises in Indonesia. In this paper, we identified the hazard parameters to develop quantitative and dynamic hazard map of an active volcano. The Guntur volcano in Garut Region, West Java, Indonesia was selected as study area due population are resided adjacent to active volcanoes. The development of infrastructures, especially related to tourism at the eastern flank from the Summit, are growing rapidly. The remote sensing and field investigation approaches were used to obtain hazard parameters spatially. We developed a quantitative and dynamic algorithm to map spatially hazard potential of volcano based on index overlay technique. There were identified five volcano hazard parameters based on Landsat 8 and ASTER imageries: volcanic products including pyroclastic fallout, pyroclastic flows, lava and lahar, slope topography, surface brightness temperature, and vegetation density. Following this proposed technique, the hazard parameters were extracted, indexed, and calculated to produce spatial hazard values at and around Guntur Volcano. Based on this method, the hazard potential of low vegetation density is higher than high vegetation density. Furthermore, the slope topography, surface brightness temperature, and fragmental volcanic product such as pyroclastics influenced to the spatial hazard value significantly. Further study to this proposed approach will be aimed for effective and efficient analyses of volcano risk assessment.

  18. 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

  19. 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.

  20. 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

  1. Late-stage summit activity of Martian shield volcanoes

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, P. J.

    1982-01-01

    The preservation of morphologically fresh lava flows which pre-date the most recent episodes of caldera collapse at the summits of Ascraeus, Arsia and Olympus Montes indicates that explosive eruptions were not associated with this stage of Tharsis shield volcanism. The existence of resurfaced floor segments, complex wrinkle ridges, and lava terraces within the summit craters suggests that lava lakes comprised the dominant form of the intra-caldera activity. Multiple collapse episodes on Ascraeus and Olympus Montes are indicated by the nested summit craters. The most plausible cause of caldera collapse appears to be large-scale sub-terminal effusive activity, which is corroborated by the previously recognized existence of large lava flows on the flanks of these volcanoes. Due to the implied sequence of large-scale explosive (silicic) volcanism followed by effusive (basaltic) activity, it appears highly unlikely that ignimbrites or other forms of pyroclastic flows (previously proposed as possible deposits within the Olympus Mons aureole material) were ever erupted from the Tharsis Montes.

  2. Virtual Investigations of an Active Deep Sea Volcano

    NASA Astrophysics Data System (ADS)

    Sautter, L.; Taylor, M. M.; Fundis, A.; Kelley, D. S.; Elend, M.

    2013-12-01

    Axial Seamount, located on the Juan de Fuca spreading ridge 300 miles off the Oregon coast, is an active volcano whose summit caldera lies 1500 m beneath the sea surface. Ongoing construction of the Regional Scale Nodes (RSN) cabled observatory by the University of Washington (funded by the NSF Ocean Observatories Initiative) has allowed for exploration of recent lava flows and active hydrothermal vents using HD video mounted on the ROVs, ROPOS and JASON II. College level oceanography/marine geology online laboratory exercises referred to as Online Concept Modules (OCMs) have been created using video and video frame-captured mosaics to promote skill development for characterizing and quantifying deep sea environments. Students proceed at their own pace through a sequence of short movies with which they (a) gain background knowledge, (b) learn skills to identify and classify features or biota within a targeted environment, (c) practice these skills, and (d) use their knowledge and skills to make interpretations regarding the environment. Part (d) serves as the necessary assessment component of the laboratory exercise. Two Axial Seamount-focused OCMs will be presented: 1) Lava Flow Characterization: Identifying a Suitable Cable Route, and 2) Assessing Hydrothermal Vent Communities: Comparisons Among Multiple Sulfide Chimneys.

  3. Shallow outgassing changes disrupt steady lava lake activity, Kilauea Volcano

    NASA Astrophysics Data System (ADS)

    Patrick, M. R.; Orr, T. R.; Swanson, D. A.; Lev, E.

    2015-12-01

    Persistent lava lakes are a testament to sustained magma supply and outgassing in basaltic systems, and the surface activity of lava lakes has been used to infer processes in the underlying magmatic system. At Kilauea Volcano, Hawai`i, the lava lake in Halema`uma`u Crater has been closely studied for several years with webcam imagery, geophysical, petrological and gas emission techniques. The lava lake in Halema`uma`u is now the second largest on Earth, and provides an unprecedented opportunity for detailed observations of lava lake outgassing processes. We observe that steady activity is characterized by continuous southward motion of the lake's surface and slow changes in lava level, seismic tremor and gas emissions. This normal, steady activity can be abruptly interrupted by the appearance of spattering - sometimes triggered by rockfalls - on the lake surface, which abruptly shifts the lake surface motion, lava level and gas emissions to a more variable, unstable regime. The lake commonly alternates between this a) normal, steady activity and b) unstable behavior several times per day. The spattering represents outgassing of shallowly accumulated gas in the lake. Therefore, although steady lava lake behavior at Halema`uma`u may be deeply driven by upwelling of magma, we argue that the sporadic interruptions to this behavior are the result of shallow processes occurring near the lake surface. These observations provide a cautionary note that some lava lake behavior is not representative of deep-seated processes. This behavior also highlights the complex and dynamic nature of lava lake activity.

  4. Reawakening of a volcano: Activity beneath Eyjafjallajökull volcano from 1991 to 2009

    NASA Astrophysics Data System (ADS)

    Hjaltadóttir, Sigurlaug; Vogfjörd, Kristín S.; Hreinsdóttir, Sigrún; Slunga, Ragnar

    2015-10-01

    The ice-capped Eyjafjallajökull volcano, south Iceland, had been dormant for 170 years when the first signs of reawakening of the volcano were captured by seismic and geodetic measurements in 1994. These were the first clear observed signs of unrest followed by 16 years of intermittent magmatic unrest culminating in 2010 when two eruptions broke out on the flank and at the summit. We analyze seismic data from 1991 through 2008 and GPS data from 1992 to May 2009 to infer magma movements beneath the volcano. The relocated earthquakes reveal an overall pipe-like pattern northeast of the summit crater, sporadically mapping the pathway of magma from the base of the crust towards an intrusion in the upper crust. During the study period, three major seismic swarms were recorded. Two of them, in 1994 and 1999-2000, occurred in the upper and intermediate crust and accompanied crustal deformation centered at the southeastern flank. No uplift was detected during the 19- to 25-km-deep 1996 swarm, near the crust-mantle boundary, but the horizontal, ~ E-W oriented T-axes indicate a period of tension/opening, suggesting magma intruding up into the base of the crust. The GPS measured deformation during 1999-2000 can be modeled as intrusion of a horizontal, circular sill with volume of 0.030 ± 0.007 km3 at 5.0 ± 1.3 km depth. The less constrained 4.5- to 5-km-deep sill model for the 1994 episode indicates a three times smaller intruded volume (0.011 km3) than during 1999-2000. In the years between/following the intrusions, contraction was observed at the southeastern flank. The contraction from 2000.5 to 2009.3 can be fitted by a circular sill model with a volume contraction of - 0.0015 ± 0.0003 km3/year at 5.5 ± 2.0 km depth. The less well constrained model for 1994.7 to 1998.6 gives a volume contraction of -(0.0009-0.0010) km3 at a fixed depth of 5 km. The accumulated volume changes (~- 0.013 km3 for the second period, ~ 0.0037 km3 for the first period) are much larger than

  5. Reventador Volcano 2005: Eruptive activity inferred from seismo-acoustic observation

    NASA Astrophysics Data System (ADS)

    Lees, Jonathan M.; Johnson, Jeffrey B.; Ruiz, Mario; Troncoso, Liliana; Welsh, Matt

    2008-09-01

    Reventador Volcano entered an eruptive phase in 2005 which included a wide variety of seismic and infrasonic activity. These are described and illustrated: volcano-tectonic, harmonic tremor, drumbeats, chugging and spasmodic tremor, long period and very long period events. The recording of this simultaneous activity on an array of three broadband, seismo-acoustic instruments provides detailed information of the state of the conduit and vent during this phase of volcanic eruption. Quasi-periodic tremor at Reventador is similar to that observed at other volcanoes and may be used as an indicator of vent aperture. Variations in the vibration modes of the volcano, frequency fluctuations and rapid temporal fluctuations suggest the influx of new material, choking of the vent and possible modification of the conduit geometry during explosions and effusion over a period of six weeks.

  6. Influence of seismicity on the Lusi mud eruption

    NASA Astrophysics Data System (ADS)

    Rudolph, Maxwell L.; Manga, Michael; Tingay, Mark; Davies, Richard J.

    2015-09-01

    Earthquakes trigger the eruption of mud and magmatic volcanoes and influence ongoing eruptive activity. One mechanism that could trigger an eruption is clay liquefaction. Here we model the propagation of seismic waves beneath the Lusi mud eruption (East Java, Indonesia) using available seismic velocity and density models to assess the effect of subsurface structure on the amplification of incident seismic waves. We find that using an updated subsurface density and velocity structure, there is no significant amplification of incident seismic energy in the Upper Kalibeng Formation, the source of the erupting solids. Hence, the hypothesis that the Lusi eruption was triggered by clay liquefaction appears unlikely to be correct. Independent constraints from gas chemistry as well as analyses of drilling activities at the nearby Banjar-Panji 1 gas exploration well and an analysis of the effects of other earthquakes all favor a drilling trigger.

  7. 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.

  8. Use of SAR data to study active volcanoes in Alaska

    USGS Publications Warehouse

    Dean, K.G.; Engle, K.; Lu, Zhiming; Eichelberger, J.; Neal, T.; Doukas, M.

    1996-01-01

    Synthetic Aperture Radar (SAR) data of Westdahl, Veniaminof, and Novarupta volcanoes in the Aleutian Arc of Alaska were analyzed 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 analyzed using data from the European Remote Sensing Satellites (ERS), Japanese Earth Resources Satellite (JERS) and the U. S. Seasat platforms. Field observations collected by scientists from the AVO were used to verify the results from the analysis of SAR data.

  9. Use of SAR data to study active volcanoes in Alaska

    USGS Publications Warehouse

    Dean, K.G.; Engle, K.; Lu, Zhiming; 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.

  10. Methanococcoides vulcani sp. nov., a marine methylotrophic methanogen that uses betaine, choline and N,N-dimethylethanolamine for methanogenesis, isolated from a mud volcano, and emended description of the genus Methanococcoides.

    PubMed

    L'Haridon, Stéphane; Chalopin, Morgane; Colombo, Delphine; Toffin, Laurent

    2014-06-01

    A novel, strictly anaerobic, methylotrophic marine methanogen, strain SLH33(T), was isolated from deep sediment samples covered by an orange microbial mat collected from the Napoli Mud Volcano. Cells of strain SLH33(T) were Gram-stain-negative, motile, irregular cocci that occurred singly. Cells utilized trimethylamine, dimethylamine, monomethylamine, methanol, betaine, N,N-dimethylethanolamine and choline (N,N,N-trimethylethanolamine) as substrates for growth and methanogenesis. The optimal growth temperature was 30 °C; maximum growth rate was obtained at pH 7.0 in the presence of 0.5 M Na(+). The DNA G+C content of strain SLH33(T) was 43.4 mol%. Phylogenetic analyses based on 16S rRNA gene sequences placed strain SLH33(T) within the genus Methanococcoides. The novel isolate was related most closely to Methanococcoides methylutens TMA-10(T) (98.8% 16S rRNA gene sequence similarity) but distantly related to Methanococcoides burtonii DSM 6242(T) (97.6%) and Methanococcoides alaskense AK-5(T) (97.6%). DNA-DNA hybridization studies indicated that strain SLH33(T) represents a novel species, given that it shared less than 16% DNA-DNA relatedness with Methanococcoides methylutens TMA-10(T). The name Methanococcoides vulcani sp. nov. is proposed for this novel species, with strain SLH33(T) ( = DSM 26966(T) = JCM 19278(T)) as the type strain. An emended description of the genus Methanococcoides is also proposed.

  11. Geochemical and microbiological characteristics of sediments near the Malenky mud volcano (Lake Baikal, Russia), with evidence of Archaea intermediate between the marine anaerobic methanotrophs ANME-2 and ANME-3

    NASA Astrophysics Data System (ADS)

    Zemskaya, Tamara I.; Pogodaeva, Tatiayna V.; Shubenkova, Olga V.; Сhernitsina, Svetlana M.; Dagurova, Olga P.; Buryukhaev, Savelii P.; Namsaraev, Bair B.; Khlystov, Oleg M.; Egorov, Aleksandr V.; Krylov, Aleksei A.; Kalmychkov, Gennadii V.

    2010-06-01

    Detailed lithological, biogeochemical and molecular biological analyses of core sediments collected in 2002-2006 from the vicinity of the Malenky mud volcano, Lake Baikal, reveal considerable spatial variations in pore water chemical composition, with total concentrations of dissolved salts varying from 0.1 to 1.8‰. Values of methane δ13С in the sediments suggest a biogenic origin (δ13Сmin. -61.3‰, δ13Сmax. -72.9‰). Rates of sulphate reduction varied from 0.001 to 0.7 nmol cm-3 day-1, of autotrophic methanogenesis from 0.01 to 2.98 nmol CH4 cm-3 day-1, and of anaerobic oxidation of methane from 0 to 12.3 nmol cm-3 day-1. These results indicate that methanogenic processes dominate in gas hydrate-bearing sediments of Lake Baikal. Based on clone libraries of 16S rRNA genes amplified with Bacteria- and Archaea-specific primers, investigation of microbial diversity in gas hydrate-bearing sediments revealed bacterial 16S rRNA clones classified as Deltaproteobacteria, Gammaproteobacteria, Chloroflexi and OP11. Archaeal clone sequences are related to the Crenarchaeota and Euryarchaeota. Baikal sequences of Archaea form a distinct cluster occupying an intermediate position between the marine groups ANME-2 and ANME-3 of anaerobic methanotrophs.

  12. Characterization of the circulating hemocytes in mud crab (Scylla olivacea) revealed phenoloxidase activity.

    PubMed

    Mangkalanan, Seksan; Sanguanrat, Piyachat; Utairangsri, Tanatchaporn; Sritunyalucksana, Kallaya; Krittanai, Chartchai

    2014-05-01

    This study focused on an isolation and characterization of the circulating hemocytes in mud crab, Scylla olivacea. Isolation of specific cell types of hemocytes from crab hemolymph was accomplished by using 60% Percoll density gradient centrifugation. Four separated bands of the hemocytes were successfully obtained. Characterization of these isolated hemocytes by light microscope using trypan blue-rose bengal staining, rose bengal-hematoxilin staining, and phase contrast revealed four distinct types of hemocyte cells. Using their specific morphology and granularity, they were identified as hyaline cell (HC), small granular cell (SGC), large granular cell (LGC) and mixed granular cell (MGC). Transmission electron microscopy (TEM) revealed more details on specific cell size, size of cytoplasmic granule, and nuclear to cytoplasmic ratio, and confirmed the classification. Relative abundance of these cells types in the hemolymph of an adult crab were 15.50±8.22% for HC, 55.50±7.15% for SGC, 13.50±5.28% for LGC, and 15.50±3.50% for MGC. Proteomic analysis of protein expression for each specific cell types by two-dimensional electrophoresis identified two highly abundant proteins, prophenoloxidase (ProPO) and peroxinectin in LGC. Determination of phenoloxidase (PO) activity in each isolated cell types using in vitro and in situ chemical assays confirmed the presence of PO activity only in LGC. Based on an increased PO activity of crab hemolymph during the course of White Spot Syndrome Virus (WSSV) infection, these results suggest that prophenoloxidase pathway was employed for host defense mechanism against WSSV and it may link to the role of large granular hemocyte.

  13. Fifteen years of thermal activity at Vanuatu's volcanoes (2000-2015) revealed by MIROVA

    NASA Astrophysics Data System (ADS)

    Coppola, D.; Laiolo, M.; Cigolini, C.

    2016-08-01

    The Vanuatu archipelago consists of 80 islands and hosts 5 subaerial volcanoes (Yasur, Lopevi, Ambrym, Aoba and Gaua) that have shown sign of activity during the past decade. In this contribution we provide a 15 years-long datasets (2000-2015) of the thermal activity recorded at these active volcanoes by means of MIROVA (Middle InfraRed Observation of Volcanic Activity) a new volcanic hotspot detection system based on MODIS data. The analyzed volcanoes are characterized by a spectrum of volcanic activities whose thermal signature has been tracked and carefully analyzed. These include strombolian-vulcanian explosions at Yasur, lava flows at Lopevi, lava lakes at Ambrym, surtseyan-type eruptions within the Voui crater lake of Aoba and ash-dominated eruptions with strong degassing at Gaua. The collected data reveal several details of the long term eruptive dynamics at single sites such as a monthly long pulse in thermal emissions at Yasur volcano as well as at the two active craters of Ambrym (Benbow and Marum). Heating cycles within Aoba crater lake and intermittent pressurized eruptions at Lopevi volcano has also been detected and shed light in the eruptive dynamics of the analyzed volcanoes. In addition we were able to track a two years long intensification of thermal output at Benbow crater (Ambrym) that preceded the occurrence of the first intra-caldera eruptions of this volcano since 1989. We emphasize how the data provided by MIROVA represent a new, safe and affordable method for monitoring in near-real time a large spectrum of volcanic activities taking place at Vanuatu and other volcanic areas.

  14. Marvelous Mud

    ERIC Educational Resources Information Center

    Keeler, Rusty

    2011-01-01

    The author visited the Open Spaces Preschool in Whangarei, New Zealand and was surprised to see the most amazing natural preschool play. There were six preschoolers stripped down to tee shirts and underpants slipping, slopping, and sliding in the dirt spot which had now become the most lovely, silky-smooth deep-brown mud ever. Studies have…

  15. CHARACTERIZATION OF MUD/DIRT CARRYOUT ONTO PAVED ROADS FROM CONSTRUCTION AND DEMOLITION ACTIVITIES

    EPA Science Inventory

    The report characterizes fugitive dust generated by vehicular traffic on paved streets and highways resulting from mud/dirt carryout from unpaved areas as a primary source of PM-10 (particles = or < 10 micrometers in aerodynamic diameter), and evaluates three technologies for eff...

  16. 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.

  17. 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.…

  18. 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.

  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. Preparation of Granular Red Mud Adsorbent using Different Binders by Microwave Pore - Making and Activation Method

    NASA Astrophysics Data System (ADS)

    Le, Thiquynhxuan; Wang, Hanrui; Ju, Shaohua; Peng, Jinhui; Zhou, Liexing; Wang, Shixing; Yin, Shaohua; Liu, Chao

    2016-04-01

    In this work, microwave energy is used for preparing a granular red mud (GRM) adsorbent made of red mud with different binders, such as starch, sodium silicate and cement. The effects of the preparation parameters, such as binder type, binder addition ratio, microwave heating temperature, microwave power and holding time, on the absorption property of GRM are investigated. The BET surface area, strength, pore structure, XRD and SEM of the GRM absorbent are analyzed. The results show that the microwave roasting has a good effect on pore-making of GRM, especially when using organic binder. Both the BET surface area and the strength of GRM obtained by microwave heating are significantly higher than that by conventional heating. The optimum conditions are obtained as follows: 6:100 (w/w) of starch to red mud ratio, microwave roasting with a power of 2.6 kW at 500℃ for holding time of 30 min. The BET surface area, pore volume and average pore diameter of GRM prepared at the optimum conditions are 15.58 m2/g, 0.0337 cm3/g and 3.1693 A0, respectively.

  1. Hydrogen Isotopic Composition of Hornblendes From Active Volcanoes of Mexico

    NASA Astrophysics Data System (ADS)

    Taran, Y.; Kusakabe, M.; Valdez, G.; Mora, J. C.

    2002-12-01

    Horblendes (Hb) crystallize in water-rich magmas in magma chambers or in deeper zones. Isotopic composition of hydrogen in OH-groups of Hb represents the water isotopic composition of magmatic fluid or dissolved magmatic volatiles and therefore, is an isotopic characteristics of magmatic water. At lower vapor pressure in conduits and shallower magma chambers, Hb can decompose and loose water with significant isotopic effects. We measured hydrogen isotopic composition of hornblendes from modern lavas and pyroclastics of El Chichon, Colima and Popocatepetl volcanoes. Hornblendes from the last and previous pyroclastic flows of El Chichon are the more abundant mineral phases (after plagioclase), showing pleochroism from green to brown. They are relatively uniform in composition (close to magnesian hastingsite hornblende), without chemical variations between cores and rims. Using the Johnson and Rutherford (1989) calibration of the Al-in-hornblende geobarometer, the hornblendes show equilibrium with the melt at pressure of 4 kb that correspond to 12 km of depth. These pressure conditions likely represent the location of the magma chamber below El Chichon volcano, however, these pressure estimates need to be confirmed. The water content of all analyzed Hbs is 1.5-1.8 wt%, but may be higher due to a minor amount of impurities of pyroxenes which sometimes are difficult to separate from Hb. Hydrogen isotopic composition in 10 samples of Hb from El Chichon of different age and facies (pumice, lithic fragments in pyroclastics) was in a narrow range -40 to -37 permil V-SMOW. Such isotopic signature corresponds to so-called "andesitic" waters, i.e. waters from subduction-related magmas, The origin of these waters is suggested to be the recycled water from subducted oceanic sediments. The data for El Chichon volcano are in the range of the already known values for subduction-related magmas though the tectonic setting of El Chichon is more complicated. The measured isotopic

  2. Archaeal Populations in Hypersaline Sediments Underlying Orange Microbial Mats in the Napoli Mud Volcano▿†

    PubMed Central

    Lazar, Cassandre Sara; L'Haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-01-01

    Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the “active” archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the anaerobic methanotrophic Archaea (ANME) of the ANME-1, ANME-2a, and ANME-2c groups, suggesting that AOM occurred in these sediment layers. Enrichment cultures showed the presence of viable marine methylotrophic Methanococcoides in shallow sediment layers. Thus, the archaeal community diversity seems to show that active methane cycling took place in the hypersaline microbial mat-associated sediments of the Napoli mud volcano. PMID:21335391

  3. Ascent velocity and dynamics of the Fiumicino mud eruption, Rome, Italy

    NASA Astrophysics Data System (ADS)

    Vona, A.; Giordano, G.; De Benedetti, A. A.; D'Ambrosio, R.; Romano, C.; Manga, M.

    2015-08-01

    In August 2013 drilling triggered the eruption of mud near the international airport of Fiumicino (Rome, Italy). We monitored the evolution of the eruption and collected samples for laboratory characterization of physicochemical and rheological properties. Over time, muds show a progressive dilution with water; the rheology is typical of pseudoplastic fluids, with a small yield stress that decreases as mud density decreases. The eruption, while not naturally triggered, shares several similarities with natural mud volcanoes, including mud componentry, grain-size distribution, gas discharge, and mud rheology. We use the size of large ballistic fragments ejected from the vent along with mud rheology to compute a minimum ascent velocity of the mud. Computed values are consistent with in situ measurements of gas phase velocities, confirming that the stratigraphic record of mud eruptions can be quantitatively used to infer eruption history and ascent rates and hence to assess (or reassess) mud eruption hazards.

  4. Hydrogochemical tools for monitoring active volcanoes: Applications to El Chichón volcano, México.

    NASA Astrophysics Data System (ADS)

    Armienta, M. A.; de La Cruz-Reyna, S.; Ramos, S.; Morton, O.; Ceniceros, N.; Aguayo, A.; Cruz, O.

    2010-03-01

    In 1982, a series of eruptions resulted in the worst disaster linked with volcanic activity in México. The characteristics of the phenomena together with a lack of prevention measures resulted in approximately 2000 deaths. An important aspect to prevent disasters is a thorough knowledge and monitoring of the potentially destructive natural phenomena. Monitoring the activity of dormant or active volcanoes by various methods is thus a key measure to estimate the hazard and design adequate risk reduction measures. Despite of the 1982 volcanic disaster, until only a few years, hydrogeochemical monitoring was the only regular surveillance of El Chichón post-eruptive activity. The first samples of the crater-lake water were collected by Casadevall et al. in 1983. Since 1985, a systematic sampling and chemical analyses program has been carried out by the Geophysics Institute in collaboration with local authorities from the State of Chiapas. Chemical analyses of main ions and Rare Earth elements (REE) are performed in the Laboratorio de Química Analítica and Laboratorio ICP-MS of the Instituto de Geofísica, UNAM. Results are interpreted considering the physico-chemical changes that may be recognized as precursors of volcanic activity. The problem is difficult because at least two main water reservoirs feed the crater lake; besides, dissolution of acid volcanic gases, water-rock interactions and geochemical processes among dissolved species have resulted in a complex chemical behavior of the lake-water along the years. The calculated degree of neutralization, pH values, and chloride and sulfate concentrations of samples taken at different dates result in a classification of the volcano as active or inactive according to the method developed by Varekamp. A pH of 0.5, very high conductivity and a temperature of about 50°C characterized the first years following the eruptions. An overall decrease on the temperature and ionic concentrations, along with a less acid p

  5. 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.

  6. 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.

  7. 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.

  8. Methods of InSAR atmosphere correction for volcano activity monitoring

    USGS Publications Warehouse

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

    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.

  9. Inside active volcanoes; an exhibit on the move!

    USGS Publications Warehouse

    Fiske, R.S.

    1990-01-01

    All of us are aware of the emphasis currently being placed in the United States on science education and public understanding of science. Most of this emphasis is directed toward mass audiences through book publications, school curricula, and television programs; sadly, most of it deals with non-earth science topics. In an effort to take advantage of this awakened consciousness and to highlight the earth sciences, the Smithsonian Institution and the U.S Geological Survey joined forces to prepare a traveling exhibit on volcanoes that is currently touring the country. This note will serve to bring you up to date on the progress of this exhibit as it reaches the mid-point of its tour. 

  10. 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

  11. Volcano Infrasound

    NASA Astrophysics Data System (ADS)

    Johnson, J. B.; Fee, D.; Matoza, R. S.

    2013-12-01

    Open-vent volcanoes generate prodigious low frequency sound waves that tend to peak in the infrasound (<20 Hz) band. These long wavelength (> ~20 m) atmospheric pressure waves often propagate long distances with low intrinsic attenuation and can be well recorded with a variety of low frequency sensitive microphones. Infrasound records may be used to remotely monitor eruptions, identify active vents or track gravity-driven flows, and/or characterize source processes. Such studies provide information vital for both scientific study and volcano monitoring efforts. This presentation proposes to summarize and standardize some of the terminology used in the still young, yet rapidly growing field of volcano infrasound. Herein we suggest classification of typical infrasound waveform types, which include bimodal pulses, blast (or N-) waves, and a variety of infrasonic tremors (including broadband, harmonic, and monotonic signals). We summarize various metrics, including reduced pressure, intensity, power, and energy, in which infrasound excess pressures are often quantified. We also describe the spectrum of source types and radiation patterns, which are typically responsible for recorded infrasound. Finally we summarize the variety of propagation paths that are common for volcano infrasound radiating to local (<10 km), regional (out to several hundred kilometers), and global distances. The effort to establish common terminology requires community feedback, but is now timely as volcano infrasound studies proliferate and infrasound becomes a standard component of volcano monitoring.

  12. 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

  13. Controlled reduction of red mud waste to produce active systems for environmental applications: heterogeneous Fenton reaction and reduction of Cr(VI).

    PubMed

    Costa, Regina C C; Moura, Flávia C C; Oliveira, Patrícia E F; Magalhães, Fabiano; Ardisson, José D; Lago, Rochel M

    2010-02-01

    In this work, controlled reduction of red mud with H(2) was used to produce active systems for two different environmental applications, i.e. the heterogeneous Fenton reaction and the reduction of Cr(VI). Mössbauer, powder X-ray diffraction, thermal analyses and scanning electron microscopy analyses showed that at different temperatures, i.e. 300, 400, 500 and 600 degrees C, H(2) reduces red mud to different phases, mainly Fe(3)O(4), Fe(0)/Fe(3)O(4) and Fe(0). These Fe phases are dispersed on Al, Si and Ti oxides present in the red mud and show high reactivity towards two environmental applications, i.e. the heterogeneous Fenton reaction and the reduction of Cr(VI). Reduction with H(2) at 400 degrees C showed the best results for the oxidation of the model dye methylene blue with H(2)O(2) at neutral pH due to the presence of the composite Fe(0)/Fe(3)O(4). The reduced red mud at 500-600 degrees C produced Fe(0) highly active for the reduction of Cr(VI) in aqueous medium. Another feature of these red mud based system is that after deactivation due to extensive use they can be completely regenerated by simple treatment with H(2).

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

    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.

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

    PubMed Central

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

    2017-01-01

    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. PMID:28218270

  17. 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.

  18. Martian mud volcanism: Terrestrial analogs and implications for formational scenarios

    USGS Publications Warehouse

    Skinner, J.A.; Mazzini, A.

    2009-01-01

    The geology of Mars and the stratigraphic characteristics of its uppermost crust (mega-regolith) suggest that some of the pervasively-occurring pitted cones, mounds, and flows may have formed through processes akin to terrestrial mud volcanism. A comparison of terrestrial mud volcanism suggests that equivalent Martian processes likely required discrete sedimentary depocenters, volatile-enriched strata, buried rheological instabilities, and a mechanism of destabilization to initiate subsurface flow. We outline five formational scenarios whereby Martian mud volcanism might have occurred: (A) rapid deposition of sediments, (B) volcano-induced destabilization, (C) tectonic shortening, (D) long-term, load-induced subsidence, and (E) seismic shaking. We describe locations within and around the Martian northern plains that broadly fit the geological context of these scenarios and which contain mud volcano-like landforms. We compare terrestrial and Martian satellite images and examine the geological settings of mud volcano provinces on Earth in order to describe potential target areas for piercement structures on Mars. Our comparisons help to evaluate not only the role of water as a functional component of geological processes on Mars but also how Martian mud volcanoes could provide samples of otherwise inaccessible strata, some of which could contain astrobiological evidence.

  19. Ages of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region, Russia

    NASA Astrophysics Data System (ADS)

    Braitseva, O. A.; Melekestsev, I. V.; Ponomareva, V. V.; Sulerzhitsky, L. D.

    1995-12-01

    The ages of most of calderas, large explosive craters and active volcanoes in the Kuril-Kamchatka region have been determined by extensive geological, geomorphological, tephrochronological and isotopic geochronological studies, including more than 600 14C dates. Eight ‘Krakatoa-type’ and three ‘Hawaiian-type’ calderas and no less than three large explosive craters formed here during the Holocene. Most of the Late Pleistocene Krakatoa-type calderas were established around 30 000 40 000 years ago. The active volcanoes are geologically very young, with maximum ages of about 40 000 50 000 years. The overwhelming majority of recently active volcanic cones originated at the very end of the Late Pleistocene or in the Holocene. These studies show that all Holocene stratovolcanoes in Kamchatka were emplaced in the Holocene only in the Eastern volcanic belt. Periods of synchronous, intensified Holocene volcanic activity occurred within the time intervals of 7500 7800 and 1300 1800 14C years BP.

  20. 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)

  1. 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.

  2. Mud Flow - Slow and Fast

    NASA Astrophysics Data System (ADS)

    Mei, C. C.; Liu, K.-F.; Yuhi, M.

    Heavy and persistent rainfalls in mountainous areas can loosen the hillslope and induce mud flows which can move stones, boulders and even trees, with destructive power on their path. In China where 70% of the land surface is covered by mountains, debris flows due to landslides or rainfalls affect over 18.6% of the nation. Over 10,000 debris flow ravines have been identified; hundreds of lives are lost every year [1]. While accurate assessment is still pending, mud flows caused by Hurr icane Mitch in 1998 have incurred devastating floods in Central America. In Honduras alone more than 6000 people perished. Half of the nation's infrastructures were damaged. Mud flows can also be the result of volcanic eruption. Near the volcano, lava and pyroclastic flows dominate. Further downstream solid particles become smaller and can mix with river or lake water, rainfall, melting snow or ice, or eroded soil, resulting in hyperconcentrated mud mixed with rocks. The muddy debris can travel at high speeds over tens of miles down the hill slopes and devastate entire communities. In 1985 the catastrophic eruption of Nevado del Ruiz in Colombia resulted in mud flows which took the life of 23,000 inhabitants in the town of Amero [2]. During the eruption of Mt. Pinatubo in Phillipnes in 1991, one cubic mile of volcanic ash and rock fragments fell on the mountain slopes. Seasonal rain in the following months washed down much of the loose deposits, causing damage to 100,000 villages. These catastrophes have been vividly recorded in the film documentary by Lyons [3].

  3. 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.

  4. 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.

  5. Extreme efficiency of mud volcanism in dewatering accretionary prisms

    NASA Astrophysics Data System (ADS)

    Kopf, Achim; Klaeschen, Dirk; Mascle, Jean

    2001-07-01

    Drilling results from two mud volcanoes on the Mediterranean Ridge accretionary complex as well as bottom sampling and the wealth of geophysical data acquired recently have provided fundamental knowledge of the 3D geometry of mud extrusions. Mud volcanism is generally related to buoyancy (density inversion), and is triggered by the collision of the African and Eurasian blocks, forcing undercompacted clayey sediments to extrude along faults in the central and hinterlandward parts of the prism. Volumetric estimates of extruded mud in several well-studied areas were based on pre-stack depth-migrated seismic profiles across the entire, up to >150 km wide, prism. The resulting volumes of mud were combined with ages from mud dome drilling, so that rates of mud extrusion were obtained. Subtracting the solid rock mass from the bulk mud volume using physical property data, fluid flux as a function of mud volcanism alone has been quantified for the first time. The volume of fluid extruding with the mud is found to be variable, but reaches up to 15 km 3 fluid per km trench length and Ma along cross sections with abundant mud volcanoes. Such large fluid quantities in a region some 50-150 km behind the deformation front exceed estimates from those elsewhere (where undoubtedly the majority of the interstitial fluid is lost due to compaction). Such fluids near the backstop are likely to result predominantly from mineral dehydration and diagenetic reactions at depth, and consequently provide a window to understand deeper processes along the deep décollement. More importantly, the enormous rates with which such fluids and liquified mud escape along the out-of-sequence faults alter fluid budget calculations in subduction zones drastically.

  6. 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

  7. 1996 volcanic activity in Alaska and Kamchatka: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Neal, Christina A.; McGimsey, Robert G.

    1997-01-01

    During 1996, the Alaska Volcano Observatory (AVO) responded to eruptive activity, anomalous seismicity, or suspected volcanic activity at 10 of the approximately 40 active volcanic centers in the state of Alaska. As part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also disseminated information about eruptions and other volcanic unrest at six volcanic centers on the Kamchatka Peninsula and in the Kurile Islands, Russia.

  8. 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.

  9. Geothermal activity and energy of the Yakedake volcano, Gifu-Nagano, Japan

    SciTech Connect

    Iriyama, Jun

    1996-12-31

    The temperature of the most active solfatara in the summit crater of the Yakedake volcano (altitude 2,455 m Gifu-Nagano, Japan) was 92.2 and 129.4{degrees}C in September 1995 and in October 1994, respectively. The temperature of solfatara in the northern summit dome at an altitude of 2,240 to 2,270 m ranged from 68.2 to 92.5{degrees}C in September 1995. The water sample from a crater pond, Shoga-ike, located on the summit, showed a pH and electrical conductivity of 4.38 and 42.2 {mu}S/cm in October 1991, 4.35 and 42.4 {mu}S/cm in September 1992, 4.11 and 76.6 {mu}S/cm in October 1994, and 4.30 and 45.1 {mu}S/cm in September 1995, respectively. In 1960, the water sample from the same pond showed the pH and electrical conductivity of 3.7 and 80.8 {mu}S/cm, respectively. Although the values of pH and electrical conductivity in 1994 approached to the values at the volcano`s pre-eruption in 1960, the eruption in the summit dome did not occur in 1995. However, a large steam explosion occurred in the Nakanoyu area of the southeastern Mountainside of the volcano. The geothermal energy within the summit dome at an altitude of 2,050 to 2,455 m of the Yakedake volcano is calculated, using new data, to be about 4.8 x 10{sup 17} J, which represents a thermal power output of 5.1 x 10{sup 2} MW{sub th} averaged over 30 yrs.

  10. The Activity Of The Colima Volcano From 1999 To The 2003

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Nuñez-Cornu, F.; Reyes-Davila, G.; Diaz-Torres, J.

    2004-12-01

    The Colima Volcano has shown intense activity since the 10th of February 1999. This explosive activity of 1999 and 2000 generated an elliptical crater of 260 x 265 m, which began to be filled in by a Dome from October 2001, at February 2002 the volume of the Dome was of approximately 2x106 m3 spreading over the edges of the crater and starting to flow during the following 11 months, in this period small lobes formed on the flanks of the volcano. Constants landslides originated in these lobes filled ravines of San Antonio, El Cordovan, El Muerto, El Cafesito and Atenquique (subsequent to the earthquake of January of the 2003) with non consolidated materials, increasing the hazard of lahares during the rainy season. Beginning February 2003 the explosive activity increased, most significantly from April to August, when the plumes reached heights over 2000 meters above the crater, occasionally small pyroclastic flows were observed. The explosive events continue to date. We mapped the most significant morphological changes produced at the summit by the activity described, using three photogrammetric flights conducted by INEGI (2003) and CARTODATA (2002 and 2003). These were data complemented by a very large number of photographs taken on helicopter flights undertaken during these months. Both the photographs and the digital mapping have provided detailed information to quantify the geomorphologic evolution of the superior section of the volcano, in the course of the last five years.

  11. Analysis of the seismicity activity of the volcano Ceboruco, Nayarit, Mexico

    NASA Astrophysics Data System (ADS)

    Rodriguez-Ayala, N. A.; Nunez-Cornu, F. J.; Escudero, C. R.; Zamora-Camacho, A.; Gomez, A.

    2014-12-01

    The Ceboruco is a stratovolcano is located in the state of Nayarit,Mexico (104 ° 30'31 .25 "W, 21 ° 7'28 .35" N, 2280msnm). This is an volcano active, as part of the Trans-Mexican Volcanic Belt, Nelson (1986) reports that it has had activity during the last 1000 years has averaged eruptions every 125 years or so, having last erupted in 1870, currently has fumarolic activity. In the past 20 years there has been an increase in the population and socio-economic activities around the volcano (Suárez Plascencia, 2013); which reason the Ceboruco study has become a necessity in several ways. Recent investigations of seismicity (Rodríguez Uribe et al., 2013) have classified the earthquakes in four families Ceboruco considering the waveform and spectral features. We present analysis included 57 days of seismicity from March to October 2012, in the period we located 97 events with arrivals of P and S waves clear, registered in at least three seasons, three components of the temporal network Ceboruco volcano.

  12. Seismicity at Uturuncu Volcano, Bolivia: Volcano-Tectonic Earthquake Swarms Triggered by the 2010 Maule, Chile Earthquake and Non-Triggered Background Activity

    NASA Astrophysics Data System (ADS)

    Christensen, D. H.; Chartrand, Z. A.; Jay, J.; Pritchard, M. E.; West, M. E.; McNutt, S. R.

    2010-12-01

    We find that the 270 ky dormant Uturuncu Volcano in SW Bolivia exhibits relatively high rates of shallow, volcano-tectonic seismicity that is dominated by swarm-like activity. We also document that the 27 February 2010 Mw 8.8 Maule, Chile earthquake triggered an exceptionally high rate of seismicity in the seconds to days following the main event. Although dormant, Uturuncu is currently being studied due to its large-scale deformation rate of 1-2 cm/yr uplift as revealed by InSAR. As part of the NASA-funded Andivolc project to investigate seismicity of volcanoes in the central Andes, a seismic network of 15 stations (9 Mark Products L22 short period and 6 Guralp CMG40T intermediate period sensors) with an average spacing of about 10 km was installed at Uturuncu from April 2009 to April 2010. Volcano-tectonic earthquakes occur at an average rate of about 3-4 per day, and swarms of 5-60 events within a span of minutes to hours occur a few times per month. Most of these earthquakes are located close to the summit at depths near and above sea level. The largest swarm occurred on 28 September 2009 and consisted of 60 locatable events over a time span of 28 hours. The locations of volcano-tectonic earthquakes at Uturuncu are oriented in a NW-SE trend, which matches the dominant orientation of regional faults and suggests a relationship between the fault system at Uturuncu and the regional tectonics of the area; a NW-SE trending fault beneath Uturuncu may serve to localize stresses that are accumulating over the broad area of uplift. Based on automated locations, the maximum local magnitude of these events is approximately M = 4 and the average magnitude is approximately M = 2. An initial estimate of the b-value is about b = 1.2. The Mw 8.8 Maule earthquake on 27 February 2010 triggered hundreds of local volcano-tectonic events at Uturuncu. High-pass filtering of the long period surface waves reveals that the first triggered events occurred with the onset of the Rayleigh

  13. 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

  14. 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.

  15. Long-term explosive degassing and debris flow activity at West Mata submarine volcano

    NASA Astrophysics Data System (ADS)

    Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; Caplan-Auerbach, J.; Embley, R. W.; Merle, S. G.; Walker, S. L.; Lau, T.-K.; Chadwick, W. W.

    2015-03-01

    West Mata is a 1200 m deep submarine volcano where explosive boninite eruptions were observed in 2009. The acoustic signatures from the volcano's summit eruptive vents Hades and Prometheus were recorded with an in situ (~25 m range) hydrophone during ROV dives in May 2009 and with local (~5 km range) moored hydrophones between December 2009 and August 2011. The sensors recorded low frequency (1-40 Hz), short duration explosions consistent with magma bubble bursts from Hades, and broadband, 1-5 min duration signals associated with episodes of fragmentation degassing from Prometheus. Long-term eruptive degassing signals, recorded through May 2010, preceded a several month period of declining activity. Degassing episodes were not recorded acoustically after early 2011, although quieter effusive eruption activity may have continued. Synchronous optical measurements of turbidity made between December 2009 and April 2010 indicate that turbidity maxima resulted from occasional south flank slope failures triggered by the collapse of accumulated debris during eruption intervals.

  16. Seismic activity related to the degassing of the Gorely volcano (Kamchatka)

    NASA Astrophysics Data System (ADS)

    Abramenkov, S. S.; Shapiro, N.; Koulakov, I.; Abkadyirov, I.; Frank, W.; Jakovlev, A.

    2015-12-01

    We analyzed continuous seismic records from a temporary network of 21 broadband seismograph that we installed in Gorely volcano (Kamchatka, Russia) between August 2013 and August 2014. During the studied period, the activity of Gorely was characterized by a sustained gas emission. We developed a source scanning algorithm based on summation of seismogram envelopes to automatically detect seismic events characterized by emerging signals without clear arrivals of P or S waves. With the help of this method, we detected and located numerous events originated from the vicinity of the main crater and caused by the volcano degassing. We then studied variations in spatio-temporal distribution of this seismic emission to characterize the evolution of the volcanic activity.

  17. Esmeralda Bank: Geochemistry of an active submarine volcano in the Mariana Island Arc

    NASA Astrophysics Data System (ADS)

    Stern, Robert J.; Bibee, L. D.

    1984-05-01

    Esmeralda Bank is the southernmost active volcano in the Izu-Volcano-Mariana Arc. This submarine volcano is one of the most active vents in the western Pacific. It has a total volume of about 27 km3, rising to within 30 m of sea level. Two dredge hauls from Esmeralda recovered fresh, nearly aphyric, vesicular basalts and basaltic andesites and minor basaltic vitrophyre. These samples reflect uniform yet unusual major and trace element chemistries. Mean abundances of TiO2 (1.3%) and FeO* (12.6%) are higher and CaO (9.2%) and Al2O3 (15.1%) are lower than rocks of similar silica content from other active Mariana Arc volcanoes. Mean incompatible element ratios K/Rb (488) and K/Ba (29) of Esmeralda rocks are indistinguishable from those of other Mariana Arc volcanoes. On a Ti-Zr plot, Esmeralda samples plot in the field of oceanic basalts while other Mariana Arc volcanic rocks plot in the field for island arcs. Incompatible element ratios K/Rb and K/Ba and isotopic compositions of Sr (87Sr/86Sr=0.70342 0.70348), Nd (ɛND=+7.6 to +8.1), and O(δ18O=+5.8 to +5.9) are incompatible with models calling for the Esmeralda source to include appreciable contributions from pelagic sediments or fresh or altered abyssal tholeiite from subduction zone melting. Instead, incompatible element and isotopic ratios of Esmeralda rocks are similar to those of intra-plate oceanic islands or “hot-spot” volcanoes in general and Kilauean tholeiites in particular. The conclusion that the source for Esmeralda lavas is an ocean-island type mantle reservoir is preferred. Esmeralda Bank rare earth element patterns are inconsistent with models calling for residual garnet in the source region, but are adequately modelled by 7 10% equilibrium partial melting of spinel lherzolite. This is supported by consideration of the results of melting experiments at 20 kbars, 1,150° C with CO2 and H2O as important volatile components. These experiments further indicate that low MgO (4.1%), MgO/FeO*(0.25) and

  18. Shrimp Populations on Northwest Rota, an Active Volcano of the Mariana Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Tunnicliffe, V.; Juniper, S. K.; Limén, H.; Jones, W. J.; Vrijenhoek, R.; Webber, R.; Eerkes-Medrano, D.

    2004-12-01

    NW Rota-1 is a submarine volcano that manifested active volcanic and hydrothermal activity during submersible surveys in March 2004 (see Embley et al.). Substratum on the volcano summit (520 m depth) was entirely basalt outcrop or variously-sized ejecta lying near the angle of repose. While no fauna inhabited the rim of the volcanic pit, patches of shrimp were located within 25 m and on the nearby summit. Two species are present. Opaepele cf. loihi shows few morphological differences from either a nearby population on Eifuku Volcano (see Chadwick et al.) at 1700 m depth or from the type locality in Hawaii. A molecular comparison of COI sequences of 13 specimens found little difference from two Hawaiian sequences. Video observations detail frequent feeding activity using spatulate chelipeds to trim microbial filaments as the cephalothorax sways across the substratum. The second species is an undescribed Alvinocaris. Juveniles of this species appear to form clusters distinct from Opaepele where they also graze on filaments. Sparse adults of Alvinocaris range up to 5.5 cm long and display aggressive behaviour moving through patches of smaller shrimp. Densities of Opaepele were highest on sloping rock walls (over 500 per sq.m.) whereas adult Alvinocaris were more abundant on rubble. This division may reflect food preference: microbial filaments versus polychaetes and meiofauna. Characterization of particulates from these substrata was conducted using visual sorting and stable isotope composition. As Alvinocaris matures, the chelipeds enlarge, enabling a greater predatory capacity. Measurements of Opaepele from digital in situ images reveal a population structure suggesting a recent recruitment. Average size is significantly smaller than the Eifuku population and no egg-bearing females were collected. The disjunct range of this species where it occurs on active volcanoes 6000 km apart is puzzling. Further work on intermediate sites and into the reproductive strategy of

  19. Study of novel mechano-chemical activation process of red mud to optimize nitrate removal from water.

    PubMed

    Alighardashi, A; Gharibi, H R; Raygan, Sh; Akbarzadeh, A

    2016-01-01

    Red mud (RM) is the industrial waste of alumina production and causes serious environmental risks. In this paper, a novel activation procedure for RM (mechano-chemical processing) is proposed in order to improve the nitrate adsorption from water. High-energy milling and acidification were selected as mechanical and chemical activation methods, respectively. Synthesized samples of adsorbent were produced considering two parameters of activation: acid concentrations and acidification time in two selected milling times. Optimization of the activation process was based on nitrate removal from a stock solution. Experimental data were analyzed with two-way analysis of variance and Kruskal-Wallis methods to verify and discover the accuracy and probable errors. Best conditions (acceptable removal percentage > 75) were 17.6% w/w for acid concentrate and 19.9 minutes for acidification time in 8 hours for milling time. A direct relationship between increase in nitrate removal and increasing the acid concentration and acidification time was observed. The adsorption isotherms were studied and compared with other nitrate adsorbents. Characterization tests (X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectrophotometry, dynamic light scattering, surface area analysis and scanning electron microscopy) were conducted for both raw and activated adsorbents. Results showed noticeable superiority in characteristics after activation: higher specific area and porosity, lower particle size and lower agglomeration in structure.

  20. 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.

  1. 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

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

    PubMed

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

    2013-10-30

    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.

  3. Autonomous thermal camera system for monitoring the active lava lake at Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Peters, N.; Oppenheimer, C.; Kyle, P.

    2014-02-01

    In December 2012, the Mount Erebus Volcano Observatory installed a thermal infrared camera system to monitor the volcano's active lava lake. The new system is designed to be autonomous, and capable of capturing images of the lava lake continuously throughout the year. This represents a significant improvement over previous systems which required the frequent attention of observatory researchers and could therefore only be operated during a few weeks of the annual field campaigns. The extreme environmental conditions at the summit of Erebus pose significant challenges for continuous monitoring equipment, and a custom-made system was the only viable solution. Here we describe the hardware and software of the new system in detail and report on a publicly available online repository where data will be archived. Aspects of the technical solutions we had to find in order to overcome the challenges of automating this equipment may be relevant in other environmental science domains where remote instrument operation is involved.

  4. Autonomous thermal camera system for monitoring the active lava lake at Erebus volcano, Antarctica

    NASA Astrophysics Data System (ADS)

    Peters, N.; Oppenheimer, C.; Kyle, P.

    2013-10-01

    In December 2012, the Mount Erebus Volcano Observatory installed a thermal infrared camera system to monitor the volcano's active lava lake. The new system is designed to be autonomous, and capable of capturing images of the lava lake continuously throughout the year. This represents a significant improvement over previous systems which required the frequent attention of observatory researchers and could therefore only be operated during a few weeks of the annual field campaigns. The extreme environmental conditions at the summit of Erebus pose significant challenges for continuous monitoring equipment, and a custom made system was the only viable solution. Here we describe the hardware and software of the new system in detail and report on a publicly-available online repository where data will be archived. Aspects of the technical solutions we had to find in order to overcome the challenges of automating this equipment may be relevant in other environmental science domains where remote instrument operation is involved.

  5. 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.

  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. Passive vs. active degassing modes at an open-vent volcano (Stromboli, Italy)

    NASA Astrophysics Data System (ADS)

    Tamburello, G.; Aiuppa, A.; Kantzas, E. P.; McGonigle, A. J. S.; Ripepe, M.

    2012-12-01

    We report here on a UV-camera based field experiment performed on Stromboli volcano during 7 days in 2010 and 2011, aimed at obtaining the very first simultaneous assessment of all the different forms (passive and active) of SO2 release from an open-vent volcano. Using the unprecedented spatial and temporal resolution of the UV camera, we obtained a 0.8 Hz record of the total SO2 flux from Stromboli over a timeframe of ∼14 h, which ranged between 0.4 and 1.9 kg s-1 around a mean value of 0.7 kg s-1 and we concurrently derived SO2 masses for more than 130 Strombolian explosions and 50 gas puffs. From this, we show erupted SO2 masses have a variability of up to one order of magnitude, and range between 2 and 55 kg (average ∼20 kg), corresponding to a time integrated flux of 0.05±0.01 kg s-1. Our experimental constraints on individual gas puff mass (0.03-0.42 kg of SO2, averaging 0.19 kg) are the first of their kind, equating to an emission rate ranging from 0.02 to 0.27 kg s-1. On this basis, we conclude that puffing is two times more efficient than Strombolian explosions in the magmatic degassing process, and that active degassing (explosions+puffing) accounts for ∼23% (ranging from 10% to 45%) of the volcano's total SO2 flux, e.g., passive degassing between the explosions contributes the majority (∼77%) of the released gas. We furthermore integrate our UV camera gas data for the explosions and puffs, with independent geophysical data (infrared radiometer data and very long period seismicity), to offer key and novel insights into the degassing dynamics within the shallow conduit systems of this open-vent volcano.

  8. 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.

  9. 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.

  10. Sequentially sampled gas hydrate water, coupled with pore water and bottom water isotopic and ionic signatures at the Kukuy mud volcano, Lake Baikal: ambiguous deep-rooted source of hydrate-forming water

    NASA Astrophysics Data System (ADS)

    Minami, Hirotsugu; Hachikubo, Akihiro; Sakagami, Hirotoshi; Yamashita, Satoshi; Soramoto, Yusuke; Kotake, Tsuyoshi; Takahashi, Nobuo; Shoji, Hitoshi; Pogodaeva, Tatyana; Khlystov, Oleg; Khabuev, Andrey; Naudts, Lieven; De Batist, Marc

    2014-06-01

    The isotopic and ionic composition of pure gas hydrate (GH) water was examined for GHs recovered in three gravity cores (165-193 cm length) from the Kukuy K-9 mud volcano (MV) in Lake Baikal. A massive GH sample from core St6GC4 (143-165 cm core depth interval) was dissociated progressively over 6 h in a closed glass chamber, and 11 sequentially collected fractions of dissociated GH water analyzed. Their hydrogen and oxygen isotopic compositions, and the concentrations of Cl- and HCO3 - remained essentially constant over time, except that the fraction collected during the first 50 minutes deviated partly from this pattern. Fraction #1 had a substantially higher Cl- concentration, similar to that of pore water sampled immediately above (135-142 cm core depth) the main GH-bearing interval in that core. Like the subsequent fractions, however, the HCO3 - concentration was markedly lower than that of pore water. For the GH water fractions #2 to #11, an essentially constant HCO3 -/Cl- ratio of 305 differed markedly from downcore pore water HCO3 -/Cl- ratios of 63-99. Evidently, contamination of the extracted GH water by ambient pore water probably adhered to the massive GH sample was satisfactorily restricted to the initial phase of GH dissociation. The hydrogen and oxygen isotopic composition of hydrate-forming water was estimated using the measured isotopic composition of extracted GH water combined with known isotopic fractionation factors between GH and GH-forming water. Estimated δD of -126 to -133‰ and δ18O of -15.7 to -16.7‰ differed partly from the corresponding signatures of ambient pore water (δD of -123‰, δ18O of -15.6‰) and of lake bottom water (δD of -121‰, δ18O of -15.8‰) at the St6GC4 coring site, suggesting that the GH was not formed from those waters. Observations of breccias in that core point to a possible deep-rooted water source, consistent with published thermal measurements for the neighboring Kukuy K-2 MV. By contrast, the pore

  11. Io’s active volcanoes during the New Horizons era: Insights from New Horizons imaging

    NASA Astrophysics Data System (ADS)

    Rathbun, J. A.; Spencer, J. R.; Lopes, R. M.; Howell, R. R.

    2014-03-01

    In February 2007, the New Horizons spacecraft flew by the Jupiter system, obtaining images of Io, the most volcanically active body in the Solar System. The Multicolor Visible Imaging Camera (MVIC), a four-color (visible to near infrared) camera, obtained 17 sets of images. The Long-Range Reconnaissance Imager (LORRI), a high-resolution panchromatic camera, obtained 190 images, including many of Io eclipsed by Jupiter. We present a complete view of the discrete point-like emission sources in all images obtained by these two instruments. We located 54 emission sources and determined their brightnesses. These observations, the first that observed individual Ionian volcanoes on short timescales of seconds to minutes, demonstrate that the volcanoes have stable brightnesses on these timescales. The active volcanoes Tvashtar (63N, 124W) and E. Girru (22N, 245W) were observed by both LORRI and MVIC, both in the near-infrared (NIR) and methane (CH4) filters. Tvashtar was additionally observed in the red filter, which allowed us to calculate a color temperature of approximately 1200 K. We found that, with some exceptions, most of the volcanoes frequently active during the Galileo era continued to be active during the New Horizons flyby. We found that none of the seven volcanoes observed by New Horizons multiple times over short timescales showed substantial changes on the order of seconds and only one, E. Girru exhibited substantial variation over minutes to days, increasing by 25% in just over an hour and decreasing by a factor of 4 over 6 days. Observations of Tvashtar are consistent with a current eruption similar to previously observed eruptions and are more consistent with the thermal emission of a lava flow than the fire fountains inferred from the November 1999 observations. These data also present new puzzles regarding Ionian volcanism. Since there is no associated surface change or low albedo feature that could be identified nearby, the source of the emission from

  12. 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

  13. Stratigraphic constraints for explosive activity in the past 100 ka at Etna Volcano, Italy

    NASA Astrophysics Data System (ADS)

    Coltelli, Mauro; Del Carlo, Paola; Vezzoli, Luigina

    2000-08-01

    The pyroclastic deposits of Etna have been correlated over the whole volcanic edifice for the first time, allowing the construction of a continuous record of tephra-producing events, which extends from approximately 100 ka to the Present. In this interval, five main periods of explosive activity have been identified: (a) 100-ka strombolian to subplinian activity; (b) 80- to 100-ka plinian benmoreitic activity; (c) 16- to 80-ka strombolian to subplinian from basaltic to mugearitic activity; (d) 15.5- to 15-ka plinian benmoreitic activity accompanying the caldera-forming eruptions of the Ellittico Volcano; and (e) the most recent 13-ka basaltic explosive activity of strombolian and subplinian type of the present edifice that also includes the 122-B.C. plinian eruption. This study results in a semi-quantitative and in some cases quantitative definition of the intensity and chronology of the explosive activity at Etna. Moreover, this work gives a new significance to the volcanic hazards of Etna, a volcano generally considered to be the site of gentle effusive eruptions.

  14. Holocene eruptive activity of El Chichon volcano, Chiapas, Mexico

    NASA Technical Reports Server (NTRS)

    Tilling, R. I.; Rubin, M.; Sigurdsson, H.; Carey, S.; Duffield, W. A.; Rose, W. I.

    1984-01-01

    Geologic and radiometric-age data indicate that El Chichon was frequently and violently active during the Holocene, including eruptive episodes about 600, 1250, and 1700 years ago and several undated, older eruptions. These episodes, involving explosive eruptions of sulfur-rich magma and associated domegrowth processes, were apparently separated by intervals of approximately 350 to 650 years. Some of El Chichon's eruptions may correlate with unusual atmospheric phenomena around A.D. 1300 and possibly A.D. 623.

  15. Holocene eruptive activity of El Chichon volcano, Chiapas, Mexico

    NASA Astrophysics Data System (ADS)

    Tilling, R. I.; Rubin, M.; Sigurdsson, H.; Carey, S.; Duffield, W. A.; Rose, W. I.

    1984-05-01

    Geologic and radiometric-age data indicate that El Chichon was frequently and violently active during the Holocene, including eruptive episodes about 600, 1250, and 1700 years ago and several undated, older eruptions. These episodes, involving explosive eruptions of sulfur-rich magma and associated domegrowth processes, were apparently separated by intervals of approximately 350 to 650 years. Some of El Chichon's eruptions may correlate with unusual atmospheric phenomena around A.D. 1300 and possibly A.D. 623.

  16. Chemical evolution of thermal springs at Arenal Volcano, Costa Rica: Effect of volcanic activity, precipitation, seismic activity, and Earth tides

    NASA Astrophysics Data System (ADS)

    López, D. L.; Bundschuh, J.; Soto, G. J.; Fernández, J. F.; Alvarado, G. E.

    2006-09-01

    Arenal Volcano in NW Costa Rica, Central America has been active during the last 37 years. However, only relatively low temperature springs have been identified on its slopes with temperatures less than around 60 °C. The springs are clustered on the NE and NW slopes of the volcano, close to contacts between the recent and older volcanic products or at faults that intercept the volcano. This volcano is located in a rain forest region with annual rainfall averaging around 5 m. During the last 15 years, the temperature and chemical composition of 4 hot springs and 2 cold springs have been monitored approximately every 3 months. In addition, two more thermal sites were identified recently and sampled, as well as two boreholes located on a fault NE of the volcano. Scatter plots of chemical species such as Cl and B suggest that the waters in these discharges belong to the same aquifer with a saline end member similar to Río Tabacón at the beginning of the study period (1990) and the deeper borehole (B-2) in 2004. The waters of Quebrada Bambú and Quebrada Fría represent a more dilute end member. Both long-term (over the 15 years) and short-term or seasonal decreases in concentration and steady or decreasing temperature are noted in NW springs. Springs located at the NE show increasing temperatures and ion concentrations, except for bicarbonate that has decreased in concentration for all the springs. This behavior is likely associated with a shallow source for the solutes and heat for this aquifer. To the NW the early lavas and pyroclastic flows have been cooling down, decreasing the contribution of leaching products to the infiltrating waters. To the NE, pyroclastic flows to the N during the last decade are contributing increasing concentrations of solutes and heat throughout water infiltration and circulation within the faults and the surficial drainage that has a NE regional trend. For the short-term or seasonal variations, concentrations of chemical constituents

  17. Teaching Ecological Interactions with Mud Dauber Nests.

    ERIC Educational Resources Information Center

    Matthews, Robert W.

    1997-01-01

    Describes the use of mud dauber wasp nests in laboratory activities in ecology and behavior and life science classes. Provides students with an opportunity to develop and practice basic skills including dissection, identification, observation, measurement, and communication. Discusses the life of mud daubers, obtaining and storing nests,…

  18. 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.

  19. Monitoring eruption activity from temporal stress changes at Mt. Ontake volcano, Japan

    NASA Astrophysics Data System (ADS)

    Terakawa, T.; Kato, A.; Yamanaka, Y.; Maeda, Y.; Horikawa, S.; Matsuhiro, K.; Okuda, T.

    2015-12-01

    On 27 September 2014, Mt. Ontake in Japan produced a phreatic (steam type) eruption with a Volcanic Explosivity Index value of 2 after being dormant for seven years. The local stress field around volcanoes is the superposition of the regional stress field and stress perturbations related to volcanic activity. Temporal stress changes over periods of weeks to months are generally attributed to volcanic processes. Here we show that monitoring temporal changes in the local stress field beneath Mt. Ontake, using focal mechanism solutions of volcano-tectonic (VT) earthquakes, is an effective tool for assessing the state of volcanic activity. We estimated focal mechanism solutions of 157 VT earthquakes beneath Mt. Ontake from August 2014 to March 2015, assuming that the source was double-couple. Pre-eruption seismicity was dominated by normal faulting with east-west tension, whereas most post-eruption events were reverse faulting with east-west compression. The misfit angle between observed slip vectors and those derived theoretically from the regional (i.e., background) stress pattern is used to evaluate the deviation of the local stress field, or the stress perturbation related to volcanic activity. The moving average of misfit angles tended to exceed 90° before the eruption, and showed a marked decrease immediately after the eruption. This indicates that during the precursory period the local stress field beneath Mt. Ontake was rotated by stress perturbations caused by the inflation of magmatic/hydrothermal fluids. Post-eruption events of reverse faulting acted to shrink the volcanic edifice after expulsion of volcanic ejecta, controlled by the regional stress field. The misfit angle is a good indicator of the state of volcanic activity. The monitoring method by using this indicator is applicable to other volcanoes and may contribute to the mitigation of volcanic hazards.

  20. 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.

  1. What drives centuries-long polygenetic scoria cone activity at Barren Island volcano?

    NASA Astrophysics Data System (ADS)

    Sheth, Hetu

    2014-12-01

    Barren Island in the Andaman Sea is an active mafic stratovolcano, which had explosive and effusive eruptions, followed by caldera formation, in prehistoric time (poorly dated). A scoria cone within the caldera, marking volcanic resurgence, was active periodically from 1787 to 1832 (the historic eruptions). Since 1991, the same scoria cone has produced six eruptions, commonly including lava flows. Links between Barren Island's eruptions and giant earthquakes (such as the 26 December 2004 Great Sumatra megathrust earthquake) have been suggested, though there is no general correlation between them. The ≥ 227-year-long activity of the scoria cone, named here Shanku ("cone"), is normally driven by purely magmatic processes. I present a "source to surface" model for Barren Island and Shanku, including the source region, deeper and shallow magma chambers, volcanotectonics, dyking from magma chambers, and eruptions and eruptive style as controlled by crustal stresses, composition and volatile content. Calculations show that dykes ~ 0.5 m thick and a few hundred meters long, originating from shallow-level magma chambers (~ 5 km deep), are suitable feeders of the Shanku eruptions. Shanku, a polygenetic scoria cone (at least 13 eruptions since 1787), has three excellent analogues, namely Anak Krakatau (40 eruptions since 1927), Cerro Negro (23 eruptions since 1850), and Yasur (persistent activity for the past hundreds of years). This is an important category of volcanoes, gradational between small "monogenetic" scoria cones and larger "polygenetic" volcanoes.

  2. Source mechanism of very-long-period signals accompanying dome growth activity at Merapi volcano, Indonesia

    USGS Publications Warehouse

    Hidayat, D.; Chouet, B.; Voight, B.; Dawson, P.; Ratdomopurbo, A.

    2002-01-01

    Very-long-period (VLP) pulses with period of 6-7s, displaying similar waveforms, were identified in 1998 from broadband seismographs around the summit crater. These pulses accompanied most of multiphase (MP) earthquakes, a type of long-period event locally defined at Merapi Volcano. Source mechanisms for several VLP pulses were examined by applying moment tensor inversion to the waveform data. Solutions were consistent with a crack striking ???70?? and dipping ???50?? SW, 100m under the active dome, suggest pressurized gas transport involving accumulation and sudden release of 10-60 m3 of gas in the crack over a 6s interval.

  3. 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.

  4. Very Long Period Seismicity Accompanying Increasing Shallower Activity at Cotopaxi Volcano

    NASA Astrophysics Data System (ADS)

    Arias, G.; Molina Polania, C. I.; Ruiz, M. C.; Kumagai, H.; Hernandez, S.; Plain, M.; Mothes, P. A.; Yepez, M.; Barrington, C.; Hidalgo, S.

    2015-12-01

    Cotopaxi is an andesitic stratovolcano, located in the highland region of Ecuador, which renewed its activity in April 2015, showing an increased number of volcano-tectonic (VT), long-period (LP), very long period events (VLP), and tremors. The VLP events were recorded in several episodes between 2002 and 2014, and have been interpreted as volumetric changes due to the release of gas and subsequent pressure drop and recovery in the magma intrusion. The two peaks of VLP seismicity in June 2002 and April 2015 preceded an increase of surficial activity (fumarolic increase) and the deformation data during those episodes suggested a small intrusion of magma beneath the volcano.Using polarization analysis, we found that most of these events were located at 2-3 km depth beneath the volcano summit, while the deformation data suggests the intrusion is deeper (5-10 km deep). Using tiltmeter data, Mogi point source modelling on successive periods of inflation and deflation show a significant shallowing of sources since the end of May 2015, matching the recent very large spike in SO2 emissions (~3000 t/d). From mid-February until the gas emission spikes in May 2015, Mogi source modelling has indicated inflation/deflation events at 11 to 10 km depth, having shallowed to a depth of between 8 and 7 km after the SO2 emission increase. Shallow source volumes suggested by deformation indicate values of 4 - 31x106 m3, with the most recent, most shallow inflation currently at 8x106 m3.

  5. Water chemistry of lakes related to active and inactive Mexican volcanoes

    NASA Astrophysics Data System (ADS)

    Armienta, María Aurora; Vilaclara, Gloria; De la Cruz-Reyna, Servando; Ramos, Silvia; Ceniceros, Nora; Cruz, Olivia; Aguayo, Alejandra; Arcega-Cabrera, Flor

    2008-12-01

    Water chemistry of crater lakes, maars and water reservoirs linked to some Mexican volcanoes within and outside the Mexican Volcanic Belt has been determined for several years and examined regarding environmental and volcanic factors. All the analyzed lakes are relatively small with a maximum depth of 65 m, and are located in regions with different climates, from semi-arid to very humid, with altitudes ranging from 100 to more than 4000 m a.s.l. Crater lakes in active volcanoes (El Chichón, Popocatépetl) have very low pH, moderate to high temperatures and major ion concentrations varying with the level of volcanic unrest. Lakes in sub-arid and temperate-arid regions (like maars in Puebla and Guanajuato states) show high alkalinity and pH, with bicarbonate/carbonate, chloride, sodium and magnesium as predominant ions. Lakes located in humid climates (Central Michoacán and Veracruz state) have low mineralization and near-neutral pH values. In general, conservative dissolved ions and conductivity appear to be mostly controlled by precipitation/evaporation and by the ionic concentration of groundwater inputs. Calcium, magnesium, sulfate concentrations and pH are strongly influenced by volcanic-rock or volcanic gas interactions with water. The influence of low-level volcanic activity on crater lakes may be obscured by water-rock interactions, and climatic factors. One of the aims of this paper is to define the relative influence of these factors searching for a reference frame to recognize the early volcanic precursors in volcano-related lakes.

  6. Spontaneous Potential Anomalies on Active Volcanoes: New Time and Spatial Series from Masaya, Telica, and Cerro Negro, Nicaragua

    NASA Astrophysics Data System (ADS)

    Lehto, H.; Pearson, S.; Connor, C.; Sanford, W.; Saballos, A.

    2006-12-01

    Considerable effort worldwide has gone into monitoring heat and mass transfer at active volcanoes because such information may provide clues about changes in volcanic activity and impending eruptions. Here we present new time and spatial series of spontaneous potential (SP) anomalies from Masaya and Telica volcanoes, and spatial series collected at Cerro Negro volcano. Our primary purpose is to investigate correlations between more easily and cheaply monitored SP and CO2 gas flux, measured by an infrared CO2 analysis system. SP data were collected using nonpolarizing Pb-PbCL2 electrodes that we constructed following the approach of Petiau. Mapping at both Masaya, and Cerro Negro reveals broad correlations between SP anomalies and CO2 flux through soils. In addition, we monitored temperature, barometric pressure, and rainfall at one minute intervals from May-August, 2006 at Masaya and Telica volcanoes. During this period it is clear that SP responds to changes in volcanic activity, with transient anomalies of 75 mV as well as atmospheric forcing due to rainfall, producing anomalies of 56 mV and related phenomena. Preliminary lab experiments provide further details of the electrokinetic origin of these SP anomalies. Our preliminary work supports the idea that large and inexpensive networks of electrodes might track changes in SP anomalies associated with changes in mass flow at active volcanoes.

  7. 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.

  8. Observing active deformation of volcanoes in North America: Geodetic data from the Plate Boundary Observatory and associated networks

    NASA Astrophysics Data System (ADS)

    Puskas, C. M.; Phillips, D. A.; Mattioli, G. S.; Meertens, C. M.; Hodgkinson, K. M.; Crosby, C. J.; Enders, M.; Feaux, K.; Mencin, D.; Baker, S.; Lisowski, M.; Smith, R. B.

    2013-12-01

    The EarthScope Plate Boundary Observatory (PBO), operated by UNAVCO, records deformation of the geologically diverse North America western plate boundary, with subnetworks of instruments concentrated at selected active and potentially active volcanoes. These sensors record deformation and earthquakes and allow monitoring agencies and researchers to analyze changes in ground motion and seismicity. The intraplate volcanoes at Yellowstone and Long Valley are characterized by uplift/subsidence cycles, high seismicity, and hydrothermal activity but there have been no historic eruptions at either volcano. PBO maintains dense GPS networks of 20-25 stations at each of these volcanoes, with an additional 5 boreholes at Yellowstone containing tensor strainmeters, short-period seismometers, and borehole tiltmeters. Subduction zone volcanoes in the Aleutian Arc have had multiple historic eruptions, and PBO maintains equipment at Augustine (8 GPS), Akutan (8 GPS, 4 tiltmeters), and Unimak Island (14 GPS, 8 tiltmeters). The Unimak stations are at the active Westdahl and Shishaldin edifices and the nearby, inactive Isanotski volcano. In the Cascade Arc, PBO maintains networks at Mount St. Helens (15 GPS, 4 borehole strainmeters and seismometers, 8 borehole tiltmeters), Shasta (7 GPS, 1 borehole strainmeter and seismometer), and Lassen Peak (8 GPS). Data from many of these stations in the Pacific Northwest and California are also provided as realtime streams of raw and processed data. Real-time GPS data, along with high-rate GPS data, will be an important new resource for detecting and studying future rapid volcanic deformation events and earthquakes. UNAVCO works closely with the USGS Volcano Hazards Program, archiving data from USGS GPS stations in Alaska, Cascadia, and Long Valley. The PBO and USGS networks combined provide more comprehensive coverage than PBO alone, particularly of the Cascade Arc, where the USGS maintains a multiple instruments near each volcano. Ground

  9. Vailulu’u Seamount, Samoa: Life and death on an active submarine volcano

    PubMed Central

    Staudigel, Hubert; Hart, Stanley R.; Pile, Adele; Bailey, Bradley E.; Baker, Edward T.; Brooke, Sandra; Connelly, Douglas P.; Haucke, Lisa; German, Christopher R.; Hudson, Ian; Jones, Daniel; Koppers, Anthony A. P.; Konter, Jasper; Lee, Ray; Pietsch, Theodore W.; Tebo, Bradley M.; Templeton, Alexis S.; Zierenberg, Robert; Young, Craig M.

    2006-01-01

    Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu’u seamount. Nafanua grew from the 1,000-m-deep crater floor in <4 years and could reach the sea surface within decades. Vents fill Vailulu’u crater with a thick suspension of particulates and apparently toxic fluids that mix with seawater entering from the crater breaches. Low-temperature vents form Fe oxide chimneys in many locations and up to 1-m-thick layers of hydrothermal Fe floc on Nafanua. High-temperature (81°C) hydrothermal vents in the northern moat (945-m water depth) produce acidic fluids (pH 2.7) with rising droplets of (probably) liquid CO2. The Nafanua summit vent area is inhabited by a thriving population of eels (Dysommina rugosa) that feed on midwater shrimp probably concentrated by anticyclonic currents at the volcano summit and rim. The moat and crater floor around the new volcano are littered with dead metazoans that apparently died from exposure to hydrothermal emissions. Acid-tolerant polychaetes (Polynoidae) live in this environment, apparently feeding on bacteria from decaying fish carcasses. Vailulu’u is an unpredictable and very active underwater volcano presenting a potential long-term volcanic hazard. Although eels thrive in hydrothermal vents at the summit of Nafanua, venting elsewhere in the crater causes mass mortality. Paradoxically, the same anticyclonic currents that deliver food to the eels may also concentrate a wide variety of nektonic animals in a death trap of toxic hydrothermal fluids. PMID:16614067

  10. Acoustic Recordings of Strombolian and Subplinian Activity at Shishaldin Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    Caplan-Auerbach, J.; McNutt, S. R.; Vergniolle, S.; Boichu, M.

    2002-05-01

    New data from a pressure sensor provide a detailed perspective on the 1999 eruption of Shishaldin volcano, Alaska. The eruption was well monitored by a 6-station seismic network and frequent satellite passes, but visual observations were minimal. To refine our interpretation of the 1999 eruption we investigate acoustic data recorded on a pressure sensor 6.5 km north of Shishaldin. Three types of acoustic signals were identified, representing different types of eruptive behavior. On April 19, 1999 the pressure sensor recorded a monotonic (2-3 Hz) hum that grew in amplitude for more than 13 hours. At 19:35 UTC on April 19, the humming signal abruptly ended and seismic tremor amplitude increased dramatically. Four minutes later, a broadband (1-15 Hz) signal was recorded on both the pressure sensor and the seismometers, suggesting the onset of the main Subplinian phase. The Subplinian phase appears in the acoustic record as a 50-min broadband signal, over which several low-frequency bursts are superimposed. The final acoustic phase detected by the pressure sensor was a series of discrete pulses, interpreted to be strong Strombolian gas explosions. The strongest explosions, recorded on April 23rd were associated with a small, ash-poor plume and strong seismic tremor. In time series, these events are similar to gas explosions observed at other volcanoes such as Stromboli and Karymsky, but are of lower frequency (1-2 Hz) and are 1-2 orders of magnitude (up to 60 Pa at 6.5 km) larger. Waveform modeling allows us to constrain the size and overpressure of the bubbles, as well as the amount of gas and magma released during the Strombolian phase of the eruption. The acoustic data may be used to investigate the change from Strombolian activity to Subplinian, and back to Strombolian. The 1999 Shishaldin eruption shows that pressure sensors can serve as an excellent complement to traditional means of monitoring remote volcanoes.

  11. Volcano hazards in the San Salvador region, El Salvador

    USGS Publications Warehouse

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

    2001-01-01

    communities. Another concern is a landslide and an associated debris flow (a watery flow of mud, rock, and debris--also known as a lahar) that could occur during periods of no volcanic activity. An event of this type occurred in 1998 at Casita volcano in Nicaragua when extremely heavy rainfall from Hurricane Mitch triggered a landslide that moved down slope and transformed into a rapidly moving debris flow that destroyed two villages and killed more than 2000 people. Historical landslides up to a few hundred thousand cubic meters in volume have been triggered on San Salvador volcano by torrential rainstorms and earthquakes, and some have transformed into debris flows that have inundated populated areas down stream. Destructive rainfall- and earthquake-triggered landslides and debris flows on or near San Salvador volcano in September 1982 and January 2001 demonstrate that such mass movements in El Salvador have also been lethal. This report describes the kinds of hazardous events that occur at volcanoes in general and the kinds of hazardous geologic events that have occurred at San Salvador volcano in the past. The accompanying volcano-hazards-zonation maps show areas that are likely to be at risk when hazardous events occur again.

  12. Origin and distribution of thiophenes and furans in gas discharges from active volcanoes and geothermal systems.

    PubMed

    Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

    2010-03-31

    The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C(2)-C(20) species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C(4)H(8)O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection.

  13. 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.

  14. Relationship between fumarole gas composition and eruptive activity at Galeras Volcano, Colombia

    SciTech Connect

    Fischer, T.P.; Williams, S.N.; Arehart, G.B.; Sturchio, N.C.

    1996-06-01

    Forecasting volcanic eruptions is critical to the mitigation of hazards for the millions of people living dangerously close to active volcanoes. Volcanic gases collected over five years from Galeras Volcano, Colombia, and analyzed for chemical and isotopic composition show the effects of long-term degassing of the magma body and a gradual decline in sulfur content of the gases. In contrast, short-term (weeks), sharp variations are the precursors to explosive eruptions. Selective absorption of magmatic SO{sub 2} and HCl due to interaction with low-temperature geothermal waters allows the gas emissions to become dominated by CO{sub 2}. Absorption appears to precede an eruption because magmatic volatiles are slowed or retained by a sealing carapace, reducing the total flux of volatiles and allowing the hydrothermal volatiles to dominate gas emissions. Temporal changes in gas compositions were correlated with eruptive activity and provide new evidence bearing on the mechanism of this type of `pneumatic` explosive eruptions. 18 refs., 5 figs.

  15. Carbonado-like diamond from the Avacha active volcano in Kamchatka, Russia

    NASA Astrophysics Data System (ADS)

    Kaminsky, Felix V.; Wirth, Richard; Anikin, Leonid P.; Morales, Luiz; Schreiber, Anja

    2016-11-01

    In addition to a series of finds of diamond in mafic volcanic and ultramafic massive rocks in Kamchatka, Russia, a carbonado-like diamond aggregate was identified in recent lavas of the active Avacha volcano. This aggregate differs from 'classic carbonado' by its location within an active volcanic arc, well-formed diamond crystallites, and cementing by Si-containing aggregates rather than sintering. The carbonado-like aggregate contains inclusions of Mn-Ni-Si-Fe alloys, native β-Mn, tungsten and boron carbides, which are uncommon for both carbonado and monocrystalline diamonds. Mn-Ni-Si-Fe alloys, trigonal W2C and trigonal B4C are new mineral species that were not previously found in the natural environment. The formation of the carbonado-like diamond aggregate started with formation at 850-1000 °C of tungsten and boron carbides, Mn-Ni-Si-Fe alloys and native β-Mn, which were used as seeds for the subsequent crystallization of micro-sized diamond aggregate. In the final stage, the diamond aggregate was cemented by amorphous silica, tridymite, β-SiC, and native silicon. The carbonado-like aggregate was most likely formed at near-atmospheric pressure conditions via the CVD mechanism during the course or shortly after one of the volcanic eruption pulses of the Avacha volcano. Volcanic gases played a great role in the formation of the carbonado-like aggregate.

  16. Origin and Distribution of Thiophenes and Furans in Gas Discharges from Active Volcanoes and Geothermal Systems

    PubMed Central

    Tassi, Franco; Montegrossi, Giordano; Capecchiacci, Francesco; Vaselli, Orlando

    2010-01-01

    The composition of non-methane organic volatile compounds (VOCs) determined in 139 thermal gas discharges from 18 different geothermal and volcanic systems in Italy and Latin America, consists of C2–C20 species pertaining to the alkanes, alkenes, aromatics and O-, S- and N-bearing classes of compounds. Thiophenes and mono-aromatics, especially the methylated species, are strongly enriched in fluids emissions related to hydrothermal systems. Addition of hydrogen sulphide to dienes and electrophilic methylation involving halogenated radicals may be invoked for the formation of these species. On the contrary, the formation of furans, with the only exception of C4H8O, seems to be favoured at oxidizing conditions and relatively high temperatures, although mechanisms similar to those hypothesized for the production of thiophenes can be suggested. Such thermodynamic features are typical of fluid reservoirs feeding high-temperature thermal discharges of volcanoes characterised by strong degassing activity, which are likely affected by conspicuous contribution from a magmatic source. The composition of heteroaromatics in fluids naturally discharged from active volcanoes and geothermal areas can then be considered largely dependent on the interplay between hydrothermal vs. magmatic contributions. This implies that they can be used as useful geochemical tools to be successfully applied in both volcanic monitoring and geothermal prospection. PMID:20480029

  17. Monitoring Monitoring Evolving Activity at Popocatepetl Volcano, Mexico, 2000-2001

    NASA Astrophysics Data System (ADS)

    Martin-DelPozzo, A.; Aceves, F.; Bonifaz, R.; Humberto, S.

    2001-12-01

    After 6 years of small eruptions, activity at Mexico's 5,452m high Popocatepetl Volcano in central Mexico, peaked in the December 2000-January 2001 eruptions. Precursors included an important increase in seismicity as well as in magmatic components of spring water and small scale deformation which resulted in growth of a new crater dome from January 16 on. Evacuation of the towns nearest the volcano over Christmas was decided because of the possibility of pyroclastic flows. During the previous years, crater dome growth, contraction and explosive clearing has dominated the activity. The January 22 eruption produced an eruption column approximately 17km high with associated pyroclastic flows. Ejecta was composed of both basic and evolved scoria and pumice and dome lithics. A large proportion of the juvenile material was intermediate between these 2 endmenbers (59-63percent SiO2 and 3.5 to 5.5 MgO) consistent with a small basic pulse entering a more evolved larger batch of magma. The January eruption left a large pit which has been partially infilled by another crater dome this August 2001.

  18. How caldera collapse shapes the shallow emplacement and transfer of magma in active volcanoes

    NASA Astrophysics Data System (ADS)

    Corbi, F.; Rivalta, E.; Pinel, V.; Maccaferri, F.; Bagnardi, M.; Acocella, V.

    2015-12-01

    Calderas are topographic depressions formed by the collapse of a partly drained magma reservoir. At volcanic edifices with calderas, eruptive fissures can circumscribe the outer caldera rim, be oriented radially and/or align with the regional tectonic stress field. Constraining the mechanisms that govern this spatial arrangement is fundamental to understand the dynamics of shallow magma storage and transport and evaluate volcanic hazard. Here we show with numerical models that the previously unappreciated unloading effect of caldera formation may contribute significantly to the stress budget of a volcano. We first test this hypothesis against the ideal case of Fernandina, Galápagos, where previous models only partly explained the peculiar pattern of circumferential and radial eruptive fissures and the geometry of the intrusions determined by inverting the deformation data. We show that by taking into account the decompression due to the caldera formation, the modeled edifice stress field is consistent with all the observations. We then develop a general model for the stress state at volcanic edifices with calderas based on the competition of caldera decompression, magma buoyancy forces and tectonic stresses. These factors control: 1) the shallow accumulation of magma in stacked sills, consistently with observations; 2) the conditions for the development of circumferential and/or radial eruptive fissures, as observed on active volcanoes. This top-down control exerted by changes in the distribution of mass at the surface allows better understanding of how shallow magma is transferred at active calderas, contributing to forecasting the location and type of opening fissures.

  19. 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.

  20. 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.

  1. The structure of the Campanian Plain and the activity of the Neapolitan volcanoes (Italy)

    NASA Astrophysics Data System (ADS)

    Scandone, Roberto; Bellucci, Francesca; Lirer, Lucio; Rolandi, Giuseppe

    1991-08-01

    The central Campanian Plain is dominated by the structural depression of Acerra whose origin is tectonic, but may have been enlarged and further depressed after the eruption of the Campanian Ignimbrite (42-25 ka). The deposits of the Campanian Ignimbrite are possibly the results of multiple eruptions with huge pyroclastic deposits that covered all the Campanian Plain. The more recent activity of Vesuvius, Campi Flegrei and Procida occurred on the borders of Acerra depression and resulted from a reactivation of regional faults after the Campanian Ignimbrite cycle. The activity of Vesuvius produced the building of a stratovolcano mostly by effusive and plinian explosive eruptions. The Campi Flegrei area, on the contrary, was dominated by the eruption of the Neapolitan Yellow Tuff at 12 ka that produced a caldera collapse of the Gulf of Pozzuoli. The caldera formation controlled the emplacement of the recent activity of Campi Flegrei and the new volcanoes were formed only within the caldera or along its rim.

  2. 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

  3. Social studies of volcanology: knowledge generation and expert advice on active volcanoes

    NASA Astrophysics Data System (ADS)

    Donovan, Amy; Oppenheimer, Clive; Bravo, Michael

    2012-04-01

    This paper examines the philosophy and evolution of volcanological science in recent years, particularly in relation to the growth of volcanic hazard and risk science. It uses the lens of Science and Technology Studies to examine the ways in which knowledge generation is controlled and directed by social forces, particularly during eruptions, which constitute landmarks in the development of new technologies and models. It also presents data from a survey of volcanologists carried out during late 2008 and early 2009. These data concern the felt purpose of the science according to the volcanologists who participated and their impressions of the most important eruptions in historical time. It demonstrates that volcanologists are motivated both by the academic science environment and by a social concern for managing the impact of volcanic hazards on populations. Also discussed are the eruptions that have most influenced the discipline and the role of scientists in policymaking on active volcanoes. Expertise in volcanology can become the primary driver of public policy very suddenly when a volcano erupts, placing immense pressure on volcanologists. In response, the epistemological foundations of volcanology are on the move, with an increasing volume of research into risk assessment and management. This requires new, integrated methodologies for knowledge collection that transcend scientific disciplinary boundaries.

  4. 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.

  5. Vein networks in hydrothermal systems provide constraints for the monitoring of active volcanoes.

    PubMed

    Cucci, Luigi; Di Luccio, Francesca; Esposito, Alessandra; Ventura, Guido

    2017-12-01

    Vein networks affect the hydrothermal systems of many volcanoes, and variations in their arrangement may precede hydrothermal and volcanic eruptions. However, the long-term evolution of vein networks is often unknown because data are lacking. We analyze two gypsum-filled vein networks affecting the hydrothermal field of the active Lipari volcanic Island (Italy) to reconstruct the dynamics of the hydrothermal processes. The older network (E1) consists of sub-vertical, N-S striking veins; the younger network (E2) consists of veins without a preferred strike and dip. E2 veins have larger aperture/length, fracture density, dilatancy, and finite extension than E1. The fluid overpressure of E2 is larger than that of E1 veins, whereas the hydraulic conductance is lower. The larger number of fracture intersections in E2 slows down the fluid movement, and favors fluid interference effects and pressurization. Depths of the E1 and E2 hydrothermal sources are 0.8 km and 4.6 km, respectively. The decrease in the fluid flux, depth of the hydrothermal source, and the pressurization increase in E2 are likely associated to a magma reservoir. The decrease of fluid discharge in hydrothermal fields may reflect pressurization at depth potentially preceding hydrothermal explosions. This has significant implications for the long-term monitoring strategy of volcanoes.

  6. 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

  7. Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system.

    PubMed

    Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

    2016-06-17

    Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report (3)He/(4)He measurements in CO2-dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a (3)He/(4)He signature of at least 7.0 Ra (being Ra the (3)He/(4)He ratio of atmospheric He equal to 1.39×10(-6)), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like (3)He/(4)He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano.

  8. Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system

    PubMed Central

    Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N.; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

    2016-01-01

    Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report 3He/4He measurements in CO2–dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a 3He/4He signature of at least 7.0 Ra (being Ra the 3He/4He ratio of atmospheric He equal to 1.39×10−6), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like 3He/4He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano. PMID:27311383

  9. Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system

    NASA Astrophysics Data System (ADS)

    Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N.; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

    2016-06-01

    Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report 3He/4He measurements in CO2–dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a 3He/4He signature of at least 7.0 Ra (being Ra the 3He/4He ratio of atmospheric He equal to 1.39×10‑6), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like 3He/4He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano.

  10. Volcanic activity observed from continuous seismic records in the region of the Klyuchevskoy group of volcanoes

    NASA Astrophysics Data System (ADS)

    Shapiro, N.; Droznin, D.; Droznina, S.; Senyukov, S.; Chebrov, V.; Gordeev, E.; Frank, W.

    2014-12-01

    We analyze continuous seismic records from 18 permanent stations operated in vicinity of the Klyuchevskoy group of volcanos (Kamchatka, Russia) during the period between 2009 and 2014. We explore the stability of the inter-station cross-correlation to detect different periods of sustained emission from seismic energy. The main idea of this approach is that cross-correlation waveforms computed from a wavefield emitted by a seismic source from a fixed position remain stable during the period when this source is acting. The detected periods of seismic emission correspond to different episodes of activity of volcanoes: Klyuchevskoy, Tolbachik, Shiveluch, and Kizimen. For Klyuchevskoy and Tolbachik whose recent eruptions are mostly effusive, the detected seismic signals correspond to typical volcanic tremor, likely caused by degassing processes. For Shiveluch and Kizimen producing more silicic lavas, the observed seismic emission often consists of many repetitive long period (LP) seismic events that might be related to the extrusion of viscous magmas. We develop an approach for automatic detection of these individual LP events in order to characterize variations of their size and recurrence in time.

  11. Volcanic activity observed from continuous seismic records in the region of the Klyuchevskoy group of volcanoes

    NASA Astrophysics Data System (ADS)

    Shapiro, N.; Droznin, D.; Droznina, S.; Senyukov, S.; Chebrov, V.; Gordeev, E.; Frank, W.

    2015-12-01

    We analyze continuous seismic records from 18 permanent stations operated in vicinity of the Klyuchevskoy group of volcanos (Kamchatka, Russia) during the period between 2009 and 2014. We explore the stability of the inter-station cross-correlation to detect different periods of sustained emission from seismic energy. The main idea of this approach is that cross-correlation waveforms computed from a wavefield emitted by a seismic source from a fixed position remain stable during the period when this source is acting. The detected periods of seismic emission correspond to different episodes of activity of volcanoes: Klyuchevskoy, Tolbachik, Shiveluch, and Kizimen. For Klyuchevskoy and Tolbachik whose recent eruptions are mostly effusive, the detected seismic signals correspond to typical volcanic tremor, likely caused by degassing processes. For Shiveluch and Kizimen producing more silicic lavas, the observed seismic emission often consists of many repetitive long period (LP) seismic events that might be related to the extrusion of viscous magmas. We develop an approach for automatic detection of these individual LP events in order to characterize variations of their size and recurrence in time.

  12. Marine-to-lacustrine transition, mud volcanism, and slope instability in an active tectonic setting: the MIS 5 to 4 transition in the Sea of Marmara, Turkey

    NASA Astrophysics Data System (ADS)

    Grall, Céline; Henry, Pierre; Kendé, Julia; Namık Çaǧatay, M.; Kadir Eriş, K.; Paillès, Christine; Sorlien, Christopher; Shillington, Donna; McHugh, Cecilia; Steckler, Michael; Çifçi, Günay; Géli, Louis

    2016-04-01

    MTDs. At the transition from Marine Isotope Stage (MIS) 5 to 4, sea-level fell from 25 to 85 m below the modern sea-level resulting in the disconnection of the Sea of Marmara. Sapropels deposited on the shelf before the disconnection and are attributed to MIS-5 (Cagatay et al. 2009). Grall et al, (2014) proposed that MTDs found above the Red-H1 were deposited at the beginning of MIS-4 at ~70 ka and that MTD complexes found during earlier glacial cycles also accumulated after marine to lacustrine-disconnections, possibly in relation with hydrate dissociation and/or clay swelling. Buried mud volcanoes located within the NNAF damage zone pierce the Red-H1 reflector but not the reflector above, suggesting that the last main eruption may also happens at the beginning of MIS-4. We will present preliminary assessment of the paleoenvironmental changes across the MIS-5 to 4 transition from bio-indicators and geochemistry.

  13. Late Holocene phases of dome growth and Plinian activity at Guagua Pichincha volcano (Ecuador)

    NASA Astrophysics Data System (ADS)

    Robin, Claude; Samaniego, Pablo; Le Pennec, Jean-Luc; Mothes, Patricia; van der Plicht, Johannes

    2008-09-01

    Since the eruption which affected Quito in AD 1660, Guagua Pichincha has been considered a hazardous volcano. Based on field studies and twenty 14C dates, this paper discusses the eruptive activity of this volcano, especially that of the last 2000 years. Three major Plinian eruptions with substantial pumice discharge occurred in the 1st century, the 10th century, and in AD 1660. The ages of organic paleosols and charcoal from block-and-ash flow and fallout deposits indicate that these eruptions occurred near the end of 100 to 200 year-long cycles of discontinuous activity which was comprised of dome growth episodes and minor pumice fallouts. The first cycle took place from ~ AD 1 to 140. The second one developed during the 9th and 10th centuries, lasted 150-180 yr, and included the largest Plinian event, with a VEI of 5. The third, historic cycle, about 200 yr in duration, includes pyroclastic episodes around AD 1450 and AD 1500, explosive activity between AD 1566 and AD 1582, possible precursors of the 1660 eruption in the early decades of the 17th century, and finally the 1660 eruption (VEI 4). A fourth event probably occurred around AD 500, but its authenticity requires confirmation. The Plinian events occurred at the end of these cycles which were separated by repose periods of at least 300 yr. Older volcanic activity of similar type occurred between ~ 4000 and ~ 3000 yr BP. Because ash fallout and related mudflows represent a serious hazard for Quito's metropolitan area, the significance of the increasing phreatic activity observed from 1981 to 1998, and the 1999-2001 magmatic episode of dome growth and collapse are discussed. These probably represent a short step in a longer evolution which may result in a major Plinian event in the future decades or in the next century, comparable to that which occurred during the 1st, 10th, and 17th centuries.

  14. Subglacial melting associated with activity at Bárdarbunga volcano, Iceland, explored using numerical reservoir simulations

    NASA Astrophysics Data System (ADS)

    Reynolds, Hannah I.; Gudmundsson, Magnús T.; Högnadóttir, Thórdís

    2015-04-01

    Increased seismic activity was observed within the caldera of Bárdarbunga, a central volcano beneath Vatnajökull glacier, on 16 August 2014. The seismicity traced the path of a lateral dyke, initially propagating to the south east of the volcano, before changing course and continuing beyond the northern extent of the glacier. A short fissure eruption occurred at the site of the Holuhraun lavas on 29 August, lasting for approximately 5 hours and producing less than 1 million cubic meters of lava, before recommencing in earnest on 31 August with the large effusive eruption, which is still ongoing at the time of writing. The glacier surface has been monitored aerially since the onset of heightened seismic activity, and the caldera and dyke propagation path surveyed using radar profiling. Ice cauldrons are shallow depressions which form on the glacier surface due to basal melting, as a manifestation of heat flux from below; the melting ice acts as a calorimeter, allowing estimations of heat flux magnitude to be made. Several cauldrons were observed outside the caldera, two to the south east of Bárdarbunga, and three located above the path of the dyke under the Dyngjujökull outlet glacier. The cauldrons range in volume from approximately 0.001 km3 to 0.02 km3. We present time series data of the development and evolution of these cauldrons, with estimates of the heat flux magnitudes involved. The nature of the heat source required to generate the aforementioned cauldrons is not obvious and two scenarios are explored: 1) small subglacial eruptions; or 2) increased geothermal activity induced by the dyke intrusion. We investigate these scenarios using analytical and finite element modelling, considering the surface heat flux produced, and timescales and spatial extent of associated surface anomalies. A range of permeabilities has been explored. It is found that an intrusion of a dyke or sill into rocks where the groundwater is near or at the boiling point curve can

  15. Santa Maria Volcano, Guatemala

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The eruption of Santa Maria volcano in 1902 was one of the largest eruptions of the 20th century, forming a large crater on the mountain's southwest flank. Since 1922, a lava-dome complex, Santiaguito, has been forming in the 1902 crater. Growth of the dome has produced pyroclastic flows as recently as the 2001-they can be identified in this image. The city of Quezaltenango (approximately 90,000 people in 1989) sits below the 3772 m summit. The volcano is considered dangerous because of the possibility of a dome collapse such as one that occurred in 1929, which killed about 5000 people. A second hazard results from the flow of volcanic debris into rivers south of Santiaguito, which can lead to catastrophic flooding and mud flows. More information on this volcano can be found at web sites maintained by the Smithsonian Institution, Volcano World, and Michigan Tech University. ISS004-ESC-7999 was taken 17 February 2002 from the International Space Station using a digital camera. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Searching and viewing of additional images taken by astronauts and cosmonauts is available at the NASA-JSC Gateway to

  16. Volcanic activity in the Acambay Graben: a < 25 Ka subplinian eruption from the Temascalcingo volcano and implications for volcanic hazard.

    NASA Astrophysics Data System (ADS)

    Pedrazzi, Dario; Aguirre Díaz, Gerardo; Sunyé Puchol, Ivan; Bartolini, Stefania; Geyer, Adelina

    2016-04-01

    The Trans-Mexican Volcanic Belt (TMVB) contains a large number of stratovolcanoes, some well-known, as Popocatepetl, Iztaccihuatl, Nevado de Toluca, or Colima and many others of more modest dimensions that are not well known but constitute the majority in the TMVB. Such volcanoes are, for example, Tequila, San Juan, Sangangüey, Cerro Culiacán, Cerro Grande, El Zamorano, La Joya, Palo Huerfano, Jocotitlán, Altamirano and Temascalcingo, among many others. The Temascalcingo volcano (TV) is an andesitic-dacitic stratovolcano located in the Trans-Mexican Volcanic Belt (TMVB) at the eastern part of the Acambay Graben (northwest portion of Estado de México). The TV is composed mainly by dacitic, porphyritic lavas, block and ash deposits and subordinate pumice fall deposits and ignimbrites (Roldán-Quintana et al., 2011). The volcanic structure includes a summit caldera that has a rectangular shape, 2.5×3.5 km, with the largest side oriented E-W, parallel to major normal faults affecting the edifice. The San Mateo Pumice eruption is one of the greatest paroxysmal episodes of this volcano with pumice deposits mainly exposed at the scarp of the Acambay-Tixmadeje fault and at the northern and northeastern flanks of TV. It overlies a paleosol dated at 25 Ka. A NE-trending dispersion was obtained from field data covering an area of at least 80 km2. These deposits overlie older lava flows and mud flows and are discontinuously covered and eroded by younger reworked deposits of Temascalcingo volcano. This event represents a highly explosive phase that generated a relatively thick and widespread pumice fallout deposit that may occur again in future eruptions. A similar eruption today would have a significantly impact in the region, overall due to the fact that there has been no systematic assessment of the volcanic hazard in any of the studies that have been conducted so far in the area. So, this is a pending and urgent subject that must be tackled without delay. Financed by

  17. 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.

  18. Chlorine isotopes of thermal springs in arc volcanoes for tracing shallow magmatic activity

    NASA Astrophysics Data System (ADS)

    Li, Long; Bonifacie, Magali; Aubaud, Cyril; Crispi, Olivier; Dessert, Céline; Agrinier, Pierre

    2015-03-01

    The evaluation of the status of shallow magma body (i.e., from the final intrusion stage, to quiescence, and back to activity), one of the key parameters that trigger and sustain volcanic eruptions, has been challenging in modern volcanology. Among volatile tracers, chlorine (Cl) uniquely exsolves at shallow depths and is highly hydrophilic. Consequently, Cl enrichment in volcanic gases and thermal springs has been proposed as a sign for shallow magmatic activities. However, such enrichment could also result from numerous other processes (e.g., water evaporation, dissolution of old chloride mineral deposits, seawater contamination) that are unrelated to magmatic activity. Here, based on stable isotope compositions of chloride and dissolved inorganic carbon, as well as previous published 3He/4He data obtained in thermal springs from two recently erupted volcanoes (La Soufrière in Guadeloupe and Montagne Pelée in Martinique) in the Lesser Antilles Arc, we show that the magmatic Cl efficiently trapped in thermal springs displays negative δ37Cl values (≤ - 0.65 ‰), consistent with a slab-derived origin but distinct from the isotope compositions of chloride in surface reservoirs (e.g. seawater, local meteoric waters, rivers and cold springs) displaying common δ37Cl values of around 0‰. Using this δ37Cl difference as an index of magmatic Cl, we further examined thermal spring samples including a 30-year archive from two thermal springs in Guadeloupe covering samples from its last eruption in 1976-1977 to 2008 and an island-wide sampling event in Martinique in 2008 to trace the evolution of magmatic Cl in the volcanic hydrothermal systems over time. The results show that magmatic Cl can be rapidly flushed out of the hydrothermal systems within <30 to 80 years after the eruption, much quicker than other volatile tracers such as CO2 and noble gases, which can exsolve at greater depths and constantly migrate to the surface. Because arc volcanoes often have well

  19. The Onset of Channelling in a Fluidized Mud Layer

    NASA Astrophysics Data System (ADS)

    Papanicolaou, T.; Tsakiris, A. G.; Billing, B. M.

    2012-12-01

    Fluidization of a soil occurs when the drag force exerted on the soil grains by upwelling water equals the submerged weight of the soil grains, hence reducing the effective (or contact) stress between the soil grains to zero. In nature, fluidization is commonly encountered in localized portions of highly saturated mud layers found in tidal flats, estuaries and lakes, where upward flow is initiated by significant pore water pressure gradients triggered by wave or tidal action. The water propagates through the fluidized mud layer by forming channels (or vents), carrying the fluidized mud to the surface and forming mud volcano structures. The presence of these fluidization channels alters the mud layer structure with implications on its hydraulic and geotechnical properties, such as the hydraulic conductivity. Despite the importance of these channels, the conditions that lead to their formation and their effects on the mud layer structure still remain poorly documented. The present study couples experimental and theoretical methods aimed at quantifying the conditions, under which fluidization of a saturated mud layer is accompanied by the formation of channels, and assessing the effects of channeling on the mud layer structure. Fluidization and channel formation in a mud layer were reproduced in the laboratory using a carefully designed fluidization column attached to a pressurized vessel (plenum). To eliminate any effects of the material, the mud was produced from pure kaolin clay and deionized water. Local porosity measurements along the mud layer prior, during and after fluidization were conducted using an Americium-241 gamma source placed on a fully automated carriage. Different water inflow rates, q, were applied to the base of the mud layer and the plenum pressure was monitored throughout the experiment. These experiments revealed that for high q values, a single vertical channel formed and erupted at the center of the fluidization column. Instead for low q

  20. The Pulse of the Volcano: Discovery of Episodic Activity at Prometheus on Io

    NASA Technical Reports Server (NTRS)

    Davies, A. G.

    2003-01-01

    The temporal behaviour of thermal output from a volcano yields valuable clues to the processes taking place at and beneath the surface. Galileo Near Infrared Mapping Spectrometer (NIMS) data show that the ionian volcanoes Prometheus and Amirani have significant thermal emission in excess of nonvolcanic background emission in every geometrically appropriate NIMS observation. The 5 micron brightness of these volcanoes shows considerable variation from orbit to orbit. Prometheus in particular exhibits an episodicity that yields valuable constraints to the mechanisms of magma supply and eruption. This work is part of an on-going study to chart and quantify the thermal emission of Io's volcanoes, determine mass eruption rates, and note eruption style.

  1. Icelandic Volcanoes Geohazard Supersite and FUTUREVOLC: role of interferometric synthetic aperture radar to identify renewed unrest and track magma movement beneath the most active volcanoes in Iceland

    NASA Astrophysics Data System (ADS)

    Parks, Michelle; Dumont, Stéphanie; Spaans, Karsten; Drouin, Vincent; Sigmundsson, Freysteinn; Hooper, Andrew; Michalczewska, Karolina; Ófeigsson, Benedikt

    2014-05-01

    FUTUREVOLC is an integrated volcano monitoring project, funded by the European Commission (FP7) and led by the University of Iceland and the Icelandic Meteorological Office (IMO). The project is a European collaborative effort, comprising 26 partners, aimed at integrating ground based and satellite observations for improved monitoring and evaluation of volcanic hazards. Iceland has also recently been declared a Geohazard Supersite by the Committee on Earth Observation Satellites, based on its propensity for relatively frequent eruptions and their potentially hazardous, long ranging effects. Generating a long-term time series of ground displacements is key to gaining a better understanding of sub-volcanic processes, including the detection of new melt and migration of magma within the crust. The focus of the FUTUREVOLC deformation team is to generate and interpret an extended time series of high resolution deformation measurements derived from InSAR observations, in the vicinity of the four most active volcanoes in Iceland: Grímsvötn, Katla, Hekla and Bárdarbunga. A comprehensive network of continuous deformation monitoring equipment, led by IMO and collaborators, is already deployed at these volcanoes, including GPS, tilt and borehole strainmeters. InSAR observations are complementary to field based measurements and their high spatial resolution assists in resolving the geometry and location of the source of the deformation. InSAR and tilt measurements at Hekla indicate renewed melt supply to a sub-volcanic reservoir after the last eruption in 2000. Recent deformation studies utilising data spanning this eruption, have provided insight into the shallow plumbing system which may explain the large reduction in eruption repose interval following the 1970 eruption. Although InSAR and GPS observations at Katla volcano (between 2001 and 2009) suggest no indication of magma induced deformation outside the ice-cap, it is possible that a small flood at Mýrdalsjökull in

  2. Broadband seismic monitoring of active volcanoes using deterministic and stochastic approaches

    NASA Astrophysics Data System (ADS)

    Kumagai, H.; Nakano, M.; Maeda, T.; Yepes, H.; Palacios, P.; Ruiz, M. C.; Arrais, S.; Vaca, M.; Molina, I.; Yamashina, T.

    2009-12-01

    We systematically used two approaches to analyze broadband seismic signals observed at active volcanoes: one is waveform inversion of very-long-period (VLP) signals in the frequency domain assuming possible source mechanisms; the other is a source location method of long-period (LP) and tremor using their amplitudes. The deterministic approach of the waveform inversion is useful to constrain the source mechanism and location, but is basically only applicable to VLP signals with periods longer than a few seconds. The source location method uses seismic amplitudes corrected for site amplifications and assumes isotropic radiation of S waves. This assumption of isotropic radiation is apparently inconsistent with the hypothesis of crack geometry at the LP source. Using the source location method, we estimated the best-fit source location of a VLP/LP event at Cotopaxi using a frequency band of 7-12 Hz and Q = 60. This location was close to the best-fit source location determined by waveform inversion of the VLP/LP event using a VLP band of 5-12.5 s. The waveform inversion indicated that a crack mechanism better explained the VLP signals than an isotropic mechanism. These results indicated that isotropic radiation is not inherent to the source and only appears at high frequencies. We also obtained a best-fit location of an explosion event at Tungurahua when using a frequency band of 5-10 Hz and Q = 60. This frequency band and Q value also yielded reasonable locations for the sources of tremor signals associated with lahars and pyroclastic flows at Tungurahua. The isotropic radiation assumption may be valid in a high frequency range in which the path effect caused by the scattering of seismic waves results in an isotropic radiation pattern of S waves. The source location method may be categorized as a stochastic approach based on the nature of scattering waves. We further applied the waveform inversion to VLP signals observed at only two stations during a volcanic crisis

  3. Volcanomagnetic signals associated with the quasi-continuous activity of the andesitic Merapi volcano, Indonesia: 1990-1995

    NASA Astrophysics Data System (ADS)

    Zlotnicki, J.; Bof, M.

    Merapi volcano in Java island (Indonesia) is an andesitic stratovolcano which presents long periods of effusive activity during which an endogeneous dome is continuously growing. The viscous lava dome gives rise to unstable blocks which collapse or turn into pyroclastic flows. When the volcano does not exhibit any surface activity, the overpressure within the volcano slowly increases. Depending on the quietness duration, the unrest of the volcano can start with an explosive phase during which the former dome is partly destroyed. Magnetic variations of different time constant are observed during the 1990-1995 period which includes one gas plume emission on August 26, 1990 and two eruptions on January 20, 1992 and on November 22, 1994. Compared with other types of active volcanoes, the observed volcanomagnetic variations are very small, at the most a few nanoteslas (nT). To discriminate the variations associated with the global activity from the signals correlated with each unrest phase, one has to dissociate the different time constant variations over the six-year time span. When long-term trends are removed from the magnetic field in each station of the network, an outstanding correlation between all the magnetic differences is emphasised. The midterm variations point out 2 cycles of activity which fit the stress field evolution within the edifice leading to the 1992 and 1994 eruptions. A new cycle has started in May 1995. In every identified cycle, rapid volcanomagnetic signals are well associated with stress field changes (May 1991, September 1991, February 1993, December 1993, …). Some of the volcanomagnetic variations are short-term precursory signals as the three months decrease, up to 1.3 nT, preceding the 1992 eruption. The comparison between magnetic data, seismicity and surface phenomena implies that the midterm volcanomagnetic variations associated with the cycles of Merapi activity are of piezomagnetic origin.

  4. 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.

  5. 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

  6. Predicting mud toxicity

    SciTech Connect

    Bleler, R. )

    1991-10-01

    Acute toxicity of drilling muds is measured in the U.S. by the mysid shrimp test. Drilling muds that fail the test cannot be discharged into the Gulf of Mexico, and such muds and their cuttings must be brought onshore for disposal. Discharge of water-based muds that pass the test is permitted in most instances. Because of the economic implications associated with hauling cuttings and fluids, a model that predicts test results on the basis of mud composition is clearly desirable. This paper focuses on the modeling of mysid shrimp test data. European laboratories use different test species and procedures. It seems plausible to expect, however, that the line of reasoning used here could apply to the modeling of aquatic data on other test species once a sufficient quantity of such data becomes available.

  7. Developments in analysis of basaltic ash applied to recent activity at Etna and Stromboli volcanoes

    NASA Astrophysics Data System (ADS)

    Lautze, N. C.; Taddeucci, J.; Andronico, D.; Tornetta, L.; Cannata, C.; Houghton, B. F.; Cristaldi, A.

    2009-12-01

    Advances in analytical techniques coupled with recent high levels of activity at Etna and Stromboli have offered a unique opportunity to sample and analyze of basaltic ash particles. We have performed new micro-scale analysis of basaltic ash from a variety of eruptive conditions: a weak ash-producing event at Etna on 11 November 2006, ash emission, paroxysmal explosions and lava-sea water interaction during the 2007 eruptive crisis of Stromboli volcano, and finally more typical Strombolian activity in 2008 at Stromboli. Etna samples were collected at eight locations between 2 and 20 km from source. Stromboli samples were collected between 28 February and 19 March 2007, and from single explosions in September 2008. A JEOL JSM 6500 Field Emission Scanning Electron Microprobe (FE-SEM) was used to image and quantify millimeter- to submicron-scale features of ash particles. Beside qualitative observation of the particles, semi-automated FE-SEM data include particle morphoscopy (area, perimeter, compactness, equivalent diameter) and surface chemistry. The morphoscopy data can be compared to grain size data collected by conventional techniques, while the surface chemistry data can be considered a proxy for component analysis, more typically performed using a binocular microscope, as it reflects the degree of crystallinity and alteration of the particles. Preliminary data indicate that insight into the particle source and eruptive dynamics of both volcanoes can be obtained from detailed analysis of the ash. In particular, the different sources of ash at Stromboli have highly distinctive alteration signatures, while the Etna samples exemplify the potential of the approach to discern subtle differences in ash particles from the same plume collected at different locations, thus outlining relatively small-scale plume zonations.

  8. How caldera collapse shapes the shallow emplacement and transfer of magma in active volcanoes

    NASA Astrophysics Data System (ADS)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Bagnardi, Marco; Acocella, Valerio

    2016-04-01

    Calderas are topographic depressions formed by the collapse of a partly drained magma reservoir. At volcanic edifices with calderas, eruptive fissures can circumscribe the outer caldera rim, be oriented radially and/or align with the regional tectonic stress field. Constraining the mechanisms that govern this spatial arrangement is fundamental to understand the dynamics of shallow magma storage and transport and evaluate volcanic hazard. Here we use numerical models to show that the previously unappreciated unloading effect of caldera formation may contribute significantly to the stress budget of a volcano. We first test this hypothesis against the ideal case of Fernandina, Galápagos, where previous models only partly explained the peculiar pattern of circumferential and radial eruptive fissures and the geometry of the intrusions determined by inverting the deformation data. We show that by taking into account the decompression due to the caldera formation, the modeled edifice stress field is consistent with all the observation. We then develop a general model for the stress state at volcanic edifices with calderas based on the competition of caldera decompression, magma buoyancy forces and tectonic stresses. These factors control the shallow accumulation of magma in stacked sills, consistently with observations as well as the conditions for the development of circumferential and/or radial eruptive fissures, as observed on active volcanoes. This top-down control exerted by changes in the distribution of mass at the surface allows better understanding of how shallow magma is transferred at active calderas, contributing to forecasting the location and type of opening fissures.

  9. Seismicity and eruptive activity at Fuego Volcano, Guatemala: February 1975 -January 1977

    USGS Publications Warehouse

    Yuan, A.T.E.; McNutt, S.R.; Harlow, D.H.

    1984-01-01

    We examine seismic and eruptive activity at Fuego Volcano (14??29???N, 90?? 53???W), a 3800-m-high stratovolcano located in the active volcanic arc of Guatemala. Eruptions at Fuego are typically short-lived vulcanian eruptions producing ash falls and ash flows of high-alumina basalt. From February 1975 to December 1976, five weak ash eruptions occurred, accompanied by small earthquake swarms. Between 0 and 140 (average ??? 10) A-type or high-frequency seismic events per day with M > 0.5 were recorded during this period. Estimated thermal energies for each eruption are greater by a factor of 106 than cumulative seismic energies, a larger ratio than that reported for other volcanoes. Over 4000 A-type events were recorded January 3-7, 1977 (cumulative seismic energy ??? 109 joules), yet no eruption occurred. Five 2-hour-long pulses of intense seismicity separated by 6-hour intervals of quiescence accounted for the majority of events. Maximum likelihood estimates of b-values range from 0.7 ?? 0.2 to 2.1 ?? 0.4 with systematically lower values corresponding to the five intense pulses. The low values suggest higher stress conditions. During the 1977 swarm, a tiltmeter located 6 km southeast of Fuego recorded a 14 ?? 3 microradian tilt event (down to SW). This value is too large to represent a simple change in the elastic strain field due to the earthquake swarm. We speculate that the earthquake swarm and tilt are indicative of subsurface magma movement. ?? 1984.

  10. Utilization of red mud in cement production: a review.

    PubMed

    Liu, Xiaoming; Zhang, Na

    2011-10-01

    Red mud is a solid waste residue of the digestion of bauxite ores with caustic soda for alumina production. Its disposal remains a worldwide issue in terms of environmental concerns. During the past decades, extensive work has been done by a lot of researchers to develop various economic ways for the utilization of red mud. One of the economic ways is using red mud in cement production, which is also an efficient method for large-scale recycling of red mud. This paper provides a review on the utilization of red mud in cement production, and it clearly points out three directions for the use of red mud in cement production, namely the preparation of cement clinkers, production of composite cements as well as alkali-activated cements. In the present paper, the chemical and mineralogical characteristics of red mud are summarized, and the current progresses on these three directions are reviewed in detail.

  11. Volcano infrasound: A review

    NASA Astrophysics Data System (ADS)

    Johnson, Jeffrey Bruce; Ripepe, Maurizio

    2011-09-01

    Exploding volcanoes, which produce intense infrasound, are reminiscent of the veritable explosion of volcano infrasound papers published during the last decade. Volcano infrasound is effective for tracking and quantifying eruptive phenomena because it corresponds to activity occurring near and around the volcanic vent, as opposed to seismic signals, which are generated by both surface and internal volcanic processes. As with seismology, infrasound can be recorded remotely, during inclement weather, or in the dark to provide a continuous record of a volcano's unrest. Moreover, it can also be exploited at regional or global distances, where seismic monitoring has limited efficacy. This paper provides a literature overview of the current state of the field and summarizes applications of infrasound as a tool for better understanding volcanic activity. Many infrasound studies have focused on integration with other geophysical data, including seismic, thermal, electromagnetic radiation, and gas spectroscopy and they have generally improved our understanding of eruption dynamics. Other work has incorporated infrasound into volcano surveillance to enhance capabilities for monitoring hazardous volcanoes and reducing risk. This paper aims to provide an overview of volcano airwave studies (from analog microbarometer to modern pressure transducer) and summarizes how infrasound is currently used to infer eruption dynamics. It also outlines the relative merits of local and regional infrasound surveillance, highlights differences between array and network sensor topologies, and concludes with mention of sensor technologies appropriate for volcano infrasound study.

  12. 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 ...

  13. Enrichment of heavy metals in the inner shelf mud of the East China Sea and its indication to human activity

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Fan, Dejiang; Li, Weiran; Wang, Liang; Zhang, Xilin; Liu, Ming; Guo, Zhigang

    2014-11-01

    The Yangtze River Basin, which has a population of 0.4 billion and an economic output accounting for 50% of China's Gross Domestic Product (GDP), is one of the most developed regions in China. With dramatic developments in the economy, large quantities of pollutants have entered the Yangtze River and have eventually been discharged into the East China Sea (ECS), and then most of them were preserved in the inner shelf coastal mud areas of the ECS. The inner shelf costal mud areas of the ECS, with sedimentation rate ranging from 0.8 cm/a to 1.2 cm/a, are an ideal place to obtain the high-resolution heavy metal record. In this work, two sediment cores collected in the inner shelf of the coastal mud areas of the ECS in 2009 were used to reconstruct historical records of anthropogenic heavy metal input from the Yangtze River Basin. The temporal distribution of enrichment factors (EFs) is in good accordance with social development of Yangtze River Basin. Before the 1930s, the EFs of Pb and Zn are considered as the background level of study area, according to the agricultural country of China in that time. The much higher EFs of Pb and Zn from the 1930s to 1980s were associated with significant improvement of industry of the Yangtze River Basin. After 1983, the dramatical incensement of EFs of Pb and Zn responded to the remarkable economic development of the Yangtze River Basin. Of particular interest, the construction of the Three Gorges Dam (TGD) in 2003 possibly induced a significant increase in the heavy metal levels in the coastal ECS, and the ban on leaded gasoline in China induced a remarkable decrease in Pb levels. Although heavy metal levels have increased since the 1930s, the coastal mud area of the ECS remains under low ecological risk.

  14. International Volcanological Field School in Kamchatka and Alaska: Experiencing Language, Culture, Environment, and Active Volcanoes

    NASA Astrophysics Data System (ADS)

    Eichelberger, J. C.; Gordeev, E.; Ivanov, B.; Izbekov, P.; Kasahara, M.; Melnikov, D.; Selyangin, O.; Vesna, Y.

    2003-12-01

    The Kamchatka State University of Education, University of Alaska Fairbanks, and Hokkaido University are developing an international field school focused on explosive volcanism of the North Pacific. An experimental first session was held on Mutnovsky and Gorely Volcanoes in Kamchatka during August 2003. Objectives of the school are to:(1) Acquaint students with the chemical and physical processes of explosive volcanism, through first-hand experience with some of the most spectacular volcanic features on Earth; (2) Expose students to different concepts and approaches to volcanology; (3) Expand students' ability to function in a harsh environment and to bridge barriers in language and culture; (4) Build long-lasting collaborations in research among students and in teaching and research among faculty in the North Pacific region. Both undergraduate and graduate students from Russia, the United States, and Japan participated. The school was based at a mountain hut situated between Gorely and Mutnovsky Volcanoes and accessible by all-terrain truck. Day trips were conducted to summit craters of both volcanoes, flank lava flows, fumarole fields, ignimbrite exposures, and a geothermal area and power plant. During the evenings and on days of bad weather, the school faculty conducted lectures on various topics of volcanology in either Russian or English, with translation. Although subjects were taught at the undergraduate level, lectures led to further discussion with more advanced students. Graduate students participated by describing their research activities to the undergraduates. A final session at a geophysical field station permitted demonstration of instrumentation and presentations requiring sophisticated graphics in more comfortable surroundings. Plans are underway to make this school an annual offering for academic credit in the Valley of Ten Thousand Smokes, Alaska and in Kamchatka. The course will be targeted at undergraduates with a strong interest in and

  15. A forward modeling approach to relate geophysical observables at active volcanoes to deep magma dynamics

    NASA Astrophysics Data System (ADS)

    Montagna, C. P.; Longo, A.; Papale, P.; Vassalli, M.; Saccorotti, G.; Cassioli, A.

    2010-12-01

    Geophysical signals usually recorded at active volcanoes mainly consist of i) seismicity - high frequency volcano-tectonic events, volcanic tremor, and LP, VLP, and ULP events, ii) ground displacement, and iii) gravity changes. These signals are inverted to constrain the characteristics of the underground signal source, usually under the simplifying assumptions of point source or small volume homogeneous source with simple geometry. We have instead designed a forward approach, that complements the more classical inverse approaches, whereby magma chamber dynamics are numerically solved for compressible-to-incompressible multi-component magmas in geometrically complex systems constituted by one or more magma chambers connected through dykes. Our new code, that we named GALES (GAlerkin LEast Squares), solves the complex time-space-dependent dynamics of convection and mixing of magmas with different composition and properties, and reveals patterns of overpressure much more complex than commonly assumed in inverse analyses. Time-space-dependent stress distributions computed along the rigid magma-wall boundaries are employed as boundary conditions in either numerical simulations of wave propagation through the rock system by taking into account wall rock heterogeneities and topographic surface, or semi-analytical solutions of the Green’s functions in homogeneous infinite space. Ground displacement computed at the topographic surface ranges from the seismic to the quasi-static frequency band. Density variations associated to the simulated magma convection dynamics are instead employed to determine the corresponding gravity change at the surface. Seismicity, ground deformation, and gravity changes associated to deep magma dynamics are therefore computed as a function of time at different points on the Earth’s surface. Performed numerical simulations involve cases with largely different magma/dyke size, geometry and depth, and magma compositions from basaltic to

  16. 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 ...

  17. Linking observations at active volcanoes to physical processes through conduit flow modelling

    NASA Astrophysics Data System (ADS)

    Thomas, Mark; Neuberg, Jurgen

    2010-05-01

    Low frequency seismic events observed on volcanoes such as Soufriere hills, Montserrat may offer key indications about the state of a volcanic system. To obtain a better understanding of the source of these events and of the physical processes that take place within a volcano it is necessary to understand the conditions of magma a depth. This can be achieved through conduit flow modelling (Collier & Neuberg, 2006). 2-D compressible Navier-Stokes equations are solved through a Finite Element approach, for differing initial water and crystal contents, magma temperatures, chamber overpressures and geometric shapes of conduit. In the fully interdependent modelled system each of these variables has an effect on the magma density, viscosity, gas content, and also the pressure within the flow. These variables in turn affect the magma ascent velocity and the overall eruption dynamics of an active system. Of particular interest are the changes engendered in the flow by relativity small variations in the conduit geometry. These changes can have a profound local effect of the ascent velocity of the magma. By restricting the width of 15m wide, 5000m long vertical conduit over a 100m distance a significant acceleration of the magma is seen in this area. This has implications for the generation of Low-Frequency (LF) events at volcanic systems. The strain-induced fracture of viscoelastic magma or brittle failure of melt has been previously discussed as a possible source of LF events by several authors (e.g. Tuffen et al., 2003; Neuberg et al., 2006). The location of such brittle failure however has been seen to occur at relativity shallow depths (<1000m), which does not agree with the location of recorded LF events. By varying the geometry of the conduit and causing accelerations in the magma flow, localised increases in the shear strain rate of up to 30% are observed. This provides a mechanism of increasing the depth over witch brittle failure of melt may occur. A key observable

  18. The Geothermal Systems along the Watukosek fault system (East Java, Indonesia):The Arjuno-Welirang Volcanic Complex and the Lusi Mud-Eruption

    NASA Astrophysics Data System (ADS)

    Inguaggiato, Salvatore; Mazzini, Adriano; Vita, Fabio; Sciarra, Alessandra

    2016-04-01

    The Java Island is characterized by an intense volcanic activity with more then 100 active volcanoes. Moreover, this island is also known by the presence of many mud volcanoes and hydrothermal springs. In particular, in the 2006 several sudden hot mud eruptions, with fluids around 100° C, occurred in the NE side of the island resulting in a prominent eruption named Lusi (contraction of Lumpur Sidoarjo) located along the major Watukosek strike-slip fault zone. The Watukosek fault system, strikes from the Arjuno-Welirang volcanic complex, intersects Lusi and extends towards the NE of the Java island. Conversely of the normal mud eruptions (cold fluids emitted in a short time period of few days), the Lusi eruption was characterized by a persistent effusive hot fluids emissions for a long-time period of, so far, nearly a decade. Moreover, the isotopic composition of emitted gases like Helium showed a clear magmatic origin. For this reasons we decided to investigate the near Arjuno-Welirang complex located on the same strike-slip fault. Arjuno-Welirang is a twin strato-volcano system located in the East of Java along the Watukosek fault, at about 25 km SW respect to the Lusi volcano system. It features two main peaks: Arjuno (3339 masl) and Welirang (3156 masl). The last recorded eruptive activity took place in August 1950 from the flanks of Kawah Plupuh and in October 1950 from the NW part of the Gunung Welirang. This strato-volcano is characterized by a S-rich area, with high T-vent fumarole at least up to 220° C (and likely higher), located mainly in the Welirang crater. In addition, several hot springs vent from the flanks of the volcano, indicate the presence of a large hydrothermal system. During July 2015, in the framework of the Lusi Lab project (ERC grant n° 308126), we carried out a geochemical field campaign on the Arjuno-Welirang volcano hydrothermal system area, sampling water and dissolved gases from the thermal and cold springs located on the flanks of

  19. Evolution of a small hydrothermal eruption episode through a mud pool of varying depth and rheology, White Island, NZ

    NASA Astrophysics Data System (ADS)

    Edwards, M. J.; Kennedy, B. M.; Jolly, A. D.; Scheu, B.; Jousset, P.

    2017-02-01

    White Island volcano, New Zealand was a host to multiple hydrothermal eruptive episodes within a mud-sulphur pool in 2013. Although hydrothermal activity is common at White Island, past events have largely gone undescribed in favour of the larger phreatomagmatic and magmatic eruptions. Here, we detail the first and longest hydrothermal episode of 2013, lasting from 15 January to 7 February using video and photo analysis from tour operators and staff responsible for monitoring the volcano. Differences in the dominant bubble burst style across this episode led to the classification of four distinct eruption regimes: (1) multiple irregular bursts on the pool surface, (2) larger distinct symmetric hemispheres with starbursts and/or followed by mud heaves, (3) no initial pool surface deformation but a vertical steam jet followed by a sometimes large directed mud heave and (4) no lake and continuous pulsating dry ash and block venting. The progression through these regimes is associated with a lowering lake level and a concomitantly increasing viscosity of the pool, which initially comprises a low viscosity muddy water, and partially evaporates to yield a shallow layer of high viscosity mud that ends with the complete drying up of the mud pool. Formation of primary mud hemispheres or gas jets is followed by heaves or secondary upheaval events. The heights of these heaves are used as a measure of explosivity. Heights increase from ˜8 m during regime 1 on 15 January to ˜102 m during regime 3 on 28 January. Venting of dry mud during regime 4 developed on 29 January before a regression back to regime 1 took place on 7 February as the pool re-established. Through observations of the shapes of ejected mud clots, we propose that the increasing explosivity of higher number regimes is primarily due to increasing slug bubble lengths teamed with increasing mud pool viscosity. We attribute a lesser control to the decreasing depth of the pool during its progressive desiccation

  20. Cotopaxi volcano's unrest and eruptive activity in 2015: mild awakening after 73 years of quiescence

    NASA Astrophysics Data System (ADS)

    Hidalgo, Silvana; Bernard, Benjamin; Battaglia, Jean; Gaunt, Elizabeth; Barrington, Charlotte; Andrade, Daniel; Ramón, Patricio; Arellano, Santiago; Yepes, Hugo; Proaño, Antonio; Almeida, Stefanie; Sierra, Daniel; Dinger, Florian; Kelly, Peter; Parra, René; Bobrowski, Nicole; Galle, Bo; Almeida, Marco; Mothes, Patricia; Alvarado, Alexandra

    2016-04-01

    Cotopaxi volcano (5,897 m) is located 50 km south of Quito, the capital of Ecuador. The most dangerous hazards of this volcano are the devastating lahars that can be generated by the melting of its ice cap during pyroclastic flow-forming eruptions. The first seismic station was installed in 1976. Cotopaxi has been monitored by the Instituto Geofísico (Escuela Politécnica Nacional) since 1983. Presently the monitoring network is comprised of 11 broadband and 5 short period seismometers, 4 scanning DOAS, 1 infrared and 5 visible cameras, 7 DGPS, 5 tiltmeters, 11 AFM (lahar detectors) and a network of ashmeters. Due to the recent unrest, the monitoring of the volcano has been complemented by campaign airborne Multi-GAS and thermal IR measurements and ground-based mobile DOAS and stationary solar FTIR. After 73 years of quiescence, the first sign of unrest was a progressive increase in the amplitude of transient seismic events in April 2015. Since May 20, an increase in SO2 emissions from ˜500 t/d to ˜3 kt/day was detected followed by the appearance of seismic tremor on June 4. Both SO2 emissions of up to 5 kt/day and seismic tremor were observed until August 14 when a swarm of volcano-tectonic earthquakes preceded the first phreatic explosions. These explosions produced ash and gas columns reaching up to 9 km above the crater. The ash fall produced by the opening phase covered over 500 km2 with a submillimetric deposit corresponding to a mass of 1.65E+8 kg (VEI 1). During this period of explosions, SO2 emission rates up to 24 kt/day were observed, the highest thus far. The ash was dominantly hydrothermally altered and oxidized lithic fragments, hydrothermal minerals (alunite, gypsum), free crystals of plagioclase and pyroxenes, and little juvenile material. Unrest continued after August 14, with three episodes of ash emission. However, the intensity of ash fallout, average seismic amplitude, and SO2 emissions during each successive episode progressively decreased

  1. Shallow-Water Mud Acoustics

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Shallow- Water Mud Acoustics William L. Siegmann...shallow water over mud sediments and of acoustic detection, localization, and classification of objects buried in mud. OBJECTIVES • Develop...including long-range conveyance of information; detection, localization, and classification of objects buried in mud; and improvement of shallow water

  2. Radioactivity of peat mud used in therapy.

    PubMed

    Karpińska, Maria; Mnich, Krystian; Kapała, Jacek; Bielawska, Agnieszka; Kulesza, Grzegorz; Mnich, Stanisław

    2016-02-01

    The aim of the study was to determine the contents of natural and artificial isotopes in peat mud and to estimate the radiation dose absorbed via skin in patients during standard peat mud treatment. The analysis included 37 samples collected from 8 spas in Poland. The measurements of isotope concentration activity were conducted with the use of gamma spectrometry methods. The skin dose in a standard peat mud bath therapy is approximately 300 nSv. The effective dose of such therapy is considered to be 22 nSv. The doses absorbed during peat mud therapy are 5 orders of magnitude lower than effective annual dose absorbed from the natural radiation background by a statistical Pole (3.5 mSv). Neither therapeutic nor harmful effect is probable in case of such a small dose of ionising radiation.

  3. Small-scale volcanoes on Mars: distribution and types

    NASA Astrophysics Data System (ADS)

    Broz, Petr; Hauber, Ernst

    2015-04-01

    Volcanoes differ in sizes, as does the amount of magma which ascends to a planetary surface. On Earth, the size of volcanoes is anti-correlated with their frequency, i.e. small volcanoes are much more numerous than large ones. The most common terrestrial volcanoes are scoria cones (active over most (if not all) of its history, a similar distribution of volcano size might be expected. Martian small-scale volcanoes were not intensely studied for a long time due to a lack of high-resolution data enabling their proper identification; however their existence and basic characteristics were predicted on theoretical grounds. Streams of new high-resolution images now enable discovering and studying kilometer-size volcanoes with various shapes in unprecedented detail. Several types of small-scale volcanoes in various regions on Mars were recently described. Scoria cones provide a record of magmatic volatile content and have been identified in Tharsis (Ulysses Colles), on flanks of large volcanoes (e.g., Pavonis Mons), in the caldera of Ulysses Patera, in chaotic terrains or other large depressions (Hydraotes Colles, Coprates Chasma) and in the northern lowlands. Tuff rings and tuff cones, formed as a result of water-magma interaction, seem to be relatively rare on Mars and were only tentatively identified in three locations (Nepenthes/Amenthes region, Arena Colles and inside Lederberg crater), and alternative interpretations (mud volcanoes) seem possible. Other relatively rare volcanoes seem to be lava domes, reported only from two regions (Acracida Planitia and Terra Sirenum). On the other hand, small shields and rootless cones (which are not primary volcanic landforms) represent widely spread phenomena recognized in Tharsis and Elysium. Based on these new observations, the distribution of small volcanoes on Mars seems to be much more widespread than anticipated a decade

  4. 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

  5. The heartbeat of the volcano: The discovery of episodic activity at Prometheus on Io

    USGS Publications Warehouse

    Davies, A.G.; Wilson, L.; Matson, D.; Leone, G.; Keszthelyi, L.; Jaeger, W.

    2006-01-01

    The temporal signature of thermal emission from a volcano is a valuable clue to the processes taking place both at and beneath the surface. The Galileo Near Infrared Mapping Spectrometer (NIMS) observed the volcano Prometheus, on the jovian moon Io, on multiple occasions between 1996 and 2002. The 5 micron (??m) brightness of this volcano shows considerable variation from orbit to orbit. Prometheus exhibits increases in thermal emission that indicate episodic (though non-periodic) effusive activity in a manner akin to the current Pu'u 'O'o-Kupaianaha (afterwards referred to as the Pu'u 'O'o) eruption of Kilauea, Hawai'i. The volume of material erupted during one Prometheus eruption episode (defined as the interval from minimum thermal emission to peak and back to minimum) from 6 November 1996 to 7 May 1997 is estimated to be ???0.8 km3, with a peak instantaneous volumetric flux (effusion rate) of ???140 m3 s-1, and an averaged volumetric flux (eruption rate) of ???49 m3 s-1. These quantities are used to model subsurface structure, magma storage and magma supply mechanisms, and likely magma chamber depth. Prometheus appears to be supplied by magma from a relatively shallow magma chamber, with a roof at a minimum depth of ???2-3 km and a maximum depth of ???14 km. This is a much shallower depth range than sources of supply proposed for explosive, possibly ultramafic, eruptions at Pillan and Tvashtar. As Prometheus-type effusive activity is widespread on Io, shallow magma chambers containing magma of basaltic or near-basaltic composition and density may be common. This analysis strengthens the analogy between Prometheus and Pu'u 'O'o, at least in terms of eruption style. Even though the style of eruption appears to be similar (effusive emplacement of thin, insulated, compound pahoehoe flows) the scale of activity at Prometheus greatly exceeds current activity at Pu'u 'O'o in terms of volume erupted, area covered, and magma flux. Whereas the estimated magma chamber at

  6. A Fluorescein Tracer Release Experiment in the Hydrothermally Active Crater of Vailulu'u Volcano, Samoa

    NASA Astrophysics Data System (ADS)

    Hart, S. R.; Staudigel, H.; Workman, R.; Koppers, A.; Girard, A.

    2001-12-01

    Vailulu'u (Rockne) volcano marks the active end of the Samoa hotspot chain. The volcano is 4400 meters high, with a summit crater 2000 meters wide by 400 meters deep and summit peaks reaching to within 600 meters of the sea surface. The crater is hydrothermally active, as witnessed by intense particulate concentrations in the water column (values to 1.4 NTU's), a particulate smog ``halo'' surrounding the summit and extending out many kilometers, high Mn concentrations and 3He/4He ratios (values to 3.8 ppb and 8.6 Ra, respectively), and bottom-water temperature anomalies of 0.5oC. Basalts from the crater have been dated in the range 5-50 years, and likely reflect eruptions associated with a 1995 earthquake swarm. On April 3, 2001, we released a 20 kg point-source charge of fluorescein dye 30 meters above the 975m deep crater floor. The dye was dissolved in a 180 liter mixture of propanol and water, adjusted to a density 1.3 per mil heavier than the ambient water at the release depth. Released from a rubberized bag by means of a galvanic link. First detection of the released dye was 39 hours after the deployment; the dye was in a 50 meter thick layer, with a concentration peak at 900 meters (relative to the release depth of 945m). Tracking was carried out by a CTD-based fluorometer operated in tow-yo mode from the U.S.C.G. Icebreaker Polar Sea. The detection limit was 25 picograms/gram, and the maximum detected concentration was 18,000 pg/g (if evenly dispersed in the lower 150 meters of water in the crater, the expected concentration would be approx. 130 pg/g). While the dye pool was only surveyed for 4 days due to ship-transit constraints, significant horizontal and vertical dispersion was apparent. Vertical dispersion velocities were typically 0.05 cm/sec; horizontal velocities were typically higher by a factor of 10. An approximate diapycnal or eddy diffusivity, K, can be calculated from the rate of vertical spreading of the dye layer: K = Z2/2(t-t0), where Z is

  7. Seismic body wave separation in volcano-tectonic activity inferred by the Convolutive Independent Component Analysis

    NASA Astrophysics Data System (ADS)

    Capuano, Paolo; De Lauro, Enza; De Martino, Salvatore; Falanga, Mariarosaria; Petrosino, Simona

    2015-04-01

    One of the main challenge in volcano-seismological literature is to locate and characterize the source of volcano/tectonic seismic activity. This passes through the identification at least of the onset of the main phases, i.e. the body waves. Many efforts have been made to solve the problem of a clear separation of P and S phases both from a theoretical point of view and developing numerical algorithms suitable for specific cases (see, e.g., Küperkoch et al., 2012). Recently, a robust automatic procedure has been implemented for extracting the prominent seismic waveforms from continuously recorded signals and thus allowing for picking the main phases. The intuitive notion of maximum non-gaussianity is achieved adopting techniques which involve higher-order statistics in frequency domain., i.e, the Convolutive Independent Component Analysis (CICA). This technique is successful in the case of the blind source separation of convolutive mixtures. In seismological framework, indeed, seismic signals are thought as the convolution of a source function with path, site and the instrument response. In addition, time-delayed versions of the same source exist, due to multipath propagation typically caused by reverberations from some obstacle. In this work, we focus on the Volcano Tectonic (VT) activity at Campi Flegrei Caldera (Italy) during the 2006 ground uplift (Ciaramella et al., 2011). The activity was characterized approximately by 300 low-magnitude VT earthquakes (Md < 2; for the definition of duration magnitude, see Petrosino et al. 2008). Most of them were concentrated in distinct seismic sequences with hypocenters mainly clustered beneath the Solfatara-Accademia area, at depths ranging between 1 and 4 km b.s.l.. The obtained results show the clear separation of P and S phases: the technique not only allows the identification of the S-P time delay giving the timing of both phases but also provides the independent waveforms of the P and S phases. This is an enormous

  8. 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.

  9. Subsurface mass migration at active volcanoes: what we learnt from the VOLUME project

    NASA Astrophysics Data System (ADS)

    Saccorotti, G.; Volume Team

    2009-04-01

    Movements of multiphase fluids beneath active volcanoes are generally detected at the surface in terms of changes in geophysical and geochemical observables. The prompt detection and interpretation of such signals thus represent a crucial step toward the short-term evaluation of volcanic hazard. Funded through the European 6th framework program, the VOLUME project joined 19 institutions from 6 EU and 5 extra-european countries under the common goal of improving our understanding of how subsurface mass movement manifests itself at the surface, in turn revealing the significance of such movements as precursors to impending eruptions. We integrated high-end experimental procedures with a robust modeling framework to address some of the most relevant issues of modern, quantitative volcanology. In particular, our studies focused on: (i) Unrevealing the complex interplay between hydrothermal and magmatic fluids in generating the observed geophysical / geochemical signals, (ii) Detailing the location, geometry and dynamics of magma pathways and storage zones (iii) Probing variations of the elastic parameters of volcanic media in response to stress changes induced by mass migration, and (iv) Developing a robust computational framework for forward-modelling the geophysical observables resulting from the dynamics of multiphase magmatic systems. VOLUME activities developed at both european and extra-european volcanoes. We present here the most striking results obtained at two italian test-sites, namely Etna and Campi Flegrei, for which we had available data sets of unprecedented sensitivity and temporal resolution. Results from Etna include a) mapping of the shallow plumbing system from Moment-Tensor inversion of broadband seismic signal, b) the detection of deep magma intrusion from inversion of joint gravity-tremor anomalies; c) the measurement of changes in both elastic anisotropy and seismic velocity concomitant to the waning stage of the 2002 NE flank lava effusion; and

  10. Active high-resolution seismic tomography of compressional wave velocity and attenuation structure at Medicine Lake Volcano, Northern California Cascade Range

    NASA Astrophysics Data System (ADS)

    Evans, John R.; Zucca, John J.

    1988-12-01

    We determine compressional wave velocity and attenuation structures for the upper crust beneath Medicine Lake volcano in northeast California using a high-resolution active source seismic tomography method. Medicine Lake volcano is a basalt through rhyolite shield volcano of the Cascade Range, lying east of the range axis. The Pg wave from eight explosive sources which has traveled upward through the target volume to a dense array of 140 seismographs provides 1- to 2-km resolution in the upper 5 to 7 km of the crust beneath the volcano. The experiment tests the hypothesis that Cascade Range volcanoes of this type are underlain only by small silicic magma chambers. We image a low-velocity low-Q region not larger than a few tens of cubic kilometers in volume beneath the summit caldera, supporting the hypothesis. A shallower high-velocity high-density feature, previously known to be present, is imaged for the first time in full plan view; it is east-west elongate, paralleling a topographic lineament between Medicine Lake volcano and Mount Shasta. This lineament is interpreted to be the result of an old crustal weakness now affecting the emplacement of magma, both on direct ascent from the lower crust and mantle and in migration from the shallow silicic chamber to summit vents. Differences between this high-velocity feature and the equivalent feature at Newbeny volcano, a volcano in central Oregon resembling Medicine Lake volcano, may partly explain the scarcity of surface hydrothermal features at Medicine Lake volcano. A major low-velocity low-Q feature beneath the southeast flank of the volcano, in an area with no Holocene vents, is interpreted as tephra, flows, and sediments from the volcano deeply ponded on the downthrown side of the Gillem fault, a normal fault mapped at the surface north of the volcano. A high-Q normal-velocity feature beneath the north rim of the summit caldera may be a small, possibly hot, subsolidus intrusion. A high-velocity low-Q region

  11. 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

  12. 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.

  13. 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

  14. Strombolian surface activity regimes at Yasur volcano, Vanuatu, as observed by Doppler radar, infrared camera and infrasound

    NASA Astrophysics Data System (ADS)

    Meier, K.; Hort, M.; Wassermann, J.; Garaebiti, E.

    2016-08-01

    In late 2008 we recorded a continuous multi-parameter data set including Doppler radar, infrared and infrasound data at Yasur volcano, Vanuatu. Our recordings cover a transition in explosive style from ash-rich to ash-free explosions followed again by a phase of high ash discharge. To assess the present paradigm of Strombolian behavior in this study we investigate the geophysical signature of these different explosive episodes and compare our results to observations at Stromboli volcano, Italy. To this end we characterize Yasur's surface activity in terms of material movement, temperature and excess pressure. The joint temporal trend in these data reveals smooth variations of surface activity and regime-like persistence of individual explosion forms over days. Analysis of all data types shows ash-free and ash-rich explosive styles similar to those found at Stromboli volcano. During ash-free activity low echo powers, high explosion velocities and high temperatures result from the movement of isolated hot ballistic clasts. In contrast, ash-rich episodes exhibit high echo powers, low explosion velocities and low temperatures linked to the presence of colder ash-rich plumes. Furthermore ash-free explosions cause high excess pressure signals exhibiting high frequencies opposed to low-amplitude, low-frequency signals accompanying ash-rich activity. To corroborate these findings we compare fifteen representative explosions of each explosive episode. Explosion onset velocities derived from Doppler radar and infrared camera data are in excellent agreement and consistent with overall observations in each regime. Examination of infrasound recordings likewise confirms our observations, although a weak coupling between explosion velocity and excess pressure indicates changes in wave propagation. The overall trend in explosion velocity and excess pressure however demonstrates a general correlation between explosive style and explosion intensity, and points to stability of the

  15. Numerical Tsunami Hazard Assessment of the Only Active Lesser Antilles Arc Submarine Volcano: Kick 'em Jenny.

    NASA Astrophysics Data System (ADS)

    Dondin, F. J. Y.; Dorville, J. F. M.; Robertson, R. E. A.

    2015-12-01

    The Lesser Antilles Volcanic Arc has potentially been hit by prehistorical regional tsunamis generated by voluminous volcanic landslides (volume > 1 km3) among the 53 events recognized so far. No field evidence of these tsunamis are found in the vincity of the sources. Such a scenario taking place nowadays would trigger hazardous tsunami waves bearing potentially catastrophic consequences for the closest islands and regional offshore oil platforms.Here we applied a complete hazard assessment method on the only active submarine volcano of the arc Kick 'em Jenny (KeJ). KeJ is the southernmost edifice with recognized associated volcanic landslide deposits. From the three identified landslide episodes one is associated with a collapse volume ca. 4.4 km3. Numerical simulations considering a single pulse collapse revealed that this episode would have produced a regional tsunami. An edifice current volume estimate is ca. 1.5 km3.Previous study exists in relationship to assessment of regional tsunami hazard related to shoreline surface elevation (run-up) in the case of a potential flank collapse scenario at KeJ. However this assessment was based on inferred volume of collapse material. We aim to firstly quantify potential initial volumes of collapse material using relative slope instability analysis (RSIA); secondly to assess first order run-ups and maximum inland inundation distance for Barbados and Trinidad and Tobago, i.e. two important economic centers of the Lesser Antilles. In this framework we present for seven geomechanical models tested in the RSIA step maps of critical failure surface associated with factor of stability (Fs) for twelve sectors of 30° each; then we introduce maps of expected potential run-ups (run-up × the probability of failure at a sector) at the shoreline.The RSIA evaluates critical potential failure surface associated with Fs <1 as compared to areas of deficit/surplus of mass/volume identified on the volcanic edifice using (VolcanoFit 2

  16. Characterising Seismicity at Alutu, an Actively Deforming Volcano in the Main Ethiopian Rift

    NASA Astrophysics Data System (ADS)

    Wilks, M.; Nowacki, A.; Kendall, J. M.; Wookey, J. M.; Biggs, J.; Bastow, I. D.; Ayele, A.; Bedada, T.

    2013-12-01

    The Main Ethiopian Rift (MER) provides a unique example of the tectonic and volcanic processes occuring during the transition from continental rifting to oceanic spreading. Situated 100 km south of Addis Ababa along the eastern rift margin, Alutu is a silicic stratovolcano that geodetic measurements (InSAR and GPS) have shown is actively deforming. Though the volcano has received relatively little scientific attention it is also a site of economic significance as a geothermal power plant resides within the caldera. As part of ARGOS (Alutu Research Geophysical ObservationS), a multi-disciplinary project aiming to investigate the magmatic and hydrothermal processes occuring at Alutu, a seismic network of 12 broadband seismometers was deployed in January 2012. Other components of ARGOS include InSAR, GPS, geologic mapping and magnetotellurics. From the seismic dataset, P- and S-wave arrivals across the array were manually picked and used to locate events using a non-linear earthquake location algorithm (NonLinLoc) and a predefined 1D velocity model. Perturbations were later applied to this velocity model to investigate the sensitivity of the locations and evaluate the true uncertainties of the solutions. Over 1000 events were successfully located during 2012, where picks were possible at 4 or more stations. Seismicity clusters at both shallow depths (z<2 km) beneath the caldera and at deeper depths of 5-15 km. There is a significant increase in seismicity during the rainy months, suggesting the shallow events may be related to the hydrothermal system. We interpret the deeper events as being magmatic in origin. Events are also located along the eastern border faults that bound the outer edges of the MER and highlights that seismicity arises concurrently via tectonic processes. An adapted version of Richter's original local magnitude scale (ML) to account for attenuation within the MER (Keir et al., 2006) was then used to compute magnitudes for the best located events

  17. Dynamics and kinematics of eruptive activity at Fuego volcano, Guatemala 2005--2009

    NASA Astrophysics Data System (ADS)

    Lyons, John J.

    Volcanoes are the surficial expressions of complex pathways that vent magma and gasses generated deep in the Earth. Geophysical data record at least the partial history of magma and gas movement in the conduit and venting to the atmosphere. This work focuses on developing a more comprehensive understanding of explosive degassing at Fuego volcano, Guatemala through observations and analysis of geophysical data collected in 2005--2009. A pattern of eruptive activity was observed during 2005--2007 and quantified with seismic and infrasound, satellite thermal and gas measurements, and lava flow lengths. Eruptive styles are related to variable magma flux and accumulation of gas. Explosive degassing was recorded on broadband seismic and infrasound sensors in 2008 and 2009. Explosion energy partitioning between the ground and the atmosphere shows an increase in acoustic energy from 2008 to 2009, indicating a shift toward increased gas pressure in the conduit. Very-long-period (VLP) seismic signals are associated with the strongest explosions recorded in 2009 and waveform modeling in the 10--30 s band produces a best-fit source location 300 m west and 300 m below the summit crater. The calculated moment tensor indicates a volumetric source, which is modeled as a dike feeding a SW-dipping (35°) sill. The sill is the dominant component and its projection to the surface nearly intersects the summit crater. The deformation history of the sill is interpreted as: (1) an initial inflation due to pressurization, followed by (2) a rapid deflation as overpressure is explosively release, and finally (3) a reinflation as fresh magma flows into the sill and degasses. Tilt signals are derived from the horizontal components of the seismometer and show repetitive inflation-deflation cycles with a 20 minute period coincident with strong explosions. These cycles represent the pressurization of the shallow conduit and explosive venting of overpressure that develops beneath a partially

  18. Spectral Analysis of the Signals Associated with Increased Activity in Popocatepetl Volcano April 2012

    NASA Astrophysics Data System (ADS)

    Cuenca, J.

    2013-05-01

    After several decades of being inactive in 1994 had a strong reactivation. Since then he has had long periods where volcanic activity including increased growth and destruction of a dome. In April 2012 Popocatepetl Volcano activity showed an increase in the emission of gas and ash, and Vulcanian type explosions. As a result the National Center for Disaster Prevention (CENAPRED) raised the yellow phase from 2 to 3. Spectrally analyzes seismic activity characteristic of the types of events (explosions, LP, Type-B and tremors) that provides information of the source processes that cause it, despite sustained change reflected by the complexity of the volcanic apparatus, through of: 1) the spectral content of the process provides the source, 2) the spectral ratio H / V, its associated amplification and dominant frequencies, 3) time frequency analysis showing the variation in frequency, 4) the particle motion to analyze its retrograde or prograde acting in a volcanic complex medium. The calculation of H / V was performed by each hour using windows with duration of 80 seconds in the broadband seismic station "Canario" (PPPB). The predominant frequencies of H / V are around 1.4-1.8 Hz to 2.1-2.6 Hz and amplifications from 2.3 to 6.9 times. Analysis of H / V of 48 hours (days 16 and April 17) for the case of 1.4-1.8 Hz was observed: (1) From 0-9 hours there is no amplification. (2) The seismic amplification increases from 10 to 11 hours. (3) A first crisis reaches a maximum at 13 hours with about 6 times of amplification. (4) From 14 to 15 hours there is a strong relaxation of the activity. (5) The activity begins to increase from 16 to 23 hours where it reaches its maximum amplification of almost 7 times. (6) The following two hours and is kept exceeding 6 times of amplification. (7) Then is followed by a decrease to 4 hours on the day 17, from which is maintained at a level variable. (8) At 18 hours of the day 17 grows the amplification at 6.2 times, which conforms a

  19. Locadiff with ambient seismic noise : theoretical background and application to monitoring volcanoes and active faults.

    NASA Astrophysics Data System (ADS)

    Larose, Eric; Obermann, Anne; Planes, Thomas; Rossetto, Vincent; Margerin, Ludovic; Sens-Schoenfelder, Christoph; Campillo, Michel

    2015-04-01

    This contribution will cover recent theoretical, numerical, and field data processing developments aiming at modeling how coda waves are perturbed (in phase and amplitude) by mechanical changes in the crust. Using continuous ambient seismic noise, we cross-correlate data every day and compare the coda of the correlograms. We can relative velocity changes and waveform decorrelation along the year, that are related to mechanical changes in the shallow crust, associated to the seismic or volcanic activity, but also to environmental effects such as hydrology. Bibliography : Anne Obermann, Thomas Planes, Eric Larose and Michel Campillo, Imaging pre- and co-eruptive structural changes of a volcano with ambient seismic noise, J. Geophys. Res. 118 6285-6294 (2013). A. Obermann, B. Froment, M. Campillo, E. Larose, T. Planès, B. Valette, J. H. Chen, and Q. Y. Liu, Seismic noise correlations to image structural and mechanical changes associated with the Mw7.9 2008-Wenchuan earthquake, J. Geophys. Res. Solid Earth, 119, 1-14,(2014). Thomas Planès, Eric Larose, Ludovic Margerin, Vincent Rossetto, Christoph Sens-Schoenfelder, Decorrelation and phase-shift of coda waves induced by local changes : Multiple scattering approach and numerical validation, Waves in Random and Complex Media 24, 99-125, (2014)

  20. Coupling of Activity at Neighbouring Volcanoes in Iceland: Ground Deformation and Activity at the Bárðarbunga-Tungnafellsjökull and Eyjafjallajökull-Katla Volcano Pairs

    NASA Astrophysics Data System (ADS)

    Parks, M.; Heimisson, E. R.; Sigmundsson, F.; Hooper, A. J.; Ofeigsson, B.; Vogfjord, K. S.; Arnadottir, T.; Dumont, S.; Drouin, V.; Bagnardi, M.; Spaans, K.; Hreinsdottir, S.; Friðriksdóttir, H. M.; Jonsdottir, K.; Guðmundsson, G.; Hensch, M.; Hjaltadottir, S.; Hjartardottir, A. R.; Einarsson, P.; Gudmundsson, M. T.; Hognadottir, T.; Lafemina, P.; Geirsson, H.; Sturkell, E.; Magnússon, E.

    2015-12-01

    Interferometric Synthetic Aperture Radar (InSAR) techniques are used to generate a time series of high-resolution deformation measurements, in the vicinity of two pairs of closely spaced volcanoes in Iceland: Bárðarbunga and Tungnafellsjökull, as well as Eyjafjallajökull and Katla. Following the declaration of Icelandic Volcanoes as a Permanent Geohazard Supersite in 2013, a considerable amount of SAR data was made available for both past and future satellite acquisitions, including new X-band images and historic C-band images. InSAR time series have been formed using these data and compared to other geodetic and microseismic measurements to determine the most likely processes responsible for recently observed deformation and/or seismicity. A comprehensive network of seismometers and continuous GPS stations are already deployed at these volcanoes and a series of campaign GPS measurements have been undertaken since 2010. We present an overview of the temporal variation in InSAR observations and these complementary field based measurements at Bárðarbunga and Tungnafellsjökull from 2014-2015 (covering the recent eruption at Holuhraun and contemporaneous slow collapse of the Bárðarbunga caldera), and Eyjafjallajökull and Katla volcanoes from 2010 onwards, after the 2010 explosive eruption of Eyjafjallajökull. We undertake a joint InSAR-GPS inversion using a Markov-chain Monte Carlo approach. The best-fit source geometries responsible for both the inflation of a 50 km long dyke and simultaneous deflation of the Bárðarbunga central volcano during the 2014-2015 unrest and eruption are found. Using these we calculate the stress changes associated with the Bárðarbunga deformation events and compare our results to the location of earthquake swarms in the vicinity of neighbouring Tungnafellsjökull, where seismic activity increased significantly following the onset of unrest at Bárðarbunga in August 2014. We also determine the optimal source parameters for

  1. 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

  2. Evidence for Basinwide Mud Volcanism in Acidalia Planitia, Mars

    NASA Technical Reports Server (NTRS)

    Oehler, Dorothy Z.; Allen, Carlton C.

    2010-01-01

    High-albedo mounds in Acidalia Planitia occur in enormous numbers. They have been variously interpreted as pseudocraters, cinder cones, tuff cones, pingos, ice disintegration features, or mud volcanoes. Our work uses regional mapping, basin analysis, and new data from the Context Camera (CTX), High Resolution Imaging Science Experiment (HiRISE), and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to re-assess the origin and significance of these structures.

  3. Crustal deformation and volcanic earthquakes associated with the recent volcanic activity of Iwojima Volcano, Japan

    NASA Astrophysics Data System (ADS)

    Ueda, H.; Fujita, E.; Tanada, T.

    2013-12-01

    Iwojima is an active volcanic island located within a 10 km wide submarine caldera about 1250 km to the south of Tokyo, Japan. The seismometer and GPS network of National Research Institute for Earth Science and Disaster Prevention (NIED) in Iwojima has observed a repeating island wide uplift more than 1 m associated with large number of volcanic earthquakes every several years. During 2006-2012, we observed more than 20000 volcanic earthquakes and an uplift of about 3 m, and precursory volcanic earthquakes and rapid crustal deformation just before the small submarine eruption near the northern coast of Iwojima in April 2012. In a restless volcano such as Iwojima, it is important issue to distinguish whether rapid crustal deformation and intense earthquake activity lead to an eruption or not. According to a long period geodetic observation by Ukawa et al. (2006), the crustal deformation of Iwojima can be classify into 2 phases. The first is an island wide large uplift centering on Motoyama area (the eastern part of the island, the center of the caldera), and the second is contraction and subsidence at local area centering on Motoyama and uplift around that area. They are interpreted by superposition of crustal deformations by a shallow contraction source and a deep seated inflation source beneath Motoyama. The earthquake activity of Iwojima highly correlates with the island wide large uplift, suggesting the earthquakes are almost controlled by a magma accumulation into a deep seated magma chamber. In contrast to the activity, the precursory activity of the eruption in 2012 is deviated from the correlation. The rapid crustal deformation just before and after the eruption in 2012 can be interpreted by rapid inflation and deflation of a shallow sill source about 1km deep, respectively, suggesting that it was caused by a shallow hydrothermal activity. The result shows that we can probably distinguish an abnormal activity related with a volcanic eruption when we observe

  4. 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.

  5. Monitoring Morphological Changes at Colima Volcano Crater and Explosive Activity in 2003

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Nunez-Cornu, F.; Reyes-Davila, G.

    2003-12-01

    The Colima Volcano is located in the West of the Volcanic Mexican Belt, since February 10 1999 has presented an alternated efusive and explosive activity, which has generated constant morphological changes at the summit. As result of the several explosions occurred in 1999, 2000 and at the beginning of the year 2001, a new crater was formed with dimensions of 260 for 225 meters, and an average depth of 40 m. This crater began to be filled by the end of October 31, 2001 by a extrusion dome that reach an approximate volume 2 x 106 m3. In the first week of February 2002 this dome reach the edge of the crater, beginning to form lava flows by the western, northeastern, and south flanks. This effusive activity continued in 2002, and small gas emission and explosions were observed. In April 2003 the number of explosions and degassings became more frequent in the dome, this activity was registred by the seismic networks (RESCO and RESJAL) and recorded by video cameras located at Jalisco Civil Defense Nevado Base, 5 km away of the volcano. Aerial reconnaissance carried out in May 16 showed a complete change in the morphology of the dome as was observed in February 2002, identifying a new crater with a elipsoidal concave shape with approximate dimensions of 140 x 110 m and a depth in its central part of 15 mts. In the SE flank we observed another crater with similar form to the previous one whose dimensions are of 30 x 20 m with depth of 15 m, where continuous explosions have been appraised. At dawn of June 17, August 2 and 28, 2003 explosions happened that reached an altitude between 2000 and 3000 m, which were of smaller magnitude than happened the 22 of February of the 2000. These explosions were preceded of prolonged periods of tremor reported by RESCO. This explosive activity also present gas emission gas in form of jets, with duration from some seconds until more a than minute and altitude of approximate 500 meters, like the occurred on June 7, its point of emission

  6. 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.

  7. Mud volcanism and authigenic carbonates related to methane-rich fluids migration in the late Neogene marls of S.E. Spain

    NASA Astrophysics Data System (ADS)

    Pierre, C.; Blanc-Valleron, M. M.; Rouchy, J. M.

    2015-12-01

    Methane-rich fluids that are generated at depth in organic-rich deposits migrate within the sediments to the seafloor where they are expelled to form mud volcanoes or pockmarks. Moreover, these migrating fluids are involved in diagenetic processes as authigenic carbonate formation and they may participate to gas hydrate formation. These features are well-known in the present-day continental margins but their fossil records are relatively scarce. The outcropping Tortonian and Messinian marls in S.E. Spain basins (Lorca, Fortuna, Columbares, Huercal Overa) contain abundant authigenic dolomite nodules. The oxygen and carbon isotopic compositions of these dolomites exhibit wide ranges (-1.4 < δ18O < +5.6 ; -25.6 < δ13C < +9.3) indicating that carbonate precipitation occurred within the marly sediments due to circulation of fluids modified by gas hydrates formation/dissociation, where anaerobic oxidation of methane and methanogenesis were active. In the Huercal Overa basin, there is a well-preserved mud volcano intruding vertically the Messinian marls. These two features, methane derived authigenic dolomites and mud volcanism, are testifying of the intense methane-rich fluid migration in the marly deposits of the western Mediterranean basins during the late Neogene, which was the time of major paleoenvironmental changes in the Mediterranean sea climaxing during the Messinian salinity crisis.

  8. Observed inflation-deflation cycles at Popocatepetl volcano using tiltmeters and its possible correlation with regional seismic activity in Mexico

    NASA Astrophysics Data System (ADS)

    Contreras Ruiz Esparza, M. G., Sr.; Jimenez Velazquez, J. C., Sr.; Valdes Gonzalez, C. M., Sr.; Reyes Pimentel, T. A.; Galaviz Alonso, S. A.

    2014-12-01

    Popocatepetl, the smoking mountain, is a stratovolcano located in central Mexico with an elevation of 5450 masl. The active volcano, close to some of the largest urban centers in Mexico - 60 km and 30 km far from Mexico City and Puebla, respectively - poses a high hazard to an estimated population of 500 thousand people living in the vicinity of the edifice. Accordingly, in July 1994 the Popocatepetl Volcanological Observatory (POVO) was established. The observatory is operated and supported by the National Center for Disaster Prevention of Mexico (CENAPRED), and is equipped to fully monitor different aspects of the volcanic activity. Among the instruments deployed, we use in this investigation two tiltmometers and broad-band seismometers at two sites (Chipiquixtle and Encinos), which send the information gathered continuously to Mexico City.In this research, we study the characteristics of the tiltmeters signals minutes after the occurrence of certain earthquakes. The Popocatepetl volcano starts inflation-deflation cycles due to the ground motion generated by events located at certain regions. We present the analysis of the tiltmeters and seismic signals of all the earthquakes (Mw>5) occurred from January 2013 to June 2014, recorded at Chipiquixtle and Encinos stations. First, we measured the maximum tilt variation after each earthquake. Next, we apply a band-pass filter for different frequency ranges to the seismic signals of the two seismic stations, and estimated the total energy of the strong motion phase of the seismic record. Finally, we compared both measurements and observed that the maximum tilt variations were occurring when the maximum total energy of the seismic signals were in a specific frequency range. We also observed that the earthquake records that have the maximum total energy in that frequency range were the ones with a epicentral location south-east of the volcano. We conclude that our observations can be used set the ground for an early

  9. Fundamental changes in the activity of the natrocarbonatite volcano Oldoinyo Lengai, Tanzania

    USGS Publications Warehouse

    Kervyn, M.; Ernst, G.G.J.; Keller, J.; Vaughan, R. Greg; Klaudius, J.; Pradal, E.; Belton, F.; Mattsson, H.B.; Mbede, E.; Jacobs, P.M.

    2010-01-01

    On September 4, 2007, after 25 years of effusive natrocarbonatite eruptions, the eruptive activity of Oldoinyo Lengai (OL), N Tanzania, changed abruptly to episodic explosive eruptions. This transition was preceded by a voluminous lava eruption in March 2006, a year of quiescence, resumption of natrocarbonatite eruptions in June 2007, and a volcano-tectonic earthquake swarm in July 2007. Despite the lack of ground-based monitoring, the evolution in OL eruption dynamics is documented based on the available field observations, ASTER and MODIS satellite images, and almost-daily photos provided by local pilots. Satellite data enabled identification of a phase of voluminous lava effusion in the 2 weeks prior to the onset of explosive eruptions. After the onset, the activity varied from 100 m high ash jets to 2–15 km high violent, steady or unsteady, eruption columns dispersing ash to 100 km distance. The explosive eruptions built up a ∼400 m wide, ∼75 m high intra-crater pyroclastic cone. Time series data for eruption column height show distinct peaks at the end of September 2007 and February 2008, the latter being associated with the first pyroclastic flows to be documented at OL. Chemical analyses of the erupted products, presented in a companion paper (Keller et al.2010), show that the 2007–2008 explosive eruptions are associated with an undersaturated carbonated silicate melt. This new phase of explosive eruptions provides constraints on the factors causing the transition from natrocarbonatite effusive eruptions to explosive eruptions of carbonated nephelinite magma, observed repetitively in the last 100 years at OL.

  10. A Sinuous Tumulus over an Active Lava Tube at Klauea Volcano: Evolution, Analogs, and Hazard Forecasts

    NASA Technical Reports Server (NTRS)

    Orr, Tim R.; Bleacher, Jacob E.; Patrick, Matthew R.; Wooten, Kelly M.

    2015-01-01

    Inflation of narrow tube-fed basaltic lava flows (tens of meters across), such as those confined by topography, can be focused predominantly along the roof of a lava tube. This can lead to the development of an unusually long tumulus, its shape matching the sinuosity of the underlying lava tube. Such a situation occurred during Klauea Volcanos (Hawaii, USA) ongoing East Rift Zone eruption on a lava tube active from July through November 2010. Short-lived breakouts from the tube buried the flanks of the sinuous, ridge-like tumulus, while the tumulus crest, its surface composed of lava formed very early in the flows emplacement history, remained poised above the surrounding younger flows. At least several of these breakouts resulted in irrecoverable uplift of the tube roof. Confined sections of the prehistoric Carrizozo and McCartys flows (New Mexico, USA) display similar sinuous, ridge-like features with comparable surface age relationships. We contend that these distinct features formed in a fashion equivalent to that of the sinuous tumulus that formed at Kilauea in 2010. Moreover, these sinuous tumuli may be analogs for some sinuous ridges evident in orbital images of the Tharsis volcanic province on Mars. The short-lived breakouts from the sinuous tumulus at Kilauea were caused by surges in discharge through the lava tube, in response to cycles of deflation and inflation (DI events) at Kilauea's summit. The correlation between DI events and subsequent breakouts aided in lava flow forecasting. Breakouts from the sinuous tumulus advanced repeatedly toward the sparsely populated Kalapana Gardens subdivision, destroying two homes and threatening others. Hazard assessments, including flow occurrence and advance forecasts, were relayed regularly to the Hawai?i County Civil Defense to aid their lava flow hazard mitigation efforts while this lava tube was active.

  11. The study of active submarine volcanoes and hydrothermal vents in the Southernmost Part of Okinawa Trough

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Tsai, C.; Lee, C.

    2004-12-01

    The study area is located in the Southernmost Part of Okinawa Trough (SPOT), which is a back-arc basin formed by extension of Eurasian plate. Previous research indicated two extensional stages in SPOT area. Many normal-fault structures were come into existence during both extensional processes. The SPOT is presently in an activity tectonic episode. Therefore, the area becomes a frequent earthquake and abundant magmatism. The purpose of this study is to discuss which relationship between tectonics, submarine volcanoes and hydrothermal vents in SPOT area. The investigations are continued from 1998 to 2004, we have found at least twelve active hydrothermal vents in study area. Compare the locations hydrothermal vents with fault systems, we find both of them have highly correlated. We can distinguish them into two shapes, pyramidal shape and non-pyramidal shape. According to plumes height, we are able to divide these vents into two groups near east longitude 122.5° . East of this longitude, the hydrothermal plumes are more powerful and west of it are the weaker. This is closely related to the present extensional axis (N80° E) of the southern part of the Okinawa Trough. This can be explained the reason of why the more powerful vents coming out of the east group. The east group is associated with the present back-arc spreading system. West of 122.5° , the spreading system are in a primary stage. The andesitic volcanic island, the Turtle Island, is a result of N60° E extensional tectonism with a lot of faults. Besides the pyramidal shape, this can be proved indirectly. The vents located in the west side were occurred from previous extensional faults and are weaker than the eastern. Therefore, we suggest that if last the extension keeps going on, the hydrothermal vents located at the west side of the longitude 122.5° will be intensified.

  12. 2012 volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory

    USGS Publications Warehouse

    Herrick, Julie A.; Neal, Christina A.; Cameron, Cheryl E.; Dixon, James P.; McGimsey, Robert G.

    2014-01-01

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest, or suspected unrest at 11 volcanic centers in Alaska during 2012. Of the two verified eruptions, one (Cleveland) was clearly magmatic and the other (Kanaga) was most likely a single phreatic explosion. Two other volcanoes had notable seismic swarms that probably were caused by magmatic intrusions (Iliamna and Little Sitkin). For each period of clear volcanic unrest, AVO staff increased monitoring vigilance as needed, reviewed eruptive histories of the volcanoes in question to help evaluate likely outcomes, and shared observations and interpretations with the public. 2012 also was the 100th anniversary of Alaska’s Katmai-Novarupta eruption of 1912, the largest eruption on Earth in the 20th century and one of the most important volcanic eruptions in modern times. AVO marked this occasion with several public events.

  13. Drilling mud proposal

    SciTech Connect

    Steed, W.

    1981-12-01

    A discussion of the disposal of drilling fluids from Texas oil fields was presented. The most common is the transport of the drilling mud to approved landfills. This requires that the waste be fresh waste base mud only, contained in the pit, and be maintained oil free. Other approved methods of disposal include treatment with discharge of effluent to surface streams, land application on farm land (with owner's permission), and subsurface disposal. Some common illegal disposal methods included dumping on roadsides or private property (without owner's permission).

  14. Muon dynamic radiography of density changes induced by hydrothermal activity at the La Soufrière of Guadeloupe volcano.

    PubMed

    Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d'Ars, Jean; Komorowski, Jean-Christophe

    2016-09-15

    Imaging geological structures through cosmic muon radiography is a newly developed technique which shows a great potential in volcanology. Here we demonstrate that muon radiography permits to detect and characterize mass movements in shallow hydrothermal systems of low-energy active volcanoes like the La Soufrière lava dome. We present an experiment conducted on this volcano during the Summer 2014 and bring evidence that very important density changes occurred in three domains of the lava dome. Depending on their position and on the medium porosity the volumes of these domains vary from 1 × 10(6) m(3) to 7 × 10(6) m(3). However, the total mass budget remains approximately constant : two domains show a mass loss (Δm∈ [-0.8;-0.4] × 10(9) kg) and the third one a mass gain (Δm∈ [1.5; 2.5] × 10(9) kg). We attribute the negative mass changes to the formation of steam in shallow hydrothermal reservoir previously partly filled with liquid water. This coincides with the emergence of new fumaroles on top of the volcano. The positive mass change is synchronized with the negative mass changes indicating that liquid water probably flowed from the two reservoirs invaded by steam toward the third reservoir.

  15. Muon dynamic radiography of density changes induced by hydrothermal activity at the La Soufrière of Guadeloupe volcano

    PubMed Central

    Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d’Ars, Jean; Komorowski, Jean-Christophe

    2016-01-01

    Imaging geological structures through cosmic muon radiography is a newly developed technique which shows a great potential in volcanology. Here we demonstrate that muon radiography permits to detect and characterize mass movements in shallow hydrothermal systems of low-energy active volcanoes like the La Soufrière lava dome. We present an experiment conducted on this volcano during the Summer 2014 and bring evidence that very important density changes occurred in three domains of the lava dome. Depending on their position and on the medium porosity the volumes of these domains vary from 1 × 106 m3 to 7 × 106 m3. However, the total mass budget remains approximately constant : two domains show a mass loss (Δm∈ [−0.8;−0.4] × 109 kg) and the third one a mass gain (Δm∈ [1.5; 2.5] × 109 kg). We attribute the negative mass changes to the formation of steam in shallow hydrothermal reservoir previously partly filled with liquid water. This coincides with the emergence of new fumaroles on top of the volcano. The positive mass change is synchronized with the negative mass changes indicating that liquid water probably flowed from the two reservoirs invaded by steam toward the third reservoir. PMID:27629497

  16. Muon dynamic radiography of density changes induced by hydrothermal activity at the La Soufrière of Guadeloupe volcano

    NASA Astrophysics Data System (ADS)

    Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond D’Ars, Jean; Komorowski, Jean-Christophe

    2016-09-01

    Imaging geological structures through cosmic muon radiography is a newly developed technique which shows a great potential in volcanology. Here we demonstrate that muon radiography permits to detect and characterize mass movements in shallow hydrothermal systems of low-energy active volcanoes like the La Soufrière lava dome. We present an experiment conducted on this volcano during the Summer 2014 and bring evidence that very important density changes occurred in three domains of the lava dome. Depending on their position and on the medium porosity the volumes of these domains vary from 1 × 106 m3 to 7 × 106 m3. However, the total mass budget remains approximately constant : two domains show a mass loss (Δm∈ [‑0.8‑0.4] × 109 kg) and the third one a mass gain (Δm∈ [1.5; 2.5] × 109 kg). We attribute the negative mass changes to the formation of steam in shallow hydrothermal reservoir previously partly filled with liquid water. This coincides with the emergence of new fumaroles on top of the volcano. The positive mass change is synchronized with the negative mass changes indicating that liquid water probably flowed from the two reservoirs invaded by steam toward the third reservoir.

  17. Mud to cement technology proven in offshore drilling project

    SciTech Connect

    Javanmardi, K.; Flodberg, K.D. ); Nahm, J.J. )

    1993-02-15

    One problem with conventional cements is the incompatibility of Portland cement and the drilling mud. Expensive preflushes and spacer fluids have been used, often with limited success, to attempt to separate mud and Portland cement effectively. Under downhole conditions, most spacers are ineffective in preventing high viscosities and cement contamination problems which lead to poor primary cement jobs. One solution to this problem is to convert the drilling mud into a cementitious slurry, thereby eliminating the mud/Portland cement incompatibility. The existing mud solidification technologies have received limited acceptance because of high costs, complex design, and difficult field use. Shell Development Co.'s mud solidification technology (Slag-Mix) uses finely ground, granulated blast furnace slag as the cementitious agent. The slurry is activated with predetermined amounts of common alkaline chemicals (caustic or soda ash) and a thinner/retarder, such as lignosulfonate. Slag is only slightly reactive with water. Thus, the slag can be mixed in the mud through the mud hopper. At Auger, the slag was mixed and pumped with a conventional cementing unit. On two other operations (South Timbalier Blocks 295 and 300), the slurry was mixed in the mud pits and pumped down the well with the rig pump, thus eliminating the costs associated with conventional cementing units and services.

  18. Observations of the Electrical Activity of the Redoubt Volcano in Alaska

    NASA Astrophysics Data System (ADS)

    Krehbiel, P. R.; Behnke, S. A.; Thomas, R. J.; Edens, H. E.; Rison, W.; McNutt, S. R.; Higman, B.; Holzworth, R. H.; Thomas, J. N.

    2009-12-01

    The Mt. Redoubt volcano in Alaska underwent a series of 22 major explosive eruptions over a 2.5 week period between 23 March and 4 April 2009. We were able to deploy a 4-station Lightning Mapping Array (LMA) in advance of the eruptions along a 60 km stretch of the Kenai coastline, 70-80 km east of Redoubt on the opposite side of Cook Inlet, and to monitor and control the station operations remotely via internet connections. The LMA data show that the eruptions produced spectacular lightning, both over and downwind of the volcano, lasting between 20 to 80 minutes depending on the eruption strength. The discharging was essentially continuous during the initial stages of the eruptions and gradually evolved into more discrete and spatially structured discharges displaced from 10 km up to 80 or 90 km away from Redoubt. The discharge rates and VHF radiation signals were comparable to or greater than observed in Great Plains thunderstorms, with discernible but complex 'flashes' occurring at a rate of 2-3 per second in the active stages of eruptions, decaying to about 10-15 per minute of horizontally extensive discrete discharges in later stages. Individual eruptions produced literally thousands of discharges. The approximately linear array of the mapping stations, coupled with their distance from Redoubt and the inability to have a station at a closer distance, has precluded obtaining useful altitude information from the time-of-arrival data. The exception has been lightning at the end of the March 28 eruption as the plume cloud drifted over the northern end of the LMA network; which showed negative charge at 6 km altitude and positive charge between 8 and 9 km altitude, exactly the same as seen in normally electrified thunderstorms. Three of the four stations had been deployed on 50-100m high bluffs overlooking Cook Inlet in an attempt to use sea-surface interference effects to determine altitude, as in our study of the 2006 Augustine eruptions. But only partial

  19. Remote sensing of Italian volcanos

    NASA Technical Reports Server (NTRS)

    Bianchi, R.; Casacchia, R.; Coradini, A.; Duncan, A. M.; Guest, J. E.; Kahle, A.; Lanciano, P.; Pieri, D. C.; Poscolieri, M.

    1990-01-01

    The results of a July 1986 remote sensing campaign of Italian volcanoes are reviewed. The equipment and techniques used to acquire the data are described and the results obtained for Campi Flegrei and Mount Etna are reviewed and evaluated for their usefulness for the study of active and recently active volcanoes.

  20. Acoustical Properties of Mud Sediments

    DTIC Science & Technology

    2015-09-30

    transmission loss and array response in shallow water over mud sediments and of acoustic detection, localization, and classification of objects buried...classification of objects buried in mud; and improvement of shallow water sonar systems and predictions with mud sediments. RELATED PROJECTS...Characterization Experiment. Collaboration is planned with colleagues at Woods Hole Oceanographic Institution (Jim Lynch, Tim Duda, and Ying-Tsong Lin

  1. Observations of Io's Active Volcanoes from IRTF: Imaging and Occultation Lightcurves

    NASA Astrophysics Data System (ADS)

    Rathbun, J. A.; Spencer, J. R.

    2014-12-01

    We have been observing Ionian volcanism from NASA's Infrared Telescope Facility (IRTF) for more than two decades. The frequency of our observations increases dramatically when spacecraft are observing Io in order to complement the data returned by the spacecraft. The Japanese Space Agency's (JAXA) Hisaki (Sprint-A) mission recently observd the Jupiter system from earth orbit, monitoring the Io Plasma Torus and Jovian aurora. In order to investigate the possible influence of Io volcanism on the torus, we observed Io's volcanoes from the IRTF in Hawaii between September 2013 and May 2014. We imaged Io at 2.2, 3.5, and 4.8 microns in eclipse and reflected sunlight. We also observed Io during occultation by Jupiter, which allows us to locate and characterize individual volcanic eruptions, with greater spatial accuracy, on the Jupiter-facing hemisphere. The 2013 3.5 micron images of a sunlit Io showed no obvious bright volcanic features. However, further increases in spatial resolution is possible with shift-and-add processing of short exposure images. Preliminary occultation lightcurves from 2013 show moderate levels of activity at Kaneheliki/Janus and Loki, the two volcanic centers most often observed in occultation lightcurves. Loki was much brighter in 2013 than during the New Horizons flyby in 2007, but not as bright as during the Galileo era (see figure). From February 2014 through May 2014, due to a planned upgrade on the SPEX instrument and an unplanned required repair on the NSFCam2 instrument (both of which we have used previously), we exclusively used the CSHELL instrument as an imager. Unfortunately, CSHELL was not designed for imaging and has limited spatial resolution and photometric precision, complicating image analysis.

  2. Waters associated with an active basaltic volcano, Kilauea, Hawaii: Variation in solute sources, 1973-1991

    USGS Publications Warehouse

    Tilling, R.I.; Jones, B.F.

    1996-01-01

    Chemical and isotopic analyses of samples collected from a 1262-m-deep research borehole at the summit of Kilauea Volcano provide unique time-series data for composition of waters in the uppermost part of its hydrothermal system. These waters have a distinctive geochemical signature: a very low proportion of chloride relative to other anions compared with other Hawaiian wa-ters - thermal (???30 ??C) or nonthermal (<30 ??C) - and with most thermal waters of the world. Isotope data demonstrate that the borehole waters are of essentially meteoric origin, with minimal magmatic input. The water chemistry exhibits marked temporal variations, including pronounced short-term (days to weeks) effects of rainfall dilution and longer term (months to years) decline of total solutes. The 1973-1974 samples are Na-sulfate-dominant, but samples collected after July 1975 are (Mg + Ca)-bicarbonate-dominant. This compositional shift, probably abrupt, was associated with an increase in the partial pressure of CO2 (PCO2) related to volcanic degassing of CO2 accompanying a large eruption (December 31, 1974) and associated intense seismicity. Following the initial sharp increase, the PCO2 then decreased, approaching preemption values in April 1976. Beginning in mid-1975, solute concentrations of the borehole waters decreased substantially, from ???45 meq/L to <25 meq/L in only eight months; by 1991, total solute concentrations were <17 meq/L. This decline in solutes cannot be attributed to rainfall dilution and is inferred to reflect the decreasing availability with time of the easily leachable salts of alkali metals and sulfate, which originated in sublimates and fumarolic encrustations in fractures and cavities of rocks along the hydrologic flow paths. The overall chemistry of the summit-borehole waters is largely determined by hydrolysis reactions associated with normal weathering of host tholeiitic basalts on a geologic time scale, despite short-term perturbations in composition

  3. Digital Data for Volcano Hazards in the Mount Jefferson Region, Oregon

    USGS Publications Warehouse

    Schilling, S.P.; Doelger, S.; Walder, J.S.; Gardner, C.A.; Conrey, R.M.; Fisher, B.J.

    2008-01-01

    Mount Jefferson has erupted repeatedly for hundreds of thousands of years, with its last eruptive episode during the last major glaciation which culminated about 15,000 years ago. Geologic evidence shows that Mount Jefferson is capable of large explosive eruptions. The largest such eruption occurred between 35,000 and 100,000 years ago. If Mount Jefferson erupts again, areas close to the eruptive vent will be severely affected, and even areas tens of kilometers (tens of miles) downstream along river valleys or hundreds of kilometers (hundreds of miles) downwind may be at risk. Numerous small volcanoes occupy the area between Mount Jefferson and Mount Hood to the north, and between Mount Jefferson and the Three Sisters region to the south. These small volcanoes tend not to pose the far-reaching hazards associated with Mount Jefferson, but are nonetheless locally important. A concern at Mount Jefferson, but not at the smaller volcanoes, is the possibility that small-to-moderate sized landslides could occur even during periods of no volcanic activity. Such landslides may transform as they move into lahars (watery flows of rock, mud, and debris) that can inundate areas far downstream. The geographic information system (GIS) volcano hazard data layer used to produce the Mount Jefferson volcano hazard map in USGS Open-File Report 99-24 (Walder and others, 1999) is included in this data set. Both proximal and distal hazard zones were delineated by scientists at the Cascades Volcano Observatory and depict various volcano hazard areas around the mountain.

  4. Adsorption of dichromate ions on the red mud surface

    NASA Astrophysics Data System (ADS)

    Terekhova, M. V.; Gorichev, I. G.; Lainer, Yu. A.; Artamonova, I. V.; Rusakova, S. M.

    2014-07-01

    The possibility of using a red mud (waste of alumina production) as a sorbent of dichromate ions from aqueous solutions is studied. A method for the activation of red mud by hydrochloric acid is proposed. The dependences of the amount adsorbed of dichromate ions on the pH and initial concentration of aqueous solutions are studied.

  5. Acoustic measurements of the 1999 basaltic eruption of Shishaldin volcano, Alaska 1. Origin of Strombolian activity

    USGS Publications Warehouse

    Vergniolle, S.; Boichu, M.; Caplan-Auerbach, J.

    2004-01-01

    The 1999 basaltic eruption of Shishaldin volcano (Alaska, USA) displayed both classical Strombolian activity and an explosive Subplinian plume. Strombolian activity at Shishaldin occurred in two major phases following the Subplinian activity. In this paper, we use acoustic measurements to interpret the Strombolian activity. Acoustic measurements of the two Strombolian phases show a series of explosions that are modeled by the vibration of a large overpressurised cylindrical bubble at the top of the magma column. Results show that the bubble does not burst at its maximum radius, as expected if the liquid film is stretched beyond its elasticity. But bursting occurs after one cycle of vibration, as a consequence of an instability of the air-magma interface close to the bubble minimum radius. During each Strombolian period, estimates of bubble length and overpressure are calculated. Using an alternate method based on acoustic power, we estimate gas velocity to be 30-60 m/s, in very good agreement with synthetic waveforms. Although there is some variation within these parameters, bubble length and overpressure for the first Strombolian phase are found to be ??? 82 ?? 11 m and 0.083 MPa. For the second Strombolian phase, bubble length and overpressure are estimated at 24 ?? 12 m and 0.15 MPa for the first 17 h after which bubble overpressure shows a constant increase, reaching a peak of 1.4 MPa, just prior to the end of the second Strombolian phase. This peak suggests that, at the time, the magma in the conduit may contain a relatively large concentration of small bubbles. Maximum total gas volume and gas fluxes at the surface are estimated to be 3.3 ?? 107 and 2.9 ?? 103 m3/s for the first phase and 1.0 ?? 108 and 2.2 ?? 103 m3/s for the second phase. This gives a mass flux of 1.2 ?? 103 and 8.7 ?? 102 kg/s, respectively, for the first and the second Strombolian phases. ?? 2004 Elsevier B.V. All rights reserved.

  6. Discovery of an active shallow submarine silicic volcano in the northern Izu-Bonin Arc: volcanic structure and potential hazards of Oomurodashi Volcano (Invited)

    NASA Astrophysics Data System (ADS)

    Tani, K.; Ishizuka, O.; Nichols, A. R.; Hirahara, Y.; Carey, R.; McIntosh, I. M.; Masaki, Y.; Kondo, R.; Miyairi, Y.

    2013-12-01

    Oomurodashi is a bathymetric high located ~20 km south of Izu-Oshima, an active volcanic island of the northern Izu-Bonin Arc. Using the 200 m bathymetric contour to define its summit dimensions, the diameter of Oomurodashi is ~20 km. Oomurodashi has been regarded as inactive, largely because it has a vast flat-topped summit at 100 - 150 meters below sea level (mbsl). During cruise NT07-15 of R/V Natsushima in 2007, we conducted a dive survey in a small crater, Oomuro Hole, located in the center of the flat-topped summit, using the remotely-operated vehicle (ROV) Hyper-Dolphin. The only heat flow measurement conducted on the floor of Oomuro Hole during the dive recorded an extremely high value of 4,200 mW/m2. Furthermore, ROV observations revealed that the southwestern wall of Oomuro Hole consists of fresh rhyolitic lavas. These findings suggest that Oomurodashi is in fact an active silicic submarine volcano. To confirm this hypothesis, we conducted detailed geological and geophysical ROV Hyper-Dolphin (cruise NT12-19). In addition to further ROV surveys, we carried out single-channel seismic (SCS) surveys across Oomurodashi in order to examine the shallow structures beneath the current edifice. The ROV surveys revealed numerous active hydrothermal vents on the floor of Oomuro Hole, at ~200 mbsl, with maximum water temperature measured at the hydrothermal vents reaching 194°C. We also conducted a much more detailed set of heat flow measurements across the floor of Oomuro Hole, detecting very high heat flows of up to 29,000 mW/m2. ROV observations revealed that the area surrounding Oomuro Hole on the flat-topped summit of Oomurodashi is covered by extensive fresh rhyolitic lava and pumice clasts with minimum biogenetic or manganese cover, suggesting recent eruption(s). These findings strongly indicate that Oomurodashi is an active silicic submarine volcano, with recent eruption(s) occurring from Oomuro Hole. Since the summit of Oomurodashi is in shallow water, it

  7. Characteristics of puffing activity revealed by ground-based, thermal infrared imaging: the example of Stromboli Volcano (Italy)

    NASA Astrophysics Data System (ADS)

    Gaudin, Damien; Taddeucci, Jacopo; Scarlato, Piergiorgio; Harris, Andrew; Bombrun, Maxime; Del Bello, Elisabetta; Ricci, Tullio

    2017-03-01

    Puffing, i.e., the frequent (1 s ca.) release of small (0.1-10 m3), over-pressurized pockets of magmatic gases, is a typical feature of open-conduit basaltic volcanoes worldwide. Despite its non-trivial contribution to the degassing budget of these volcanoes and its recognized role in volcano monitoring, detection and metering tools for puffing are still limited. Taking advantage of the recent developments in high-speed thermal infrared imaging, we developed a specific processing algorithm to detect the emission of individual puffs and measure their duration, size, volume, and apparent temperature at the vent. As a test case, we applied our method at Stromboli Volcano (Italy), studying "snapshots" of 1 min collected in the years 2012, 2013, and 2014 at several vents. In all 3 years, puffing occurred simultaneously at three or more vents with variable features. At the scale of the single vent, a direct relationship links puff temperature and radius, suggesting that the apparent temperature is mostly a function of puff thickness, while the real gas temperature is constant for all puffs. Once released in the atmosphere, puffs dissipate in less than 20 m. On a broader scale, puffing activity is highly variable from vent to vent and year to year, with a link between average frequency, temperature, and volume from 136 puffs per minute, 600 K above ambient temperature, 0.1 m3, and the occasional ejection of pyroclasts to 20 puffs per minute, 3 K above ambient, 20 m3, and no pyroclasts. Frequent, small, hot puffs occur at random intervals, while as the frequency decreases and size increases, an increasingly longer minimum interval between puffs, up to 0.5 s, appears. These less frequent and smaller puffs also display a positive correlation between puff volume and the delay from the previous puff. Our results suggest an important role of shallow bubble coalescence in controlling puffing activity. The smaller and more frequent puffing at "hotter" vents is in agreement with

  8. Seismic structure and origin of active intraplate volcanoes in Northeast Asia

    NASA Astrophysics Data System (ADS)

    Duan, Yonghong; Zhao, Dapeng; Zhang, Xiankang; Xia, Shaohong; Liu, Zhi; Wang, Fuyun; Li, Li

    2009-05-01

    Three-dimensional P-wave velocity structure beneath the Changbai and other intraplate volcanic areas in Northeast Asia is determined by inverting 1378 high-quality P-wave arrival times from 186 teleseismic events recorded by 61 broadband seismic stations. Low-velocity (low-V) anomalies are revealed beneath the Changbai, Longgan, Xianjindao volcanoes. High-velocity (high-V) anomalies are found in the mantle transition zone, where deep-focus earthquakes under Hunchun occur at depths of 500-600 km. The high-V anomaly reflects the deep subduction of the Pacific slab under NE Asia which may have contributed to the formation of the Changbai, Longgang, Xianjindao and Jingpohu intraplate volcanoes. A low-V anomaly is also revealed in the mantle transition zone, which may have a close relationship with the occurrence of deep earthquakes under the Hunchun area. Our results support the Big Mantle Wedge (BMW) model by Zhao et al. [Zhao, D., Lei, J., Tang, Y., 2004. Origin of the Changbai volcano in northeast China: evidence from seismic tomography, Chin. Sci. Bull. 49, 1401-1408; Zhao, D., Maruyama, S., Omori, S., 2007. Mantle dynamics of western Pacific and East Asia: insight from seismic tomography and mineral physics. Gondwana Res. 11, 120-131.] who proposed that the intraplate volcanoes in NE Asia are caused by the back-arc magmatism associated with the deep dehydration process of the subducting slab and convective circulation process in the BMW above the stagnant Pacific slab.

  9. Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer.

    PubMed

    Razak, Rafiza Abdul; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

    2015-05-21

    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.

  10. Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

    PubMed Central

    Abdul Razak, Rafiza; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

    2015-01-01

    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

  11. Red mud characterization using nuclear analytical techniques

    SciTech Connect

    Obhodas, J.; Sudac, D.; Matjacic, L.; Valkovic, V.

    2011-07-01

    Red mud is a toxic waste left as a byproduct in aluminum production Bayer process. Since it contains significant concentrations of other chemical elements interesting for industry, including REE, it is also potential secondary ore source. Recent events in some countries have shown that red mud presents a serious environmental hazard if not properly stored. The subject of our study is the red mud from an ex-aluminum plant in Obrovac, Croatia, left from processing of bauxite mined during late 70's and early 80's at the eastern Adriatic coast and since than stored in open concrete basins for more than 30 years. We have used energy dispersive x-ray fluorescence analysis (both tube and radioactive source excitation), fast neutron activation analysis and passive gamma spectrometry to identify a number of elements present in the red mud, their concentration levels and radioactivity in the red mud. The high concentrations of Al, Si, Ca, Ti and Fe have been measured. Chemical elements Sc, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Br, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Pb, Th and U were found in lower concentrations. No significant levels of radioactivity have been measured. (authors)

  12. Proceedings of the 2nd Columbia River Basalt Symposium: Maar volcanoes

    NASA Technical Reports Server (NTRS)

    Waters, A. C.; Fisher, R. V.

    1971-01-01

    Examination of maar-type volcanic cones, including tuff rings, from more than 40 localities in western North America indicates that water had access to volcano orifices during their activity. The most convincing evidence is the abundance of sideromelane (chilled basaltic glass) or its palagonitic decomposition products in the ejecta. Moreover, the volcanoes which were examined erupted in basins that either contained surface water, or else they grew above highly permeable aquifers at shallow dept. Characteristic features of maar ejecta are continuous thin beds, undulations and antidunes characteristic of base surge stratification, abundant accretionary lapilli or mud-armored rock particles, bedding sags that show soft sediment deformation, and in the subaqueous parts of the maar ramparts, great piles of subtly graded thin lenses of hyaloclastic debris.

  13. 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.

  14. High resolution infrared acquisitions droning over the LUSI mud eruption.

    NASA Astrophysics Data System (ADS)

    Di Felice, Fabio; Romeo, Giovanni; Di Stefano, Giuseppe; Mazzini, Adriano

    2016-04-01

    The use of low-cost hand-held infrared (IR) thermal cameras based on uncooled micro-bolometer detector arrays became more widespread during the recent years. Thermal cameras have the ability to estimate temperature values without contact and therefore can be used in circumstances where objects are difficult or dangerous to reach such as volcanic eruptions. Since May 2006 the Indonesian LUSI mud eruption continues to spew boiling mud, water, aqueous vapor, CO2, CH4 and covers a surface of nearly 7 km2. At this locality we performed surveys over the unreachable erupting crater. In the framework of the LUSI Lab project (ERC grant n° 308126), in 2014 and 2015, we acquired high resolution infrared images using a specifically equipped remote-controlled drone flying at an altitude of m 100. The drone is equipped with GPS and an autopilot system that allows pre-programming the flying path or designing grids. The mounted thermal camera has peak spectral sensitivity in LW wavelength (μm 10) that is characterized by low water vapor and CO2 absorption. The low distance (high resolution) acquisitions have a temperature detail every cm 40, therefore it is possible to detect and observe physical phenomena such as thermodynamic behavior, hot mud and fluids emissions locations and their time shifts. Despite the harsh logistics and the continuously varying gas concentrations we managed to collect thermal images to estimate the crater zone spatial thermal variations. We applied atmosphere corrections to calculate infrared absorption by high concentration of water vapor. Thousands of images have been stitched together to obtain a mosaic of the crater zone. Regular monitoring with heat variation measurements collected, e.g. every six months, could give important information about the volcano activity estimating its evolution. A future data base of infrared high resolution and visible images stored in a web server could be a useful monitoring tool. An interesting development will be

  15. Explosive eruptive activity and temporal magmatic changes at Yotei Volcano during the last 50,000 years, southwest Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Uesawa, Shimpei; Nakagawa, Mitsuhiro; Umetsu, Akane

    2016-10-01

    To understand the eruptive history, structure, and magmatic evolution of Yotei Volcano, southwest Hokkaido, Japan, we investigated the geology and petrology of tephras located around the base of the volcano. We identified 43 tephra units interbedded with soils (in descending stratigraphic order, tephras Y1-Y43), and four widespread regional tephras. Ten radiocarbon ages were obtained from soils beneath the Yotei tephras. On the basis of petrologic differences and, the stratigraphic positions of thick layers of volcanic ash soil, indicative of volcanic stratigraphic gaps, the Yotei tephras are divided into four groups (in ascending stratigraphic order): Yotei tephra groups I, II-1, II-2, and II-3. We calculated the age of each eruptive deposit based on the soil accumulation rate, and estimated the volume of each eruption using isopach maps or the correlation between eruption volume and the maximum thickness at ~ 10 km from the summit crater. The results regarding eruptive activity and the rate of explosive eruptions indicate four eruptive stages at Yotei Volcano over the last 50,000 years. Stage I eruptions produced Yotei tephra group I between ca. 54 cal. ka BP and up to at least ca. 46 cal. ka BP, at relatively high average eruption rates of 0.07 km3 dense-rock equivalent (DRE)/ky. After a pause in activity of ca. 8000 years, Stage II-1 to II-2 eruptions produced Yotei tephra groups II-1 and II-2 from ca. 38 to ca. 21 cal. ka BP at high average eruption rates (0.10 km3 DRE/ky), after a pause in activity of 2000-3000 years. Finally, after another pause in activity of 4000-5000 years, Stage II-3 eruptions produced Yotei tephra group II-3 from ca. 16.5 cal. ka BP until the present day, at low average eruption rates (0.009 km3 DRE/ky). Whole-rock geochemical compositions vary within each tephra group over the entire eruption history. For example, group I and II-3 tephras contain the lowest and highest abundances, respectively, of K2O, P2O5, and Zr. Group II-1 has the

  16. Characterization of volcanic activity using observations of infrasound, volcanic emissions, and thermal imagery at Karymsky Volcano, Kamchatka, Russia

    NASA Astrophysics Data System (ADS)

    Lopez, T.; Fee, D.; Prata, F.

    2012-04-01

    Karymsky Volcano is one of the most active and dynamic volcanoes in Kamchatka, with activity ranging from vigorous degassing, frequent ash emissions, and apparent vent sealing, all punctuated by daily to weekly explosive magmatic eruptions. Recent studies have highlighted the strengths in using complementary infrasound measurements and remote volcanic emission measurements to characterize volcanic activity, with the potential to discriminate emission-type, approximate ash-cloud height, and estimate SO2 emission mass. Here we use coincident measurements of infrasound, SO2, ash, and thermal radiation collected over a ten day period at Karymsky Volcano in August 2011 to characterize the observed activity and elucidate vent processes. The ultimate goal of this project is to enable different types of volcanic activity to be identified using only infrasound data, which would significantly improve our ability to continuously monitor remote volcanoes. Four types of activity were observed. Type 1 activity is characterized by discrete ash emissions occurring every 1 - 5 minutes that either jet or roil out of the vent, by plumes from 500 - 1500 m (above vent) altitudes, and by impulsive infrasonic onsets. Type 2 activity is characterized by periodic pulses of gas emission, little or no ash, low altitude (100 - 200 m) plumes, and strong audible jetting or roaring. Type 3 activity is characterized by sustained emissions of ash and gas, with multiple pulses lasting from ~1 - 3 minutes, and by plumes from 300 - 1500 m. Type 4 activity is characterized by periods of relatively long duration (~30 minutes to >1 hour) quiescence, no visible plume and weak SO2 emissions at or near the detection limit, followed by an explosive, magmatic eruption, producing ash-rich plumes to >2000 m, and centimeter to meter (or greater) sized pyroclastic bombs that roll down the flanks of the edifice. Eruption onset is accompanied by high-amplitude infrasound and occasionally visible shock

  17. Intense Seismic Activity at Chiles and Cerro Negro Volcanoes on the Colombia-Ecuador Border

    NASA Astrophysics Data System (ADS)

    Torres, R. A.; Cadena, O.; Gomez, D.; Ruiz, M. C.; Prejean, S. G.; Lyons, J. J.; White, R. A.

    2015-12-01

    The region of Chiles and Cerro Negro volcanoes, located on the Colombian-Ecuadorian border, has experienced an ongoing seismic swarm beginning in Aug. 2013. Based on concern for local residents and authorities, a cooperative broadband monitoring network was installed by the Servicio Geológico Colombiano in Colombia and the Instituto Geofísico of the Escuela Politécnica Nacional in Ecuador. Since November 2013 more than 538,000 earthquakes were recorded; although since May 2015 the seismicity has decreased significantly to an average of 70 events per day. Three large earthquake swarms with increasing energy occurred in Aug.-Oct. 2013, March-May 2014, and Sept.-Dec. 2014. By the end of 2014, roughly 400 earthquakes greater than M 3 had occurred with a maximum rate of 8000 earthquakes per day. The largest earthquake was a 5.6 ML on Oct. 20, 2014. This event produced an InSAR coseismic deformation of ~23 cm (S. Ebmeier, personal communication). Most events are typical brittle failure volcano-tectonic (VT) earthquakes that are located in a cluster beneath the southern flank of Chiles volcano, with depths between 1.5 and 10 km. Although the great majority of earthquakes are VT, some low-frequency (LF, ~0.5 Hz) and very-low-frequency (VLF) events have occurred. Particle motion analysis suggests that the VLF source migrated with time. While a VLF on Oct. 15, 2014 was located south of Chiles volcano, near the InSAR source, the VLF registered on Feb. 14, 2015 was likely located very close to Chiles Volcano. We infer that magma intrusion and resulting fluid exsolution at depths greater than 5 km are driving seismicity in the Chiles-Cerro Negro region. However earthquakes are failing in a manner consistent with regional tectonics. Relative relocations reveal a structure consistent with mapped regional faults. Thus seismicity is likely controlled by an interaction of magmatic and tectonic processes. Because the regional stress field is highly compressional and the volcanoes

  18. Petrogenesis of Na-rich paralava formed by methane flares associated with mud volcanism, Altyn-Emel National Park, Kazakhstan

    NASA Astrophysics Data System (ADS)

    Grapes, Rodney; Sokol, Ella; Kokh, Svetlana; Kozmenko, Olga; Fishman, Ilia

    2013-04-01

    High-Na slag-like rocks (paralava) with 4.5-11 % Na2O from the Altyn-Emel mud volcanic field, Kazakhstan, are the products of melting of sediment + salt mixtures by methane flares associated with mud extrusion. The main minerals of the paralavas are diopside and wollastonite which have quench morphologies. Other high-temperature phases (crystallizing from melt and vapour phase) are tridymite, cristobalite, chlorapatite, alkali feldspar, pyrrhotite, native iron and silicon, iron phosphides, titanite, rutile, and carbon. The paralavas lack the Na-Ca silicates devitrite and combeite, but have high-Na and Na-K glasses that have not been homogenized despite low viscosities of <10-3.5 Pa s. The large number of ignition foci in the Altyn-Emel mud volcano field indicates gas venting from small, shallow reservoirs. The methane flares are inferred to have been small and the fire events short-lived. Fires were extinguished once overpressure released during eruption, methane venting stopped and melted rocks rapidly quenched. The periodicity of eruptions and methane flaring most likely depends on the recurrence of earthquakes ( M < 5) which are frequent in this tectonically active area.

  19. 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

  20. 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

  1. An actinomycete isolate from solitary wasp mud nest having strong antibacterial activity and kills the Candida cells due to the shrinkage and the cytosolic loss

    PubMed Central

    Kumar, Vijay; Naik, Bindu; Gusain, Omprakash; Bisht, Gajraj S.

    2014-01-01

    An actinomycetes strain designated as MN 2(6) was isolated from the solitary wasp mud nest. The isolate was identified using polyphasic taxonomy. It produced the extensive branched brown substrate and white aerial hyphae that changed into grayish black. The aerial mycelia produced the spiral spore chains with rugose spore surface. The growth was observed between temperature range of 27–37°C, pH 8–10 and below salt concentration of 6% (w/v). The comparative analysis of 16S rRNA gene sequence and phylogenetic relationship showed that strain MN 2(6) lies in clade with Streptomyces hygroscopicus subsp. hygroscopicus NRRL 2387T, Streptomyces sporocinereus NBRC 100766T and Streptomyces demainii NRRL B-1478T with which it shares a 16S rRNA gene sequence similarity of 99.3%. The strain MN 2(6) can be differentiated from type strains based on phenotypic characteristics. The strain MN 2(6) showed most promising activity against Gram-positive, Gram-negative bacteria, acid-fast bacilli and Candida species suggesting broad-spectrum characteristics of the active metabolite. Evaluation of anti-candidal activity of the metabolite of strain MN 2(6) by scanning electron microscopy (SEM) revealed changed external morphology of yeast. It kills the Candida cells due to the shrinkage and the cytosolic loss. However, further studies are required to elucidate the structure of the active metabolite produced by the isolate MN 2(6). PMID:25191320

  2. Chronology of Postglacial Eruptive Activity and Calculation of Eruption Probabilities for Medicine Lake Volcano, Northern California

    USGS Publications Warehouse

    Nathenson, Manuel; Donnelly-Nolan, Julie M.; Champion, Duane E.; Lowenstern, Jacob B.

    2007-01-01

    Medicine Lake volcano has had 4 eruptive episodes in its postglacial history (since 13,000 years ago) comprising 16 eruptions. Time intervals between events within the episodes are relatively short, whereas time intervals between the episodes are much longer. An updated radiocarbon chronology for these eruptions is presented that uses paleomagnetic data to constrain the choice of calibrated ages. This chronology is used with exponential, Weibull, and mixed-exponential probability distributions to model the data for time intervals between eruptions. The mixed exponential distribution is the best match to the data and provides estimates for the conditional probability of a future eruption given the time since the last eruption. The probability of an eruption at Medicine Lake volcano in the next year from today is 0.00028.

  3. Subaqueous cryptodome eruption, hydrothermal activity and related seafloor morphologies on the andesitic North Su volcano

    NASA Astrophysics Data System (ADS)

    Thal, Janis; Tivey, Maurice; Yoerger, Dana R.; Bach, Wolfgang

    2016-09-01

    North Su is a double-peaked active andesite submarine volcano located in the eastern Manus Basin of the Bismarck Sea that reaches a depth of 1154 m. It hosts a vigorous and varied hydrothermal system with black and white smoker vents along with several areas of diffuse venting and deposits of native sulfur. Geologic mapping based on ROV observations from 2006 and 2011 combined with morphologic features identified from repeated bathymetric surveys in 2002 and 2011 documents the emplacement of a volcanic cryptodome between 2006 and 2011. We use our observations and rock analyses to interpret an eruption scenario where highly viscous, crystal-rich andesitic magma erupted slowly into the water-saturated, gravel-dominated slope of North Su. An intense fragmentation process produced abundant blocky clasts of a heterogeneous magma (olivine crystals within a rhyolitic groundmass) that only rarely breached through the clastic cover onto the seafloor. Phreatic and phreatomagmatic explosions beneath the seafloor cause mixing of juvenile and pre-existing lithic clasts and produce a volcaniclastic deposit. This volcaniclastic deposit consists of blocky, non-altered clasts next, variably (1-100%) altered clasts, hydrothermal precipitates and crystal fragments. The usually applied parameters to identify juvenile subaqueous lava fragments, i.e. fluidal shape or chilled margin, were not applicable to distinguish between pre-existing non-altered clasts and juvenile clasts. This deposit is updomed during further injection of magma and mechanical disruption. Gas-propelled turbulent clast-recycling causes clasts to develop variably rounded shapes. An abundance of blocky clasts and the lack of clasts typical for the contact of liquid lava with water is interpreted to be the result of a cooled, high-viscosity, crystal-rich magma that failed as a brittle solid upon stress. The high viscosity allows the lava to form blocky and short lobes. The pervasive volcaniclastic cover on North Su is

  4. Satellite relay telemetry in the surveillance of active volcanoes and major fault zones

    NASA Technical Reports Server (NTRS)

    Eaton, J. P.; Ward, P. L.

    1972-01-01

    A review was made of efforts to develop a dense telemetered microearthquake network to study earthquake mechanics along the San Andreas fault and the strain mechanics of the Kilauea Volcano. The principle elements and objectives of the ERTS-A proposal are outlined. Some of the aspects of the earthquake network and the results obtained from it as well as some promising experiments in computerized record processing are discussed.

  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. Three-dimensional P-wave velocity structure of Bandai volcano in northeastern Japan inferred from active seismic survey

    NASA Astrophysics Data System (ADS)

    Yamawaki, Teruo; Tanaka, Satoru; Ueki, Sadato; Hamaguchi, Hiroyuki; Nakamichi, Haruhisa; Nishimura, Takeshi; Oikawa, Jun; Tsutsui, Tomoki; Nishi, Kiyoshi; Shimizu, Hiroshi; Yamaguchi, Sosuke; Miyamachi, Hiroki; Yamasato, Hitoshi; Hayashi, Yutaka

    2004-12-01

    The three-dimensional P-wave velocity structure of the Bandai volcano has been revealed by tomographic inversion using approximately 2200 travel-time data collected during an active seismic survey comprising 298 temporary seismic stations and eight artificial shots. The key result of this study is the delineation of a high-velocity anomaly (Vp>4.6 km/s at sea-level) immediately below the summit peak. This feature extends to depths of 1-2 km below sea-level. The near-surface horizontal position of the high-velocity anomaly coincides well with that of a positive Bouguer gravity anomaly. Geological data demonstrate that sector collapses have occurred in all directions from the summit and that the summit crater has been repeatedly refilled with magmatic material. These observations suggest that the high-velocity region revealed in this study is a manifestation of an almost-solidified magmatic plumbing system. We have also noted that a near-surface low-velocity region (Vp<3.0 km/s at sea-level) on the southern foot of the volcano corresponds to the position of volcanic sediments including ash and debris avalanche material. In addition, we have made use of the tomographic results to recompute the hypocenters of earthquake occurring during seismic swarms beneath the summit in 1988 and 2000. Relocating the earthquakes using the three-dimensional velocity model clearly indicates that they predominantly occurred on two steeply dipping planes. Low-frequency earthquakes observed during the swarms in 2000 occurred in the seismic gap between the two clusters. The hypocentral regions of the seismic swarms and the low-frequency earthquakes are close to the higher-velocity zone beneath the volcano's summit. These observations suggest that the recent seismic activity beneath the summit is likely associated with thermal energy being released within the solidifying magmatic plumbing system.

  7. Activity of Nyiragongo and Nyamulagira Volcanoes (Dem. Rep. of Congo) Revealed Using Geological, Geophysical and InSAR data

    NASA Astrophysics Data System (ADS)

    Wauthier, C.; Cayol, V.; Hooper, A.; Kervyn, F.; Marinkovic, P.; D'Oreye, N.; Poland, M. P.

    2010-12-01

    Ground-based monitoring of active volcanoes in Africa can be problematic due to political instabilities, safety issues and poor accessibility. Remote-sensing techniques such as Differential Interferometric Synthetic Aperture Radar (DInSAR, more commonly InSAR), are therefore very useful and provide robust observational tools for natural hazard assessment, regardless of local conditions. Nyiragongo and Nyamulagira volcanoes (which experienced nine eruptions from December 1996 to January 2010) are located in the western branch of the East African Rift (Virunga Volcanic Province, North Kivu, Dem. Rep. of Congo). InSAR has recorded ground displacements related to most of the tectonic and volcanic events that have occurred since 1996 using SAR images from the JERS, ERS-1/2, ENVISAT, RADARSAT-1, RADARSAT-2 and ALOS satellites. This database provides excellent spatial and temporal resolution of deformation, leading to insights into tectonic and volcanic processes. Loss of coherence within the SAR signal due to rapid-changing equatorial vegetation hampers the use of InSAR as a volcano-tectonic monitoring tool. We partially overcome this limitation using 1) a large number of SAR images, including about 150 ENVISAT and more than 100 RADARSAT-1 images, 2) short repeat times of 24 and 35 days for RADARSAT-1 and ENVISAT, respectively, and 3) satellites with longer wavelengths, such as JERS and ALOS. Using a large dataset combining short revisit time SAR images significantly increases the chances of producing interferograms with good coherence. A longer wavelength radar signal better penetrates vegetation cover, also increasing coherence. Furthermore, useful data were retrieved in low-coherence areas by applying the “StaMPS” (Stanford Method for Persistent Scatterers) method, which combines a small baseline and persistent scatterers approach, to our largest SAR datasets. Using several look angles from both ascending and descending orbital tracks, we were able to characterize

  8. Corrective Action Decision Document/Closure Report for Corrective Action Unit 234: Mud Pits, Cellars, and Mud Spills Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Grant Evenson

    2008-05-01

    This Corrective Action Decision Document/Closure Report has been prepared for Corrective Action Unit (CAU) 234, Mud Pits, Cellars, and Mud Spills, located in Areas 2, 3, 4, 12, and 15 at the Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order (FFACO, 1996; as amended February 2008). Corrective Action Unit 234 is comprised of the following 12 corrective action sites: •02-09-48, Area 2 Mud Plant #1 •02-09-49, Area 2 Mud Plant #2 •02-99-05, Mud Spill •03-09-02, Mud Dump Trenches •04-44-02, Mud Spill •04-99-02, Mud Spill •12-09-01, Mud Pit •12-09-04, Mud Pit •12-09-08, Mud Pit •12-30-14, Cellar •12-99-07, Mud Dump •15-09-01, Mud Pit The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation supporting the recommendation for closure of CAU 234 with no further corrective action. To achieve this, corrective action investigation (CAI) activities were performed as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 234: Mud Pits, Cellars, and Mud Spills (NNSA/NSO, 2007). The purpose of the CAI was to fulfill the following data needs as defined during the data quality objective (DQO) process: •Determine whether contaminants of concern are present. •If contaminants of concern are present, determine their extent. •Provide sufficient information and data to complete appropriate corrective actions. The CAU 234 dataset from the investigation results was evaluated based on the data quality indicator parameters. This evaluation demonstrated the quality and acceptability of the dataset for use in fulfilling the DQO data needs.

  9. 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.

  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. Serpentinite mud volcanism: observations, processes, and implications.

    PubMed

    Fryer, Patricia

    2012-01-01

    Large serpentinite mud volcanoes form on the overriding plate of the Mariana subduction zone. Fluids from the descending plate hydrate (serpentinize) the forearc mantle and enable serpentinite muds to rise along faults to the seafloor. The seamounts are direct windows into subduction processes at depths far too deep to be accessed by any known technology. Fluid compositions vary with distance from the trench, signaling changes in chemical reactions as temperature and pressure increase. The parageneses of rocks in the mudflows permits us to constrain the physical conditions of the decollement region. If eruptive episodes are related to seismicity, seafloor observatories at these seamounts hold the potential to capture a subduction event and trace the effects of eruption on the biological communities that the slab fluids support, such as extremophile Archaea. The microorganisms that inhabit this high-pH, extreme environment support their growth by utilizing chemical constituents present in the slab fluids. Some researchers now contend that the serpentinization process itself may hold the key to the origin of life on Earth.

  12. A large hydrothermal reservoir beneath Taal Volcano (Philippines) revealed by magnetotelluric observations and its implications to the volcanic activity

    PubMed Central

    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 interc