Remote Monitoring of Post-eruption Volcano Environment Based-On Wireless Sensor Network (WSN): The Mount Sinabung Case

NASA Astrophysics Data System (ADS)

Soeharwinto; Sinulingga, Emerson; Siregar, Baihaqi

2017-01-01

An accurate information can be useful for authorities to make good policies for preventive and mitigation after volcano eruption disaster. Monitoring of environmental parameters of post-eruption volcano provides an important information for authorities. Such monitoring system can be develop using the Wireless Network Sensor technology. Many application has been developed using the Wireless Sensor Network technology, such as floods early warning system, sun radiation mapping, and watershed monitoring. This paper describes the implementation of a remote environment monitoring system of mount Sinabung post-eruption. The system monitor three environmental parameters: soil condition, water quality and air quality (outdoor). Motes equipped with proper sensors, as components of the monitoring system placed in sample locations. The measured value from the sensors periodically sends to data server using 3G/GPRS communication module. The data can be downloaded by the user for further analysis.The measurement and data analysis results generally indicate that the environmental parameters in the range of normal/standard condition. The sample locations are safe for living and suitable for cultivation, but awareness is strictly required due to the uncertainty of Sinabung status.

Mt. Spurr's 1992 eruptions

USGS Publications Warehouse

1993-01-01

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

An assessment of seismic monitoring in the United States; requirement for an Advanced National Seismic System

USGS Publications Warehouse

,

1999-01-01

This report assesses the status, needs, and associated costs of seismic monitoring in the United States. It sets down the requirement for an effective, national seismic monitoring strategy and an advanced system linking national, regional, and urban monitoring networks. Modernized seismic monitoring can provide alerts of imminent strong earthquake shaking; rapid assessment of distribution and severity of earthquake shaking (for use in emergency response); warnings of a possible tsunami from an offshore earthquake; warnings of volcanic eruptions; information for correctly characterizing earthquake hazards and for improving building codes; and data on response of buildings and structures during earthquakes, for safe, cost-effective design, engineering, and construction practices in earthquake-prone regions.

Mount St. Helens a decade after the 1980 eruptions: magmatic models, chemical cycles, and a revised hazards assessment

USGS Publications Warehouse

Pallister, J.S.; Hoblitt, R.P.; Crandell, D.R.; Mullineaux, D.R.

1992-01-01

Available geophysical and geologic data provide a simplified model of the current magmatic plumbing system of Mount St. Helens (MSH). This model and new geochemical data are the basis for the revised hazards assessment presented here. The assessment is weighted by the style of eruptions and the chemistry of magmas erupted during the past 500 years, the interval for which the most detailed stratigraphic and geochemical data are available. This interval includes the Kalama (A. D. 1480-1770s?), Goat Rocks (A.D. 1800-1857), and current eruptive periods. In each of these periods, silica content decreased, then increased. The Kalama is a large amplitude chemical cycle (SiO2: 57%-67%), produced by mixing of arc dacite, which is depleted in high field-strength and incompatible elements, with enriched (OIB-like) basalt. The Goat Rocks and current cycles are of small amplitude (SiO2: 61%-64% and 62%-65%) and are related to the fluid dynamics of magma withdrawal from a zoned reservoir. The cyclic behavior is used to forecast future activity. The 1980-1986 chemical cycle, and consequently the current eruptive period, appears to be virtually complete. This inference is supported by the progressively decreasing volumes and volatile contents of magma erupted since 1980, both changes that suggest a decreasing potential for a major explosive eruption in the near future. However, recent changes in seismicity and a series of small gas-release explosions (beginning in late 1989 and accompanied by eruption of a minor fraction of relatively low-silica tephra on 6 January and 5 November 1990) suggest that the current eruptive period may continue to produce small explosions and that a small amount of magma may still be present within the conduit. The gas-release explosions occur without warning and pose a continuing hazard, especially in the crater area. An eruption as large or larger than that of 18 May 1980 (???0.5 km3 dense-rock equivalent) probably will occur only if magma rises from an inferred deep (???7 km), relative large (5-7 km3) reservoir. A conservative approach to hazard assessment is to assume that this deep magma is rich in volatiles and capable of erupting explosively to produce voluminous fall deposits and pyroclastic flows. Warning of such an eruption is expectable, however, because magma ascent would probably be accompanied by shallow seismicity that could be detected by the existing seismic-monitoring system. A future large-volume eruption (???0.1 km3) is virtually certain; the eruptive history of the past 500 years indicates the probability of a large explosive eruption is at least 1% annually. Intervals between large eruptions at Mount St. Helens have varied widely; consequently, we cannot confidently forecast whether the next large eruption will be years decades, or farther in the future. However, we can forecast the types of hazards, and the areas that will be most affected by future large-volume eruptions, as well as hazards associated with the approaching end of the current eruptive period. ?? 1992 Springer-Verlag.

78 FR 16864 - Agency Information Collection Activities: Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-19

... eruptions Description of Respondents: Individuals affected by a volcanic ash fall events each year (if an...: 1028-NEW Abstract: The USGS provides warnings and notification to the public of volcanic activity in.... Users browsing the AVO Web site during eruptions will be directed towards a web form allowing them to...

Precursory swarms of long-period events at Redoubt Volcano (1989-1990), Alaska: Their origin and use as a forecasting tool

USGS Publications Warehouse

Chouet, B.A.; Page, R.A.; Stephens, C.D.; Lahr, J.C.; Power, J.A.

1994-01-01

During the eruption of Redoubt Volcano from December 1989 through April 1990, the Alaska Volcano Observatory issued advance warnings of several tephra eruptions based on changes in seismic activity related to the occurrence of precursory swarms of long-period (LP) seismic events (dominant period of about 0.5 s). The initial eruption on December 14 occurred after 23 years of quiescence and was heralded by a 23-hour swarm of LP events that ended abruptly with the eruption. After a series of vent-clearing explosions over the next few days, dome growth began on December 21. Another swarm, with LP events similar to those of the first, began on the 26th and ended in a major tephra eruption on January 2. Eruptions continued over the next two weeks and then ceased until February 15, when a large eruption initiated a long phase of repetitive dome-building and dome-destroying episodes that continued into April. Warnings were issued before the major events on December 14 and January 2, but as the eruptive sequence continued after January 2, the energy of the swarms decreased and forecasting became more difficult. A significant but less intense swarm preceded the February 15 eruption, which was not forecast. This eruption destroyed the only seismograph on the volcanic edifice and stymied forecasting until March 4, when the first of three new stations was installed within 3 km of the active vent. From March 4 to the end of the sequence on April 21, there were eight eruptions, six of which were preceded by detectable swarms of LP events. Although weak, these swarms provided the basis for warnings issued before the eruptions on March 23 and April 6. The initial swarm on December 13 had the following features: (1) short duration (23 hours); (2) a rapidly accelerating rate of seismic energy release over the first 18 hours of the swarm, followed by a decline of activity during the 5 hours preceding the eruption; (3) a magnitude range from -0.4 to 1.6; (4) nearly identical LP signatures with a dominant period near 0.5 s; (5) dilatational first motions everywhere; and (6) a stationary source location at a depth of 1.4 km beneath the crater. This occurrence of long-period events suggests a model involving the interaction of magma with groundwater in which magmatic gases, steam and water drive a fixed conduit at a stationary point throughout the swarm. The initiation of that sequence of events is analogous to the failure of a pressure-relief valve connecting a lower, supercharged magma-dominated reservoir to a shallow hydrothermal system. A three-dimensional model of a vibrating fluid-filled crack recently developed by Chouet is found to be compatible with the seismic data and yields the following parameters for the LP source: crack length, 280-380 m; crack width, 140-190 m; crack thickness, 0.05-0.20 m; crack stiffness, 100-200; sound speed of fluid, 0.8-1.3 km/s; compressional-wave speed of rock, 5.1 km/s; density ratio of fluid to rock, ???0.4; and ratio of bulk modulus of fluid to rigidity of rock, 0.03-0.07. The fluid-filled crack is excited intermittently by an impulsive pressure drop that varies in magnitude within the range of 0.4 to 40 bar. Such disturbance appears to be consistent with a triggering mechanism associated with choked flow conditions in the crack. ?? 1994.

Peacemaking, Complex Emergencies, and Disaster Response: What Happens, How Do You Respond?

DTIC Science & Technology

1999-02-01

territories have been hit by several major hurricanes in recent years, including Hurricane Andrew (South Florida, 1992), Hurricane Hugo (South Carolina...recent eruptions on Montserrat (in the Caribbean) and in the Cape Verde islands are examples of such small-scale eruptions. Figure 18 shows the...timeline for recent volcanic eruptions on Mont- serrat, and in the Cape Verde Islands. In the case of Montserrat , the warning time was essentially

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

USGS Publications Warehouse

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

2016-01-01

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

Improved satellite-based emergency alerting system

NASA Astrophysics Data System (ADS)

Bernard, E. N.; Milburn, H. B.

1991-12-01

Rapid-onset natural hazards have claimed more than 2.8 million lives worldwide in the past 20 years. This category includes such events as earthquakes, landslides, hurricanes, tornadoes, floods, volcanic eruptions, wildfires, and tsunamis. Effective hazard mitigation is particularly difficult in such cases, since the time available to issue warnings can be very short or even nonexistent. A general approach to mitigate the effects of these disasters was demonstrated in 1988 that included preevent emergency planning, real-time hazard assessment, and rapid warning via satellite communication links. This article reports on improvements in this satellite-based emergency alerting communication system that have reduced the response time from 87 to 17 sec and expanded the broadcast coverage from 40 percent to 62 percent of the earth's surface.

U.S. Geological Survey Volcano Hazards Program—Assess, forecast, prepare, engage

USGS Publications Warehouse

Stovall, Wendy K.; Wilkins, Aleeza M.; Mandeville, Charles W.; Driedger, Carolyn L.

2016-07-13

At least 170 volcanoes in 12 States and 2 territories have erupted in the past 12,000 years and have the potential to erupt again. Consequences of eruptions from U.S. volcanoes can extend far beyond the volcano’s immediate area. Many aspects of our daily life are vulnerable to volcano hazards, including air travel, regional power generation and transmission infrastructure, interstate transportation, port facilities, communications infrastructure, and public health. The U.S. Geological Survey has the Federal responsibility to issue timely warnings of potential volcanic activity to the affected populace and civil authorities. The Volcano Hazards Program (VHP) is funded to carry out that mission and does so through a combination of volcano monitoring, short-term warnings, research on how volcanoes work, and community education and outreach.

Advances in volcano monitoring and risk reduction in Latin America

NASA Astrophysics Data System (ADS)

McCausland, W. A.; White, R. A.; Lockhart, A. B.; Marso, J. N.; Assitance Program, V. D.; Volcano Observatories, L. A.

2014-12-01

We describe results of cooperative work that advanced volcanic monitoring and risk reduction. The USGS-USAID Volcano Disaster Assistance Program (VDAP) was initiated in 1986 after disastrous lahars during the 1985 eruption of Nevado del Ruiz dramatizedthe need to advance international capabilities in volcanic monitoring, eruption forecasting and hazard communication. For the past 28 years, VDAP has worked with our partners to improve observatories, strengthen monitoring networks, and train observatory personnel. We highlight a few of the many accomplishments by Latin American volcano observatories. Advances in monitoring, assessment and communication, and lessons learned from the lahars of the 1985 Nevado del Ruiz eruption and the 1994 Paez earthquake enabled the Servicio Geológico Colombiano to issue timely, life-saving warnings for 3 large syn-eruptive lahars at Nevado del Huila in 2007 and 2008. In Chile, the 2008 eruption of Chaitén prompted SERNAGEOMIN to complete a national volcanic vulnerability assessment that led to a major increase in volcano monitoring. Throughout Latin America improved seismic networks now telemeter data to observatories where the decades-long background rates and types of seismicity have been characterized at over 50 volcanoes. Standardization of the Earthworm data acquisition system has enabled data sharing across international boundaries, of paramount importance during both regional tectonic earthquakes and during volcanic crises when vulnerabilities cross international borders. Sharing of seismic forecasting methods led to the formation of the international organization of Latin American Volcano Seismologists (LAVAS). LAVAS courses and other VDAP training sessions have led to international sharing of methods to forecast eruptions through recognition of precursors and to reduce vulnerabilities from all volcano hazards (flows, falls, surges, gas) through hazard assessment, mapping and modeling. Satellite remote sensing data-sharing facilitatescross-border identification and warnings of ash plumes for aviation. Overall, long-term strategies of data collection and experience-sharing have helped Latin American observatories improve their monitoring and create informed communities cognizant of vulnerabilities inherent in living near volcanoes.

77 FR 34400 - Agency Information Collection Activities: Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... warnings and notification to the public of volcanic activity in the U.S. in order to reduce the loss of... eruptions will be directed towards a web form allowing them to fill in ash fall information and submit the... track eruption clouds and associated fallout downwind. These reports from the public will also give...

Resolving the architecture of monogenetic feeder systems from exposures of extinct volcanic fields

NASA Astrophysics Data System (ADS)

Muirhead, J.; Van Eaton, A. R.; Re, G.; White, J. D. L.; Ort, M. H.

2016-12-01

Monogenetic volcanic fields pose hazards to a number of major cities worldwide. During an eruption, the evolution of the intrusive feeder network modulates eruption behavior and location, as well as the warning signs of impending activity. However, historical examples of monogenetic eruptions are rare, particularly those monitored with the modern tools required to constrain the geometry and interconnectivity of subsurface intrusive feeders (e.g., InSAR, GPS). Geologic exposures in extinct fields around the Colorado Plateau provide clues to the geometry of shallow intrusions (<1000 m depth) that feed monogenetic volcanoes. We present field- and satellite-based observations of exposed intrusions in the Hopi Buttes volcanic field (Arizona), which reveal that many eruptions were fed by interconnected dike-sill systems. Results from the Hopi Buttes show that volcanic cone alignment studies are biased to the identification of dike intrusions, and thereby neglect the important contributions of sills to shallow feeder systems. For example, estimates of intruded volumes in fields exhumed by uplift and erosion in Utah and Arizona show that sills make up 30 - 92% of the shallow intruded volume within 1000 m of the paleosurface. By transporting magma toward and away from eruptive conduits, these sills likely played a role in modulating eruption styles (e.g., explosive vs effusive) and controlling lateral vent migrations. Sill transitions at Hopi Buttes would have produced detectable surface uplifts, and illustrate the importance of geological studies for informing interpretations of geodetic and seismological data during volcanic crises.

Developing effective warning systems: Ongoing research at Ruapehu volcano, New Zealand

NASA Astrophysics Data System (ADS)

Leonard, Graham S.; Johnston, David M.; Paton, Douglas; Christianson, Amy; Becker, Julia; Keys, Harry

2008-05-01

PurposeThis paper examines the unique challenges to volcanic risk management associated with having a ski area on an active volcano. Using a series of simulated eruption/lahar events at Ruapehu volcano, New Zealand, as a context, a model of risk management that integrates warning system design and technology, risk perceptions and the human response is explored. Principal resultsDespite increases in the observed audibility and comprehension of the warning message, recall of public education content, and people's awareness of volcanic risk, a persistent minority of the public continued to demonstrate only moderate awareness of the correct actions to take during a warning and failed to respond effectively. A relationship between level of staff competence and correct public response allowed the level of public response to be used to identify residual risk and additional staff training needs. The quality of staff awareness, action and decision-making has emerged as a critical factor, from detailed staff and public interviews and from exercise observations. Staff actions are especially important for mobilising correct public response at Ruapehu ski areas due to the transient nature of the visitor population. Introduction of education material and staff training strategies that included the development of emergency decision-making competencies improved knowledge of correct actions, and increased the proportion of people moving out of harm's way during blind tests. Major conclusionsWarning effectiveness is a function of more than good hazard knowledge and the generation and notification of an early warning message. For warning systems to be effective, these factors must be complemented by accurate knowledge of risk and risk management actions. By combining the Ruapehu findings with those of other warning system studies in New Zealand, and internationally, a practical five-step model for effective early warning systems is discussed. These steps must be based upon sound and regularly updated underpinning science and be tied to formal effectiveness evaluation, which is fed back into system improvements. The model presented emphasises human considerations, the development of which arguably require even more effort than the hardware components of early warning systems.

Human Response to Emergency Warning

NASA Astrophysics Data System (ADS)

Sorensen, J.

2009-12-01

Almost every day people evacuate from their homes, businesses or other sites, even ships, in response to actual or predicted threats or hazards. Evacuation is the primary protective action utilized in large-scale emergencies such as hurricanes, floods, tornados, tsunamis, volcanic eruptions, or wildfires. Although often precautionary, protecting human lives by temporally relocating populations before or during times of threat remains a major emergency management strategy. One of the most formidable challenges facing emergency officials is evacuating residents for a fast-moving and largely unpredictable event such as a wildfire or a local tsunami. How to issue effective warnings to those at risk in time for residents to take appropriate action is an on-going problem. To do so, some communities have instituted advanced communications systems that include reverse telephone call-down systems or other alerting systems to notify at-risk residents of imminent threats. This presentation examines the effectiveness of using reverse telephone call-down systems for warning San Diego residents of wildfires in the October of 2007. This is the first systematic study conducted on this topic and is based on interviews with 1200 households in the evacuation areas.

Spatial and temporal variations of diffuse CO2 degassing at El Hierro volcanic system: Relation to the 2011-2012 submarine eruption

NASA Astrophysics Data System (ADS)

Melián, Gladys; Hernández, Pedro A.; Padrón, Eleazar; Pérez, Nemesio M.; Barrancos, José; Padilla, Germán.; Dionis, Samara; Rodríguez, Fátima; Calvo, David; Nolasco, Dacil

2014-09-01

We report herein the results of extensive diffuse CO2 emission surveys performed on El Hierro Island in the period 1998-2012. More than 17,000 measurements of the diffuse CO2 efflux were carried out, most of them during the volcanic unrest period that started in July 2011. Two significant precursory signals based on geochemical and geodetical studies suggest that a magma intrusion processes might have started before 2011 in El Hierro Island. During the preeruptive and eruptive periods, the time series of the diffuse CO2 emission released by the whole island experienced two significant increases. The first started almost 2 weeks before the onset of the submarine eruption, reflecting a clear geochemical anomaly in CO2 emission, most likely due to increasing release of deep-seated magmatic gases to the surface. The second one, between 24 October and 27 November 2011, started before the most energetic seismic events of the volcanic-seismic unrest. The data presented here demonstrate that combined continuous monitoring studies and discrete surveys of diffuse CO2 emission provide important information to optimize the early warning system in volcano monitoring programs and to monitor the evolution of an ongoing volcanic eruption, even though it is a submarine eruption.

Merapi 2010 eruption—Chronology and extrusion rates monitored with satellite radar and used in eruption forecasting

USGS Publications Warehouse

Pallister, John S.; Schneider, David; Griswold, Julia P.; Keeler, Ronald H.; Burton, William C.; Noyles, Christopher; Newhall, Christopher G.; Ratdomopurbo, Antonius

2013-01-01

Despite dense cloud cover, satellite-borne commercial Synthetic Aperture Radar (SAR) enabled frequent monitoring of Merapi volcano's 2010 eruption. Near-real-time interpretation of images derived from the amplitude of the SAR signals and timely delivery of these interpretations to those responsible for warnings, allowed satellite remote sensing for the first time to play an equal role with in situ seismic, geodetic and gas monitoring in guiding life-saving decisions during a major volcanic crisis. Our remotely sensed data provide an observational chronology for the main phase of the 2010 eruption, which lasted 12 days (26 October–7 November, 2010). Unlike the prolonged low-rate and relatively low explosivity dome-forming and collapse eruptions of recent decades at Merapi, the eruption began with an explosive eruption that produced a new summit crater on 26 October and was accompanied by an ash column and pyroclastic flows that extended 8 km down the flanks. This initial explosive event was followed by smaller explosive eruptions on 29 October–1 November, then by a period of rapid dome growth on 1–4 November, which produced a summit lava dome with a volume of ~ 5 × 106 m3. A paroxysmal VEI 4 magmatic eruption (with ash column to 17 km altitude) destroyed this dome, greatly enlarged the new summit crater and produced extensive pyroclastic flows (to ~ 16 km radial distance in the Gendol drainage) and surges during the night of 4–5 November. The paroxysmal eruption was followed by a period of jetting of gas and tephra and by a second short period (12 h) of rapid dome growth on 6 November. The eruption ended with low-level ash and steam emissions that buried the 6 November dome with tephra and continued at low levels until seismicity decreased to background levels by about 23 November. Our near-real-time commercial SAR documented the explosive events on 26 October and 4–5 November and high rates of dome growth (> 25 m3 s− 1). An event tree analysis for the previous 2006 Merapi eruption indicated that for lava dome extrusion rates > 1.2 m3 s− 1, the probability of a large (1872-scale) eruption was ~ 10%. Consequently, the order-of-magnitude greater rates in 2010, along with the explosive start of the eruption on 26 October, the large volume of lava accumulating at the summit by 4 November, and the rapid and large increases in seismic energy release, deformation and gas emissions were the basis for warnings of an unusually large eruption by the Indonesian Geological Agency's Center for Volcanology and Geologic Hazard Mitigation (CVGHM) and their Volcano Research and Technology Development Center (BPPTK) in Yogyakarta — warnings that saved thousands of lives.

Scientific and public responses to the ongoing volcanic crisis at Popocatépetl Volcano, Mexico: Importance of an effective hazards-warning system

USGS Publications Warehouse

De la Cruz-Reyna, Servando; Tilling, Robert I.

2008-01-01

Volcanic eruptions and other potentially hazardous natural phenomena occur independently of any human actions. However, such phenomena can cause disasters when a society fails to foresee the hazardous manifestations and adopt adequate measures to reduce its vulnerability. One of the causes of such a failure is the lack of a consistent perception of the changing hazards posed by an ongoing eruption, i.e., with members of the scientific community, the Civil Protection authorities and the general public having diverging notions about what is occurring and what may happen. The problem of attaining a perception of risk as uniform as possible in a population measured in millions during an evolving eruption requires searching for communication tools that can describe—as simply as possible—the relations between the level of threat posed by the volcano, and the level of response of the authorities and the public. The hazards-warning system adopted at Popocatépetl Volcano, called the Volcanic Traffic Light Alert System(VTLAS), is a basic communications protocol that translates volcano threat into seven levels of preparedness for the emergency-management authorities, but only three levels of alert for the public (color coded green–yellow–red). The changing status of the volcano threat is represented as the most likely scenarios according to the opinions of an official scientific committee analyzing all available data. The implementation of the VTLAS was intended to reduce the possibility of ambiguous interpretations of intermediate levels by the endangered population. Although the VTLAS is imperfect and has not solved all problems involved in mass communication and decision-making during a volcanic crisis, it marks a significant advance in the management of volcanic crises in Mexico.

The Run-up to Volcanic Eruption Unveiled by Forensic Petrology and Geophysical Observations

NASA Astrophysics Data System (ADS)

Rasmussen, D. J.; Plank, T. A.; Roman, D. C.

2017-12-01

Volcanoes often warn of impending eruptions. However, one of the greatest challenges in volcano research is translating precursory geophysical signals into physical magmatic processes. Petrology offers powerful tools to study eruption run-up that benefit from direct response to magmatic forcings. Developing these tools, and tying them to geophysical observations, will help us identify eruption triggers (e.g., magmatic recharge, gas build-up, tectonic events) and understand the significance of monitored signals of unrest. We present an overview of petrologic tools used for studying eruption run-up, highlighting results from our study of the 1999 eruption of Shishaldin volcano. Olivine crystals contain chemical gradients, the consequence of diffusion following magma mixing events, which is modeled to determine mixing timescales. Modeled timescales provide strong evidence for at least three mixing events, which were triggered by magmatic recharge. Petrologic barometers indicate these events occurred at very shallow depths (within the volcanic edifice). The first mixing event occurred nine months before eruption, which was signaled by a swarm of deep-long period earthquake. Minor recharge events followed over two months, which are indicated by a second deep-long period earthquake swarm and a change in the local stress orientation measured by shear-wave splitting. Following these events, the system was relatively quiet until a large mixing event occurred 45 days prior to eruption, which was heralded by a large earthquake (M5.2). Following this event, geophysical signals of unrest intensified and became continuous. The final mixing event, beginning roughly a week before eruption, represents the final perturbation to the system before eruption. Our findings point to a relatively long run-up, which was subtle at first and intensified several weeks before eruption. This study highlights the strong link between geophysical signals of volcanic unrest and magmatic events, and helps open the door for the application of forensic petrology to unmonitored eruptions.

Volcano Hazards Assessment for Medicine Lake Volcano, Northern California

USGS Publications Warehouse

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

2007-01-01

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

Large, Moderate or Small? The Challenge of Measuring Mass Eruption Rates in Volcanic Eruptions

NASA Astrophysics Data System (ADS)

Gudmundsson, M. T.; Dürig, T.; Hognadottir, T.; Hoskuldsson, A.; Bjornsson, H.; Barsotti, S.; Petersen, G. N.; Thordarson, T.; Pedersen, G. B.; Riishuus, M. S.

2015-12-01

The potential impact of a volcanic eruption is highly dependent on its eruption rate. In explosive eruptions ash may pose an aviation hazard that can extend several thousand kilometers away from the volcano. Models of ash dispersion depend on estimates of the volcanic source, but such estimates are prone to high error margins. Recent explosive eruptions, including the 2010 eruption of Eyjafjallajökull in Iceland, have provided a wealth of data that can help in narrowing these error margins. Within the EU-funded FUTUREVOLC project, a multi-parameter system is currently under development, based on an array of ground and satellite-based sensors and models to estimate mass eruption rates in explosive eruptions in near-real time. Effusive eruptions are usually considered less of a hazard as lava flows travel slower than eruption clouds and affect smaller areas. However, major effusive eruptions can release large amounts of SO2 into the atmosphere, causing regional pollution. In very large effusive eruptions, hemispheric cooling and continent-scale pollution can occur, as happened in the Laki eruption in 1783 AD. The Bárdarbunga-Holuhraun eruption in 2014-15 was the largest effusive event in Iceland since Laki and at times caused high concentrations of SO2. As a result civil protection authorities had to issue warnings to the public. Harmful gas concentrations repeatedly persisted for many hours at a time in towns and villages at distances out to 100-150 km from the vents. As gas fluxes scale with lava fluxes, monitoring of eruption rates is therefore of major importance to constrain not only lava but also volcanic gas emissions. This requires repeated measurements of lava area and thickness. However, most mapping methods are problematic once lava flows become very large. Satellite data on thermal emissions from eruptions have been used with success to estimate eruption rate. SAR satellite data holds potential in delivering lava volume and eruption rate estimates, although availability and repeat times of radar platforms is still low compared to e.g. the thermal satellites. In the 2014-15 eruption, lava volume was estimated repeatedly from an aircraft-based system that combines radar altimeter with an on-board DGPS, yielding a several estimates of lava volume and time-averaged mass eruption rate.

Monitoring a restless volcano: The 2004 eruption of Mount St. Helens

USGS Publications Warehouse

Gardner, C.

2005-01-01

Although the precise course of volcanic activity is difficult to predict, volcanologists are pretty adept at interpreting volcanic signals from well-monitored volcanoes in order to make short-term forecasts. Various monitoring tools record effects to give us warning before eruptions, changes in eruptive behavior during eruptions, or signals that an eruption is ending. Foremost among these tools is seismic monitoring. The character, size, depth and rate of earthquakes are all important to the interpretation of what is happening belowground. The first inkling of renewed activity at Mount St. Helens began in the early hours of Sept. 23, when a seismic swarm - tens to hundreds of earthquakes over days to a week - began beneath the volcano. This article details the obervations made during the eruptive sequence.

Volcanic Eruptions and Climate

NASA Astrophysics Data System (ADS)

Robock, A.

2012-12-01

Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of these aerosol clouds produce responses in the climate system. Observations and numerical models of the climate system show that volcanic eruptions produce global cooling and were the dominant natural cause of climate change for the past millennium, on timescales from annual to century. Major tropical eruptions produce winter warming of Northern Hemisphere continents for one or two years, while high latitude eruptions in the Northern Hemisphere weaken the Asian and African summer monsoon. The Toba supereruption 74,000 years ago caused very large climate changes, affecting human evolution. However, the effects did not last long enough to produce widespread glaciation. An episode of four large decadally-spaced eruptions at the end of the 13th century C.E. started the Little Ice Age. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade had a small effect on global temperature trends. The June 13, 2011 Nabro eruption in Eritrea produced the largest stratospheric aerosol cloud since Pinatubo, and the most of the sulfur entered the stratosphere not by direct injection, but by slow lofting in the Asian summer monsoon circulation. Volcanic eruptions warn us that while stratospheric geoengineering could cool the surface, reducing ice melt and sea level rise, producing pretty sunsets, and increasing the CO2 sink, it could also reduce summer monsoon precipitation, destroy ozone, allowing more harmful UV at the surface, produce rapid warming when stopped, make the sky white, reduce solar power, perturb the ecology with more diffuse radiation, damage airplanes flying in the stratosphere, degrade astronomical observations, affect remote sensing, and affect stargazing.

CALIPSO Featured Articles

Atmospheric Science Data Center

2016-06-13

... Nighttime Ash Tracking  - Vertical profile of the volcanic ash helps modelers issue more accurate warnings to pilots. ... train of satellites follows the atmospheric effects of a volcanic eruption. ...

Volcanic activity and satellite-detected thermal anomalies at 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. A large nuee ardente eruption occurred at Santiaguito volcano, within the test area on 16 September 1973. Through a system of local observers, the eruption has been described, reported to the international scientific community, extent of affected area mapped, and the new ash sampled. A more extensive report on this event will be prepared. The eruption is an excellent example of the kind of volcanic situation in which satellite thermal imagery might be useful. The Santiaguito dome is a complex mass with a whole series of historically active vents. It's location makes access difficult, yet its activity is of great concern to large agricultural populations who live downslope. Santiaguito has produced a number of large eruptions with little apparent warning. In the earlier ground survey large thermal anomalies were identified at Santiaguito. There is no way of knowing whether satellite monitoring could have detected changes in thermal anomaly patterns related to this recent event, but the position of thermal anomalies on Santiaguito and any changes in their character would be relevant information.

Changes in the Orientation of Local Stresses Prior to and During Magmatic Activity at the Soufriere Hills Volcano, Montserrat

NASA Astrophysics Data System (ADS)

Roman, D. C.; Neuberg, J.; Luckett, R. R.; White, R. A.

2005-12-01

Systematic changes in the orientation of double-couple fault-plane solutions (FPS) for volcanotectonic (VT) earthquakes have been linked to stress changes induced by the dilation of the magmatic conduit system and may precede the onset of eruption by weeks to months, potentially providing advance warning of an impending eruption. To determine whether analysis of FPS for VT earthquakes recorded during the ongoing eruption of the Soufriere Hills Volcano, Montserrat, could be used to detect the arrival of magma in the mid-level conduit system, we produced a large catalog of high-quality FPS that spanned several phases of the eruption, and then analyzed this catalog to determine whether a temporal correlation exists between eruptive activity and FPS orientation. We repicked VT earthquakes recorded on the Montserrat Volcano Observatory analog and digital seismic networks from the beginning of the eruption in 1995 to May 2005 and relocated them using a 1D velocity model. We then determined well-constrained FPS for the relocated earthquakes. Well-contrained FPS for 607 VT earthquakes indicate primarily oblique strike-slip faulting. In August 1995 (prior to the onset of lava extrusion in September 1995), October 1996-June 1997 (during a period of dome-building), May-November 1999 (prior to the restart of the eruption in November 1999 following a year-long pause), and April-May 2005 (prior to the restart of the eruption in June-August 2005 following a two year pause), FPS pressure (p-) axes are oriented approximately perpendicular to the inferred direction of regional maximum compressive stress around Montserrat. In contrast, FPS p-axes for earthquakes accompanying a pause in the eruption in 1998-1999, and from December 1999-March 2005 are oriented approximately parallel to regional maximum compression. VT earthquakes with FPS p-axes oriented perpendicular to regional maximum compression are thought to reflect local stresses induced by the inflation of a dike-like magmatic conduit system beneath Soufriere Hills prior to and during episodes of eruption.

Satellite monitoring of remote volcanoes improves study efforts in Alaska

NASA Astrophysics Data System (ADS)

Dean, K.; Servilla, M.; Roach, A.; Foster, B.; Engle, K.

Satellite monitoring of remote volcanoes is greatly benefitting the Alaska Volcano Observatory (AVO), and last year's eruption of the Okmok Volcano in the Aleutian Islands is a good case in point. The facility was able to issue and refine warnings of the eruption and related activity quickly, something that could not have been done using conventional seismic surveillance techniques, since seismometers have not been installed at these locations.AVO monitors about 100 active volcanoes in the North Pacific (NOPAC) region, but only a handful are observed by costly and logistically complex conventional means. The region is remote and vast, about 5000 × 2500 km, extending from Alaska west to the Kamchatka Peninsula in Russia (Figure 1). Warnings are transmitted to local communities and airlines that might be endangered by eruptions. More than 70,000 passenger and cargo flights fly over the region annually, and airborne volcanic ash is a threat to them. Many remote eruptions have been detected shortly after the initial magmatic activity using satellite data, and eruption clouds have been tracked across air traffic routes. Within minutes after eruptions are detected, information is relayed to government agencies, private companies, and the general public using telephone, fax, and e-mail. Monitoring of volcanoes using satellite image data involves direct reception, real-time monitoring, and data analysis. Two satellite data receiving stations, located at the Geophysical Institute, University of Alaska Fairbanks (UAF), are capable of receiving data from the advanced very high resolution radiometer (AVHRR) on National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites and from synthetic aperture radar (SAR) equipped satellites.

Dynamics of a large, restless, rhyolitic magma system at Laguna del Maule, southern Andes, Chile

USGS Publications Warehouse

Singer, Brad S.; Andersen, Nathan L.; Le Mével, Hélène; Feigl, Kurt L.; DeMets, Charles; Tikoff, Basil; Thurber, Clifford H.; Jicha, Brian R.; Cardonna, Carlos; Córdova, Loreto; Gil, Fernando; Unsworth, Martyn J.; Williams-Jones, Glyn; Miller, Craig W.; Fierstein, Judith; Hildreth, Edward; Vazquez, Jorge A.

2014-01-01

Explosive eruptions of large-volume rhyolitic magma systems are common in the geologic record and pose a major potential threat to society. Unlike other natural hazards, such as earthquakes and tsunamis, a large rhyolitic volcano may provide warning signs long before a caldera-forming eruption occurs. Yet, these signs—and what they imply about magma-crust dynamics—are not well known. This is because we have learned how these systems form, grow, and erupt mainly from the study of ash flow tuffs deposited tens to hundreds of thousands of years ago or more, or from the geophysical imaging of the unerupted portions of the reservoirs beneath the associated calderas. The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007, the crust there has been inflating at an astonishing rate of at least 25 cm/yr. This unique opportunity to investigate the dynamics of a large rhyolitic system while magma migration, reservoir growth, and crustal deformation are actively under way is stimulating a new international collaboration. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ca. 20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. The next phase of this investigation seeks to enlarge the sets of geophysical and geochemical data and to use these observations in numerical models of system dynamics.

Constraints and conundrums resulting from ground-deformation measurements made during the 2004-2005 dome-building eruption of Mount St. Helens, Washington: Chapter 14 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

USGS Publications Warehouse

Dzurisin, Daniel; Lisowski, Michael; Poland, Michael P.; Sherrod, David R.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

2008-01-01

Lack of precursory inflation suggests that the volcano was poised to erupt magma already stored in a crustal reservoir when JRO1 was installed in 1997. Trilateration and campaign GPS data indicate surface dilatation, presumably caused by reservoir expansion between 1982 and 1991, but no measurable deformation between 1991 and 2003. We conclude that all three of the traditionally reliable eruption precursors (seismicity, ground deformation, and volcanic gas emission) failed to provide warning that an eruption was imminent until a few days before a visible welt appeared at the surface--a situation reminiscent of the 1980 north-flank bulge at Mount St. Helens.

Monitoring and Modeling: The Future of Volcanic Eruption Forecasting

NASA Astrophysics Data System (ADS)

Poland, M. P.; Pritchard, M. E.; Anderson, K. R.; Furtney, M.; Carn, S. A.

2016-12-01

Eruption forecasting typically uses monitoring data from geology, gas geochemistry, geodesy, and seismology, to assess the likelihood of future eruptive activity. Occasionally, months to years of warning are possible from specific indicators (e.g., deep LP earthquakes, elevated CO2 emissions, and aseismic deformation) or a buildup in one or more monitoring parameters. More often, observable changes in unrest occur immediately before eruption, as magma is rising toward the surface. In some cases, little or no detectable unrest precedes eruptive activity. Eruption forecasts are usually based on the experience of volcanologists studying the activity, but two developing fields offer a potential leap beyond this practice. First, remote sensing data, which can track thermal, gas, and ash emissions, as well as surface deformation, are increasingly available, allowing statistically significant research into the characteristics of unrest. For example, analysis of hundreds of volcanoes indicates that deformation is a more common pre-eruptive phenomenon than thermal anomalies, and that most episodes of satellite-detected unrest are not immediately followed by eruption. Such robust datasets inform the second development—probabilistic models of eruption potential, especially those that are based on physical-chemical models of the dynamics of magma accumulation and ascent. Both developments are essential for refining forecasts and reducing false positives. For example, many caldera systems have not erupted but are characterized by unrest that, in another context, would elicit strong concern from volcanologists. More observations of this behavior and better understanding of the underlying physics of unrest will improve forecasts of such activity. While still many years from implementation as a forecasting tool, probabilistic physio-chemical models incorporating satellite data offer a complement to expert assessments that, together, can form a powerful forecasting approach.

Detecting and Cataloging Global Explosive Volcanism Using the IMS Infrasound Network

NASA Astrophysics Data System (ADS)

Matoza, R. S.; Green, D. N.; LE Pichon, A.; Fee, D.; Shearer, P. M.; Mialle, P.; Ceranna, L.

2015-12-01

Explosive volcanic eruptions are among the most powerful sources of infrasound observed on earth, with recordings routinely made at ranges of hundreds to thousands of kilometers. These eruptions can also inject large volumes of ash into heavily travelled aviation corridors, thus posing a significant societal and economic hazard. Detecting and counting the global occurrence of explosive volcanism helps with progress toward several goals in earth sciences and has direct applications in volcanic hazard mitigation. This project aims to build a quantitative catalog of global explosive volcanic activity using the International Monitoring System (IMS) infrasound network. We are developing methodologies to search systematically through IMS infrasound array detection bulletins to identify signals of volcanic origin. We combine infrasound signal association and source location using a brute-force, grid-search, cross-bearings approach. The algorithm corrects for a background prior rate of coherent infrasound signals in a global grid. When volcanic signals are identified, we extract metrics such as location, origin time, acoustic intensity, signal duration, and frequency content, compiling the results into a catalog. We are testing and validating our method on several well-known case studies, including the 2009 eruption of Sarychev Peak, Kuriles, the 2010 eruption of Eyjafjallajökull, Iceland, and the 2015 eruption of Calbuco, Chile. This work represents a step toward the goal of integrating IMS data products into global volcanic eruption early warning and notification systems. Additionally, a better characterization of volcanic signal detection helps improve understanding of operational event detection, discrimination, and association capabilities of the IMS network.

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.

Warning signals for eruptive events in spreading fires

PubMed Central

Fox, Jerome M.; Whitesides, George M.

2015-01-01

Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This paper describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., “wind–fire coupling”—a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. In this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind–fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., “blowup fires” in forests). PMID:25675491

Warning signals for eruptive events in spreading fires.

PubMed

Fox, Jerome M; Whitesides, George M

2015-02-24

Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This paper describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., "wind-fire coupling"-a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. In this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind-fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., "blowup fires" in forests).

Warning signals for eruptive events in spreading fires

DOE PAGES

Fox, Jerome M.; Whitesides, George M.

2015-02-09

Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This study describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., “wind–firemore » coupling”—a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. Here, in this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind–fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Lastly, findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., “blowup fires” in forests).« less

Warning signals for eruptive events in spreading fires

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

Fox, Jerome M.; Whitesides, George M.

Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This study describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., “wind–firemore » coupling”—a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. Here, in this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind–fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Lastly, findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., “blowup fires” in forests).« less

Eruptive history of the Dieng Mountains region, central Java, and potential hazards from future eruptions

USGS Publications Warehouse

Miller, C. Dan; Sushyar, R.; ,; Hamidi, S.

1983-01-01

The Dieng Mountains region consists of a complex of late Quaternary to recent volcanic stratocones, parasitic vents, and explosion craters. Six age groups of volcanic centers, eruptive products, and explosion craters are recognized in the region based on their morphology, degree of dissection, stratigraphic relationships, and degree of weathering. These features range in age from tens of thousands of years to events that have occurred this century. No magmatic eruptions have occurred in the Dieng Mountains region for at least several thousand years; volcanic activity during this time interval has consisted of phreatic eruptions and non-explosive hydrothermal activity. If future volcanic events are similar to those of the last few thousand years, they will consist of phreatic eruptions, associated small hot mudflows, emission of suffocating gases, and hydrothermal activity. Future phreatic eruptions may follow, or accompany, periods of increased earthquake activity; the epicenters for the seismicity may suggest where eruptive activity will occur. Under such circumstances, the populace within several kilometers of a potential eruption site should be warned of a possible eruption, given instructions about what to do in the event of an eruption, or temporarily evacuated to a safer location.

The Promise and Challenges of High Rate GNSS for Environmental Monitoring and Response

NASA Astrophysics Data System (ADS)

LaBrecque, John

2017-04-01

The decadal vision Global Geodetic Observing System recognizes the potential of high rate real time GNSS for environmental monitoring. The GGOS initiated a program to advance GNSS real time high rate measurements to augment seismic and other sensor systems for earthquake and tsunami early warning. High rate multi-GNSS networks can provide ionospheric tomography for the detection and tracking of land, ocean and atmospheric gravity waves that can provide coastal warning of tsunamis induced by earthquakes, volcanic eruptions, severe weather and other catastrophic events. NASA has collaborated on a microsatellite constellation of GPS receivers to measure ocean surface roughness to improve severe storm tracking and a equatorial system of GPS occultation receivers to measure ionospheric and atmospheric dynamics. Systems such as these will be significantly enhanced by the availability of a four fold increase in GNSS satellite systems with new and enhanced signal structures and by the densification of regional multi-GNSS networks. These new GNSS capabilities will rely upon improved and cost effective communications infrastructure for a network of coordinated real time analysis centers with input to national warning systems. Most important, the implementation of these new real time GNSS capabilities will rely upon the broad international support for the sharing of real time GNSS much as is done in weather and seismic observing systems and as supported by the Committee of Experts on UN Global Geodetic Information Management (UNGGIM).

An experiment to detect and locate lightning associated with eruptions of Redoubt Volcano

USGS Publications Warehouse

Hoblitt, R.P.

1994-01-01

A commercially-available lightning-detection system was temporarily deployed near Cook Inlet, Alaska in an attempt to remotely monitor volcanogenic lightning associated with eruptions of Redoubt Volcano. The system became operational on February 14, 1990; lightning was detected in 11 and located in 9 of the 13 subsequent eruptions. The lightning was generated by ash clouds rising from pyroclastic density currents produced by collapse of a lava dome emplaced near Redoubt's summit. Lightning discharge (flash) location was controlled by topography, which channeled the density currents, and by wind direction. In individual eruptions, early flashes tended to have a negative polarity (negative charge is lowered to ground) while late flashes tended to have a positive polarity (positive charge is lowered to ground), perhaps because the charge-separation process caused coarse, rapid-settling particles to be negatively charged and fine, slow-settling particles to be positively charged. Results indicate that lightning detection and location is a useful adjunct to seismic volcano monitoring, particularly when poor weather or darkness prevents visual observation. The simultaneity of seismicity and lightning near a volcano provides the virtual certainty that an ash cloud is present. This information is crucial for aircraft safety and to warn threatened communities of impending tephra falls. The Alaska Volcano Observatory has now deployed a permanent lightning-detection network around Cook Inlet. ?? 1994.

Statistical forecasting of repetitious dome failures during the waning eruption of Redoubt Volcano, Alaska, February-April 1990

USGS Publications Warehouse

Page, R.A.; Lahr, J.C.; Chouet, B.A.; Power, J.A.; Stephens, C.D.

1994-01-01

The waning phase of the 1989-1990 eruption of Redoubt Volcano in the Cook Inlet region of south-central Alaska comprised a quasi-regular pattern of repetitious dome growth and destruction that lasted from February 15 to late April 1990. The dome failures produced ash plumes hazardous to airline traffic. In response to this hazard, the Alaska Volcano Observatory sought to forecast these ash-producing events using two approaches. One approach built on early successes in issuing warnings before major eruptions on December 14, 1989 and January 2, 1990. These warnings were based largely on changes in seismic activity related to the occurrence of precursory swarms of long-period seismic events. The search for precursory swarms of long-period seismicity was continued through the waning phase of the eruption and led to warnings before tephra eruptions on March 23 and April 6. The observed regularity of dome failures after February 15 suggested that a statistical forecasting method based on a constant-rate failure model might also be successful. The first statistical forecast was issued on March 16 after seven events had occurred, at an average interval of 4.5 days. At this time, the interval between dome failures abruptly lengthened. Accordingly, the forecast was unsuccessful and further forecasting was suspended until the regularity of subsequent failures could be confirmed. Statistical forecasting resumed on April 12, after four dome failure episodes separated by an average of 7.8 days. One dome failure (April 15) was successfully forecast using a 70% confidence window, and a second event (April 21) was narrowly missed before the end of the activity. The cessation of dome failures after April 21 resulted in a concluding false alarm. Although forecasting success during the eruption was limited, retrospective analysis shows that early and consistent application of the statistical method using a constant-rate failure model and a 90% confidence window could have yielded five successful forecasts and two false alarms; no events would have been missed. On closer examination, the intervals between successive dome failures are not uniform but tend to increase with time. This increase attests to the continuous, slowly decreasing supply of magma to the surface vent during the waning phase of the eruption. The domes formed in a precarious position in a breach in the summit crater rim where they were susceptible to gravitational collapse. The instability of the February 15-April 21 domes relative to the earlier domes is attributed to reaming the lip of the vent by a laterally directed explosion during the major dome-destroying eruption of February 15, a process which would leave a less secure foundation for subsequent domes. ?? 1994.

Automated detection and cataloging of global explosive volcanism using the International Monitoring System infrasound network

NASA Astrophysics Data System (ADS)

Matoza, Robin S.; Green, David N.; Le Pichon, Alexis; Shearer, Peter M.; Fee, David; Mialle, Pierrick; Ceranna, Lars

2017-04-01

We experiment with a new method to search systematically through multiyear data from the International Monitoring System (IMS) infrasound network to identify explosive volcanic eruption signals originating anywhere on Earth. Detecting, quantifying, and cataloging the global occurrence of explosive volcanism helps toward several goals in Earth sciences and has direct applications in volcanic hazard mitigation. We combine infrasound signal association across multiple stations with source location using a brute-force, grid-search, cross-bearings approach. The algorithm corrects for a background prior rate of coherent unwanted infrasound signals (clutter) in a global grid, without needing to screen array processing detection lists from individual stations prior to association. We develop the algorithm using case studies of explosive eruptions: 2008 Kasatochi, Alaska; 2009 Sarychev Peak, Kurile Islands; and 2010 Eyjafjallajökull, Iceland. We apply the method to global IMS infrasound data from 2005-2010 to construct a preliminary acoustic catalog that emphasizes sustained explosive volcanic activity (long-duration signals or sequences of impulsive transients lasting hours to days). This work represents a step toward the goal of integrating IMS infrasound data products into global volcanic eruption early warning and notification systems. Additionally, a better understanding of volcanic signal detection and location with the IMS helps improve operational event detection, discrimination, and association capabilities.

Outstanding challenges in the seismological study of volcanic processes: Results from recent U.S. and European community-wide discussion workshops

NASA Astrophysics Data System (ADS)

Roman, D. C.; Rodgers, M.; Mather, T. A.; Power, J. A.; Pyle, D. M.

2014-12-01

Observations of volcanically induced seismicity are essential for eruption forecasting and for real-time and near-real-time warnings of hazardous volcanic activity. Studies of volcanic seismicity and of seismic wave propagation also provide critical understanding of subsurface magmatic systems and the physical processes associated with magma genesis, transport, and eruption. However, desipite significant advances in recent years, our ability to successfully forecast volcanic eruptions and fully understand subsurface volcanic processes is limited by our current understanding of the source processes of volcano-seismic events, the effects on seismic wave propagation within volcanic structures, limited data, and even the non-standardized terminology used to describe seismic waveforms. Progress in volcano seismology is further hampered by inconsistent data formats and standards, lack of state-of-the-art hardware and professional technical staff, as well as a lack of widely adopted analysis techniques and software. Addressing these challenges will not only advance scientific understanding of volcanoes, but also will lead to more accurate forecasts and warnings of hazardous volcanic eruptions that would ultimately save lives and property world-wide. Two recent workshops held in Anchorage, Alaska, and Oxford, UK, represent important steps towards developing a relationship among members of the academic community and government agencies, focused around a shared, long-term vision for volcano seismology. Recommendations arising from the two workshops fall into six categories: 1) Ongoing and enhanced community-wide discussions, 2) data and code curation and dissemination, 3) code development, 4) development of resources for more comprehensive data mining, 5) enhanced strategic seismic data collection, and 6) enhanced integration of multiple datasets (including seismicity) to understand all states of volcano activity through space and time. As presented sequentially above, these steps can be regarded as a road map for galvanizing and strengthening the volcano seismological community to drive new scientific and technical progress over the next 5-10 years.

Progressive approach to eruption at Campi Flegrei caldera in southern Italy

NASA Astrophysics Data System (ADS)

Kilburn, Christopher R. J.; de Natale, Giuseppe; Carlino, Stefano

2017-05-01

Unrest at large calderas rarely ends in eruption, encouraging vulnerable communities to perceive emergency warnings of volcanic activity as false alarms. A classic example is the Campi Flegrei caldera in southern Italy, where three episodes of major uplift since 1950 have raised its central district by about 3 m without an eruption. Individual episodes have conventionally been treated as independent events, so that only data from an ongoing episode are considered pertinent to evaluating eruptive potential. An implicit assumption is that the crust relaxes accumulated stress after each episode. Here we apply a new model of elastic-brittle failure to test the alternative view that successive episodes promote a long-term accumulation of stress in the crust. The results provide the first quantitative evidence that Campi Flegrei is evolving towards conditions more favourable to eruption and identify field tests for predictions on how the caldera will behave during future unrest.

Progressive approach to eruption at Campi Flegrei caldera in southern Italy

PubMed Central

Kilburn, Christopher R.J.; De Natale, Giuseppe; Carlino, Stefano

2017-01-01

Unrest at large calderas rarely ends in eruption, encouraging vulnerable communities to perceive emergency warnings of volcanic activity as false alarms. A classic example is the Campi Flegrei caldera in southern Italy, where three episodes of major uplift since 1950 have raised its central district by about 3 m without an eruption. Individual episodes have conventionally been treated as independent events, so that only data from an ongoing episode are considered pertinent to evaluating eruptive potential. An implicit assumption is that the crust relaxes accumulated stress after each episode. Here we apply a new model of elastic-brittle failure to test the alternative view that successive episodes promote a long-term accumulation of stress in the crust. The results provide the first quantitative evidence that Campi Flegrei is evolving towards conditions more favourable to eruption and identify field tests for predictions on how the caldera will behave during future unrest. PMID:28504261

Progressive approach to eruption at Campi Flegrei caldera in southern Italy.

PubMed

Kilburn, Christopher R J; De Natale, Giuseppe; Carlino, Stefano

2017-05-15

Unrest at large calderas rarely ends in eruption, encouraging vulnerable communities to perceive emergency warnings of volcanic activity as false alarms. A classic example is the Campi Flegrei caldera in southern Italy, where three episodes of major uplift since 1950 have raised its central district by about 3 m without an eruption. Individual episodes have conventionally been treated as independent events, so that only data from an ongoing episode are considered pertinent to evaluating eruptive potential. An implicit assumption is that the crust relaxes accumulated stress after each episode. Here we apply a new model of elastic-brittle failure to test the alternative view that successive episodes promote a long-term accumulation of stress in the crust. The results provide the first quantitative evidence that Campi Flegrei is evolving towards conditions more favourable to eruption and identify field tests for predictions on how the caldera will behave during future unrest.

'Is Ash Falling?', an online ashfall reporting tool in support of improved ashfall warnings and investigations of ashfall processes

USGS Publications Warehouse

Wallace, Kristi; Snedigar, Seth; Cameron, Cheryl

2015-01-01

The primary volcano hazard in Alaska is airborne ash, which endangers aircraft flying the busy North Pacific air routes and consequently affects global commerce. Downwind ashfall is also a significant threat to commerce, transportation and day-to-day activities in nearby Alaska communities. A web-enabled database, "Is Ash Falling?" has been developed to collect ashfall observations and encourage sample collections from the public during eruptions, enabling volcano observatory staff to concentrate on eruption response. Knowing the locations of filed ashfall reports improves public ashfall warnings and forecasts by providing on-the-ground checks for ash dispersion and fallout computer models and satellite imagery interpretation. Reports of ashfall are shared with emergency management agencies and the wider public. These reports also give scientists a more complete record of the amount, duration and other conditions of ashfall.

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.

Seismic observations of Redoubt Volcano, Alaska - 1989-2010 and a conceptual model of the Redoubt magmatic system

USGS Publications Warehouse

Power, John A.; Stihler, Scott D.; Chouet, Bernard A.; Haney, Matthew M.; Ketner, D.M.

2013-01-01

Seismic activity at Redoubt Volcano, Alaska, has been closely monitored since 1989 by a network of five to ten seismometers within 22 km of the volcano's summit. Major eruptions occurred in 1989-1990 and 2009 and were characterized by large volcanic explosions, episodes of lava dome growth and failure, pyroclastic flows, and lahars. Seismic features of the 1989-1990 eruption were 1) weak precursory tremor and a short, 23-hour-long, intense swarm of repetitive shallow long-period (LP) events centered 1.4 km below the crater floor, 2) shallow volcano-tectonic (VT) and hybrid earthquakes that separated early episodes of dome growth, 3) 13 additional swarms of LP events at shallow depths precursory to many of the 25 explosions that occurred over the more than 128 day duration of eruptive activity, and 4) a persistent cluster of VT earthquakes at 6 to 9 km depth. In contrast the 2009 eruption was preceded by a pronounced increase in deep-LP (DLP) events at lower crustal depths (25 to 38 km) that began in mid-December 2008, two months of discontinuous shallow volcanic tremor that started on January 23, 2009, a strong phreatic explosion on March 15, and a 58-hour-long swarm of repetitive shallow LP events. The 2009 eruption consisted of at least 23 major explosions between March 23 and April 5, again accompanied by shallow VT earthquakes, several episodes of shallow repetitive LP events and dome growth continuing until mid July. Increased VT earthquakes at 4 to 9 km depth began slowly in early April, possibly defining a mid-crustal magma source zone. Magmatic processes associated with the 2009 eruption seismically activated the same portions of the Redoubt magmatic system as the 1989-1990 eruption, although the time scales and intensity vary considerably among the two eruptions. The occurrence of precursory DLP events suggests that the 2009 eruption may have involved the rise of magma from lower crustal depths. Based on the evolution of seismicity during the 1989-1990 and 2009 eruptions the Redoubt magmatic system is envisioned to consist of a shallow system of cracks extending 1 to 2 km below the crater floor, a magma storage or source region at roughly 3 to 9 km depth, and a diffuse magma source region at 25 to 38 km depth. Close tracking of seismic activity allowed the Alaska Volcano Observatory to successfully issue warnings prior to many of the hazardous explosive events that occurred in 2009.

Timescales of magmatic processes prior to the ˜4.7 ka Agnano-Monte Spina eruption (Campi Flegrei caldera, Southern Italy) based on diffusion chronometry from sanidine phenocrysts

NASA Astrophysics Data System (ADS)

Iovine, Raffaella Silvia; Fedele, Lorenzo; Mazzeo, Fabio Carmine; Arienzo, Ilenia; Cavallo, Andrea; Wörner, Gerhard; Orsi, Giovanni; Civetta, Lucia; D'Antonio, Massimo

2017-02-01

Barium diffusion chronometry applied to sanidine phenocrysts from the trachytic Agnano-Monte Spina eruption (˜4.7 ka) constrains the time between reactivation and eruption of magma batches in the Campi Flegrei caldera. Backscattered electron imaging and quantitative electron microprobe measurements on 50 sanidine phenocrysts from representative pumice samples document core-to-rim compositional zoning. We focus on compositional breaks near the crystal rims that record magma mixing processes just prior to eruption. Diffusion times were modeled at a magmatic temperature of 930 °C using profiles based on quantitative BaO point analyses, X-ray scans, and grayscale swath profiles, yielding times ≤60 years between mixing and eruption. Such short timescales are consistent with volcanological and geochronological data that indicate that at least six eruptions occurred in the Agnano-San Vito area during few centuries before the Agnano-Monte Spina eruption. Thus, the short diffusion timescales are similar to time intervals between eruptions. Therefore, the rejuvenation time of magma residing in a shallow reservoir after influx of a new magma batch that triggered the eruption, and thus pre-eruption warning times, may be as short as years to a few decades at Campi Flegrei caldera.

Reducing the risk of potential hazard in tourist activities of Mount Bromo

NASA Astrophysics Data System (ADS)

Meilani, R.; Muthiah, J.; Muntasib, E. K. S. H.

2018-05-01

Mount Bromo has been crowned as one of the most beautiful mountains in the world, having a particular landscape uniqueness. Not only volcano, Bromo also has savanna, sea of sands, and culture of Tengger tribe. Its panoramic landscape has attracted a large number of tourists, both domestic and foreign, despites the threat of eruption. To ensure tourists safety and satisfaction, the potentials hazard, both from eruption and other features should be managed carefully. The study objective was to identify and map hazard potentials and identify the existing hazard management. It was carried out in Mei – June 2017. Lava, tephra, eruption cloud, ash, earthquake, land sliding, extreme weather, slope, transportation modes (jeep, motorcycle, and horse), human, and land fire were found as potential hazards in Mount Bromo. Five locations had been identified as hazard area in the tourism areas, i.e. savanna, sea of sand, Bromo caldera and Pananjakan I trail and viewing point. Early warning system should be developed as part of hazard management in the area. Capacity building of local stakeholders and visitors would be needed to reduce risk of the hazard.

Investigation of prototype volcano surveillance network

NASA Technical Reports Server (NTRS)

Eaton, J. P. (Principal Investigator); Ward, P. L.

1973-01-01

The author has identified the following significant results. Earthquake counters in Guatemala were being installed between February 13 and 17. The volcano Fuego began erupting ash and ash flows on February 23. On February 17, 6 days before the eruption there were 80 earthquakes at two counters 5 and 15 km from the volcano. This was a substantial increase of a fairly constant level of events per day recorded for the previous four days. A counter 30 km away did not show an increase. Had the DCP been operating longer and had the data been sent immediately from Goddard, it might have been possible to warn of a possible eruption six days in advance.

Atmospheric control on ground and space based early warning system for hazard linked to ash injection into the atmosphere

NASA Astrophysics Data System (ADS)

Caudron, Corentin; Taisne, Benoit; Whelley, Patrick; Garces, Milton; Le Pichon, Alexis

2014-05-01

Violent volcanic eruptions are common in the Southeast Asia which is bordered by active subduction zones with hundreds of active volcanoes. The physical conditions at the eruptive vent are difficult to estimate, especially when there are only a few sensors distributed around the volcano. New methods are therefore required to tackle this problem. Among them, satellite imagery and infrasound may rapidly provide information on strong eruptions triggered at volcanoes which are not closely monitored by on-site instruments. The deployment of an infrasonic array located at Singapore will increase the detection capability of the existing IMS network. In addition, the location of Singapore with respect to those volcanoes makes it the perfect site to identify erupting blasts based on the wavefront characteristics of the recorded signal. There are ~750 active or potentially active volcanoes within 4000 kilometers of Singapore. They have been combined into 23 volcanic zones that have clear azimuth with respect to Singapore. Each of those zones has been assessed for probabilities of eruptive styles, from moderate (Volcanic Explosivity Index of 3) to cataclysmic (VEI 8) based on remote morphologic analysis. Ash dispersal models have been run using wind velocity profiles from 2010 to 2012 and hypothetical eruption scenarios for a range of eruption explosivities. Results can be used to estimate the likelihood of volcanic ash at any location in SE Asia. Seasonal changes in atmospheric conditions will strongly affect the potential to detect small volcanic eruptions with infrasound and clouds can hide eruption plumes from satellites. We use the average cloud cover for each zone to estimate the probability of eruption detection from space, and atmospheric models to estimate the probability of eruption detection with infrasound. Using remote sensing in conjunction with infrasound improves detection capabilities as each method is capable of detecting eruptions when the other is 'blind' or 'defened' by adverse atmospheric conditions. According to its location, each volcanic zone will be associated with a threshold value (minimum VEI detectable) depending on the seasonality of the wind velocity profile in the region and the cloud cover.

Linking Surface Activity to the Deep Volcanic Plumbing System: the CALIPSO Borehole Observatory Project on Montserrat

NASA Astrophysics Data System (ADS)

Young, S. R.; Voight, B.; Mattioli, G. S.; Linde, A. T.; Sacks, I. S.; Malin, P. E.; Shalev, E.; Hidayat, D.; Elsworth, D.; Sparks, R. S.; Neuberg, J.; Dunkley, P. N.; Norton, G. E.; Herd, R. A.; Edmonds, M.; Thompson, G.; Jolly, A.; Bass, V.

2003-12-01

The prolonged and ongoing volcanic activity at SoufriŠre Hills Volcano (SHV), Montserrat, provides a rare chance for collecting multi-stream monitoring data in support of volcano research. Conventional surface geophysical instrumentation and detailed observational and geochemical data have enabled the development of a good understanding of surface and near-surface physical processes controlling eruptive style and intensity at SHV. However, the geophysical character and behavior of the deeper plumbing system, including magma storage area(s) and deep recharge processes, are not well understood. Developing better models for the deep system will assist in providing timely warning of large events or changes in eruptive style, and may also provide some clues as to the likely duration of the eruption. Installation of seismic and deformational monitoring instrumentation at depth enables a significant increase in signal to noise ratio so that smaller signals can be recorded and more distant sites (and thus deeper investigation depth) utilized. A variety of cycle-lengths have been noted during the eruption of SHV, and we hope that the new CALIPSO data stream will enable development of models in which cycles from a few hours to a few decades can be linked together in an integrated physical model. Cycle lengths of 7 to 14 weeks (depending on eruption rate and equating to the eruption of about 35 million cubic meters of magma) are likely to source from the shallower of the two upper crustal reservoirs indicated by geochemical evidence. The 30 to 35 year cycles (the fourth one of which marked the start of the current eruption) may relate to processes concerning input of basaltic magma to the deeper plumbing system. We also hope to document geophysical changes in the plumbing system induced by regional seismicity; many eastern Caribbean volcanoes (including SHV between 1933 and 1935 and in 1985) have demonstrated characteristics of unrest triggered or invigorated by regional tectonic earthquakes of Richter magnitude 5 and above. Events within the historical triggering threshold occur every few years; two such events have so far occurred since CALIPSO instrument installation (a Mw6.6 about 400km NE of Montserrat and a Mw5.7 about 150km NE of Montserrat). Both are at the lower end of historical triggering threshold parameters for magnitude and distance and neither produced measurable changes in macro-seismicity or ground deformation beneath SHV.

Deaths and injuries in the eruption of Galeras Volcano, Colombia, 14 January 1993

NASA Astrophysics Data System (ADS)

Baxter, Peter J.; Gresham, Austin

1997-05-01

Six volcanologists and three tourists were killed in the crater of Galeras Volcano, Colombia, when it erupted without warning. The scientists were attending the United Nations International Decade for Natural Disaster Reduction Workshop which had been convened to improve monitoring, research and disaster mitigation at Galeras, at the time the most active and one of the most hazardous volcanoes in South America. Information on the events surrounding the eruption was obtained by sending a questionnaire to twelve scientists who had been inside the caldera at the time of the eruption or who had assisted in the search and rescue operation. The autopsy reports on the five corpses, and the few pieces of equipment and clothing retrieved from the crater area, were also studied. The main causes of death and injury were the forces at the eruptive vent and the bombardment by hot rocks ejected in the first 15 min of the eruption, ranging from blocks over 1 m in size to pea-sized lapilli which fell last. Some conclusions can be drawn for the future safety of volcanologists working in craters at high altitude. Hard hats would protect against concussion from blows to the head during escape from the danger area, and a lightweight, heat-resistant and water-repellent coverall would limit the skin burns and the risk of clothing being ignited from contact with incandescent, falling ejecta. The coverall could also be life saving by protecting immobilised casualties from hypothermia due to the rain and wind whilst waiting to be rescued, especially as the volcanic activity, cloud cover or nightfall could curtail rescue efforts. Work in hazardous craters should be strictly limited to essential tasks and periods of good visibility, and a climbing team should leave the area at least four hours before nightfall in case rescue is needed. Tourists must be warned against visiting active crater areas.

Using Digital Cameras to Detect Warning Signs of Volcanic Eruptions

NASA Astrophysics Data System (ADS)

Girona, T.; Huber, C.; Trinh, K. T.; Protti, M.; Pacheco, J. F.

2017-12-01

Monitoring volcanic outgassing is fundamental to improve the forecasting of volcanic eruptions. Recent efforts have led to the advent of new methods to measure the concentration and flux of volcanic gases with unprecedented temporal resolution, thus allowing us to obtain reliable high-frequency (up to 1 Hz) time series of outgassing activity. These high-frequency methods have shown that volcanic outgassing can be periodic sometimes (with periodicities ranging from 101 s to 103 s), although it remains unknown whether the spectral features of outgassing reflect the processes that ultimately trigger volcanic unrest and eruptions. In this study, we explore the evolution of the spectral content of the outgassing activity of Turrialba volcano (Costa Rica) using digital images (with digital brightness as a proxy for the emissions of water vapor [Girona et al., 2015]). Images were taken at 1 km distance with 1 Hz sampling rate, and the time period analyzed (from April 2016 to April 2017) is characterized by episodes of quiescent outgassing, ash explosions, and sporadic eruptions of ballistics. Our preliminary results show that: 1) quiescent states of Turrialba volcano are characterized by outgassing frequency spectra with fractal distribution; 2) superimposed onto the fractal frequency spectra, well-defined pulses with period around 100 s emerge hours to days before some of the eruptions of ballistics. An important conclusion of this study is that digital cameras can be potentially used in real-time volcano monitoring to detect warning signs of eruptions, as well as to better understand subsurface processes and track the changing conditions below volcanic craters. Our ongoing study also explores the correlation between the evolution of the spectral content of outgassing, infrasound data, and shallow seismicity. Girona, T., F. Costa, B. Taisne, B. Aggangan, and S. Ildefonso (2015), Fractal degassing from Erebus and Mayon volcanoes revealed by a new method to monitor H2O emission cycles, J. Geophys. Res. 120, 2988-3002, doi:10.1002/2014JB011797.

Infrasound reveals transition to oscillatory discharge regime during lava fountaining: Implication for early warning

NASA Astrophysics Data System (ADS)

Ulivieri, Giacomo; Ripepe, Maurizio; Marchetti, Emanuele

2013-06-01

present the analysis of ~4 million infrasonic signals which include 39 episodes of lava fountains recorded at 5.5 km from the active vents. We show that each eruptive episode is characterized by a distinctive trend in the amplitude, waveform, and frequency content of the acoustic signals, reflecting different explosive levels. Lava fountain starts with an ~93 min long violent phase of acoustic transients at ~1.25 Hz repeating every 2-5 s. Infrasound suddenly evolves into a persistent low-frequency quasi-monochromatic pressure oscillation at ~0.4 Hz. We interpret this shift as induced by the transition from the slug (discrete Strombolian) to churn flow (sustained lava fountain) regime that is reflecting an increase in the gas discharge rate. We calculate that infrasonic transition can occur at a gas superficial velocity of ≤76 m/s and it can be used to define infrasonic-based thresholds for an efficient early warning system.

Nationwide Operational Assessment of Hazards and success stories in disaster prevention and mitigation in the Philippines

NASA Astrophysics Data System (ADS)

Mahar Francisco Lagmay, Alfredo

2016-04-01

The Philippines, being a locus of typhoons, tsunamis, earthquakes, and volcanic eruptions, is a hotbed of disasters. Natural hazards inflict loss of lives and costly damage to property in the country. In 2011, after tropical storm Washi devastated cities in southern Philippines, the Department of Science and Technology put in place a responsive program to warn and give communities hours-in-advance lead-time to prepare for imminent hazards and use advanced science and technology to enhance geohazard maps for more effective disaster prevention and mitigation. Since its launch, there have been many success stories on the use of Project NOAH, which after Typhoon Haiyan was integrated into the Pre-Disaster Risk Assessment (PDRA) system of the National Disaster Risk Reduction and Management Council (NDRRMC), the government agency tasked to prepare for, and respond to, natural calamities. Learning from past disasters, NDRRMC now issues warnings, through scientific advise from DOST-Project NOAH and PAGASA (Philippine Weather Bureau) that are hazards-specific, area-focused and time-bound. Severe weather events in 2015 generated dangerous hazard phenomena such as widespread floods and massive debris flows, which if not for timely, accessible and understandable warnings, could have turned into disasters. We call these events as "disasters that did not happen". The innovative warning system of the Philippine government has so far proven effective in addressing the impacts of hydrometeorological hazards and can be employed elsewhere in the world.

DISTANT EARLY WARNING SYSTEM for Tsunamis - A wide-area and multi-hazard approach

NASA Astrophysics Data System (ADS)

Hammitzsch, Martin; Lendholt, Matthias; Wächter, Joachim

2010-05-01

The DEWS (Distant Early Warning System) [1] project, funded under the 6th Framework Programme of the European Union, has the objective to create a new generation of interoperable early warning systems based on an open sensor platform. This platform integrates OGC [2] SWE [3] compliant sensor systems for the rapid detection of hazardous events, like earthquakes, sea level anomalies, ocean floor occurrences, and ground displacements in the case of tsunami early warning. Based on the upstream information flow DEWS focuses on the improvement of downstream capacities of warning centres especially by improving information logistics for effective and targeted warning message aggregation for a multilingual environment. Multiple telecommunication channels will be used for the dissemination of warning messages. Wherever possible, existing standards have been integrated. The Command and Control User Interface (CCUI), a rich client application based on Eclipse RCP (Rich Client Platform) [4] and the open source GIS uDig [5], integrates various OGC services. Using WMS (Web Map Service) [6] and WFS (Web Feature Service) [7] spatial data are utilized to depict the situation picture and to integrate a simulation system via WPS (Web Processing Service) [8] to identify affected areas. Warning messages are compiled and transmitted in the OASIS [9] CAP (Common Alerting Protocol) [10] standard together with addressing information defined via EDXL-DE (Emergency Data Exchange Language - Distribution Element) [11]. Internal interfaces are realized with SOAP [12] web services. Based on results of GITEWS [13] - in particular the GITEWS Tsunami Service Bus [14] - the DEWS approach provides an implementation for tsunami early warning systems but other geological paradigms are going to follow, e.g. volcanic eruptions or landslides. Therefore in future also multi-hazard functionality is conceivable. The specific software architecture of DEWS makes it possible to dock varying sensors to the system and to extend the CCUI with hazard specific functionality. The presentation covers the DEWS project, the system architecture and the CCUI in conjunction with details of information logistics. The DEWS Wide Area Centre connecting national centres to allow the international communication and warning exchange is presented also. REFERENCES: [1] DEWS, www.dews-online.org [2] OGC, www.opengeospatial.org [3] SWE, www.opengeospatial.org/projects/groups/sensorweb [4] Eclipse RCP, www.eclipse.org/home/categories/rcp.php [5] uDig, udig.refractions.net [6] WMS, www.opengeospatial.org/standards/wms [7] WFS, www.opengeospatial.org/standards/wfs [8] WPS, www.opengeospatial.org/standards/wps [9] OASIS, www.oasis-open.org [10] CAP, www.oasis-open.org/specs/#capv1.1 [11] EDXL-DE, www.oasis-open.org/specs/#edxlde-v1.0 [12] SOAP, www.w3.org/TR/soap [13] GITEWS (German Indonesian Tsunami Early Warning System) is a project of the German Federal Government to aid the recon¬struction of the tsunami-prone Indian Ocean region, www.gitews.org [14] The Tsunami Service Bus is the GITEWS sensor system integration platform offering standardised services for the detection and monitoring of tsunamis

The effects of volcanoes on health: preparedness in Mexico.

PubMed

Zeballos, J L; Meli, R; Vilchis, A; Barrios, L

1996-01-01

The article reviews the most important aspects of volcanic eruptions and presents a summary of the harmful materials they emit. The main health effects can be classified as either physical (trauma, respiratory diseases, etc.) or psychological (depression, anxiety, nightmares, neurosis, etc.). Popocatépetl, the most famous active volcano in Mexico, lies on the borders of the States of Mexico, Puebla and Morelos. In 1993, seismic activity intensified, as did as the emission of fumaroles, followed in December 1994 by moderate tremors and strong emissions of gases and ash. In 1996, a number of seismic events led to an unexpected explosion. A daily emission of 8,000 to 15,000 tonnes of sulfur dioxide has been measured. Popocatépetl is located in a densely populated region of Mexico. A complex network to monitor the volcano using sophisticated equipment has been set up, including visual surveillance, seismic, geochemical and geodesic monitoring. An early warning system (SINAPROC/CENAPRED) has been developed to keep the population permanently informed. The warning system uses colour codes: green for normal, yellow for alert, and red for warning and evacuation. An emergency plan has been prepared, including evacuation and preparation for medical centres and hospitals in the region, as well as intense public information campaigns.

Community preparedness for lava flows from Mauna Loa and Hualālai volcanoes, Kona, Hawai'i

USGS Publications Warehouse

Gregg, Chris E.; Houghton, Bruce F.; Paton, Douglas; Swanson, Donald A.; Johnston, David M.

2004-01-01

Lava flows from Mauna Loa and Huala??lai volcanoes are a major volcanic hazard that could impact the western portion of the island of Hawai'i (e.g., Kona). The most recent eruptions of these two volcanoes to affect Kona occurred in A.D. 1950 and ca. 1800, respectively. In contrast, in eastern Hawai'i, eruptions of neighboring Ki??lauea volcano have occurred frequently since 1955, and therefore have been the focus for hazard mitigation. Official preparedness and response measures are therefore modeled on typical eruptions of Ki??lauea. The combinations of short-lived precursory activity (e.g., volcanic tremor) at Mauna Loa, the potential for fast-moving lava flows, and the proximity of Kona communities to potential vents represent significant emergency management concerns in Kona. Less is known about past eruptions of Huala??lai, but similar concerns exist. Future lava flows present an increased threat to personal safety because of the short times that may be available for responding. Mitigation must address not only the specific characteristics of volcanic hazards in Kona, but also the manner in which the hazards relate to the communities likely to be affected. This paper describes the first steps in developing effective mitigation plans: measuring the current state of people's knowledge of eruption parameters and the implications for their safety. We present results of a questionnaire survey administered to 462 high school students and adults in Kona. The rationale for this study was the long lapsed time since the last Kona eruption, and the high population growth and expansion of infrastructure over this time interval. Anticipated future growth in social and economic infrastructure in this area provides additional justification for this work. The residents of Kona have received little or no specific information about how to react to future volcanic eruptions or warnings, and short-term preparedness levels are low. Respondents appear uncertain about how to respond to threatening lava flows and overestimate the minimum time available to react, suggesting that personal risk levels are unnecessarily high. A successful volcanic warning plan in Kona must be tailored to meet the unique situation there. ?? Springer-Verlag 2004.

Reducing Loss of Life and Property from Disasters: A Societal Benefit Area of the Strategic Plan for U.S. Integrated Earth Observation System (IEOS)

USGS Publications Warehouse

Helz, Rosalind L.; Gaynor, John E.

2007-01-01

Natural and technological disasters, such as hurricanes and other extreme weather events, earthquakes, volcanic eruptions, landslides and debris flows, wildland and urban-interface fires, floods, oil spills, and space-weather storms, impose a significant burden on society. Throughout the United States, disasters inflict many injuries and deaths, and cost the nation $20 billion each year (SDR, 2003). Disasters in other countries can affect U.S. assets and interests overseas (e.g. the eruption of Mt. Pinatubo in the Philippines, which effectively destroyed Clark Air Force Base). Also, because they have a disproportionate impact on developing countries, disasters are major barriers to sustainable development. Improving our ability to assess, predict, monitor, and respond to hazardous events is a key factor in reducing the occurrence and severity of disasters, and relies heavily on the use of information from well-designed and integrated Earth observation systems. To fully realize the benefits gained from the observation systems, the information derived must be disseminated through effective warning systems and networks, with products tailored to the needs of the end users and the general public.

The role of mantle CO2 in volcanism

USGS Publications Warehouse

Barnes, I.; Evans, William C.; White, L.D.

1988-01-01

Carbon dioxide is the propellant gas in volcanic eruptions and is also found in mantle xenoliths. It is speculated that CO2 occurs as a free gas phase in the mantle because there is no reason to expect CO2 to be so universally associated with volcanic rocks unless the CO2 comes from the same source as the volcanic rocks and their xenoliths. If correct, the presence of a free gas in the mantle would lead to physical instability, with excess gas pressure providing the cause of both buoyancy of volcanic melts and seismicity in volcanic regions. Convection in the mantle and episodic volcanic eruptions are likely necessary consequences. This suggestion has considerable implications for those responsible for providing warnings of impending disasters resulting from volcanic eruptions and earthquakes in volcanic regions. ?? 1988.

Volcano-tectonic earthquakes: A new tool for estimating intrusive volumes and forecasting eruptions

USGS Publications Warehouse

White, Randall A.; McCausland, Wendy

2016-01-01

Notable cases in which distal VT events preceded eruptions at long-dormant volcanoes include: Nevado del Ruiz (1984–1985), Pinatubo (1991), Unzen (1989–1995), Soufriere Hills (1995), Shishaldin (1989–1999), Tacana' (1985–1986), Pacaya (1980–1984), Rabaul (1994), and Cotopaxi (2001). Additional cases are recognized at frequently active volcanoes including Popocateptl (2001–2003) and Mauna Loa (1984). We present four case studies (Pinatubo, Soufriere Hills, Unzen, and Tacana') in which we demonstrate the above mentioned VT characteristics prior to eruptions. Using regional data recorded by NEIC, we recognized in near-real time that a huge distal VT swarm was occurring, deduced that a proportionately huge magmatic intrusion was taking place beneath the long dormant Sulu Range, New Britain Island, Papua New Guinea, that it was likely to lead to eruptive activity, and warned Rabaul Volcano Observatory days before a phreatic eruption occurred. This confirms the value of this technique for eruption forecasting. We also present a counter-example where we deduced that a VT swarm at Volcan Cosiguina, Nicaragua, indicated a small intrusion, insufficient to reach the surface and erupt. Finally, we discuss limitations of the method and propose a mechanism by which this distal VT seismicity is triggered by magmatic intrusion.

Statistical Study of Eruptive Filaments using Automated Detection and Tracking Technique

NASA Astrophysics Data System (ADS)

Joshi, Anand D.; Hanaoka, Yoichiro

2017-08-01

Solar filaments are dense and cool material suspended in the low solar corona. They are found to be on the Sun for periods up to a few weeks, and they end their lifetime either as a gradual disappearance or an eruption. We have developed an automated detection and tracking technique to study such filament eruptions using full-disc Hα images. Various processing steps are used before subjecting an image to segmentation, that would extract only the filaments. Further steps track the filaments between successive images, label them uniquely, and generate output that can be used for a comparative study. In this poster, we would use this technique to carry out a statistical study of several erupting filaments through which the common underlying properties of such eruptions can be derived. Details of the technique will also be discussed in brief. Filament eruptions are found to be closely associated with coronal mass ejections (CMEs) wherein a large mass from corona is ejected into the interplanetary space. If such a CME hits the Earth with a favourable orientation of magnetic field a geomagnetic storm can result adversely affecting electronic infrastructure in space as well as ground. The properties of filament eruptions derived can be used in future to predict an eruption in an almost real-time basis, thereby giving a warning of imminent storm.

Tourism hazard potentials in Mount Merapi: how to deal with the risk

NASA Astrophysics Data System (ADS)

Muthiah, J.; Muntasib, E. K. S. H.; Meilani, R.

2018-05-01

Mount Merapi as one of the most popular natural tourism destination in Indonesia, indicated as disaster prone area. Hazard management is required to ensure visitors safety. Hazard identification and mapping are prerequisite in developing proper hazard management recommendation. This study aimed to map hazard potentials’ geographical positions obtained with geographical positioning system and to identify the hazard management being implemented. Data collection was carried out in Mei – June 2017 through observation and interview. Hiking trail and Lava tour area was selected as the study site, since the sites are the main areas for tourism activities in Mount Merapi. The type of hazards found in the area included lava, tephra, eruption cloud, ash, earthquake, land slide, extreme weather, slope and loose rock. Early warning system had been developed in this area, however the mechanism to regulate tourism activities still had to be improved. Local tourism entrepreneurs should be involved in the network of early warning system stakeholders to ensure tourist safety, and their capacity should be improved in order to be able to perform the measures needed for handling accident and disaster occurrences. Interpretive media explaining hazard potentials may be used to improve visitors’ awareness and ability to cope with the risk.

An operational integrated short-term warning solution for solar radiation storms: introducing the Forecasting Solar Particle Events and Flares (FORSPEF) system

NASA Astrophysics Data System (ADS)

Anastasiadis, Anastasios; Sandberg, Ingmar; Papaioannou, Athanasios; Georgoulis, Manolis; Tziotziou, Kostas; Jiggens, Piers; Hilgers, Alain

2015-04-01

We present a novel integrated prediction system, of both solar flares and solar energetic particle (SEP) events, which is in place to provide short-term warnings for hazardous solar radiation storms. FORSPEF system provides forecasting of solar eruptive events, such as solar flares with a projection to coronal mass ejections (CMEs) (occurrence and velocity) and the likelihood of occurrence of a SEP event. It also provides nowcasting of SEP events based on actual solar flare and CME near real-time alerts, as well as SEP characteristics (peak flux, fluence, rise time, duration) per parent solar event. The prediction of solar flares relies on a morphological method which is based on the sophisticated derivation of the effective connected magnetic field strength (Beff) of potentially flaring active-region (AR) magnetic configurations and it utilizes analysis of a large number of AR magnetograms. For the prediction of SEP events a new reductive statistical method has been implemented based on a newly constructed database of solar flares, CMEs and SEP events that covers a large time span from 1984-2013. The method is based on flare location (longitude), flare size (maximum soft X-ray intensity), and the occurrence (or not) of a CME. Warnings are issued for all > C1.0 soft X-ray flares. The warning time in the forecasting scheme extends to 24 hours with a refresh rate of 3 hours while the respective warning time for the nowcasting scheme depends on the availability of the near real-time data and falls between 15-20 minutes. We discuss the modules of the FORSPEF system, their interconnection and the operational set up. The dual approach in the development of FORPSEF (i.e. forecasting and nowcasting scheme) permits the refinement of predictions upon the availability of new data that characterize changes on the Sun and the interplanetary space, while the combined usage of solar flare and SEP forecasting methods upgrades FORSPEF to an integrated forecasting solution. This work has been funded through the "FORSPEF: FORecasting Solar Particle Events and Flares", ESA Contract No. 4000109641/13/NL/AK

A novel technique for evaluating the volcanic cloud top altitude using GPS Radio Occultation data

NASA Astrophysics Data System (ADS)

Biondi, Riccardo; Corradini, Stefano; Guerrieri, Lorenzo; Merucci, Luca; Stelitano, Dario; Pugnaghi, Sergio

2017-04-01

Volcanic ash and sulfuric gases are a major hazards to aviation since they damage the aircraft engines also at large distance from the eruption. Many challenges given by volcanic explosive eruptions are still discussed and several issues are far from being solved. The cloud top altitude can be detected with different techniques, but the accuracy is still quite coarse. This parameter is important for the air traffic to know what altitude can be ash free, and it assumes a key role for the contribution of the eruption to the climate change. Moreover, the cloud top altitude is also strictly related to the mass ejected by the eruption and represent a key parameter for the ash and SO2 retrievals by using several techniques. The Global Positioning System (GPS) Radio Occultation (RO) technique enables real time measurement of atmospheric density structure in any meteorological condition, in remote areas and during extreme atmospheric events with high vertical resolution and accuracy and this makes the RO an interesting tool for this kind of studies. In this study we have tracked the Eyjafjöll 2010 eruption by using MODIS satellite measurements and retrieved the volcanic cloud top altitudes by using two different procedures exploiting the thermal infrared CO2 absorption bands around 13.4 micrometers. The first approach is a modification of the standard CO2 slicing method while the second is based on look up tables computations. We have then selected all the RO profiles co-located with the volcanic cloud and implemented an algorithm based on the variation of the bending angle for detecting the cloud top altitude with high accuracy. The results of the comparison between the MODIS and RO volcanic height retrievals are encouraging and suggesting that, due to their independence from weather conditions and due to their high vertical resolution, the RO observations can contribute to improved detection and monitoring of volcanic clouds and to support warning systems.

An overview of the Icelandic Volcano Observatory response to the on-going rifting event at Bárðarbunga (Iceland) and the SO2 emergency associated with the gas-rich eruption in Holuhraun

NASA Astrophysics Data System (ADS)

Barsotti, Sara; Jonsdottir, Kristin; Roberts, Matthew J.; Pfeffer, Melissa A.; Ófeigsson, Benedikt G.; Vögfjord, Kristin; Stefánsdóttir, Gerður; Jónasdóttir, Elin B.

2015-04-01

On 16 August, 2014, Bárðarbunga volcano entered a new phase of unrest. Elevated seismicity in the area with up to thousands of earthquakes detected per day and significant deformation was observed around the Bárðarbunga caldera. A dike intrusion was monitored for almost two weeks until a small, short-lived effusive eruption began on 29 August in Holuhraun. Two days later a second, more intense, tremendously gas-rich eruption started that is still (as of writing) ongoing. The Icelandic Volcano Observatory (IVO), within the Icelandic Meteorological Office (IMO), monitors all the volcanoes in Iceland. Responsibilities include evaluating their related hazards, issuing warnings to the public and Civil Protection, and providing information regarding risks to aviation, including a weekly summary of volcanic activity provided to the Volcanic Ash Advisory Center in London. IVO has monitored the Bárðarbunga unrest phase since its beginning with the support of international colleagues and, in collaboration with the University of Iceland and the Environment Agency of Iceland, provides scientific support and interpretation of the ongoing phenomena to the local Civil Protection. The Aviation Color Code, for preventing hazards to aviation due to ash-cloud encounter, has been widely used and changed as soon as new observations and geophysical data from the monitoring network have suggested a potential evolution in the volcanic crisis. Since the onset of the eruption, IVO is monitoring the gas emission by using different and complementary instrumentations aimed at analyzing the plume composition as well as estimating the gaseous fluxes. SO2 rates have been measured with both real-time scanning DOASes and occasional mobile DOAS traveses, near the eruption site and in the far field. During the first month-and-a-half of the eruption, an average flux equal to 400 kg/s was registered, with peaks exceeding 1,000 kg/s. Along with these measurements the dispersal model CALPUFF has been initialized daily and run to provide the dispersal of the SO2 volcanic cloud across the country. Daily 72-hours forecasts of SO2 ground concentration are available on the IMO webpage. If critical concentration are expected in inhabited areas, the meteorologist on duty is in charge to promptly issuing a specific warning on the web. The IMO web-page has also been improved with a registration form, open to the public, for reporting SO2 contamination and poor air quality conditions due to the eruption. A long-term hazard assessment for the high concentrations of SO2 affecting the country has also been requested from IVO (IMO) by the Icelandic Civil Protection. For this purpose two hazard zoning maps, showing the areas potentially affected by specific concentration levels have been produced. The two maps have been constructed for probability of occurrence equaling 50% and 90%, respectively. Based on all these information and advices, the Civil Protection is taking decisions for what concerns precautionary measures like for example the limitation of accessibility to the eruption site, the evacuation of exposed areas, and the issuing of warnings and information for mitigating discomforts to inhabitants and tourists.

Multi-disciplinary Monitoring of the 2014 Eruption of Fogo Volcano, Cape Verde

NASA Astrophysics Data System (ADS)

Fernandes, R. M. S.; Faria, B. V. E.

2015-12-01

The Fogo volcano, located in the Cape Verde Archipelago (offshore Western Africa), is a complete stratovolcano system. It is the most recent expression of the Cape Verde hotspot, that has formed the archipelago. The summit reaches ~2830m above sea level, and raises 1100m above Chã das Caldeiras, an almost flat circular area. The last eruption of Fogo started on November 23, 2014 (~10:00UTC), after 19 years of inactivity. C4G, a distributed research infrastructure created in 2014 in the framework of the Portuguese Roadmap for Strategic Research Infrastructures, collaborated immediately with INMG, the Cape Verdean Meteorological and Geophysical Institut with the goal of complementing the permanent geophysical monitoring network in operation on Fogo island. The INMG permanent network is composed of seven seismographic stations and three tiltmeter stations, with real-time data transmitted. On the basis of increased pre-event activity (which started in October 2014), INMG issued a formal alert of an impending eruption to the Civil Protection Agency, about 24 hours before the onset of the eruption. Although the eruption caused no casualties or personal injuries due to the warnings issued, the lava expelled by the eruption (which last until the end of January) destroyed the two main villages in the caldera (~1000 inhabitants) and covered vast areas of agricultural land, causing very large economic losses and an uncertain future of the local populations. The C4G team installed a network of seven GNSS receivers and nine seismometers, distributed by the entire island. The data collection started on 28th November 2014, and continued until the end of January 2015. The mission also included a new detailed gravimetric survey of the island, the acquisition of geological samples, and the analysis of the air quality during the eruption. We present here a detailed description of the monitoring efforts carried out during the eruption as well as initial results of the analysis of the data collected. This monitoring effort carried out at the request and in collaboration with INMG, was made possible by an emergency financial support provided by Fundação para a Ciência e Tecnologia, Portugal.

Tiny crystals give away the where and when of magma ascent

NASA Astrophysics Data System (ADS)

Ruth, D. C. S.; Costa Rodriguez, F.; Bouvet de Maisonneuve, C.; Franco, L.; Cortes, J. A.; Calder, E.

2016-12-01

Open vent volcanoes exhibit passive degassing and can transition to explosive behavior, with limited or no warning. Melt inclusion chemistry and volatile contents have been used to infer the inner dynamics of magma storage, recharge, degassing, and eruption triggering mechanisms. However, the interpretation of melt inclusion chemistry is ambiguous because it cannot constrain the residence times of the host crystals, which could have various sources and growth histories. To resolve this issue we combine diffusion chronometry and melt inclusion entrapment pressures from olivine crystals sourced from the 2008 eruption of Llaima volcano (Chile). Olivine crystals (core Fo70-84, rim Fo77-84) are dominantly reverse zoned, although normal zoned and complex zoned crystals are observed. These data reflect mixing between the mafic injecting magma and the crystal-rich resident magma. Fe/Mg diffusion timescales range between 16 and 1375 days. The diffusion data show a non-uniform distribution with no discernible peaks, indicating that magma injection is likely progressive, rather than punctuated. Entrapment pressures range between 8 and 151 MPa, overlapping with an inferred crystal-rich region. Longer timescales correspond to higher pressures, strongly suggesting a link between magma residence time and ascent from depth. To our knowledge, this relationship has not been previously demonstrated. We infer that mafic magma intruded at depths of 5 km below the edifice and mingled with a pre-existing crystal-mush 3 yr before the eruption. Magma migration and mingling continued and stalled at 2.5 km depth about a year prior to the eruption. Precursory activity such as volcano-tectonic and long period seismicity, and a series of minor explosions overlap with the diffusion times 6 months before the eruption. Similar diffusion timescales have been reported for eruptions at other open vent volcanoes. Our study provides the first temporal and spatial constraints on magma storage and ascent before an eruption. Furthermore at Llaima, and potentially open vent systems, the progressive nature of magma injection suggests that additional processes (e.g. variable ascent rates, changing viscosity, etc.) are needed to trigger an eruption.

Vesuvius: Earthquakes from 1600 up to the 1631 eruption

NASA Astrophysics Data System (ADS)

Guidoboni, Emanuela; Mariotti, Dante

2011-03-01

This study examines the seismicity of Vesuvius in the decades leading up to the great eruption of 16th December 1631. The period 1600-1631 is analyzed with the aims to point out any long-term seismic precursor of the eruption. The historical research has focused on contemporary Neapolitan memoirs and a large screening of diplomatic correspondence from the main Italian courts of the age (Florence, Mantua, Parma, Venice and the Vatican). Information was gathered on 18 earthquakes that were felt in Naples between 1601 and 1630. These data were listed with the sequence of 34 shocks that took place in November and December 1631, that preceded the beginning of the eruption. The 52 seismic events that have been highlighted overall are unknown in the parametric catalogues of Italian historical seismicity and 17 are unknown even in the scientific literature. The authors' view is that it makes little sense to talk of one single previous seismic precursor in this case, given the frequent seismic sequences and tremors noted by contemporaries from January 1616 onwards. The present state of knowledge suggests that seismic activity is a strong, early and persistent warning sign of an eruption of Vesuvius, of the same type as that of December 1631.

Comparison of Galunggung1982-83 and Eyjafjalla-2010 Eruptions: definition of eruption dynamics from 3D Ash Surface Morphology

NASA Astrophysics Data System (ADS)

Aydar, E.; Höskuldsson, A.; Ersoy, O.; Gourgaud, A.

2012-04-01

We consider that all works, concepts on aviation safety, security codes, establishment of warning systems etc begin in 1982, when two commercial jumbo jets en route to Australia across Indonesia suffered loss of engine thrust from ingesting volcanic ash from the erupting Galunggung Volcano, Java, and descended more than 20,000 ft before the engines could be restarted (Casadevall, 1991). It is not the only incident of this kind but this Galunggung eruption had a pionner character attracting attention on aviation safety against volcanic eruptions in international community. As the needs for precautions on aviation safety against volcanic ash encounters began with Galunggung 1982 eruption and as we all concerned by the measures taken by ICAO due to Eyjafjallajökull-2010 eruption, we aimed to investigate this last huge airspace perturbing eruption and compare the volcanic ashes produced by those two eruptions. Volcanic ash characterization should be most important parameter to understand how the eruption concerned unrolled. Galunggung 1982-83 eruption was exceptionally long, lasting about nine months between 5 April 1982-8 January 1983). During this well known eruption, the composition of the erupted magma evolved from andesite (58% SiO2) to Mg-rich basalt (47% SiO2), while the style of the eruption changed drastically through time (Katili and Sudrdajat, 1984; Sudrajat and Tilling, 1984; Gourgaud et al., 1989 gourgaud etal 2000). Paralel to chemical changes and water consumption, eruption dynamic was also changed and occured in three eruption phases with different eruptive styles as an initial Vulcanian phase (5 April-13 May), a phreatomagmatic phase (17 May-28 October) and a Strombolian phase (3 November-8 January), have been recognized (Katili and Sudradjat,1984). We examined the surficial morphological features of proximal tephra collected from Galunggung and Eyjafjalla volcanoes. Surface texture and morphology of volcanic ash particles change according to various fragmentation mechanisms. Several common types of ashes produced during phreatomagmatic fragmentation process bear blocky-equant, mosslike, plate-like and drop or spherical shapes, besides, magmatic fragmentation leads to the formation of vesiculated fragments. We applied some quantitative statistical parameters for surface descriptors of volcanic ashes such as "Average roughness of profile (Ra), Maximum valley height of roughness profile (Rv), profile irregularities of roughness profile, Surface Area (SA), Volume (V), Fractal Dimension of Roughness (DAS)". We compared quantitative morphological data acquired from both eruptions. The grain size distribution of Eyjafjalla-2010 eruption, ash surface morphology, tephras types and textural parameters exhibit that magma input was important during the first phase (14-16 April) than following days. First phase ashes have either tubular vesicles as classically known for plinian deposits or curviplanar cut vesicles and some brittle fracturations, characteristics of phreatomagmatism. Interestingly, coarse fragmentation happened after the first phase. There is great similarities between two eruptions, but in reverse sens that in Galunggung, the eruption started with vulcanian style then phreatomatism and lasted with strombolian activity. Besides in Eyjafjalla-2010, eruptive phase started with basaltic activities at the North, then phreatomagmatism and toward the end a slight vulcanian style happened.

Detection of volcanic eruptions from space by their sulfur dioxide clouds

NASA Technical Reports Server (NTRS)

Krueger, A. J.

1985-01-01

The capabilities of the total ozone mapping spectrometer (TOMS) on the Nimbus 7 satellite for tracking volcano plumes are assessed. TOMS was installed on the sun-synchronous polar orbiting satellite to measure spatial variations in the global total ozone field. Radiance absorption coefficients of the atmosphere for four near-UV wavelengths from 312.5-380.0 are measured. Data from the El Chichon eruption in March-April 1982 revealed that SO2 was an absorbing species at 312.5 and 317.5 nm. The near-UV absorption level differences between SO2 and O3 permit discriminating the atmospheric densities of each species. An examination of the data base generated by TOMS since 1978 showed the perceptible tracks of all known major eruptions in the 1978-1982 time period. A constellation of three of the polar orbiting TOMS would be sufficient to provide near-real time alerts of plumes to warn aircraft of the hazards.

Feasibility Study of Earthquake Early Warning in Hawai`i For the Mauna Kea Thirty Meter Telescope

NASA Astrophysics Data System (ADS)

Okubo, P.; Hotovec-Ellis, A. J.; Thelen, W. A.; Bodin, P.; Vidale, J. E.

2014-12-01

Earthquakes, including large damaging events, are as central to the geologic evolution of the Island of Hawai`i as its more famous volcanic eruptions and lava flows. Increasing and expanding development of facilities and infrastructure on the island continues to increase exposure and risk associated with strong ground shaking resulting from future large local earthquakes. Damaging earthquakes over the last fifty years have shaken the most heavily developed areas and critical infrastructure of the island to levels corresponding to at least Modified Mercalli Intensity VII. Hawai`i's most recent damaging earthquakes, the M6.7 Kiholo Bay and M6.0 Mahukona earthquakes, struck within seven minutes of one another off of the northwest coast of the island in October 2006. These earthquakes resulted in damage at all thirteen of the telescopes near the summit of Mauna Kea that led to gaps in telescope operations ranging from days up to four months. With the experiences of 2006 and Hawai`i's history of damaging earthquakes, we have begun a study to explore the feasibility of implementing earthquake early warning systems to provide advanced warnings to the Thirty Meter Telescope of imminent strong ground shaking from future local earthquakes. One of the major challenges for earthquake early warning in Hawai`i is the variety of earthquake sources, from shallow crustal faults to deeper mantle sources, including the basal decollement separating the volcanic pile from the ancient oceanic crust. Infrastructure on the Island of Hawai`i may only be tens of kilometers from these sources, allowing warning times of only 20 s or less. We assess the capability of the current seismic network to produce alerts for major historic earthquakes, and we will provide recommendations for upgrades to improve performance.

Early Detection of Eruptive Dykes Revealed by Normalized Difference Vegetation Index (NDVI) on Nyiragongo and Etna Volcanoes: Implications for Dyke Wedge Emplacement, Monitoring, and Risk Assessment.

NASA Astrophysics Data System (ADS)

Komorowski, J.; Houlié, N.; Kasereka, C. M.; Ciraba, H.

2006-12-01

Flank-fissure eruptions involve lateral injection and propagation of magma in a volcanic edifice along pre- existing fractures in the direction of a volcanic rift zone (VRZ) where magma intrusion and lava flow production are concentrated over time. Gradual dyke wedge emplacement on volcano flanks and in VRZ's does not necessarily trigger large amplitude deformation signals susceptible to be recorded months or even years before the actual eruption. We show that active and potentially eruptive areas in a VRZ can be detected up to 2 years before the arrival to the surface of the final eruptive dyke and venting of lava flows by processing satellite images applying a Normalized Difference Vegetation Index (NDVI) algorithm. A positive NDVI anomaly is indicative of excessive photosynthetic plant activity. A posteriori analysis of satellite images reveal that a high- NDVI linear anomaly was apparent in vegetated areas of VRZ's on Etna from 2000 to 2002 and on Nyiragongo in June 2001, several months to years before eruptive fractures formed directly above the NDVI anomaly. We propose that the observed NDVI linear anomalies are the signature of the integrated physico-chemical effects (increased heat and CO2 flux, H2O condensation) caused by the structurally-controlled progressive injection and propagation, in a VRZ and a few months to years before the eruption, of a series of dykes (dyke wedge) that did not reach the surface. We focus of Nyiragongo volcano where historical flank-fissure eruptions from lava lake drainage in 1977 and 2002 show a link with tectonics of the Kivu rift (western branch of the East African Rift System). In 2002, dykes were injected in the southern VRZ bounded by Kivu rift normal faults and propagated over 14 km producing lava flows that caused widespread destruction in the city of Goma. Data from Nyiragongo suggest that as a dyke wedge is formed and repeatedly reactivated, final eruptive dykes can be injected easily and can propagate rapidly further along the VRZ impacting populated areas far from the magmatic conduit. This has important implications for understanding the current process of magma convection feeding the active Nyiragongo lava lake as well as potential small-volume lateral magma injections into the reactivated southern VRZ. The NDVI processing methodology has potentially important implications for monitoring networks on deeply vegetated restless volcanoes with limited or difficult access. More importantly, on volcanoes where eruptive style changes from crater-centered to eccentric flank activity or for which new inactive VRZ's could be reactivated towards populated areas, our methodology constitutes a new tool for early detection of potential flank eruptive vents. By improving the understanding of the link between edifice structure and eruptive activity of effusive volcanoes it can significantly improve integrated risk analysis and the effectiveness of early-detection warning systems for populations at risk.

The Ongoing 2011 Eruption of Cordón Caulle (Southern Andes) and its Related Hazards

NASA Astrophysics Data System (ADS)

Amigo, A.; Lara, L. E.; Silva, C.; Orozco, G.; Bertin, D.

2011-12-01

On June 4, 2011, at 18:45 UTC, Cordón Caulle volcano (Southern Andes, 40.52S, 72.14W) erupted explosively after 51 years of quiescence. The last eruption occurred in 1960 and was triggered by the great Mw 9.5 Chile earthquake. The ongoing eruption started after 2 months of increased shallow seismicity as recorded by OVDAS (the volcano observatory at Sernageomin). This close monitoring effort allowed a timely eruption forecast with at least 3 hours of warning, which facilitated the crisis response. In addition to this successful performance, for the first time in Chile volcanic hazards were assessed in advance supporting the emergency management. In particular, tephra dispersal was daily forecasted using the ASHFALL advection-diffusion model and potential lahars and PDC impact zones were delineated according to numerical approaches. The first eruptive stage lasted 27 hours. It was characterized by ca. 15-km strong Plinian-like column, associated with the emission of 0.2 - 0.4 km3 of magma (DRE). Tephra fallout mostly occurred in Chile and Argentina, although fine particles and aerosols circumnavigated the globe twice, causing disruptions on air navigation across the Southern Hemisphere. The second ongoing eruptive stage has been characterized by persistent weak plumes and lava emission at effusion rates in the range of 20 and 60 m3/s, which total volume is estimated <0.20 km3 (at the end of July 2011). Eruptive products have virtually the same bulk composition as those of the historical 1921 and 1960 eruptions, corresponding to phenocryst-poor rhyodacites (67 - 70% SiO2) for what a pre-eruptive temperature of ca. 920C could be inferred. In contrast to the previous eruptive cycles, the ongoing eruption has not evolved (at the time of writing) as a fissure eruption although the vent is atop of fault scarp that borders the Pleistocene-Holocene extensional graben of the Cordón Caulle. This episode is a good case of successful eruption forecast and hazards assessment but it is also an important case-study of silicic eruptions in an arc segment where mostly mafic magmas have been erupted during the Holocene.

New Coastal Tsunami Gauges: Application at Augustine Volcano, Cook Inlet, Alaska

NASA Astrophysics Data System (ADS)

Burgy, M.; Bolton, D. K.

2006-12-01

Recent eruptive activity at Augustine Volcano and its associated tsunami threat to lower Cook Inlet pointed out the need for a quickly deployable tsunami detector which could be installed on Augustine Island's coast. The detector's purpose would be to verify tsunami generation by direct observation of the wave at the source to support tsunami warning decisions along populated coastlines. To fill this need the Tsunami Mobile Alert Real-Time (TSMART) system was developed at NOAA's West Coast/Alaska Tsunami Warning Center with support from the University of Alaska Tsunami Warning and Environmental Observatory for Alaska program (TWEAK) and the Alaska Volcano Observatory (AVO). The TSMART system consists of a pressure sensor installed as near as possible to the low tide line. The sensor is enclosed in a water-tight hypalon bag filled with propylene-glycol to prevent silt damage to the sensor and freezing. The bag is enclosed in a perforated, strong plastic pipe about 16 inches long and 8 inches in diameter enclosed at both ends for protection. The sensor is cabled to a data logger/radio/power station up to 300 feet distant. Data are transmitted to a base station and made available to the warning center in real-time through the internet. This data telemetry system can be incorporated within existing AVO and Plate Boundary Observatory networks which makes it ideal for volcano-tsunami monitoring. A TSMART network can be utilized anywhere in the world within 120 miles of an internet connection. At Augustine, two test stations were installed on the east side of the island in August 2006. The sensors were located very near the low tide limit and covered with rock, and the cable was buried to the data logger station which was located well above high tide mark. Data logger, radio, battery and other electronics are housed in an enclosure mounted to a pole which also supports an antenna and solar panel. Radio signal is transmitted to a repeater station higher up on the island which then transmits the data to a base station in Homer, Alaska. Sea level data values are transmitted every 15 seconds and displayed at the tsunami warning center in Palmer, Alaska.

Recurrent patterns in fluid geochemistry data prior to phreatic eruptions

NASA Astrophysics Data System (ADS)

Rouwet, Dmitri; Sandri, Laura; Todesco, Micol; Tonini, Roberto; Pecoraino, Giovannella; Diliberto, Iole Serena

2016-04-01

Not all volcanic eruptions are magma-driven: the sudden evaporation and expansion of heated groundwater may cause phreatic eruptions, where the magma involvement is absent or negligible. Active crater lakes top some of the volcanoes prone to phreatic activity. This kind of eruption may occur suddenly, and without clear warning: on September 27, 2014 a phreatic eruption of Ontake, Japan, occurred without timely precursors, killing 57 tourists near the volcano summit. Phreatic eruptions can thus be as fatal as higher VEI events, due to the lack of recognised precursory signals, and because of their explosive and violent nature. In this study, we tackle the challenge of recognising precursors to phreatic eruptions, by analysing the records of two "phreatically" active volcanoes in Costa Rica, i.e. Poás and Turrialba, respectively with and without a crater lake. These volcanoes cover a wide range of time scales in eruptive behaviour, possibly culminating into magmatic activity, and have a long-term multi-parameter dataset mostly describing fluid geochemistry. Such dataset is suitable for being analysed by objective pattern recognition techniques, in search for recurrent schemes. The aim is to verify the existence and nature of potential precursory patterns, which will improve our understanding of phreatic events, and allow the assessment of the associated hazard at other volcanoes, such as Campi Flegrei or Vulcano, in Italy. Quantitative forecast of phreatic activity will be performed with BET_UNREST, a Bayesian Event Tree tool recently developed within the framework of FP7 EU VUELCO project. The study will combine the analysis of fluid geochemistry data with pattern recognition and phreatic eruption forecast on medium and short-term. The study will also provide interesting hints on the features that promote or hinder phreatic activity in volcanoes that host well-developed hydrothermal circulation.

Identifying open and closed system behaviors at Tungurahua volcano (Ecuador) using SO2 and seismo-acoustic measurements

NASA Astrophysics Data System (ADS)

Hidalgo, Silvana; Battaglia, Jean; Bernard, Benjamin; Steele, Alexander; Arellano, Santiago; Galle, Bo

2014-05-01

Tungurahua is one of the most active volcanoes in Ecuador. It is located in Central Ecuador, 160 km South of Quito and 8 km South of the touristic town of Baños. Tungurahua had one eruption every century since 1500, with an activity characterized by ash fallouts and pyroclastic and lava flows. The current eruptive period of Tungurahua began in 1999 with multiple episodes of explosive activity that have threatened the local population. The monitoring network is constituted by 5 short period and 5 broadband seismic stations, 4 DOAS permanent instruments, 4 tiltmeters, 2 permanent high resolution GPS, 4 digital cameras and 10 acoustic flow monitors. The correct interpretation of the different data acquired by this network allows a better understanding of the eruptive behavior of Tungurahua in order to provide early warning to the local population. Tungurahua changed its behavior from a continuously erupting volcano, as it was until 2008, to a sporadically erupting one, showing clear quiescence phases lasting from 40 to 184 days, and intense activity phases lasting from 15 to 70 days. Activity phases are characterized by Strombolian and Vulcanian eruptive styles, producing ash fallouts and in a few occasions pyroclastic flows. In terms of hazard to the local population, one of the goals of monitoring Tungurahura is to forecast the onset and evolution of eruptive phases. In particular the occurrence of large Vulcanian explosions which occur when the conduit is closed is a major issue. Since 2010 we focused our study on the relation between SO2 gas emissions, the seismic and acoustic energies of explosions and the tremor amplitudes. The first observation of comparing these different datasets is that the correlation between seismic and SO2 degassing is not straightforward, and actually the relation reflects the conditions at the vent: open or closed. The onset of eruptive phases in open conduit conditions can be identified which leads to an effective eruption forecasting. An example of this behavior is the eruptive phase between December 2009 and March 2010 when SO2 measurements increased 4 days before the amplitude of tremor and 9 days before the occurrence of the first explosions. Conversely, if the vent is closed at the beginning of a phase and no evident seismic precursors are observed forecasting is hardly possible. During an ongoing eruptive phase, the relation between these parameters allows to identify periods when the conduit is totally open as degassing may occur almost without generating any seismicity. Therefore the forecasting of escalating open conduit activity or a partial closing of the system is possible. Such a case was observed and forecasted on December 2011. In this work, we present observational evidence of these mechanisms which are used to identify possible patterns of evolution of the activity, contributing to a more effective volcanic hazard assessment.

The Influence of Conduit Processes During Basaltic Plinian Eruptions.

NASA Astrophysics Data System (ADS)

Houghton, B. F.; Sable, J. E.; Wilson, C. J.; Coltelli, M.; Del Carlo, P.

2001-12-01

Basaltic volcanism is most typically thought to produce effusion of lava, with the most explosive manifestations ranging from mild Strombolian activity to more energetic fire fountain eruptions. However, some basaltic eruptions are now recognized as extremely violent, i.e. generating widespread phreatomagmatic, subplinian and Plinian fall deposits. These eruptions are particularly dangerous because the ascent rate of basaltic magma prior to eruption can be very rapid (giving warning times as little as a few hours) and because their precursors may be ignored or misunderstood. The main question addressed in this talk is: what conditions in the conduit cause basaltic magma to adopt an eruption style more typical of chemically evolved, highly viscous magmas? Possible mechanisms (acting singly, or in concert) are: (1) interaction between magma and water, (ii) very rapid ascent producing a delayed onset of degassing then exceptionally rapid "runaway" vesiculation at shallow levels in the conduit, (iii) microlite crystallization and degassing of the magma during ascent leading to increased viscosity. We focus here on two examples of basaltic Plinian volcanism: the 1886 eruption of Tarawera, New Zealand, which is the youngest known basaltic Plinian eruption and the only one for which there are detailed written eyewitness accounts, and the well documented 122 BC eruption of Mount Etna, Italy. Field and laboratory evidence suggests that the Plinian phase of the 1886 eruption was a consequence of two processes. Firstly rheologic changes during magma ascent accompanied early (pre-fragmentation) interaction between the basaltic melt and water-bearing rhyolitic units forming the conduit walls and, secondly, late-stage magma:water interaction. In contrast, during the 122 BC eruption tectonic processes, such as slope failure or permanent displacement of a mobile flank of the volcano, appear to have triggered exceptionally rapid ascent, delayed onset of degassing and exceptionally rapid vesiculation at shallow levels in the conduit.

Evolving Hazard Monitoring and Communication at San Vicente Volcano, El Salvador

NASA Astrophysics Data System (ADS)

Bowman, L. J.; Gierke, J. S.

2014-12-01

El Salvador has 20 potentially active volcanoes, four of which have erupted in the last 100 years. Since San Vicente Volcano has had no historic eruptions, monitoring is not a high priority; especially given the current eruptive crisis at San Miguel Volcano. Though probability of eruptive hazards remains low at San Vicente, it is arguably one of the most hazardous volcanoes in the country due to rainfall-induced landslides and debris-flow risk. At least 250 deaths occurred in November 2009 from landslides and debris flows triggered by Hurricane Ida. This disaster caused the Universidad de El Salvador - Facultad Multidisciplinaria Paracentral (UES-FMP, San Vicente, El Salvador) to partner with governmental and nongovernmental organizations (including the U.S. Peace Corps, U.S. Fulbright Program, Korean International Cooperation Agency, Protección Civil and the Centro de Protección para Desastres (CEPRODE)) to focus its faculty and student research toward hazard monitoring and risk studies. Newly established monitoring efforts include: measurement of surface cracks and localized rainfall by Protección Civil and local residents using crude extensometers and rain gauges; installation of six weather stations that operate within the most at-risk municipalities; seismic refraction surveys to better characterize stratigraphy and seasonal water table changes; and most recently, a USAID/NSF-funded initiative partnered with the UES-FMP to monitor seasonal hydrologic conditions related to flooding and groundwater recharge. The information from these initiatives is now used to communicate current conditions and warnings through a network of two-way radios established by CEPRODE and Protección Civil. Representatives from the multi-institutional team also communicate the data to authorities who make better-informed decisions regarding warnings and evacuations, as well as determine suitable areas for population relocation in the event of a crisis. Data will eventually be used to model and forecast potential hazard events.

Program for Volcanic Risk Reduction in the Americas: Translation of Science into Policy and Practice

NASA Astrophysics Data System (ADS)

Mangan, Margaret; Pierson, Thomas; Wilkinson, Stuart; Westby, Elizabeth; Driedger, Carolyn; Ewert, John

2016-04-01

In 2013, the United States Geological Survey (USGS) and the U.S. Agency for International Development/Office of Foreign Disaster Assistance (USAID/OFDA) inaugurated Volcanic Risk Reduction in the Americas, a program that brings together binational delegations of scientists, civil authorities, and emergency response managers to discuss the challenges of integrating volcano science into crisis response and risk reduction practices. During reciprocal visits, delegations tour areas impacted by volcanic unrest and/or eruption, meet with affected communities, and exchange insights and best practices. The 2013 exchange focused on hazards at Mount Rainier (Washington, USA) and Nevado del Ruiz (Caldas/Tolima, Colombia). Both of these volcanoes are highly susceptible to large volcanic mudflows (lahars). The Colombia-USA exchange allowed participants to share insights on lahar warning systems, self-evacuation planning, and effective education programs for at-risk communities. [See Driedger and Ewert (2015) Abstract 76171 presented at 2015 Fall AGU, San Francisco, Calif., Dec 14-18]. The second exchange, in 2015, took place between the USA and Chile, focusing on the Long Valley volcanic region (California, USA) and Chaitén volcano (Lagos, Chile) - both are centers of rhyolite volcanism. The high viscosity of rhyolite magma can cause explosive eruptions with widespread destruction. The rare but catastrophic "super eruptions" of the world have largely been the result of rhyolite volcanism. Chaitén produced the world's first explosive rhyolite eruption in the age of modern volcano monitoring in 2008-2009. Rhyolite eruptions of similar scale and style have occurred frequently in the Long Valley volcanic region, most recently about 600 years ago. The explosivity and relative rarity of rhyolite eruptions create unique challenges to risk reduction efforts. The recent Chaitén eruption was unexpected - little was known of Chaitén's eruptive history, and because of this, monitoring instrumentation and response protocols were nonexistent. Though devastating to the community, no lives were lost during the eruption - largely due to the impromptu, yet decisive, actions by local leaders. The situation at Long Valley is at the other end of the preparedness/response spectrum - the eruptive history is well known, and because of sporadic, intense volcanic unrest over the last three decades, sophisticated monitoring networks are in place to detect eruption precursors. The challenge for the Long Valley community is thus maintaining readiness in the face of waxing and waning unrest without eruption. Collectively, the stories heard by delegates visiting Chaitén and Long Valley confirm that communities are not prepared for natural disasters unless both risk awareness and risk reduction efforts become an integral and ongoing part of community life. Each delegate left with new perspectives on how best to achieve this.

Pre-, Syn- and Post Eruptive Seismicity of the 2011 Eruption of Nabro Volcano, Eritrea

NASA Astrophysics Data System (ADS)

Goitom, Berhe; Hammond, James; Kendall, Michael; Nowacky, Andy; Keir, Derek; Oppenheimer, Clive; Ogubazghi, Ghebrebrhan; Ayele, Atalay; Ibrahim, Said; Jacques, Eric

2014-05-01

Nabro volcano, located in south-east Eritrea, East Africa, lies at the eastern margin of the Afar Rift and the Danakil Depression. Its tectonic behaviour is controlled by the divergence of the Arabian, Nubian and Somali plates. Nabro volcano was thought to be seismically quiet until it erupted in June 2011 with limited warning. The volcano erupted on June 12, 2011 around 20:32 UTC, following a series of earthquakes on that day that reached a maximum magnitude of 5.8. It is the first recorded eruption of Nabro volcano and only the second in Eritrea, following the Dubbi eruption in 1861. A lava flow emerged from the caldera and travelled about 20 km from the vent and buried settlements in the area. At the time of this eruption there was no seismic network in Eritrea, and hence the volcano was not monitored. In this study we use ten Ethiopian, one Yemeni and one Djibouti stations to investigate the seismicity of the area before, during and after the eruption. Four Eritrean seismic stations deployed in June 2011, four days after the eruption, are also included in the dataset. Travel time picks supplied by colleagues from Djibouti were also incorporated into the dataset. Our analysis covers roughly three months before and after the eruption and shows that Nabro was seismically quiet before the eruption (nine events), with the exception of one major earthquake (4.8 magnitude) that occurred on March 31, 2011. In contrast, the region shows continued seismic activity after the eruption (92 events). During the eruption seismicity levels are high (123 events), with two days particularly active, June 12 and June 17 with 85 and 28 discrete events, respectively. Maximum magnitudes of 5.8 and 5.9 were recorded on these two days. The two days of increased seismicity are consistent with satellite observations of the eruption which show two distinct phases of the eruption. The period between these two phases was dominated by volcanic tremor. The tremor signal lasted for almost one month following the initiation of the eruption. In summary, we have shown that the volcano was relatively quiet before eruption but continued to be seismically active for an extended period of time afterwards.

The Volcano Disaster Assistance Program—Helping to save lives worldwide for more than 30 years

USGS Publications Warehouse

Lowenstern, Jacob B.; Ramsey, David W.

2017-10-20

What do you do when a sleeping volcano roars back to life? For more than three decades, countries around the world have called upon the U.S. Geological Survey’s (USGS) Volcano Disaster Assistance Program (VDAP) to contribute expertise and equipment in times of crisis. Co-funded by the USGS and the U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance (USAID/OFDA), VDAP has evolved and grown over the years, adding newly developed monitoring technologies, training and exchange programs, and eruption forecasting methodologies to greatly expand global capabilities that mitigate the impacts of volcanic hazards. These advances, in turn, strengthen the ability of the United States to respond to its own volcanic events.VDAP was formed in 1986 in response to the devastating volcanic mudflow triggered by an eruption of Nevado del Ruiz volcano in Colombia. The mudflow destroyed the city of Armero on the night of November 13, 1985, killing more than 25,000 people in the city and surrounding areas. Sadly, the tragedy was avoidable. Better education of the local population and clear communication between scientists and public officials could have allowed warnings to be received, understood, and acted upon prior to the disaster.VDAP strives to ensure that such a tragedy will never happen again. The program’s mission is to assist foreign partners, at their request, in volcano monitoring and empower them to take the lead in mitigating hazards at their country’s threatening volcanoes. Since 1986, team members have responded to over 70 major volcanic crises at more than 50 volcanoes and have strengthened response capacity in 12 countries. The VDAP team consists of approximately 20 geologists, geophysicists, and engineers, who are based out of the USGS Cascades Volcano Observatory in Vancouver, Washington. In 2016, VDAP was a finalist for the Samuel J. Heyman Service to America Medal for its work in improving volcano readiness and warning systems worldwide, helping countries to forecast eruptions, save lives, and reduce economic losses while enhancing America’s ability to respond to domestic volcanic events.

Communicating likelihoods and probabilities in forecasts of volcanic eruptions

NASA Astrophysics Data System (ADS)

Doyle, Emma E. H.; McClure, John; Johnston, David M.; Paton, Douglas

2014-02-01

The issuing of forecasts and warnings of natural hazard events, such as volcanic eruptions, earthquake aftershock sequences and extreme weather often involves the use of probabilistic terms, particularly when communicated by scientific advisory groups to key decision-makers, who can differ greatly in relative expertise and function in the decision making process. Recipients may also differ in their perception of relative importance of political and economic influences on interpretation. Consequently, the interpretation of these probabilistic terms can vary greatly due to the framing of the statements, and whether verbal or numerical terms are used. We present a review from the psychology literature on how the framing of information influences communication of these probability terms. It is also unclear as to how people rate their perception of an event's likelihood throughout a time frame when a forecast time window is stated. Previous research has identified that, when presented with a 10-year time window forecast, participants viewed the likelihood of an event occurring ‘today’ as being of less than that in year 10. Here we show that this skew in perception also occurs for short-term time windows (under one week) that are of most relevance for emergency warnings. In addition, unlike the long-time window statements, the use of the phrasing “within the next…” instead of “in the next…” does not mitigate this skew, nor do we observe significant differences between the perceived likelihoods of scientists and non-scientists. This finding suggests that effects occurring due to the shorter time window may be ‘masking’ any differences in perception due to wording or career background observed for long-time window forecasts. These results have implications for scientific advice, warning forecasts, emergency management decision-making, and public information as any skew in perceived event likelihood towards the end of a forecast time window may result in an underestimate of the likelihood of an event occurring ‘today’ leading to potentially inappropriate action choices. We thus present some initial guidelines for communicating such eruption forecasts.

Residentś risk perception of and response to SO2 risk in east Iceland during the volcanic eruption in Bárðarbunga/Holuhraun 2014-2015

NASA Astrophysics Data System (ADS)

Gísladóttir, Guðrún; Jóhannesdóttir, Guðrún

2016-04-01

Many Icelandic communities are exposed to volcanic eruptions every two to three years. In order to reduce risk and enhance resilience in communities exposed to volcanic hazards, involvement of local communities is essential during all phases of disaster management, from prevention and preparedness, to response and recovery. Preparedness plans for volcanic eruptions are in place for many of the volcanic hazards in Iceland especially evacuation of residents due to immediate threat from glacial outburst floods from sub-glacial eruptions. Some of the recent risks associated with volcanic eruptions have had a slow onset (volcanic gas) while others have had a sudden onset (volcanic ash). The risks are both linked to air quality in inhabited areas and dispersal are highly dependent on prevailing winds so timely forecast and modelling is needed in order to inform the population about the risk. Without preparedness plans many communities in Iceland were exposed to an unanticipated volcanic gas risks from Sulphur Dioxide (SO2) in 2014-2015 during an eruption in Bárðarbunga/Holuhraun. With no system in place to measure the highly toxic gas from the eruption, the Environmental Agency, The Department of Civil Protection and Emergency Management and the Directorate of Health set up a system with over 40 handheld gas detectors and online links to 7 detectors around Iceland to monitor the gas. The defined health limit of SO2 is 350 μg/m3 for one hour, while 2600 μg/m3 for 15 minutes for working outdoors. Nevertheless, some communities in Iceland experienced much higher values and the highest measured concentration in communities during the eruption was 21.000 μg/m3. When the concentration of SO2 reached the level of >1000 μg/m3 a warning was issued and SMS text messages were sent to all mobile phones in the affected area. In order to engage with residents during the eruption the Civil Protection and local authorities, Directorate of Health, scientist and specialists organized special community meetings in the affected areas in order to inform and advise the inhabitants about consequences and preparedness of the SO2 risks. Here, we present the results from a survey conducted in both urban and rural communities east of the eruption site in order to investigate residentś perception and understanding of the risk, the efficiency of information and communication from officials during the eruption as well as the potential health effects from the SO2 pollution. In depth interviews were carried out with local authorities, Civil Protection officials and inhabitants in the SO2 affected areas with the aim to investigate their mitigation measures, response, and exposure during the eruption. It is important to identify public risk perception and their understanding of the pollution, and recognize factors that influence their preparedness during periods of heavy pollution in order to increase the society's resilience to volcanic risk.

Integrating volcanic gas monitoring with other geophysical networks in Iceland

NASA Astrophysics Data System (ADS)

Pfeffer, Melissa A.

2017-04-01

The Icelandic Meteorological Office/Icelandic Volcano Observatory is rapidly developing and improving the use of gas measurements as a tool for pre- and syn-eruptive monitoring within Iceland. Observations of deformation, seismicity, hydrological properties, and gas emissions, united within an integrated approach, can provide improved understanding of subsurface magma movements. This is critical to evaluate signals prior to and during volcanic eruptions, issue timely eruption warnings, forecast eruption behavior, and assess volcanic hazards. Gas measurements in Iceland need to be processed to account for the high degree of gas composition alteration due to interaction with external water and rocks. Deeply-sourced magmatic gases undergo reactions and modifications as they move to the surface that exercise a strong control on the composition of surface emissions. These modifications are particularly strong at ice-capped volcanoes where most surface gases are dissolved in glacial meltwater. Models are used to project backwards from surface gas measurements to what the magmatic gas composition was prior to upward migration. After the pristine magma gas composition has been determined, it is used together with fluid compositions measured in mineral hosted melt inclusions to calculate magmatic properties to understand magma storage and migration and to discern if there have been changes in the volcanic system. The properties derived from surface gas measurements can be used as input to models interpreting deformation and seismic observations, and can be used as an additional, independent observation when interpreting hydrological and seismic changes. An integrated approach aids with determining whether observed hydro/geological changes can be due to the presence of shallow magma. Constraints on parameters such as magma gas content, viscosity and compressibility can be provided by the approach described above, which can be utilized syn-eruptively to help explain differences between erupted volumes and the inferred volume change of magma chambers. We will describe two recent examples of integrated monitoring in Iceland 1) syn-eruptive gas and deformation measurements used to simulate the subsurface properties of the magma from the 2014-2015 eruption of Bárðarbunga and 2) hydrological, seismic, and gas measurements made during the 2014 Sólheimajökull jökulhlaup used to discriminate between magmatic and hydrothermal origin of the flood and to perform a frequency analysis of past minor hydrothermal jökulhlaups.

Nature and Intensity of the 22-23 April 2015 Eruptions of Volcán Calbuco, Chile, from Satellite, Lightning, and Field Observations

NASA Astrophysics Data System (ADS)

Van Eaton, A. R.; Amigo, A.; Bertin, D.; Mastin, L. G.; Giacosa, R.; Behnke, S. A.

2015-12-01

On 22 April 2015, Calbuco Volcano in southern Chile erupted for the first time in 43 years. The two primary phases of eruption, separated by a few hours, produced pyroclastic density currents, lahars, and spectacular vertical eruption columns that rose into the stratosphere. Clear weather conditions allowed the populated areas of Puerto Montt and Puerto Varas full view of the lightning-rich eruption, which was rapidly shared through social media. A wealth of remote-sensing data was also publically available in near real-time. We used this information to assess the eruption behavior by combining satellite-based umbrella growth rates, and the location and frequency of volcanic lightning. Umbrella expansion rates from GOES-13 satellite retrievals correspond to eruption rates of about 4x106 kg s-1 for the first eruptive phase and 6x106 kg s-1 for the second phase, following the approach of Pouget et al. (2013, JVGR, 258, 100-112). The location and timing of lightning flashes were obtained from the World Wide Lightning Location Network (WWLLN) Global Volcanic Lightning Monitor, which is updated approximately every minute (Ewert et al., 2010, Fall AGU Abstract AE31A-04). Interestingly, the onset of detected flashes was delayed by ~30 min after the start of each eruptive phase. Lighting provided a useful proxy for the waxing or waning intensity of the eruption, and helped identify the end of significant ash emissions. Using the 1-D volcanic plume model Plumeria, we have also simulated the vertical distribution of ash and ice in the plumes to examine potential causes of the extraordinary amount of volcanic lightning (1,094 flashes detected). Our analysis provides information on eruption timing, duration, and mass flow rate, which are necessary for ash dispersal modeling within hours of eruption. Results are also consistent with the field-based measurements of total erupted volume. We suggest that the combination of satellite-detected umbrella expansion rates with lightning data may provide a useful approach to constrain near real-time inputs for ash dispersal models and hazard warnings.

Using Websites to Convey Scientific Uncertainties for Volcanic Processes and Potential Hazards

NASA Astrophysics Data System (ADS)

Venezky, D. Y.; Lowenstern, J. B.; Hill, D. P.

2005-12-01

The Yellowstone Volcano Observatory (YVO) and Long Valley Observatory (LVO) websites have greatly increased the public's awareness and access to information about scientific uncertainties for volcanic processes by communicating at multiple levels of understanding and varied levels of detail. Our websites serve a broad audience ranging from visitors unaware of the calderas, to lay volcano enthusiasts, to scientists, federal agencies, and emergency managers. Both Yellowstone and Long Valley are highly visited tourist attractions with histories of caldera-forming eruptions large enough to alter global climate temporarily. Although it is much more likely that future activity would be on a small scale at either volcano, we are constantly posed questions about low-probability, high-impact events such as the caldera-forming eruption depicted in the recent BBC/Discovery movie, "Supervolcano". YVO and LVO website objectives include: providing monitoring data, explaining the likelihood of future events, summarizing research results, helping media provide reliable information, and expanding on information presented by the media. Providing detailed current information is a crucial website component as the public often searches online to augment information gained from often cryptic pronouncements by the media. In May 2005, for example, YVO saw an order of magnitude increase in page requests on the day MSNBC ran the misleading headline, "Yellowstone eruption threat high." The headline referred not to current events but a general rating of Yellowstone as one of 37 "high threat" volcanoes in the USGS National Volcano Early Warning System report. As websites become a more dominant source of information, we continuously revise our communication plans to make the most of this evolving medium. Because the internet gives equal access to all information providers, we find ourselves competing with various "doomsday" websites that sensationalize and distort the current understanding of natural systems. For example, many sites highlight a miscalculated repose period for caldera-forming eruptions at Yellowstone and conclude that a catastrophic eruption is overdue. Recent revisions on the YVO website have discussed how intervals are calculated and why the commonly quoted values are incorrect. Our aim is to reduce confusion by providing clear, simple explanations that highlight the process by which scientists reach conclusions and calculate associated uncertainties.

Can we develop an effective early warning system for volcanic eruptions using `off the shelf' webcams and low-light cameras?

NASA Astrophysics Data System (ADS)

Harrild, M.; Webley, P. W.; Dehn, J.

2016-12-01

An effective early warning system to detect volcanic activity is an invaluable tool, but often very expensive. Detecting and monitoring precursory events, thermal signatures, and ongoing eruptions in near real-time is essential, but conventional methods are often logistically challenging, expensive, and difficult to maintain. Our investigation explores the use of `off the shelf' webcams and low-light cameras, operating in the visible to near-infrared portions of the electromagnetic spectrum, to detect and monitor volcanic incandescent activity. Large databases of webcam imagery already exist at institutions around the world, but are often extremely underutilised and we aim to change this. We focus on the early detection of thermal signatures at volcanoes, using automated scripts to analyse individual images for changes in pixel brightness, allowing us to detect relative changes in thermally incandescent activity. Primarily, our work focuses on freely available streams of webcam images from around the world, which we can download and analyse in near real-time. When changes in activity are detected, an alert is sent to the users informing them of the changes in activity and a need for further investigation. Although relatively rudimentary, this technique provides constant monitoring for volcanoes in remote locations and developing nations, where it is not financially viable to deploy expensive equipment. We also purchased several of our own cameras, which were extensively tested in controlled laboratory settings with a black body source to determine their individual spectral response. Our aim is to deploy these cameras at active volcanoes knowing exactly how they will respond to varying levels of incandescence. They are ideal for field deployments as they are cheap (0-1,000), consume little power, are easily replaced, and can provide telemetered near real-time data. Data from Shiveluch volcano, Russia and our spectral response lab experiments are presented here.

Modeling Seasonal Thermal Radiance Cycles for Change Detection at Volcanic / Geothermal Areas

NASA Astrophysics Data System (ADS)

Vaughan, R.; Beuttel, B. S.

2013-12-01

Remote sensing observations of thermal features associated with (and often preceding) volcanic activity have been used for decades to detect and monitor volcanism. However, anomalous thermal precursors to volcanic eruptions are usually only recognized retrospectively. One of the reasons for this is that precursor thermal activity is often too subtle in magnitude (spatially, temporally, or in absolute temperature) to be unambiguously detected in time to issue warnings or forecasts. Part of the reason for this is the trade-off between high spatial and high temporal resolution associated with satellite imaging systems. Thus, the goal of this work has been to develop some techniques for using high-temporal-resolution, coarse-spatial-resolution imagery to try to detect subtle thermal anomalies. To identify anomalies, background thermal activity must first be characterized. Every active, or potentially active, volcano has a unique thermal history that provides information about normal background thermal activity due to seasonal or diurnal variations. Understanding these normal variations allows recognition of anomalous activity that may be due to volcanic / hydrothermal processes - ultimately with a lead time that may be sufficient to issue eruption warnings or forecasts. Archived MODIS data, acquired ~daily from 2000 to 2012, were used to investigate seasonal thermal cycles at three volcanic areas with different types of thermal features: Mount St. Helens, which had a dacite dome-building eruption from 2004-2008; Mount Ruapehu, which has a 500-m diameter active summit crater lake; and Yellowstone, which is a large active geothermal system that has hundreds of hot springs and fumarole fields spread out over a very large area. The focus has been on using MODIS 1-km sensor radiance data in the MIR and TIR wavelength regions that are sensitive to thermal emission from features that range in temperature from hundreds of °C, down to tens of °C (below the boiling temperature of water). To detect such features it is best to use data acquired at night, as this maximizes the delta T between the thermal target and non-thermal background and minimizes the effects of the Sun. Decadal time-series plots of nighttime MODIS sensor radiance data over the target areas show that seasonal thermal cycles due to varying solar incidence angle can be modeled with a sine function and removed to reveal subtle changes in TIR radiance. The seasonal sine function is unique to each volcanic / geothermal area and can be modeled iteratively using a least squares fit to the cloud of radiance data. The sine function model can also be used to generate a first-order cloud cover approximation for the nighttime TIR data. This work helps establish a framework for improved thermal alarm algorithms, automated thermal detection methods, and operational monitoring techniques for active, or potentially active, volcanoes throughout the world. This type of background study is a step toward establishing a global volcanic eruption forecasting system using satellite-based remote sensing data that are sensitive to subtle precursor thermal anomalies.

Eighteen years of geochemical monitoring at the oceanic active volcanic island of El Hierro (Canary Islands, Spain)

NASA Astrophysics Data System (ADS)

Asensio-Ramos, María; Alonso, Mar; Sharp, Emerson; Woods, Hannah; Barrancos, José; Pérez, Nemesio M.

2016-04-01

We report herein the latest results of a diffuse CO2 efflux survey at El Hierro volcanic system carried out during the summer period of 2015 to constrain the total CO2 output from the studied area a during post-eruptive period. El Hierro Island (278 km2) is the youngest and the SW-most of the Canary Islands. On July 16, 2011, a seismic-volcanic crisis started with the occurrence of more than 11,900 seismic events and significant deformation along the island. On October 10, 2011, the dominant character of seismicity changed dramatically from discrete earthquakes to continuous tremor, a clear indication that magma was rapidly approaching the surface immediately before the onset of the eruption, October 12. Eruption was declared over on 5 March, 2012. In order to monitor the volcanic activity of El Hierro Island, from 1998 to 2015 diffuse CO2 emission studies have been performed at El Hierro volcanic system in a yearly basis (˜600 observation sites) according to the accumulation chamber method. Spatial distribution maps were constructed following the sequential Gaussian simulation (sGs) procedure. To quantify the total CO2 emission from the studied area, 100 simulations for each survey have been performed. During the eruption period, soil CO2 efflux values range from non-detectable (˜0.5 g m-2 d-1) up to 457 g m-2 d-1, reaching in November 27, 2011, the maximum CO2 output estimated value of all time series, 2,398 t d-1, just before the episodes of maximum degassing observed as vigorous bubbling at the sea surface and an increment in the amplitude of the tremor signal. During the 2015 survey, soil CO2 efflux values ranged from non-detectable up to 41 g m-2 d-1. The spatial distribution of diffuse CO2 emission values seemed to be controlled by the main volcano structural features of the island. The total diffuse CO2 output released to atmosphere was estimated at 575 ± 24 t d-1, value slightly higher that the background CO2 emission estimated at 422 t d-1 (Melián et al., 2014). The above data demonstrate that discrete surveys of diffuse CO2 emission provide important information to optimize the early warning system in volcano monitoring programs and to monitor the evolution of an ongoing volcanic eruption, even though it is a submarine eruption. References: Melián et al., 2014. J. Geophys. Res. DOI: 10.1002/2014JB011013.

Detection and Tracking of Volcanic Ash and SO2 and its Impact to Aviation

NASA Astrophysics Data System (ADS)

Osiensky, J.; Hall, T.

2008-12-01

The eruptions of Okmok and Kasatochi Volcanoes in August 2008 produced a combination of volcanic ash and SO2 (sulfur dioxide) that impacted aviation across Alaska and the North Pacific Region. The Anchorage Volcanic Ash Advisory Center (A-VAAC) worked closely with the Alaska Volcano Observatory (AVO) and Federal Aviation Administration (FAA) Air Route Traffic Control Center (ARTCC) to ensure that accurate and timely detection and forecast of the ash plume occurred. Volcanic ash poses a hazard to all forms of transportation, but has been shown to be especially dangerous to aviation. Even a small eruption with limited vertical extent to the ash cloud impacts aviation traffic. A significant eruption where the ash cloud penetrates the jet airways (greater than 20,000 feet) requires major re-routing of air traffic, or even the cancellation of flights to ensure the safety of the airways. The AAWU and the AVO have demonstrated substantial experience successfully tracking volcanic ash clouds during the past 15 years. The AAWU issues special aviation warnings for volcanic ash (Volcanic Ash SIGMETs (Significant Meteorological Information)) to warn aircraft of impending ash hazards. However, an additional potential hazard to aviation associated with volcanic eruptions is being examined. A Sulfur Dioxide (SO2) cloud was identified and tracked across the Aleutians, Gulf of Alaska, and eventually into the Lower 48 states. The size and coverage of the SO2 clouds from the Okmok and Kasatochi eruptions may be unprecedented. There are currently no requirements to advise, or warn for SO2 as a hazard to aviation. However, SO2 has been demonstrated as a marker for potential areas of lower concentration volcanic ash. Dispersion models, such as NOAAs HYSPLIT, that are used to track volcanic ash are currently not tuned to track gases such as SO2. SO2 may not be a direct hazard to aviation per se; However, SO2 mixed with water produces H2SO4 (sulfuric acid), and long term exposure to even low concentrations of sulfuric acid may lead to deterioration of airframe paint and acrylic aircraft windows as well as sulfate deposits in the engines. Airlines typically avoid SO2 clouds because these clouds often contain small amounts of ash as well. Relatively new OMI (Ozone Monitoring Instrument) data from the EOS-Aura satellite provides a much higher resolution depiction of the SO2 cloud; However, a major drawback to this capability is that the OMI sensor is located on a Polar Orbiter satellite (where the frequency of this data is sparse). Forecasters in Alaska typically receive only one pass per day from the OMI due to its orbital path. Additional research is needed to better define thresholds and impacts of volcanic ash and SO2 as it relates to aviation. More importantly this research must be transferred rapidly from the research community into forecast operations.

Changing Weather Extremes Call for Early Warning of Potential for Catastrophic Fire

NASA Astrophysics Data System (ADS)

Boer, Matthias M.; Nolan, Rachael H.; Resco De Dios, Víctor; Clarke, Hamish; Price, Owen F.; Bradstock, Ross A.

2017-12-01

Changing frequencies of extreme weather events and shifting fire seasons call for enhanced capability to forecast where and when forested landscapes switch from a nonflammable (i.e., wet fuel) state to the highly flammable (i.e., dry fuel) state required for catastrophic forest fires. Current forest fire danger indices used in Europe, North America, and Australia rate potential fire behavior by combining numerical indices of fuel moisture content, potential rate of fire spread, and fire intensity. These numerical rating systems lack the physical basis required to reliably quantify forest flammability outside the environments of their development or under novel climate conditions. Here, we argue that exceedance of critical forest flammability thresholds is a prerequisite for major forest fires and therefore early warning systems should be based on a reliable prediction of fuel moisture content plus a regionally calibrated model of how forest fire activity responds to variation in fuel moisture content. We demonstrate the potential of this approach through a case study in Portugal. We use a physically based fuel moisture model with historical weather and fire records to identify critical fuel moisture thresholds for forest fire activity and then show that the catastrophic June 2017 forest fires in central Portugal erupted shortly after fuels in the region dried out to historically unprecedented levels.

An alternative modeling framework for better interpretation of the observed volcano-hydrothermal system data

NASA Astrophysics Data System (ADS)

Yue, Z. Q. Q.

2015-12-01

Many phenomena and data related to volcanoes and volcano eruptions have been observed and collected over the past four hundred years. They have been interpreted with the conventional and widely accepted hypothesis or theory of hot magma fluid from mantle. However, the prediction of volcano eruption sometimes is incorrect. For example, the devastating eruption of the Mount Ontake on Sept. 27, 2014 was not predicted and/or warned at all, which caused 55 fatalities, 9 missing and more than 60 injured. Therefore, there is a need to reconsider the cause and mechanism of active volcano and its hydrothermal system. On the basis of more than 30 year study and research in geology, volcano, earthquake, geomechanics, geophysics, geochemistry and geohazards, the author has developed a new and alternative modeling framework (or hypothesis) to better interpret the observed volcano-hydrothermal system data and to more accurately predict the occurrence of volcano explosion. An active volcano forms a cone-shape mountain and has a crater with vertical pipe conduit to allow hot lava, volcanic ash and gases to escape or erupt from its chamber (Figure). The chamber locates several kilometers below the ground rocks. The active volcanos are caused by highly compressed and dense gases escaped from the Mantle of the Earth. The gases are mainly CH4 and further trapped in the upper crustal rock mass. They make chemical reactions with the surrounding rocks in the chamber. The chemical reactions are the types of reduction and decomposition. The reactions change the gas chemical compounds into steam water gas H2O, CO2, H2S, SO2 and others. The oxygen in the chemical reaction comes from the surrounding rocks. So, the product lava has a less amount of oxygen than that of the surrounding rocks. The gas-rock chemical reactions produce heat. The gas expansion and penetration power and the heat further break and crack the surrounding rock mass and make them into lavas, fragments, ashes or bombs. The pyroclastic deposits are carried out of the chamber by the gas expansion and uplift power and form the cone-shape mountain. The crust loses its rocks and the chamber becomes larger and larger. Eventually, the last eruption occurs and breaks the upper rocks and the cone mountain. The pyroclatic rocks collapse into the chamber space and leave a basin or lake.

Forecasting volcanic unrest using seismicity: The good, the bad and the time consuming

NASA Astrophysics Data System (ADS)

Salvage, Rebecca; Neuberg, Jurgen W.

2013-04-01

Volcanic eruptions are inherently unpredictable in nature, with scientists struggling to forecast the type and timing of events, in particular in real time scenarios. Current understanding suggests that the use of statistical patterns within precursory datasets of seismicity prior to eruptive events could hold the potential to be used as real time forecasting tools. They allow us to determine times of clear deviation in data, which might be indicative of volcanic unrest. The identification of low frequency seismic swarms and the acceleration of this seismicity prior to observed volcanic unrest may be key in developing forecasting tools. The development of these real time forecasting models which can be implemented at volcano observatories is of particular importance since the identification of early warning signals allows danger to the proximal population to be minimized. We concentrate on understanding the significance and development of these seismic swarms as unrest develops at the volcano. In particular, analysis of accelerations in event rate, amplitude and energy rates released by seismicity prior to eruption suggests that these are important indicators of developing unrest. Real time analysis of these parameters simultaneously allows possible improvements to forecasting models. Although more time and computationally intense, cross correlation techniques applied to continuous seismicity prior to volcanic unrest scenarios allows all significant seismic events to be analysed, rather than only those which can be detected by an automated identification system. This may allow a more accurate forecast since all precursory seismicity can be taken into account. In addition, the classification of seismic events based on spectral characteristics may allow us to isolate individual types of signals which are responsible for certain types of unrest. In this way, we may be able to better forecast the type of eruption that may ensue, or at least some of its prevailing characteristics.

New Security and Justice Sector Partnership Models: Implications of the Arab Uprisings

DTIC Science & Technology

2014-01-01

clear boiling point that even before the Arab uprisings erupted, Clinton warned regional regimes that they needed to change or risk “sinking into the...but without any clear operational definition of security capac- ity, no consistent logic for allocating funds and determining appropriate expenditure...reference point for gauging performance and determining whether and how program implementation needs to be altered. While this approach is most

Volcano Hazards Program

USGS Publications Warehouse

Venezky, Dina Y.; Myers, Bobbie; Driedger, Carolyn

2008-01-01

Diagram of common volcano hazards. The U.S. Geological Survey Volcano Hazards Program (VHP) monitors unrest and eruptions at U.S. volcanoes, assesses potential hazards, responds to volcanic crises, and conducts research on how volcanoes work. When conditions change at a monitored volcano, the VHP issues public advisories and warnings to alert emergency-management authorities and the public. See http://volcanoes.usgs.gov/ to learn more about volcanoes and find out what's happening now.

Geology of El Chichon volcano, Chiapas, Mexico

NASA Astrophysics Data System (ADS)

Duffield, Wendell A.; Tilling, Robert I.; Canul, Rene

1984-03-01

The (pre-1982) 850-m-high andesitic stratovolcano El Chichón, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, México. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chichón is built on Tertiary siltstone and sandstone, underlain by Cretaceous dolomitic limestone; a 4-km-deep bore hole near the east base of the volcano penetrated this limestone and continued 770 m into a sequence of Jurassic or Cretaceous evaporitic anhydrite and halite. The basement rocks are folded into generally northwest-trending anticlines and synclines. El Chichón is built over a small dome-like structure superposed on a syncline, and this structure may reflect cumulative deformation related to growth of a crustal magma reservoir beneath the volcano. The cone of El Chichón consists almost entirely of pyroclastic rocks. The pre-1982 cone is marked by a 1200-m-diameter (explosion?) crater on the southwest flank and a 1600-m-diameter crater apparently of similar origin at the summit, a lava dome partly fills each crater. The timing of cone and dome growth is poorly known. Field evidence indicates that the flank dome is older than the summit dome, and K-Ar ages from samples high on the cone suggest that the flank dome is older than about 276,000 years. At least three pyroclastic eruptions have occurred during the past 1250 radiocarbon years. Nearly all of the pyroclastic and dome rocks are moderately to highly porphyritic andesite, with plagioclase, hornblende and clinopyroxene the most common phenocrysts. Geologists who mapped El Chichón in 1980 and 1981 warned that the volcano posed a substantial hazard to the surrounding region. This warning was proven to be prophetic by violent eruptions that occurred in March and April of 1982. These eruptions blasted away nearly all of the summit dome, blanketed the surrounding region with tephra, and sent pyroclastic flows down radial drainages on the flanks of the cone; about 0.3 km 3 of material (density of all products normalized to 2.6 g cm -3) was erupted. More debris entered the stratosphere than from any other volcanic eruption within at least the past two decades. Halite and a calcium sulfate mineral (anhydrite?) recovered from the stratospheric cloud, and anhydrite as a common accessory mineral in 1982 juvenile erupted products may reflect contamination of El Chichón magma by the evaporite sequence revealed by drilling.

Geology of El Chichon volcano, Chiapas, Mexico

USGS Publications Warehouse

Duffield, W.A.; Tilling, R.I.; Canul, R.

1984-01-01

The (pre-1982) 850-m-high andesitic stratovolcano El Chicho??n, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, Me??xico. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chicho??n is built on Tertiary siltstone and sandstone, underlain by Cretaceous dolomitic limestone; a 4-km-deep bore hole near the east base of the volcano penetrated this limestone and continued 770 m into a sequence of Jurassic or Cretaceous evaporitic anhydrite and halite. The basement rocks are folded into generally northwest-trending anticlines and synclines. El Chicho??n is built over a small dome-like structure superposed on a syncline, and this structure may reflect cumulative deformation related to growth of a crustal magma reservoir beneath the volcano. The cone of El Chicho??n consists almost entirely of pyroclastic rocks. The pre-1982 cone is marked by a 1200-m-diameter (explosion?) crater on the southwest flank and a 1600-m-diameter crater apparently of similar origin at the summit, a lava dome partly fills each crater. The timing of cone and dome growth is poorly known. Field evidence indicates that the flank dome is older than the summit dome, and K-Ar ages from samples high on the cone suggest that the flank dome is older than about 276,000 years. At least three pyroclastic eruptions have occurred during the past 1250 radiocarbon years. Nearly all of the pyroclastic and dome rocks are moderately to highly porphyritic andesite, with plagioclase, hornblende and clinopyroxene the most common phenocrysts. Geologists who mapped El Chicho??n in 1980 and 1981 warned that the volcano posed a substantial hazard to the surrounding region. This warning was proven to be prophetic by violent eruptions that occurred in March and April of 1982. These eruptions blasted away nearly all of the summit dome, blanketed the surrounding region with tephra, and sent pyroclastic flows down radial drainages on the flanks of the cone; about 0.3 km3 of material (density of all products normalized to 2.6 g cm-3) was erupted. More debris entered the stratosphere than from any other volcanic eruption within at least the past two decades. Halite and a calcium sulfate mineral (anhydrite?) recovered from the stratospheric cloud, and anhydrite as a common accessory mineral in 1982 juvenile erupted products may reflect contamination of El Chicho??n magma by the evaporite sequence revealed by drilling. ?? 1984.

Geochemical and petrological indicators of volcanic behavior: Merapi volcano, Java, Indonesia

NASA Astrophysics Data System (ADS)

Troll, V. R.; Deegan, F. M.; Jolis, E. M.; Chadwick, J.; Blythe, L. S.; Freda, C.; Hilton, D. R.; Schwarzkopf, L. M.; Gertisser, R.; Zimmer, M.

2011-12-01

Gunung Merapi, one of Indonesia's most active volcanoes, is characterized by long periods of dome growth and intermittent explosive pyroclastic events. Merapi currently degasses continuously through high-T fumaroles (>200°C), and erupts crystal-rich basaltic-andesite that contains a large range of igneous and calc-silicate crustal inclusions. To evaluate mechanisms that trigger explosive eruptions, we sampled lavas, inclusions (xenoliths), and gas from active fumaroles. Additionally, we established a time-integrated experiment reaction series mimicking crustal assimilation at Merapi under magmatic conditions. Merapi lava contains abundant plagioclase crystals which show complex zoning and vary in anorthite (An) content between 40 and 95 mol% across resorption surfaces. A negative correlation between An mol% and other indicators of magmatic fractionation, such as MgO and FeO, has been observed. Moreover, Sr isotope analyses of discrete zones in plagioclase yields 87Sr/86Sr values that notably exceed those of the host lavas. Zones with the highest An content also tend to show the highest radiogenic Sr values, consistent with a Ca-rich, high-87Sr/86Sr crustal contaminant. Abundant metamorphosed limestone xenoliths contain compositionally identical feldspar to the high-An population in the lavas, demonstrating that magma-crust interaction is a significant process at Merapi. Carbon isotope ratios of fumarole CO2 sampled during quiescent degassing periods form a baseline of δ13C2001-2008 = -4.1%. The notable exceptions are the 2006 values, obtained immediately after the eruption and the 6.4 magnitude Yogyakarta earthquake, which show elevated δ13C values up to -2.4%. Notably, the rise in δ13C values coincided with an increase in eruptive intensity and volcano seismicity by a factor of 3 to 5 for several weeks after the earthquake. This is consistent with addition of a late-stage, crustal volatile component added to purely mantle and slab-derived volatile sources. This observation argues for extensive and ongoing magma-crust interaction beneath the volcano, especially during eruptive and/or seismic events. Our high P-T experiments show that interaction between Merapi magma and limestone can rapidly liberate crustal CO2 on a timescale of only seconds to minutes. We therefore expect vigorous CO2 bubble nucleation and growth on a scale of perhaps hours to days in nature. Late volatile input could therefore accelerate or trigger explosive eruptions independently of magmatic recharge and fractionation by sudden over-pressurization of the upper parts of the magma system. Such an event would provide shallow seismic warning signals immediately prior to an erratic, CO2-driven, eruption crisis. Thus we conclude that crust-mantle interaction processes have serious implications for eruptive behavior, volatile emission, and hazard management at Merapi and similar systems elsewhere.

Popocatepetl Erupts

NASA Technical Reports Server (NTRS)

2002-01-01

The Popocatepetl Volcano, almost 30 miles south of Mexico City, erupted yesterday (December 18, 2000) in what authorities are calling its most spectacular eruption since 800 A.D. This morning, Popocatepetl (pronounced poh-poh-kah-TEH-peh-til) continued spewing red-hot rocks as well as a column of smoke and ash about 2.5 miles high into the atmosphere. This true-color image of the volcano was acquired today by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) flying aboard the OrbView-2 satellite. In this image, Popocatepetl's plume (greyish pixels) can be seen blowing southward, away from Mexico City. There is a large cloud bank (bright white pixels) just to the east of the volcanic plume. Although Popocatepetl has been active since 1994-when it awoke from a 70-year slumber-this most recent eruption is most concerning to the greater Mexico City region's 20 million residents. The volcano demonstrated what it can do in 800 A.D. when it belched forth enough lava to fill many of the valleys in the surrounding region. Earlier, scientists warned the citizens of Mexico that there is a dome of lava at the base of the volcano that is causing pressure to build inside. They are concerned that, if it continues to build unabated, this pressure could cause even larger eruptions in the future. Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

The Global Framework for Providing Information about Volcanic-Ash Hazards to International Air Navigation

NASA Astrophysics Data System (ADS)

Romero, R. W.; Guffanti, M.

2009-12-01

The International Civil Aviation Organization (ICAO) created the International Airways Volcano Watch (IAVW) in 1987 to establish a requirement for international dissemination of information about airborne ash hazards to safe air navigation. The IAVW is a set of operational protocols and guidelines that member countries agree to follow in order to implement a global, multi-faceted program to support the strategy of ash-cloud avoidance. Under the IAVW, the elements of eruption reporting, ash-cloud detecting, and forecasting expected cloud dispersion are coordinated to culminate in warnings sent to air traffic controllers, dispatchers, and pilots about the whereabouts of ash clouds. Nine worldwide Volcanic Ash Advisory Centers (VAAC) established under the IAVW have the responsibility for detecting the presence of ash in the atmosphere, primarily by looking at imagery from civilian meteorological satellites, and providing advisories about the location and movement of ash clouds to aviation meteorological offices and other aviation users. Volcano Observatories also are a vital part of the IAVW, as evidenced by the recent introduction of a universal message format for reporting the status of volcanic activity, including precursory unrest, to aviation users. Since 2003, the IAVW has been overseen by a standing group of scientific, technical, and regulatory experts that assists ICAO in the development of standards and other regulatory material related to volcanic ash. Some specific problems related to the implementation of the IAVW include: the lack of implementation of SIGMET (warning to aircraft in flight) provisions and delayed notifications of volcanic eruptions. Expected future challenges and developments involve the improvement in early notifications of volcanic eruptions, the consolidation of the issuance of SIGMETs, and the possibility of determining a “safe” concentration of volcanic ash.

Climate Throughout Geologic Time Was Cooled by Sequences of Explosive Volcanic Eruptions Forming Aerosols That Reflect and Scatter Ultraviolet Solar Radiation and Warmed by Relatively Continuous Extrusion of Basaltic Lava that Depletes Ozone, Allowing More Solar Ultraviolet Radiation to Reach Earth

NASA Astrophysics Data System (ADS)

Ward, P. L.

2015-12-01

Active volcanoes of all sizes and eruptive styles, emit chlorine and bromine gases observed to deplete ozone. Effusive, basaltic volcanic eruptions, typical in Hawaii and Iceland, extrude large lava flows, depleting ozone and causing global warming. Major explosive volcanoes also deplete ozone with the same emissions, causing winter warming, but in addition eject megatons of water and sulfur dioxide into the lower stratosphere where they form sulfuric-acid aerosols whose particles grow large enough to reflect and scatter ultraviolet sunlight, causing net global cooling for a few years. The relative amounts of explosive and effusive volcanism are determined by the configuration of tectonic plates moving around Earth's surface. Detailed studies of climate change throughout geologic history, and since 1965, are not well explained by greenhouse-gas theory, but are explained quite clearly at OzoneDepletionTheory.info. Ozone concentrations vary substantially by the minute and show close relationships to weather system highs and lows (as pointed out by Dobson in the 1920s), to the height of the tropopause, and to the strength and location of polar vortices and jet streams. Integrating the effects of volcanism on ozone concentrations and the effects of ozone concentrations on synoptic weather patterns should improve weather forecasting. For example, the volcano Bárðarbunga, in central Iceland, extruded 85 km2 of basaltic lava between August 29, 2014, and February 28, 2015, having a profound effect on weather. Most surprising, more than a week before the March 4 eruption of Eyjafjallajökull in 2010, substantial amounts of ozone were released in the vicinity of the volcano precisely when surface deformation showed that magma first began moving up from sills below 4 km depth. Ozone similarly appears to have been emitted 3.5 months before the Pinatubo eruption in 1991. Readily available daily maps of ozone concentrations may allow early warning of an imminent volcanic eruption.

Measuring Volcanic Thermal Output

NASA Astrophysics Data System (ADS)

Reath, K.

2017-12-01

In most cases, volcanic eruptions are preceded by some form of unrest that can be used as an early warning sign of an impending eruption or provide insight into changing hazards during an eruption, contingent upon this unrest being properly monitored and understood. Many ground and satellite monitoring techniques have been developed to identify the varying types volcanic unrest, including seismic, degassing, deformation, and thermal measurements. High spatial resolution thermal infrared (TIR) remote sensing, such as the thermal images acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor, have proven particularly effective at identifying and tracking variations in thermal unrest in the form of volcanic thermal anomalies. However, the majority of ASTER thermal anomaly studies have focused on tracking the variations in the temperature of the hottest pixel above background in the anomaly. Whereas, this remains a valid method as it reveals valuable information about variations occurring at the main vent of a volcano, it does not incorporate the thermal output of the entire anomaly, which typically expands beyond one pixel due to the heating of the surrounding area. By developing a weighted area method that considers both the thermal anomaly area and temperature the total thermal output of an anomaly can be measured. It some case studies, such as the period before the 2016 Sabancaya eruption, both temperature and area increase before an eruptive event. Here, the weighted area methods demonstrates a clearer increase in thermal unrest than the traditional above temperature method. In other case studies, such as the thermal anomaly observed at Lascar volcano, the area of the anomaly remains relatively constant. This limits the variation in values between these two methods. However, by incorporating data from both of these methods, valuable interpretations can be made about the dynamics of the main vent where compared to the full thermal system. A variety of volcanoes will be demonstrated in this presentation to understand the conditions where this technique is most helpful and how the weighted area method enables a more complete analysis of the volcanic processes occurring both before and during eruption.

Short-term seismic precursors to Icelandic eruptions 1973-2014.

NASA Astrophysics Data System (ADS)

Einarsson, Páll

2018-05-01

Networks of seismographs of high sensitivity have been in use in the vicinity of active volcanoes in Iceland since 1973. During this time 21 confirmed eruptions have occurred and several intrusions where magma did not reach the surface. All these events have been accompanied by characteristic seismic activity. Long-term precursory activity is characterised by low-level, persistent seismicity (months-years), clustered around an inflating magma body. Whether or not a magma accumulation is accompanied by seismicity depends on the tectonic setting, interplate or intraplate, the depth of magma accumulation, the previous history and the state of stress. All eruptions during the time of observation had a detectable short-term seismic precursor marking the time of dike propagation towards the surface. The precursor times varied between 15 minutes and 13 days. In half of the cases the precursor time was less than 2 hours. Three eruptions stand out for their long duration of the immediate precursory activity, Heimaey 1973 with 30 hours, Gjálp 1996 with 34 hours, and Bárðarbunga 2014 with 13 days. In the case of Heimaey the long time is most likely the consequence of the great depth of the magma source, 15-25 km. The Gjálp eruption had a prelude that was unusual in many respects. The long propagation time may have resulted from a complicated triggering scenario involving more than one magma chamber. The Bárðarbunga eruption at Holuhraun issued from the distal end of a dike that took 13 days to propagate laterally for 48 km before it opened to the surface. Out of the 21 detected precursors 14 were noticed soon enough to lead to a public warning of the coming eruption. In 4 additional cases the precursory signal was noticed before the eruption was seen. In only 3 cases was the eruption seen or detected before the seismic precursor was verified.

Solar Demon: near real-time solar eruptive event detection on SDO/AIA images

NASA Astrophysics Data System (ADS)

Kraaikamp, Emil; Verbeeck, Cis

Solar flares, dimmings and EUV waves have been observed routinely in extreme ultra-violet (EUV) images of the Sun since 1996. These events are closely associated with coronal mass ejections (CMEs), and therefore provide useful information for early space weather alerts. The Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) generates such a massive dataset that it becomes impossible to find most of these eruptive events manually. Solar Demon is a set of automatic detection algorithms that attempts to solve this problem by providing both near real-time warnings of eruptive events and a catalog of characterized events. Solar Demon has been designed to detect and characterize dimmings, EUV waves, as well as solar flares in near real-time on SDO/AIA data. The detection modules are running continuously at the Royal Observatory of Belgium on both quick-look data and synoptic science data. The output of Solar Demon can be accessed in near real-time on the Solar Demon website, and includes images, movies, light curves, and the numerical evolution of several parameters. Solar Demon is the result of collaboration between the FP7 projects AFFECTS and COMESEP. Flare detections of Solar Demon are integrated into the COMESEP alert system. Here we present the Solar Demon detection algorithms and their output. We will focus on the algorithm and its operational implementation. Examples of interesting flare, dimming and EUV wave events, and general statistics of the detections made so far during solar cycle 24 will be presented as well.

Detection of Natural Hazards Generated TEC Perturbations and Related New Applications

NASA Astrophysics Data System (ADS)

Komjathy, A.; Yang, Y.; Langley, R. B.

2013-12-01

Natural hazards, including earthquakes, volcanic eruptions, and tsunamis, have been significant threats to humans throughout recorded history. The Global Positioning System satellites have become primary sensors to measure signatures associated with such natural hazards. These signatures typically include GPS-derived seismic deformation measurements, co-seismic vertical displacements, and real-time GPS-derived ocean buoy positioning estimates. Another way to use GPS observables is to compute the ionospheric total electron content (TEC) to measure and monitor post-seismic ionospheric disturbances caused by earthquakes, volcanic eruptions, and tsunamis. Research at the University of New Brunswick (UNB) laid the foundations to model the three-dimensional ionosphere at NASA's Jet Propulsion Laboratory by ingesting ground- and space-based GPS measurements into the state-of-the-art Global Assimilative Ionosphere Modeling (GAIM) software. As an outcome of the UNB and NASA research, new and innovative GPS applications have been invented including the use of ionospheric measurements to detect tiny fluctuations in the GPS signals between the spacecraft and GPS receivers caused by natural hazards occurring on or near the Earth's surface. This continuing research is expected to provide early warning for tsunamis, earthquakes, volcanic eruptions, and meteor impacts, for example, using GPS and other global navigation satellite systems. We will demonstrate new and upcoming applications including recent natural hazards and artificial explosions that generated TEC perturbations to perform state-of-the-art imaging and modeling of earthquakes, tsunamis and meteor impacts. By studying the propagation properties of ionospheric perturbations generated by natural hazards along with applying sophisticated first-principles physics-based modeling, we are on track to develop new technologies that can potentially save human lives and minimize property damage.

"A tempest in a cocktail glass": mothers, alcohol, and television, 1977-1996.

PubMed

Golden, J

2000-06-01

This article examines the portrayal of pregnancy and alcohol in thirty-six national network evening news broadcasts (ABC, CBS, NBC). Early coverage focused on white, middle-class women, as scientific authorities and government officials warned against drinking during pregnancy. After 1987, however, women who drank during pregnancy were depicted as members of minority groups and as a danger to society. The thematic transition began before warning labels appeared on alcoholic beverages and gained strength from official government efforts to prevent fetal alcohol syndrome. The greatest impetus for the revised discourse, however, was the eruption of a "moral panic" over crack cocaine use. By linking fetal harm to substance abuse, the panic suggested it was in the public's interest to control the behavior of pregnant women.

A multidisciplinary system for monitoring and forecasting Etna volcanic plumes

NASA Astrophysics Data System (ADS)

Coltelli, Mauro; Prestifilippo, Michele; Spata, Gaetano; Scollo, Simona; Andronico, Daniele

2010-05-01

One of the most active volcanoes in the world is Mt. Etna, in Italy, characterized by frequent explosive activity from the central craters and from fractures opened along the volcano flanks which, during the last years, caused several damages to aviation and forced the closure of the Catania International Airport. To give precise warning to the aviation authorities and air traffic controller and to assist the work of VAACs, a novel system for monitoring and forecasting Etna volcanic plumes, was developed at the Istituto Nazionale di Geofisica e Vulcanologia, sezione di Catania, the managing institution for the surveillance of Etna volcano. Monitoring is carried out using multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager (SEVIRI) on board the Meteosat Second Generation geosynchronous satellite able to track the volcanic plume with a high time resolution, visual and thermal cameras used to monitor the explosive activity, three continuous wave X-band disdrometers which detect ash dispersal and fallout, sounding balloons used to evaluate the atmospheric fields, and finally field data collected after the end of the eruptive event needed to extrapolate important features of explosive activity. Forecasting is carried out daily using automatic procedures which download weather forecast data obtained by meteorological mesoscale models from the Italian Air Force national Meteorological Office and from the hydrometeorological service of ARPA-SIM; run four different tephra dispersal models using input parameters obtained by the analysis of the deposits collected after few hours since the eruptive event similar to 22 July 1998, 21-24 July 2001 and 2002-03 Etna eruptions; plot hazard maps on ground and in air and finally publish them on a web-site dedicated to the Italian Civil Protection. The system has been already tested successfully during several explosive events occurring at Etna in 2006, 2007 and 2008. These events produced eruption columns high up to several kilometers above sea level and, on the basis of parameters such as mass eruption rate and total grain-size distributions, showed different explosive style. The monitoring and forecasting system is going on developing through the installation of new instruments able to detect different features of the volcanic plumes (e.g. the dispersal and sedimentation processes) in order to reduce the uncertainty of the input parameters used in the modeling. This is crucial to perform a reliable forecasting. We show that multidisciplinary approaches can really give useful information on the presence of volcanic ash and consequently to prevent damages and airport disruptions.

A comprehensive approach to monitoring volcano deformation as a window on the eruption cycle

USGS Publications Warehouse

Dzurisin, D.

2003-01-01

Since the 1980 eruption of Mount St. Helens, volcanologists have made considerable progress toward predicting eruptions on the basis of precursors that typically start a few days to several months in advance. Although accurate eruption prediction is by no means routine, it may now be possible in some cases to extend the effective warning period by anticipating the onset of short-term precursors. Three promising indicators of deep magmatic processes are (1) deep, long-period earthquakes and tremor that indicate the ascent of magma through the crust, (2) magmatic CO2 emission rate as a proxy for magma supply rate, and (3) relatively broad, generally aseismic surface uplift caused by magmatic intrusions. In the latter case it is essential to sample the deformation field thoroughly in both time and space to adequately constrain source models. Until recently, this has been nearly impossible because high-precision sensors could not be deployed in sufficient numbers, nor could extensive geodetic surveys be conducted often enough. Advances in instrumentation, interferometric synthetic aperture radar (InSAR), and telecommunications are helping to overcome these limitations. As a result, comprehensive geodetic monitoring of selected volcanoes is now feasible. A combination of InSAR, large-aperture GPS surveys, microgravity surveys, and dense arrays of continuous GPS stations, strain meters, and tiltmeters can reveal both spatial and temporal patterns of ground deformation throughout the eruption cycle. Improved geodetic monitoring of many of the world's volcanoes would be a major stride toward better understanding of magmatic processes and longer-term eruption forecasts.

Hazard Assessment for POPOCATÉPETL Volcano Using Hasset: a Probability Event Tree Tool to Evaluate Future Eruptive Scenarios

NASA Astrophysics Data System (ADS)

Ferrés, D.; Reyes Pimentel, T. A.; Espinasa-Pereña, R.; Nieto, A.; Sobradelo, R.; Flores, X.; González Huesca, A. E.; Ramirez, A.

2013-05-01

Popocatépetl volcano is one of the most active in Latin America. During its last cycle of activity, beginning at the end of 1994, more than 40 episodes of dome construction and destruction have occurred inside the summit crater. Most of these episodes finished with eruptions of VEI 1-2. Eruptions of higher intensity were also registered in 1997, 2001 and 2009, of VEI≥3, which produced eruptive columns up to 8 km high and abundant and frequent ash falls on the villages at the eastern sector of the volcano. The January 22nd 2001 eruption also produced pyroclastic flows that followed several streams on the volcanic cone, reaching 4 to 6 km, and transforming to mudflows with ranges up to 15 km. The capital, Mexico City, is within the radius of 80 km from Popocatépetl volcano and can be affected by ash fall during the first months of the rainy season (May to July). Other important cities, such as Puebla and Atlixco, are located 15 to 30 km from the crater. Several villages of the states of México, Puebla and Morelos, which have a total population of 40,000 people, are inside the radius of 12 to 15 km, where the impacts of any of the products of an eruption, including pyroclastic flows, are possible. This high exposure of people and infrastructure around Popocatépetl volcano emphasizes the need of tools for early warning and the development of preventive actions to protect the population from volcanic phenomena. The diagnosis of the volcanic activity, based on the information provided by the monitoring systems, and the prognosis of the evolution of the volcano in the short-term is made by the Scientific Advisory Committee, formed by volcanologists of the National Autonomous University of Mexico, and by CENAPRED staff. From this prognosis, the alert level for the people is determined and it is spread by the code of the traffic light of volcanic alert. A volcanic event tree was constructed with the advisory of the scientific committee in the recent seismic-eruptive crisis of April-May 2012, in order to identify the most probable processes in which this unrest could have developed and to contribute to the diagnosis task. In this research, we propose a comparison between the processes identified in this preliminary volcanic event tree and another elaborated using a Hazard Assessment Event Tree probability tool (HASSET), built on a bayesian event tree structure, using mainly the information of the known eruptive history of Popocatépetl. The HASSET method is based on Bayesian Inference and is used to assess volcanic hazard of future eruptive scenarios, by evaluating the most relevant sources of uncertainty that play a role in estimating the future probability of occurrence of a specific volcanic event. The final goal is to find the most useful tools to make the diagnosis and prognosis of the Popocatépetl volcanic activity, integrating the known eruptive history of the volcano, the experience of the scientific committee and the information provided by the monitoring systems, in an interactive and user-friendly way.

Extreme Geohazards: Reducing Disaster Risk and Increasing Resilience

NASA Astrophysics Data System (ADS)

Plag, Hans-Peter; Stein, Seth; Brocklebank, Sean; Jules-Plag, Shelley; Campus, Paola

2014-05-01

Extreme natural hazards have the potential to cause global disasters and to lead to an escalation of the global sustainability crisis. Floods and droughts pose threats that could reach planetary extent, particularly through secondary economic and social impacts. Earthquakes and tsunamis cause disasters that could exceed the immediate coping capacity of the global economy, particularly in hazardous areas containing megacities, that can be particularly vulnerable to natural hazards if proper emergency protocols and infrastructures are not set in place. Recent events illustrate the destruction extreme hazards can inflict, both directly and indirectly, through domino effects resulting from the interaction with the built environment. Unfortunately, the more humanity learns to cope with relatively frequent (50 to 100 years) natural hazard events, the less concerns remain about the low-probability (one in a few hundred or more years) high-impact events. As a consequence, threats from low-probability extreme floods, droughts, and volcanic eruptions are not appropriately accounted for in Disaster Risk Reduction (DRR) discussions. With the support of the European Science Foundation (ESF), the Geohazards Community of Practice (GHCP) of the Group on Earth Observations (GEO) has developed a White Paper (WP) on the risk associated with low-probability, high-impact geohazards. These events are insufficiently addressed in risk management, although their potential impacts are comparable to those of a large asteroid impact, a global pandemic, or an extreme drought. The WP aims to increase awareness of the risk associated with these events as a basis for a comprehensive risk management. Extreme geohazards have occurred regularly throughout the past, but mostly did not cause major disasters because the exposure of human assets to such hazards and the global population density were much lower than today. The most extreme events during the last 2,000 years would cause today unparalleled damage on a global scale for a globally connected and stressed society. In particular, large volcanic eruptions could impact climate, damage anthropogenic infrastructure and interrupt resource supplies on a global scale. The occurrence of one or more of the largest volcanic eruptions that took place during the last 2,000 years under today's conditions would likely cause global disasters or catastrophes challenging civilization. Integration of these low-probability, high-impact events in DRR requires an approach focused on resilience and antifragility, as well as the ability to cope with, and recover from failure of infrastructures and social systems. Resilience results from social capital even more than from the robustness of infrastructure. While it is important to understand the hazards through the contribution of geosciences, it is equally important to understand through the contribution of social sciences and engineering the societal processes involved with coping with hazards or leading to failure. For comprehensive development of resilience to natural hazards and, in particular, extreme geohazards, synergy between geosciences, engineering and social sciences, jointed to an improved science-policy relationship is key to success. For example, a simple cost-benefit analysis shows that a comprehensive monitoring system that could identify the onset of an extreme volcanic eruption with sufficient lead time to allow for a globally coordinated preparation makes economic sense. The WP recommends implementation of such a monitoring system with global coverage, assesses the existing assets in current monitoring systems, and illustrates many benefits, besides providing early warning for extreme volcanic eruptions. However, such a monitoring system can provide resilience only via the capability of the global community to react to early warnings. The WP recommends achieving this through the establishment of a global coordination platform comparable to IPCC's role in addressing climate-change related issues to assess knowledge and related adaptive capabilities for disasters due to extreme geohazards.

Lahar—River of volcanic mud and debris

USGS Publications Warehouse

Major, Jon J.; Pierson, Thomas C.; Vallance, James W.

2018-05-09

Lahar, an Indonesian word for volcanic mudflow, is a mixture of water, mud, and volcanic rock flowing swiftly along a channel draining a volcano. Lahars can form during or after eruptions, or even during periods of inactivity. They are among the greatest threats volcanoes pose to people and property. Lahars can occur with little to no warning, and may travel great distances at high speeds, destroying or burying everything in their paths.Lahars form in many ways. They commonly occur when eruptions melt snow and ice on snow-clad volcanoes; when rains fall on steep slopes covered with fresh volcanic ash; when crater lakes, volcano glaciers or lakes dammed by volcanic debris suddenly release water; and when volcanic landslides evolve into flowing debris. Lahars are especially likely to occur at erupting or recently active volcanoes.Because lahars are so hazardous, U.S. Geological Survey scientists pay them close attention. They study lahar deposits and limits of inundation, model flow behavior, develop lahar-hazard maps, and work with community leaders and governmental authorities to help them understand and minimize the risks of devastating lahars.

Volcanic hazards and remote sensing in Pacific Latin America

NASA Astrophysics Data System (ADS)

Lyons, John; Rose, Bill; Escobar, Rüdiger

2011-06-01

PASI Workshop on Open Vent Volcanoes; San José, Costa Rica, 10-24 January 2011 ; Open-vent volcanoes are a class of volcano that contain a relatively open path from the subsurface to the atmosphere without a major vent obstruction. Their persistent, low-level activity, which poses little danger to communities, may be punctuated by violent activity without warning. These complex systems challenge and provide opportunity for observatories and national and international investigators. Long-lived eruptions are also laboratories for students and scientists and a locus for developing collaborations and field testing new instrumentation and methods. Pacific Latin America hosts a high density of active volcanoes, and many are under-monitored and under-researched despite the efforts of local volcano observatories and their accessibility to U.S. and European scientists.

California's restless giant: the Long Valley Caldera

USGS Publications Warehouse

Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

2014-01-01

Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

Drilling to investigate processes in active tectonics and magmatism

NASA Astrophysics Data System (ADS)

Shervais, J.; Evans, J.; Toy, V.; Kirkpatrick, J.; Clarke, A.; Eichelberger, J.

2014-12-01

Coordinated drilling efforts are an important method to investigate active tectonics and magmatic processes related to faults and volcanoes. The US National Science Foundation (NSF) recently sponsored a series of workshops to define the nature of future continental drilling efforts. As part of this series, we convened a workshop to explore how continental scientific drilling can be used to better understand active tectonic and magmatic processes. The workshop, held in Park City, Utah, in May 2013, was attended by 41 investigators from seven countries. Participants were asked to define compelling scientific justifications for examining problems that can be addressed by coordinated programs of continental scientific drilling and related site investigations. They were also asked to evaluate a wide range of proposed drilling projects, based on white papers submitted prior to the workshop. Participants working on faults and fault zone processes highlighted two overarching topics with exciting potential for future scientific drilling research: (1) the seismic cycle and (2) the mechanics and architecture of fault zones. Recommended projects target fundamental mechanical processes and controls on faulting, and range from induced earthquakes and earthquake initiation to investigations of detachment fault mechanics and fluid flow in fault zones. Participants working on active volcanism identified five themes: the volcano eruption cycle; eruption sustainability, near-field stresses, and system recovery; eruption hazards; verification of geophysical models; and interactions with other Earth systems. Recommended projects address problems that are transferrable to other volcanic systems, such as improved methods for identifying eruption history and constraining the rheological structure of shallow caldera regions. Participants working on chemical geodynamics identified four major themes: large igneous provinces (LIPs), ocean islands, continental hotspot tracks and rifts, and convergent plate margins (subduction zones). This workshop brought together a diverse group of scientists with a broad range of scientific experience and interests. A particular strength was the involvement of both early-career scientists, who will initiate and carry out these new research programs, and more senior researchers with many years of experience in scientific drilling and active tectonics research. Each of the themes and questions outlined above has direct benefits to society, including improving hazard assessment, direct monitoring of active systems for early warning, renewable and non-renewable resource and energy exploitation, and predicting the environmental impacts of natural hazards, emphasizing the central role that scientific drilling will play in future scientific and societal developments.

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

NASA Astrophysics Data System (ADS)

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

2010-05-01

The Bayesian Event Tree for Eruption Forecasting software (BET_EF) is a probabilistic model based on an event tree scheme that was created specifically to compute long- and short-term probabilities of different outcomes (volcanic unrest, magmatic unrest, eruption, vent location and eruption size) at long-time dormant and routinely monitored volcanoes. It is based on the assumption that upward movements of magma in a closed conduit volcano will produce detectable changes in the monitored parameters at the surface. In this perspective, the goal of BET_EF is to compute probabilities by merging information from geology, models, past data and present monitoring measurements, through a Bayesian inferential method. In the present study, we attempt to apply BET_EF to Mt Ruapehu, a very active and well-monitored volcano exhibiting the typical features of open conduit volcanoes. In such conditions, current monitoring at the surface is not necessarily able to detect short term changes at depth that may occur only seconds to minutes before an eruption. This results in so-called "blue sky eruptions" of Mt Ruapehu (for example in September 2007), that are volcanic eruptions apparently not preceded by any presently detectable signal in the current monitoring. A further complication at Mt Ruapehu arises from the well-developed hydrothermal system and the permanent crater lake sitting on top of the magmatic conduit. Both the hydrothermal system and crater lake may act to mask or change monitoring signals (if present) that magma produces deeper in the edifice. Notwithstanding these potential drawbacks, we think that an attempt to apply BET_EF at Ruapehu is worthwhile, for several reasons. First, with the exception of a few "blue sky" events, monitoring data at Mt Ruapehu can be helpful in forecasting major events, especially if a large amount of magma is intruded into the edifice and becomes available for phreatomagmatic or magmatic eruptions, as for example in 1995-96. Secondly, in setting up BET_EF for Mt Ruapehu we are forced to define quantitatively what the background activity is. This will result in a quantitative evaluation of what changes in long time monitored parameters may influence the probability of future eruptions. The slopes of Mt Ruapehu host the largest ski area in North Island, New Zealand. Lahars have been generated as a result of several eruptions in the last 50 years, and some of these have reached the ski runs in a very short time frame (around 90 seconds from the beginning of the eruption). In the light of these potentially hazardous lahars, we use the output probabilities provided by BET_EF in a practical and rational decision scheme recently proposed by Marzocchi and Woo (2009) based on a cost/benefit analysis (CBA). In such scheme, a C/L ratio is computed, based on the costs (C) of practical mitigation actions to reduce risk (e.g., a public warning scheme and other means of raising awareness, and a call for a temporary and/or partial closure of the ski area) and on the potential loss (L) if no mitigation action is taken and an eruption occurs causing lahars down the ski fields. By comparing the probability of eruption-driven lahars and the C/L ratio, it is possible to define the most rational mitigation actions that can be taken to reduce the risk to skiers, snowboarders and staff on skifield. As BET_EF probability of eruption changes dynamically as updated monitoring data are received, the authorities can decide, at any specific point in time, what is the best action according to the current monitoring of the volcano. In this respect, CBA represents a bridge linking scientific output (probabilities) and Decision Makers (practical mitigation actions).

Geophysical Observations Supporting Research of Magmatic Processes at Icelandic Volcanoes

NASA Astrophysics Data System (ADS)

Vogfjörd, Kristín. S.; Hjaltadóttir, Sigurlaug; Roberts, Matthew J.

2010-05-01

Magmatic processes at volcanoes on the boundary between the European and North American plates in Iceland are observed with in-situ multidisciplinary geophysical networks owned by different national, European or American universities and research institutions, but through collaboration mostly operated by the Icelandic Meteorological Office. The terrestrial observations are augmented by space-based interferometric synthetic aperture radar (InSAR) images of the volcanoes and their surrounding surface. Together this infrastructure can monitor magma movements in several volcanoes from the base of the crust up to the surface. The national seismic network is sensitive enough to detect small scale seismicity deep in the crust under some of the voclanoes. High resolution mapping of this seismicity and its temporal progression has been used to delineate the track of the magma as it migrates upwards in the crust, either to form an intrusion at shallow levels or to reach the surface in an eruption. Broadband recording has also enabled capturing low frequency signals emanating from magmatic movements. In two volcanoes, Eyjafjallajökull and Katla, just east of the South Iceland Seismic Zone (SISZ), seismicity just above the crust-mantle boundary has revealed magma intruding into the crust from the mantle below. As the magma moves to shallower levels, the deformation of the Earth‘s surface is captured by geodetic systems, such as continuous GPS networks, (InSAR) images of the surface and -- even more sensitive to the deformation -- strain meters placed in boreholes around 200 m below the Earth‘s surface. Analysis of these signals can reveal the size and shape of the magma as well as the temporal evolution. At near-by Hekla volcano flanking the SISZ to the north, where only 50% of events are of M>1 compared to 86% of earthquakes in Eyjafjallajökull, the sensitivity of the seismic network is insufficient to detect the smallest seismicity and so the volcano appears less active and deep seismicity has not been detected. Improved seismic station density may improve the resolution of deep processes. Due do Hekla‘s continued expansion, the concentration of the continuous GPS network has been increased around Hekla and a strain meter will be installed by the volcano in 2010. The increased density of geodetic observations is expected to increase the resolution of the depth, volume and geometry of the magma chamber. Before the volcano's latest eruption in 2000, the increased seismicity and deformation signal recorded by the nearest seismic station and strain meter (at 15 km distance) enabled a public warning to be issued of the impending eruption 30 minutes prior to eruption. The additional instrumentation around Hekla is expected to extend the previous advance warning time.

Atmospheric distribution and removal of volcanic ash after the eruption of Kasatochi volcano: A regional model study

NASA Astrophysics Data System (ADS)

Langmann, Baerbel; ZakšEk, Klemen; Hort, Matthias

2010-01-01

In August 2008, Kasatochi volcano on the Aleutian Islands erupted without much advance warning. Volcanic ash released during this eruption quickly settled out of the atmosphere, mainly into the NE Pacific Ocean. The amount of volcanic ash, as well as the ash fall area and volume into the NE Pacific Ocean, remains speculative, as only a limited number of measurements is available. We used a three-dimensional atmosphere/chemistry-aerosol model to determine the atmospheric distribution of SO2 and volcanic ash and its fallout after the eruption of Kasatochi volcano. In a first step, modeled atmospheric SO2 distributions are compared with satellite data, thereby evaluating the model capabilities to reasonably reproduce atmospheric transport patterns. For modeled volcanic ash mass a considerable reduction of the atmospheric content already occurred by 10 August, the second day after the eruption in accordance with satellite observations. Gravitational settling is the most efficient removal process for volcanic ash mass, exceeding dry and wet deposition by far. Assuming an ash volume of 0.3 km3 released during the eruption of Kasatochi volcano and a median ash particle diameter of 4 μm, the mass of volcanic ash removed at ground within the 0.1 mm isopach covers an area of 7.6 × 105 km2 over the NE Pacific Ocean and makes up 49% of the removed material out of the atmosphere. The amount of ash and that of iron attached to it is sufficient to explain measured seawater CO2 decrease at the ocean station Papa in August 2008 induced by iron fertilization and subsequent phytoplankton production.

Thermal precursors in satellite images of the 1999 eruption of Shishaldin Volcano

NASA Astrophysics Data System (ADS)

Dehn, Jonathan; Dean, Kenneson; Engle, Kevin; Izbekov, Pavel

2002-07-01

Shishaldin Volcano, Unimak Island Alaska, began showing signs of thermal unrest in satellite images on 9 February 1999. A thermal anomaly and small steam plume were detected at the summit of the volcano in short-wave thermal infrared AVHRR (advanced very high resolution radiometer) satellite data. This was followed by over 2 months of changes in the observed thermal character of the volcano. Initially, the thermal anomaly was only visible when the satellite passed nearly directly over the volcano, suggesting a hot source deep in the central crater obscured from more oblique satellite passes. The "zenith angle" needed to see the anomaly increased with time, presumably as the thermal source rose within the conduit. Based on this change, an ascent rate of ca. 14 m per day for the thermal source was estimated, until it reached the summit on around 21 March. It is thought that Strombolian activity began around this time. The precursory activity culminated in a sub-Plinian eruption on 19 April, ejecting ash to over 45,000 ft. (13,700 m). The thermal energy output through the precursory period was calculated based on geometric constraints unique to Shishaldin. These calculations show fluctuations that can be tied to changes in the eruptive character inferred from seismic records and later geologic studies. The remote location of this volcano made satellite images a necessary observation tool for this eruption. To date, this is the longest thermal precursory activity preceding a sub-Plinian eruption recorded by satellite images in the region. This type of thermal monitoring of remote volcanoes is central in the efforts of the Alaska Volcano Observatory to provide timely warnings of volcanic eruption, and mitigate their associated hazards to air-traffic and local residents.

Human survival in volcanic eruptions: Thermal injuries in pyroclastic surges, their causes, prognosis and emergency management.

PubMed

Baxter, Peter J; Jenkins, Susanna; Seswandhana, Rosadi; Komorowski, Jean-Christophe; Dunn, Ken; Purser, David; Voight, Barry; Shelley, Ian

2017-08-01

This study of burns patients from two eruptions of Merapi volcano, Java, in 1994 and 2010, is the first detailed analysis to be reported of thermal injuries in a large series of hospitalised victims of pyroclastic surges, one of the most devastating phenomena in explosive eruptions. Emergency planners in volcanic crises in populated areas have to integrate the health sector into disaster management and be aware of the nature of the surge impacts and the types of burns victims to be expected in a worst scenario, potentially in numbers and in severity that would overwhelm normal treatment facilities. In our series, 106 patients from the two eruptions were treated in the same major hospital in Yogyakarta and a third of these survived. Seventy-eight per cent were admitted with over 40% TBSA (total body surface area) burns and around 80% of patients were suspected of having at least some degree of inhalation injury as well. Thirty five patients suffered over 80% TBSA burns and only one of these survived. Crucially, 45% of patients were in the 40-79% TBSA range, with most suspected of suffering from inhalation injury, for whom survival was most dependent on the hospital treatment they received. After reviewing the evidence from recent major eruptions and outlining the thermal hazards of surges, we relate the type and severity of the injuries of these patients to the temperatures and dynamics of the pyroclastic surges, as derived from the environmental impacts and associated eruption processes evaluated in our field surveys and interviews conducted by our multi-disciplinary team. Effective warnings, adequate evacuation measures, and political will are all essential in volcanic crises in populated areas to prevent future catastrophes on this scale. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Lessons learned from the 2010 evacuations at Merapi volcano

NASA Astrophysics Data System (ADS)

Mei, Estuning Tyas Wulan; Lavigne, Franck; Picquout, Adrien; de Bélizal, Edouard; Brunstein, Daniel; Grancher, Delphine; Sartohadi, Junun; Cholik, Noer; Vidal, Céline

2013-07-01

The rapid onset and large magnitude of the 2010 eruption of Merapi posed significant challenges for evacuations and resulted in a peak number of almost 400,000 Internally Displaced Persons (IDPs). A pre-existing hazard map and an evacuation plan based on the relatively small magnitude of previous eruptions of the 20th century were utilized by emergency officials during the initial phase of the eruption (25 October-3 November, 2010). However, when the magnitude of the eruption increased greatly on 3-5 November 2010, the initial evacuation plan had to be abandoned as danger zones were expanded rapidly and the scale and pace of the evacuation increased dramatically. Fortunately, orders to evacuate were communicated quickly through a variety of communication methods and as a result many thousands of lives were saved. However, there were also problems that resulted from this rapid and larger-than-expected evacuation; and there were lessons learned that can improve future mass evacuations at Merapi and other volcanoes. We analyzed the results of 1969 questionnaires and conducted a series of interviews with community leaders and emergency officials. Results were compiled for periods both during and after the 2010 eruption. Our results show that: (1) trust in the Indonesian government and volcanologists was very high after the eruption; (2) multiple modes of communication were used to relay warnings and evacuation orders; (3) 50% to 70% of IDPs returned to the danger zone during the crisis despite evacuation orders; (4) preparation before the eruption was critical to the successes and included improvements to roads and education programs, (5) public education about hazards and evacuation protocols before the eruption was focused in the perceived highest danger zone where it was effective yet, confusion and loss of life in other areas demonstrated that education programs in all hazard zones are needed to prepare for larger-than-normal eruptions, and (6) improvements in registration of evacuees, in providing for livestock, and in activities and work programs in evacuation camps (as well as government restrictions and policy changes) are also needed to prevent evacuees from returning to their homes during the crisis period.

View of New Guinea Volcano as seen from STS-64

NASA Image and Video Library

1994-09-20

STS064-116-055 (20 Sept. 1994) --- Near the end of its mission, the crew aboard space shuttle Discovery was able to document the beginning of the second day of activity of the Rabaul volcano, on the east end of New Britain. On the morning of Sept. 19, 1994, two volcanic cones on the opposite sides of the 6-kilometer sea crater had begun to erupt with very little warning. Discovery flew just east of the eruption roughly 24 hours after it started and near the peak of its activity. The eruption, which sent a plume up to over 60,000 feet into the atmosphere, caused over 50,000 people to evacuate the area. Because winds were light at the time of the eruption, most of the ash was deposited in a region within 20 kilometers of the eruption zone. This photo shows the large white billowing eruption plume is carried in a westerly direction by the weak prevailing winds. At the base of the eruption column is a layer of yellow-brown ash being distributed by lower level winds. A sharp boundary moving outward from the center of the eruption in the lower cloud is a pulse of laterally-moving ash which results from a volcanic explosion. Geologists theorize that the large white column and the lower gray cloud are likely from the two main vents on each side of the harbor. The cloud-covered island in the foreground is New Ireland. The bay and harbor of Rabaul are covered with a layer of ash, possibly partly infilled with volcanic material. Matupit Island and the airport runway have disappeared into the bay. More than a meter of ash has fallen upon the city of Rabaul. Up to five vents were reported to have erupted at once, including the cones Vulcan and Tavurvur, which are opposites of the harbor as well as new vents below the bay. Half of the Vulcan cone has collapsed into the sea. The extra day in space due to bad weather at the landing site afforded the crew the opportunity for both still and video coverage of the event. Photo credit: NASA or National Aeronautics and Space Administration

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.

Probabilistic short-term volcanic hazard in phases of unrest: A case study for tephra fallout

NASA Astrophysics Data System (ADS)

Selva, Jacopo; Costa, Antonio; Sandri, Laura; Macedonio, Giovanni; Marzocchi, Warner

2014-12-01

During volcanic crises, volcanologists estimate the impact of possible imminent eruptions usually through deterministic modeling of the effects of one or a few preestablished scenarios. Despite such an approach may bring an important information to the decision makers, the sole use of deterministic scenarios does not allow scientists to properly take into consideration all uncertainties, and it cannot be used to assess quantitatively the risk because the latter unavoidably requires a probabilistic approach. We present a model based on the concept of Bayesian event tree (hereinafter named BET_VH_ST, standing for Bayesian event tree for short-term volcanic hazard), for short-term near-real-time probabilistic volcanic hazard analysis formulated for any potential hazardous phenomenon accompanying an eruption. The specific goal of BET_VH_ST is to produce a quantitative assessment of the probability of exceedance of any potential level of intensity for a given volcanic hazard due to eruptions within restricted time windows (hours to days) in any area surrounding the volcano, accounting for all natural and epistemic uncertainties. BET_VH_ST properly assesses the conditional probability at each level of the event tree accounting for any relevant information derived from the monitoring system, theoretical models, and the past history of the volcano, propagating any relevant epistemic uncertainty underlying these assessments. As an application example of the model, we apply BET_VH_ST to assess short-term volcanic hazard related to tephra loading during Major Emergency Simulation Exercise, a major exercise at Mount Vesuvius that took place from 19 to 23 October 2006, consisting in a blind simulation of Vesuvius reactivation, from the early warning phase up to the final eruption, including the evacuation of a sample of about 2000 people from the area at risk. The results show that BET_VH_ST is able to produce short-term forecasts of the impact of tephra fall during a rapidly evolving crisis, accurately accounting for and propagating all uncertainties and enabling rational decision making under uncertainty.

Volcanic-Ash Hazards to Aviation—Changes and Challenges since the 2010 Eruption of Eyjafjallajökull, Iceland

NASA Astrophysics Data System (ADS)

Guffanti, M.; Tupper, A.; Mastin, L. G.; Lechner, P.

2012-12-01

In response to the severe disruptions to civil aviation that resulted from atmospheric transport of ash from the eruption of Eyjafjallajökull volcano in Iceland in April and May 2010, the International Civil Aviation Organization (ICAO) quickly formed the International Volcanic Ash Task Force (IVATF), charging it to support the accelerated development of a global risk-management framework for volcanic-ash hazards to aviation. Recognizing the need for scientifically based advice on best methods to detect ash in the atmosphere and depict zones of hazardous airspace, the IVATF sought input from the global scientific community, primarily by means of the Volcanic Ash Scientific Advisory Group which was established in May 2010 by the World Meteorological Organization (WMO) and International Union of Geodesy and Geophysics to serve as a scientific resource for ICAO. The IVATF finished its work in June 2012 (see http://www.icao.int/safety/meteorology/ivatf/Pages/default.aspx for a record of its results). A major science-based outcome is that production of charts depicting areas of airspace expected to have specific ash-concentration values (e.g. <0.2, 0.2-2, 2-4, >4 mg/cu. m) will not be required of the world's nine Volcanic Ash Advisory Centers (VAACs). The VAACs are responsible for issuing warning information to the aviation sector regarding ash-cloud position and expected movement. Forecast concentrations in these charts are based primarily on dispersion models that have at least an order of magnitude in uncertainty in their output and therefore do not delineate hazardous airspace with the level of confidence needed by the aviation sector. The recommended approach to improving model-forecast accuracy is to assimilate diverse observations (e.g., satellite thermal-infrared measurements, lidar, radar, direct airborne sampling, visual sightings, etc.) into model simulations; doing that during an eruption in the demanding environment of aviation operations is a substantial challenge. A significant post-Eyjafjallajökull change has been renewed interest of the airline sector in the issue of ash hazards to aviation. Whereas it is accepted that flight into young, dense ash clouds is dangerous, many equipment manufacturers and airline operators view that dilute ash clouds (ash concentrations < ~2 mg/cu. m) can be transited without immediate safety impacts. This calls into question the long-standing mitigation strategy of complete ash avoidance. Consequently, entities under the ICAO and WMO banners, including the VAACs, are being challenged to provide more than qualitative "ash/no ash" depictions of affected airspace, while the aviation industry is being challenged to more fully specify what ash exposures cause economic as well as safety-related damage to aircraft. In the aftermath of the Eyjafjallajökull eruption, ICAO's global aviation-warning system of eruption reporting, ash cloud detecting and forecasting, and specialized messaging, implemented after highly damaging encounters of aircraft with ash clouds in the 1980's and 1990's, is still in place, but with renewed focus among all stakeholders on improving how hazardous airspace is defined and communicated.

Volcanic ash hazards and aviation risk: Chapter 4

USGS Publications Warehouse

Guffanti, Marianne C.; Tupper, Andrew C.

2015-01-01

The risks to safe and efficient air travel from volcanic-ash hazards are well documented and widely recognized. Under the aegis of the International Civil Aviation Organization, globally coordinated mitigation procedures are in place to report explosive eruptions, detect airborne ash clouds and forecast their expected movement, and issue specialized messages to warn aircraft away from hazardous airspace. This mitigation framework is based on the integration of scientific and technical capabilities worldwide in volcanology, meteorology, and atmospheric physics and chemistry. The 2010 eruption of Eyjafjallajökull volcano in Iceland, which led to a nearly week-long shutdown of air travel into and out of Europe, has prompted the aviation industry, regulators, and scientists to work more closely together to improve how hazardous airspace is defined and communicated. Volcanic ash will continue to threaten aviation and scientific research will continue to influence the risk-mitigation framework.

Use of new and old technologies and methods by the Alaska Volcano Observatory during the 2006 eruption of Augustine Volcano, Alaska

NASA Astrophysics Data System (ADS)

Murray, T. L.; Nye, C. J.; Eichelberger, J. C.

2006-12-01

The recent eruption of Augustine Volcano was the first significant volcanic event in Cook Inlet, Alaska since 1992. In contrast to eruptions at remote Alaskan volcanoes that mainly affect aviation, ash from previous eruptions of Augustine has affected communities surrounding Cook Inlet, home to over half of Alaska's population. The 2006 eruption validated much of AVO's advance preparation, underscored the need to quickly react when a problem or opportunity developed, and once again demonstrated that while technology provides us with wonderful tools, professional relationships, especially during times of crisis, are still important. Long-term multi-parametric instrumental monitoring and background geological and geophysical studies represent the most fundamental aspect of preparing for any eruption. Once significant unrest was detected, AVO augmented the existing real-time network with additional instrumentation including web cameras. GPS and broadband seismometers that recorded data on site were also quickly installed as their data would be crucial for post-eruption research. Prior to 2006, most of most of AVO's eruption response plans and protocols had focused on the threat to aviation rather than ground-based hazards. However, the relationships and protocols developed for the aviation threat were sufficient to be adapted to the ash fall hazard, though it is apparent that more work, both scientific and with response procedures, is needed. Similarly, protocols were quickly developed for warning of a flank- collapse induced tsunami. Information flow within the observatory was greatly facilitated by an internal web site that had been developed and refined specifically for eruption response. Because AVO is a partnership of 3 agencies (U.S. Geological Survey, University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys) with offices in both Fairbanks and Anchorage, web and internet-facing data servers provided reliable and rapid access to much of the information to each office. Information flow between the observatory and the public and emergency responders was accomplished through the AVO public web site, e-mail, faxes, public meetings, and frequent phone calls. AVO's newly renovated Operations Center in Anchorage provided a central 24/7 site to both receive and disseminate information and conduct media interviews. With selected real time data sets and hourly updates provided on the AVO public web site, many emergency responders and even private citizens tracked the eruption in near real time themselves.

Volcanic hazards at Mount Rainier, Washington

USGS Publications Warehouse

Crandell, Dwight Raymond; Mullineaux, Donal Ray

1967-01-01

Mount Rainier is a large stratovolcano of andesitic rock in the Cascade Range of western Washington. Although the volcano as it now stands was almost completely formed before the last major glaciation, geologic formations record a variety of events that have occurred at the volcano in postglacial time. Repetition of some of these events today without warning would result in property damage and loss of life on a catastrophic scale. It is appropriate, therefore, to examine the extent, frequency, and apparent origin of these phenomena and to attempt to predict the effects on man of similar events in the future. The present report was prompted by a contrast that we noted during a study of surficial geologic deposits in Mount Rainier National Park, between the present tranquil landscape adjacent to the volcano and the violent events that shaped parts of that same landscape in the recent past. Natural catastrophes that have geologic causes - such as eruptions, landslides, earthquakes, and floods - all too often are disastrous primarily because man has not understood and made allowance for the geologic environment he occupies. Assessment of the potential hazards of a volcanic environment is especially difficult, for prediction of the time and kind of volcanic activity is still an imperfect art, even at active volcanoes whose behavior has been closely observed for many years. Qualified predictions, however, can be used to plan ways in which hazards to life and property can be minimized. The prediction of eruptions is handicapped because volcanism results from conditions far beneath the surface of the earth, where the causative factors cannot be seen and, for the most part, cannot be measured. Consequently, long-range predictions at Mount Rainier can be based only on the past behavior of the volcano, as revealed by study of the deposits that resulted from previous eruptions. Predictions of this sort, of course, cannot be specific as to time and locale of future events, and clearly are valid only if the past behavior is, as we believe, a reliable guide. The purpose of this report is to infer the events recorded by certain postglacial deposits at Mount Rainier and to suggest what bearing similar events in the future might have on land use within and near the park. In addition, table 2 (page 22) gives possible warning signs of an impending eruption. We want to increase man's understanding of a possibly hazardous geologic environment around Mount Rainier volcano, yet we do not wish to imply for certain that the hazards described are either immediate or inevitable. However, we do believe that hazards exist, that some caution is warranted, and that some major hazards can be avoided by judicious planning. Most of the events with which we are concerned are sporadic phenomena that have resulted directly or indirectly from volcanic eruptions. Although no eruptions (other than steam emission) of the volcano in historic time are unequivocally known (Hopson and others, 1962), pyroclastic (air-laid) deposits of pumice and rock debris attest to repeated, widely spaced eruptions during the 10,000 years or so of postglacial time. In addition, the constituents of some debris flows indicate an origin during eruptions of molten rock; other debris flows, because of their large size and constituents, are believed to have been caused by steam explosions. Some debris flows, however, are not related to volcanism at all.

Optical properties of volcanic ash: improving remote sensing observations.

NASA Astrophysics Data System (ADS)

Whelley, Patrick; Colarco, Peter; Aquila, Valentina; Krotkov, Nickolay; Bleacher, Jake; Garry, Brent; Young, Kelsey; Rocha Lima, Adriana; Martins, Vanderlei; Carn, Simon

2016-04-01

Many times each year explosive volcanic eruptions loft ash into the atmosphere. Global travel and trade rely on aircraft vulnerable to encounters with airborne ash. Volcanic ash advisory centers (VAACs) rely on dispersion forecasts and satellite data to issue timely warnings. To improve ash forecasts model developers and satellite data providers need realistic information about volcanic ash microphysical and optical properties. In anticipation of future large eruptions we can study smaller events to improve our remote sensing and modeling skills so when the next Pinatubo 1991 or larger eruption occurs, ash can confidently be tracked in a quantitative way. At distances >100km from their sources, drifting ash plumes, often above meteorological clouds, are not easily detected from conventional remote sensing platforms, save deriving their quantitative characteristics, such as mass density. Quantitative interpretation of these observations depends on a priori knowledge of the spectral optical properties of the ash in UV (>0.3μm) and TIR wavelengths (>10μm). Incorrect assumptions about the optical properties result in large errors in inferred column mass loading and size distribution, which misguide operational ash forecasts. Similarly, simulating ash properties in global climate models also requires some knowledge of optical properties to improve aerosol speciation.

The Origin of the "Seasons" in Space Weather

NASA Astrophysics Data System (ADS)

Dikpati, Mausumi; Cally, Paul S.; McIntosh, Scott W.; Heifetz, Eyal

2017-11-01

Powerful `space weather' events caused by solar activity pose serious risks to human health, safety, economic activity and national security. Spikes in deaths due to heart attacks, strokes and other diseases occurred during prolonged power outages. Currently it is hard to prepare for and mitigate the impact of space weather because it is impossible to forecast the solar eruptions that can cause these terrestrial events until they are seen on the Sun. However, as recently reported in Nature, eruptive events like coronal mass ejections and solar flares, are organized into quasi-periodic "seasons", which include enhanced bursts of eruptions for several months, followed by quiet periods. We explored the dynamics of sunspot-producing magnetic fields and discovered for the first time that bursty and quiet seasons, manifested in surface magnetic structures, can be caused by quasi-periodic energy-exchange among magnetic fields, Rossby waves and differential rotation of the solar interior shear-layer (called tachocline). Our results for the first time provide a quantitative physical mechanism for forecasting the strength and duration of bursty seasons several months in advance, which can greatly enhance our ability to warn humans about dangerous solar bursts and prevent damage to satellites and power stations from space weather events.

A Summary of the History and Achievements of the Alaska Volcano Observatory.

NASA Astrophysics Data System (ADS)

Smith, R. W.

2008-12-01

Volcanoes of the Aleutian Islands, Kamchatka and the Kurile Islands present a serious threat to aviation on routes from North America to the Far East. On March 27, 1986, an eruption of Augustine Volcano deposited ash over Anchorage and disrupted air traffic in south-central Alaska. The consequences of the colocation of an active volcano and the largest city in Alaska were clearly evident. That event led to a three-way partnership between the US Geological Survey, the University of Alaska Geophysical Institute and the Alaska State Division of Geological and Geophysical Surveys that now maintains a continuous watch through ground instrumentation and satellite imagery providing data from which warnings of eruptions can be issued to airline operators and pilots. The eruption of Redoubt Volcano in December 1989 was AVO's first big test. It spewed volcanic ash to a height of 14,000 m (45,000 feet) and managed to catch KLM 867, a Boeing 747 aircraft in its plume under dark conditions while approaching Anchorage Airport. Further details of the early days of the Alaska Volcano Observatory will be described, along with its recent successes and challenges.

The Origin of the "Seasons" in Space Weather.

PubMed

Dikpati, Mausumi; Cally, Paul S; McIntosh, Scott W; Heifetz, Eyal

2017-11-07

Powerful 'space weather' events caused by solar activity pose serious risks to human health, safety, economic activity and national security. Spikes in deaths due to heart attacks, strokes and other diseases occurred during prolonged power outages. Currently it is hard to prepare for and mitigate the impact of space weather because it is impossible to forecast the solar eruptions that can cause these terrestrial events until they are seen on the Sun. However, as recently reported in Nature, eruptive events like coronal mass ejections and solar flares, are organized into quasi-periodic "seasons", which include enhanced bursts of eruptions for several months, followed by quiet periods. We explored the dynamics of sunspot-producing magnetic fields and discovered for the first time that bursty and quiet seasons, manifested in surface magnetic structures, can be caused by quasi-periodic energy-exchange among magnetic fields, Rossby waves and differential rotation of the solar interior shear-layer (called tachocline). Our results for the first time provide a quantitative physical mechanism for forecasting the strength and duration of bursty seasons several months in advance, which can greatly enhance our ability to warn humans about dangerous solar bursts and prevent damage to satellites and power stations from space weather events.

Asia-Pacific Region Global Earthquake and Volcanic Eruption Risk Management (G-EVER) project and a next-generation real-time volcano hazard assessment system

NASA Astrophysics Data System (ADS)

Takarada, S.

2012-12-01

The first Workshop of Asia-Pacific Region Global Earthquake and Volcanic Eruption Risk Management (G-EVER1) was held in Tsukuba, Ibaraki Prefecture, Japan from February 23 to 24, 2012. The workshop focused on the formulation of strategies to reduce the risks of disasters worldwide caused by the occurrence of earthquakes, tsunamis, and volcanic eruptions. More than 150 participants attended the workshop. During the workshop, the G-EVER1 accord was approved by the participants. The Accord consists of 10 recommendations like enhancing collaboration, sharing of resources, and making information about the risks of earthquakes and volcanic eruptions freely available and understandable. The G-EVER Hub website (http://g-ever.org) was established to promote the exchange of information and knowledge among the Asia-Pacific countries. Several G-EVER Working Groups and Task Forces were proposed. One of the working groups was tasked to make the next-generation real-time volcano hazard assessment system. The next-generation volcano hazard assessment system is useful for volcanic eruption prediction, risk assessment, and evacuation at various eruption stages. The assessment system is planned to be developed based on volcanic eruption scenario datasets, volcanic eruption database, and numerical simulations. Defining volcanic eruption scenarios based on precursor phenomena leading up to major eruptions of active volcanoes is quite important for the future prediction of volcanic eruptions. Compiling volcanic eruption scenarios after a major eruption is also important. A high quality volcanic eruption database, which contains compilations of eruption dates, volumes, and styles, is important for the next-generation volcano hazard assessment system. The volcanic eruption database is developed based on past eruption results, which only represent a subset of possible future scenarios. Hence, different distributions from the previous deposits are mainly observed due to the differences in vent position, volume, eruption rate, wind directions and topography. Therefore, numerical simulations with controlled parameters are needed for more precise volcanic eruption predictions. The use of the next-generation system should enable the visualization of past volcanic eruptions datasets such as distributions, eruption volumes and eruption rates, on maps and diagrams using timeline and GIS technology. Similar volcanic eruptions scenarios should be easily searchable from the eruption database. Using the volcano hazard assessment system, prediction of the time and area that would be affected by volcanic eruptions at any locations near the volcano should be possible, using numerical simulations. The system should estimate volcanic hazard risks by overlaying the distributions of volcanic deposits on major roads, houses and evacuation areas using a GIS enabled systems. Probabilistic volcanic hazards maps in active volcano sites should be made based on numerous numerical simulations. The next-generation real-time hazard assessment system would be implemented with user-friendly interface, making the risk assessment system easily usable and accessible online.

Use of NWSChat (Instant Messaging program) as a coordination tool during the 2009 Redoubt Eruptions

NASA Astrophysics Data System (ADS)

Osiensky, J. M.; Jones, D.

2009-12-01

The National Weather Service (NWS) based Instant Messaging service, NWSChat, is used for sharing critical warning decision expertise and other types of significant weather information between the NWS and partners in all levels of government, emergency managers, and the media. NWSChat allows multiple users to send messages to each other in forums known as “chat rooms.” NWSChat is used to enhance decision support during discussions related to high impact weather events, and improve outreach and real-time feed-back from partners. This information is exchanged with the media and emergency response community, who in turn play a key role in communicating the NWS’s hazardous weather messages to the public. NWSChat also provides media and emergency response partners with the ability to communicate significant event reports back to NWS operational personnel, who in turn utilize the information to make effective warning decisions. NWS partners can also use the Service as an efficient means of seeking clarifications and enhancements to the communication stream originating from the NWS. NWSChat will include a wide variety of types of information. Some of this information will include contents of official NWS products available through other NWS systems and thus available to the public. However, other NWSChat content may include preliminary data which has not been screened by NWS for accuracy or applicability; highly technical discussions, some of them speculative, regarding atmospheric or other environmental conditions; and other types of information not intended for a general audience. NWSChat participants are expected to avoid release of information to a broader audience that might be misinterpreted or cause confusion. NWSChat is an enhancement to communications between the NWS and its partners, and is not intended to replace official NWS products or official means of communications. In March 2009, the NWS stood up a Redoubt chatroom just prior to the first eruption. Those wishing to gain access to the chat room are asked to complete a short training module and send a request to a system administrator. The chat room is used by a number of government partners (federal, state, local) and non-government partners to exchange critical information during the Redoubt events. Although the chatroom is considered experimental (non-operational) at this time, the Redoubt chat room was the first time that NWSChat was used during a real time high impact event in Alaska. A formal service assessment was performed by a team from the NWS and a societal impacts specialist from academia. The draft service assessment includes information on the use of NWSChat during the Redoubt event and how it was beneficial in the exchange of important information during the eruptive events.

Tsunami evacuation mathematical model for the city of Padang

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

Kusdiantara, R.; Hadianti, R.; Badri Kusuma, M. S.

2012-05-22

Tsunami is a series of wave trains which travels with high speed on the sea surface. This traveling wave is caused by the displacement of a large volume of water after the occurrence of an underwater earthquake or volcano eruptions. The speed of tsunami decreases when it reaches the sea shore along with the increase of its amplitudes. Two large tsunamis had occurred in the last decades in Indonesia with huge casualties and large damages. Indonesian Tsunami Early Warning System has been installed along the west coast of Sumatra. This early warning system will give about 10-15 minutes to evacuatemore » people from high risk regions to the safe areas. Here in this paper, a mathematical model for Tsunami evacuation is presented with the city of Padang as a study case. In the model, the safe areas are chosen from the existing and selected high rise buildings, low risk region with relatively high altitude and (proposed to be built) a flyover ring road. Each gathering points are located in the radius of approximately 1 km from the ring road. The model is formulated as an optimization problem with the total normalized evacuation time as the objective function. The constraints consist of maximum allowable evacuation time in each route, maximum capacity of each safe area, and the number of people to be evacuated. The optimization problem is solved numerically using linear programming method with Matlab. Numerical results are shown for various evacuation scenarios for the city of Padang.« less

49 CFR 234.225 - Activation of warning system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Activation of warning system. 234.225 Section 234....225 Activation of warning system. A highway-rail grade crossing warning system shall be maintained to activate in accordance with the design of the warning system, but in no event shall it provide less than 20...

49 CFR 234.225 - Activation of warning system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Activation of warning system. 234.225 Section 234....225 Activation of warning system. A highway-rail grade crossing warning system shall be maintained to activate in accordance with the design of the warning system, but in no event shall it provide less than 20...

49 CFR 234.225 - Activation of warning system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Activation of warning system. 234.225 Section 234....225 Activation of warning system. A highway-rail grade crossing warning system shall be maintained to activate in accordance with the design of the warning system, but in no event shall it provide less than 20...

A new method for monitoring global volcanic activity. [Alaska, Hawaii, Washington, California, Iceland, Guatemala, El Salvador, and Nicaragua

NASA Technical Reports Server (NTRS)

Ward, P. L.; Endo, E.; Harlow, D. H.; Allen, R.; Eaton, J. P.

1974-01-01

The ERTS Data Collection System makes it feasible for the first time to monitor the level of activity at widely separated volcanoes and to relay these data rapidly to one central office for analysis. While prediction of specific eruptions is still an evasive goal, early warning of a reawakening of quiescent volcanoes is now a distinct possibility. A prototypical global volcano surveillance system was established under the ERTS program. Instruments were installed in cooperation with local scientists on 15 volcanoes in Alaska, Hawaii, Washington, California, Iceland, Guatemala, El Salvador and Nicaragua. The sensors include 19 seismic event counters that count four different sizes of earthquakes and six biaxial borehole tiltmeters that measure ground tilt with a resolution of 1 microradian. Only seismic and tilt data are collected because these have been shown in the past to indicate most reliably the level of volcano activity at many different volcanoes. Furthermore, these parameters can be measured relatively easily with new instrumentation.

Continuous monitoring of volcanoes with borehole strainmeters

NASA Astrophysics Data System (ADS)

Linde, Alan T.; Sacks, Selwyn

Monitoring of volcanoes using various physical techniques has the potential to provide important information about the shape, size and location of the underlying magma bodies. Volcanoes erupt when the pressure in a magma chamber some kilometers below the surface overcomes the strength of the intervening rock, resulting in detectable deformations of the surrounding crust. Seismic activity may accompany and precede eruptions and, from the patterns of earthquake locations, inferences may be made about the location of magma and its movement. Ground deformation near volcanoes provides more direct evidence on these, but continuous monitoring of such deformation is necessary for all the important aspects of an eruption to be recorded. Sacks-Evertson borehole strainmeters have recorded strain changes associated with eruptions of Hekla, Iceland and Izu-Oshima, Japan. Those data have made possible well-constrained models of the geometry of the magma reservoirs and of the changes in their geometry during the eruption. The Hekla eruption produced clear changes in strain at the nearest instrument (15 km from the volcano) starting about 30 minutes before the surface breakout. The borehole instrument on Oshima showed an unequivocal increase in the amplitude of the solid earth tides beginning some years before the eruption. Deformational changes, detected by a borehole strainmeter and a very long baseline tiltmeter, and corresponding to the remote triggered seismicity at Long Valley, California in the several days immediately following the Landers earthquake are indicative of pressure changes in the magma body under Long Valley, raising the question of whether such transients are of more general importance in the eruption process. We extrapolate the experience with borehole strainmeters to estimate what could be learned from an installation of a small network of such instruments on Mauna Loa. Since the process of conduit formation from the magma sources in Mauna Loa and other volcanic regions should be observable, continuous high sensitivity strain monitoring of volcanoes provides the potential to give short time warnings of impending eruptions. Current technology allows transmission and processing of rapidly sampled borehole strain data in real-time. Such monitoring of potentially dangerous volcanoes on a global scale would provide not only a wealth of scientific information but also significant social benefit, including the capability of diverting nearby in-flight aircraft.

New Guinea volcano (Rabaul) as seen from STS-64

NASA Image and Video Library

1994-09-29

STS064-116-064 (20 Sept. 1994) --- Near the end of the mission, the crew aboard space shuttle Discovery was able to document the beginning of the second day of activity of the Rabaul volcano, on the east end of New Britain. On the morning of Sept. 19, 1994, two volcanic cones on the opposite sides of the 6-kilometer sea crater had begun to erupt with very little warning. Discovery flew just east of the eruption roughly 24 hours after it started and near the peak of its activity. New Ireland, the cloud-covered area in the foreground, lies just east of Rabaul harbor. The eruption, which sent a plume up to over 60,000 feet into the atmosphere, caused over 50,000 people to evacuate the area. Because winds were light at the time of the eruption, most of the ash was deposited in a region within 20 kilometers of the eruption zone. This photo shows the large white billowing eruption plume is carried in a westerly direction by the weak prevailing winds. At the base of the eruption column is a layer of yellow-brown ash being distributed by lower level winds. A sharp boundary moving outward from the center of the eruption in the lower cloud is a pulse of laterally-moving ash which results from a volcanic explosion. Geologists theorize that the large white column and the lower gray cloud are likely from the two main vents on each side of the harbor. The bay and harbor of Rabaul are covered with a layer of ash, possibly partly infilled with volcanic material. Matupit Island and the airport runway have disappeared into the bay. More than a meter of ash has fallen upon the city of Rabaul. Up to five vents were reported to have erupted at once, including the two cones Vulcan and Tavurvur, which are opposites of the harbor as well as new vents below the bay. Half of the Vulcan cone has collapsed into the sea. The extra day in space due to bad weather at the landing site afforded the crew the opportunity for both still and video coverage of the event. Photo credit: NASA or National Aeronautics and Space Administration

Precursory diffuse CO2 and H2S emission signatures of the 2011-2012 El Hierro submarine eruption, Canary Islands

NASA Astrophysics Data System (ADS)

Pérez, Nemesio M.; Padilla, Germán D.; Padrón, Eleazar; Hernández, Pedro A.; Melián, Gladys V.; Barrancos, José; Dionis, Samara; Nolasco, Dácil; Rodríguez, Fátima; Calvo, David; Hernández, Íñigo

2012-08-01

On October 12, 2011, a submarine eruption began 2 km off the coast of La Restinga, south of El Hierro Island. CO2 and H2S soil efflux were continuously measured during the period of volcanic unrest by using the accumulation chamber method at two different geochemical stations, HIE01 and HIE07. Recorded CO2 and H2S effluxes showed precursory signals that preceded the submarine eruption. Beginning in late August, the CO2 efflux time series started increasing at a relatively constant rate over one month, reaching a maximum of 19 gm-2d-1 one week before the onset of the submarine volcanic eruption. The H2S efflux time series at HIE07 showed a pulse in H2S emission just one day before the initiation of the submarine eruption, reaching peak values of 42 mg m-2 d-1, 10 times the average H2S efflux recorded during the observation period. Since CO2 and H2S effluxes are strongly influenced by external factors, we applied a multiple regression analysis to remove their contribution. A statistical analysis showed that the long-term trend of the filtered data is well correlated with the seismic energy. We find that these geochemical stations are important monitoring sites for evaluating the volcanic activity of El Hierro and that they demonstrate the potential of applying continuous monitoring of soil CO2 and H2S efflux to improve and optimize the detection of early warning signals of future volcanic unrest episodes at El Hierro. Continuous diffuse degassing studies would likely prove useful for monitoring other volcanoes during unrest episodes.

The Contribution of GGOS to Understanding Dynamic Earth Processes

NASA Astrophysics Data System (ADS)

Gross, Richard

2017-04-01

Geodesy is the science of the Earth's shape, size, gravity and rotation, including their evolution in time. Geodetic observations play a major role in the solid Earth sciences because they are fundamental for the understanding and modeling of Earth system processes. Changes in the Earth's shape, its gravitational field, and its rotation are caused by external forces acting on the Earth system and internal processes involving mass transfer and exchange of angular and linear momentum. Thus, variations in these geodetic quantities of the Earth reflect and constrain mechanical and thermo-dynamic processes in the Earth system. Mitigating the impact on human life and property of natural hazards such as earthquakes, volcanic eruptions, debris flows, landslides, land subsidence, sea level change, tsunamis, floods, storm surges, hurricanes and extreme weather is an important scientific task to which geodetic observations make fundamental contributions. Geodetic observations can be used to monitor the pre-eruptive deformation of volcanoes and the pre-seismic deformation of earthquake fault zones, aiding in the issuance of volcanic eruption and earthquake warnings. They can also be used to rapidly estimate earthquake fault motion, aiding in the modeling of tsunami genesis and the issuance of tsunami warnings. Geodetic observations are also used in other areas of the Earth sciences, not just the solid Earth sciences. For example, geodesy contributes to atmospheric science by supporting both observation and prediction of the weather by geo-referencing meteorological observing data and by globally tracking change in stratospheric mass and lower tropospheric water vapor fields. Geodetic measurements of refraction profiles derived from satellite occultation data are routinely assimilated into numerical weather prediction models. Geodesy contributes to hydrologic studies by providing a unique global reference system for measurements of: sub-seasonal, seasonal and secular movements of continental and basin-scale water masses; loading and unloading of the land surface due to seasonal changes of groundwater; measurement of water level of major lakes and rivers by satellite altimetry; and improved digital terrain models as basis for flux modeling of surface water and flood modeling. Geodesy is crucial for cryospheric studies because of its ability to measure the motions of ice masses and changes in their volumes. Ice sheets, glaciers, and sea ice are intricately linked to the Earth's climate system. They store a record of past climate; they strongly affect surface energy budget, global water cycle, and sea-level change; and they are sensitive indicators of climate change. Geodesy is at the heart of all present-day ocean studies. Geodetic observations uniquely produce accurate, quantitative, and integrated observations of gravity, ocean circulation, sea surface height, ocean bottom pressure, and mass exchanges among the ocean, cryosphere, and land. Geodetic observations have made fundamental contributions to monitoring and understanding physical ocean processes. In particular, geodesy is the basic technique used to determine an accurate geoid model, allowing for the determination of absolute surface geostrophic currents, which are necessary to quantify heat transport of the ocean. Geodesy also provides the absolute reference for tide gauge measurements, allowing those measurements to be merged with satellite altimetric measurements to provide a coherent worldwide monitoring system for sea level change. In this presentation, selected examples of the contribution of geodetic observations to understanding the dynamic Earth system will be presented.

Airlock caution and warning system

NASA Technical Reports Server (NTRS)

Mayfield, W. J.; Cork, L. Z.; Malchow, R. G.; Hornback, G. L.

1972-01-01

Caution and warning system, used to monitor performance and warn of hazards or out-of-limit conditions on space vehicles, may have application to aircraft and railway transit systems. System consists of caution and warning subsystem and emergency subsystem.

Volcanic Alert System (VAS) developed during the (2011-2013) El Hierro (Canary Islands) volcanic process

NASA Astrophysics Data System (ADS)

Ortiz, Ramon; Berrocoso, Manuel; Marrero, Jose Manuel; Fernandez-Ros, Alberto; Prates, Gonçalo; De la Cruz-Reyna, Servando; Garcia, Alicia

2014-05-01

In volcanic areas with long repose periods (as El Hierro), recently installed monitoring networks offer no instrumental record of past eruptions nor experience in handling a volcanic crisis. Both conditions, uncertainty and inexperience, contribute to make the communication of hazard more difficult. In fact, in the initial phases of the unrest at El Hierro, the perception of volcanic risk was somewhat distorted, as even relatively low volcanic hazards caused a high political impact. The need of a Volcanic Alert System became then evident. In general, the Volcanic Alert System is comprised of the monitoring network, the software tools for the analysis of the observables, the management of the Volcanic Activity Level, and the assessment of the threat. The Volcanic Alert System presented here places special emphasis on phenomena associated to moderate eruptions, as well as on volcano-tectonic earthquakes and landslides, which in some cases, as in El Hierro, may be more destructive than an eruption itself. As part of the Volcanic Alert System, we introduce here the Volcanic Activity Level which continuously applies a routine analysis of monitoring data (particularly seismic and deformation data) to detect data trend changes or monitoring network failures. The data trend changes are quantified according to the Failure Forecast Method (FFM). When data changes and/or malfunctions are detected, by an automated watchdog, warnings are automatically issued to the Monitoring Scientific Team. Changes in the data patterns are then translated by the Monitoring Scientific Team into a simple Volcanic Activity Level, that is easy to use and understand by the scientists and technicians in charge for the technical management of the unrest. The main feature of the Volcanic Activity Level is its objectivity, as it does not depend on expert opinions, which are left to the Scientific Committee, and its capabilities for early detection of precursors. As a consequence of the El Hierro experience we consider the objectivity of the Volcanic Activity Level a powerful tool to focus the discussions in a Scientific Committee on the activity forecast and on the expected scenarios, rather than on the multiple explanations of the data fluctuations, which is one of the main sources of conflict in the Scientific Committee discussions. Although the Volcanic Alert System was designed specifically for the unrest episodes at El Hierro, the involved methodologies may be applied to other situations of unrest.

False alarms and missed events: the impact and origins of perceived inaccuracy in tornado warning systems.

PubMed

Ripberger, Joseph T; Silva, Carol L; Jenkins-Smith, Hank C; Carlson, Deven E; James, Mark; Herron, Kerry G

2015-01-01

Theory and conventional wisdom suggest that errors undermine the credibility of tornado warning systems and thus decrease the probability that individuals will comply (i.e., engage in protective action) when future warnings are issued. Unfortunately, empirical research on the influence of warning system accuracy on public responses to tornado warnings is incomplete and inconclusive. This study adds to existing research by analyzing two sets of relationships. First, we assess the relationship between perceptions of accuracy, credibility, and warning response. Using data collected via a large regional survey, we find that trust in the National Weather Service (NWS; the agency responsible for issuing tornado warnings) increases the likelihood that an individual will opt for protective action when responding to a hypothetical warning. More importantly, we find that subjective perceptions of warning system accuracy are, as theory suggests, systematically related to trust in the NWS and (by extension) stated responses to future warnings. The second half of the study matches survey data against NWS warning and event archives to investigate a critical follow-up question--Why do some people perceive that their warning system is accurate, whereas others perceive that their system is error prone? We find that subjective perceptions are--in part-a function of objective experience, knowledge, and demographic characteristics. When considered in tandem, these findings support the proposition that errors influence perceptions about the accuracy of warning systems, which in turn impact the credibility that people assign to information provided by systems and, ultimately, public decisions about how to respond when warnings are issued. © 2014 Society for Risk Analysis.

Crash Warning Interface Metrics: Final Report

DOT National Transportation Integrated Search

2011-08-01

The Crash Warning Interface Metrics (CWIM) project addressed issues of the driver-vehicle interface (DVI) for Advanced Crash Warning Systems (ACWS). The focus was on identifying the effects of certain warning system features (e.g., warning modality) ...

The role of the large-scale coronal magnetic field in the eruption of prominence/cavity systems

NASA Astrophysics Data System (ADS)

de Toma, G.; Gibson, S. E.; Fan, Y.; Torok, T.

2013-12-01

Prominence/cavity systems are large-scale coronal structures that can live for many weeks and even months and often end their life in the form of large coronal eruptions. We investigate the role of the surrounding ambient coronal field in stabilizing these systems against eruption. In particular, we examine the extent to which the decline with height of the external coronal magnetic field influences the evolution of these coronal systems and their likelihood to erupt. We study prominence/cavity systems during the rising phase of cycle 24 in 2010-2013, when a significant number of CMEs were associated with polar crown or large filament eruptions. We use EUV observations from SDO/AIA to identify stable and eruptive coronal cavities, and SDO/HMI magnetograms as boundary conditions to PFSS extrapolation to derive the ambient coronal field. We compute the decay index of the potential field for the two groups and find that systematic differences exist between eruptive and non-eruptive systems.

Volcanic alert system (VAS) developed during the 2011-2014 El Hierro (Canary Islands) volcanic process

NASA Astrophysics Data System (ADS)

García, Alicia; Berrocoso, Manuel; Marrero, José M.; Fernández-Ros, Alberto; Prates, Gonçalo; De la Cruz-Reyna, Servando; Ortiz, Ramón

2014-06-01

The 2011 volcanic unrest at El Hierro Island illustrated the need for a Volcanic Alert System (VAS) specifically designed for the management of volcanic crises developing after long repose periods. The VAS comprises the monitoring network, the software tools for analysis of the monitoring parameters, the Volcanic Activity Level (VAL) management, and the assessment of hazard. The VAS presented here focuses on phenomena related to moderate eruptions, and on potentially destructive volcano-tectonic earthquakes and landslides. We introduce a set of new data analysis tools, aimed to detect data trend changes, as well as spurious signals related to instrumental failure. When data-trend changes and/or malfunctions are detected, a watchdog is triggered, issuing a watch-out warning (WOW) to the Monitoring Scientific Team (MST). The changes in data patterns are then translated by the MST into a VAL that is easy to use and understand by scientists, technicians, and decision-makers. Although the VAS was designed specifically for the unrest episodes at El Hierro, the methodologies may prove useful at other volcanic systems.

Effectiveness of safety belt warning and interlock systems

DOT National Transportation Integrated Search

1973-04-01

Rental cars in Fayetteville, N.C., were equipped with four seat belt and warning systems: (Phase I) detachable shoulder and lap belt, no warning system; (Phase II) detachable shoulder and lap belt, warning system (January 1, 1972 standard); (Phase II...

Volcano-tectonic earthquakes: A new tool for estimating intrusive volumes and forecasting eruptions

NASA Astrophysics Data System (ADS)

White, Randall; McCausland, Wendy

2016-01-01

We present data on 136 high-frequency earthquakes and swarms, termed volcano-tectonic (VT) seismicity, which preceded 111 eruptions at 83 volcanoes, plus data on VT swarms that preceded intrusions at 21 other volcanoes. We find that VT seismicity is usually the earliest reported seismic precursor for eruptions at volcanoes that have been dormant for decades or more, and precedes eruptions of all magma types from basaltic to rhyolitic and all explosivities from VEI 0 to ultraplinian VEI 6 at such previously long-dormant volcanoes. Because large eruptions occur most commonly during resumption of activity at long-dormant volcanoes, VT seismicity is an important precursor for the Earth's most dangerous eruptions. VT seismicity precedes all explosive eruptions of VEI ≥ 5 and most if not all VEI 4 eruptions in our data set. Surprisingly we find that the VT seismicity originates at distal locations on tectonic fault structures at distances of one or two to tens of kilometers laterally from the site of the eventual eruption, and rarely if ever starts beneath the eruption site itself. The distal VT swarms generally occur at depths almost equal to the horizontal distance of the swarm from the summit out to about 15 km distance, beyond which hypocenter depths level out. We summarize several important characteristics of this distal VT seismicity including: swarm-like nature, onset days to years prior to the beginning of magmatic eruptions, peaking of activity at the time of the initial eruption whether phreatic or magmatic, and large non-double couple component to focal mechanisms. Most importantly we show that the intruded magma volume can be simply estimated from the cumulative seismic moment of the VT seismicity from: Log10 V = 0.77 Log ΣMoment - 5.32, with volume, V, in cubic meters and seismic moment in Newton meters. Because the cumulative seismic moment can be approximated from the size of just the few largest events, and is quite insensitive to precise locations, the intruded magma volume can be quickly and easily estimated with few short-period seismic stations. Notable cases in which distal VT events preceded eruptions at long-dormant volcanoes include: Nevado del Ruiz (1984-1985), Pinatubo (1991), Unzen (1989-1995), Soufriere Hills (1995), Shishaldin (1989-1999), Tacana' (1985-1986), Pacaya (1980-1984), Rabaul (1994), and Cotopaxi (2001). Additional cases are recognized at frequently active volcanoes including Popocateptl (2001-2003) and Mauna Loa (1984). We present four case studies (Pinatubo, Soufriere Hills, Unzen, and Tacana') in which we demonstrate the above mentioned VT characteristics prior to eruptions. Using regional data recorded by NEIC, we recognized in near-real time that a huge distal VT swarm was occurring, deduced that a proportionately huge magmatic intrusion was taking place beneath the long dormant Sulu Range, New Britain Island, Papua New Guinea, that it was likely to lead to eruptive activity, and warned Rabaul Volcano Observatory days before a phreatic eruption occurred. This confirms the value of this technique for eruption forecasting. We also present a counter-example where we deduced that a VT swarm at Volcan Cosiguina, Nicaragua, indicated a small intrusion, insufficient to reach the surface and erupt. Finally, we discuss limitations of the method and propose a mechanism by which this distal VT seismicity is triggered by magmatic intrusion.

Electrical Distribution System (EDS) and Caution and Warning System (CWS)

NASA Technical Reports Server (NTRS)

Mcclung, T.

1975-01-01

An astronaut caution and warning system is described which monitors various life support system parameters and detects out-of-range parameter conditions. The warning system generates a warning tone and displays the malfunction condition to the astronaut along with the proper corrective procedures required.

49 CFR 234.257 - Warning system operation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Warning system operation. 234.257 Section 234.257... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.257 Warning system operation. (a) Each highway-rail crossing warning system shall be tested to determine that it...

47 CFR 87.483 - Audio visual warning systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Audio visual warning systems. 87.483 Section 87... AVIATION SERVICES Stations in the Radiodetermination Service § 87.483 Audio visual warning systems. An audio visual warning system (AVWS) is a radar-based obstacle avoidance system. AVWS activates...

49 CFR 234.257 - Warning system operation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Warning system operation. 234.257 Section 234.257... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.257 Warning system operation. (a) Each highway-rail crossing warning system shall be tested to determine that it...

49 CFR 234.257 - Warning system operation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Warning system operation. 234.257 Section 234.257... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.257 Warning system operation. (a) Each highway-rail crossing warning system shall be tested to determine that it...

Understanding and forecasting phreatic eruptions driven by magmatic degassing

NASA Astrophysics Data System (ADS)

Stix, John; de Moor, J. Maarten

2018-05-01

This paper examines phreatic eruptions which are driven by inputs of magma and magmatic gas. We synthesize data from several significant phreatic systems, including two in Costa Rica (Turrialba and Poás) which are currently highly active and hazardous. We define two endmember types of phreatic eruptions, the first (type 1) in which a deeper hydrothermal system fed by magmatic gases is sealed and produces overpressure sufficient to drive explosive eruptions, and the second (type 2) where magmatic gases are supplied via open-vent degassing to a near-surface hydrothermal system, vaporizing liquid water which drives the phreatic eruptions. The surficial source of type 2 eruptions is characteristic, while the source depth of type 1 eruptions is commonly greater. Hence, type 1 eruptions tend to be more energetic than type 2 eruptions. The first type of eruption we term "phreato-vulcanian", and the second we term "phreato-surtseyan". Some systems (e.g., Ruapehu, Poás) can produce both type 1 and type 2 eruptions, and all systems can undergo sealing at various timescales. We examine a number of precursory signals which appear to be important in understanding and forecasting phreatic eruptions; these include very long period events, banded tremor, and gas ratios, in particular H2S/SO2 and CO2/SO2. We propose that if these datasets are carefully integrated during a monitoring program, it may be possible to accurately forecast phreatic eruptions.[Figure not available: see fulltext.

Studying the response of drivers against different collision warning systems: a review

NASA Astrophysics Data System (ADS)

Muzammel, M.; Yusoff, M. Zuki; Malik, A. Saeed; Mohamad Saad, M. Naufal; Meriaudeau, F.

2017-03-01

The number of vehicle accidents is rapidly increasing and causing significant economic losses in many countries. According to the World Health Organization, road accidents will become the fifth major cause of death by the year 2030. To minimize these accidents different types of collision warning systems have been proposed for motor vehicle drivers. These systems can early detect and warn the drivers about the potential danger, up to a certain accuracy. Many researchers study the effectiveness of these systems by using different methods, including Electroencephalography (EEG). From the literature review, it has been observed that, these systems increase the drivers' response and can help to minimize the accidents that may occur due to drivers unconsciousness. For these collision warning systems, tactile early warnings are found more effective as compared to the auditory and visual early warnings. This review also highlights the areas, where further research can be performed to fully analyze the collision warning system. For example, some contradictions are found among researchers, about these systems' performance for drivers within different age groups. Similarly, most of the EEG studies focus on the front collision warning systems and only give beep sound to alert the drivers. Therefore, EEG study can be performed for the rear end collision warning systems, against proper auditory warning messages which indicate the types of hazards. This EEG study will help to design more friendly collision warning system and may save many lives.

Earthquake Early Warning and Public Policy: Opportunities and Challenges

NASA Astrophysics Data System (ADS)

Goltz, J. D.; Bourque, L.; Tierney, K.; Riopelle, D.; Shoaf, K.; Seligson, H.; Flores, P.

2003-12-01

Development of an earthquake early warning capability and pilot project were objectives of TriNet, a 5-year (1997-2001) FEMA-funded project to develop a state-of-the-art digital seismic network in southern California. In parallel with research to assemble a protocol for rapid analysis of earthquake data and transmission of a signal by TriNet scientists and engineers, the public policy, communication and educational issues inherent in implementation of an earthquake early warning system were addressed by TriNet's outreach component. These studies included: 1) a survey that identified potential users of an earthquake early warning system and how an earthquake early warning might be used in responding to an event, 2) a review of warning systems and communication issues associated with other natural hazards and how lessons learned might be applied to an alerting system for earthquakes, 3) an analysis of organization, management and public policy issues that must be addressed if a broad-based warning system is to be developed and 4) a plan to provide earthquake early warnings to a small number of organizations in southern California as an experimental prototype. These studies provided needed insights into the social and cultural environment in which this new technology will be introduced, an environment with opportunities to enhance our response capabilities but also an environment with significant barriers to overcome to achieve a system that can be sustained and supported. In this presentation we will address the main public policy issues that were subjects of analysis in these studies. They include a discussion of the possible division of functions among organizations likely to be the principle partners in the management of an earthquake early warning system. Drawing on lessons learned from warning systems for other hazards, we will review the potential impacts of false alarms and missed events on warning system credibility, the acceptability of fully automated warning systems and equity issues associated with possible differential access to warnings. Finally, we will review the status of legal authorities and liabilities faced by organizations that assume various warning system roles and possible approaches to setting up a pilot project to introduce early warning. Our presentation will suggest that introducing an early warning system requires multi-disciplinary and multi-agency cooperation and thoughtful discussion among organizations likely to be providers and participants in an early warning system. Recalling our experience with earthquake prediction, we will look at early warning as a promising but unproven technology and recommend moving forward with caution and patience.

Assessment of a severe-weather warning system and disaster preparedness, Calhoun County, Alabama, 1994.

PubMed Central

Liu, S; Quenemoen, L E; Malilay, J; Noji, E; Sinks, T; Mendlein, J

1996-01-01

Tornado preparedness warning system effectiveness, and shelter-seeking behavior were examined in two Alabama areas after tornado warnings. In the area without sirens, only 28.9% of 194 respondents heard a tornado warning of these, 73.2% first received the warning from radios or television. In the area with sirens, 88.1% of 193 respondents heard a warning, and 61.8% first received the warning from a siren. Knowledge of warnings, access to shelter, and education were key predictors for seeking shelter. Our findings indicate that installing sirens, providing access to shelter, and teaching appropriate responses to warnings are important elements of an effective disaster prevention system. PMID:8561251

[Tourism ecological security early warning of Zhangjiajie, China based on the improved TOPSIS method and the grey GM (1,1)model].

PubMed

Xu, Mei; Liu, Chun la; Li, Dan; Zhong, Xiao Lin

2017-11-01

Tourism ecological security early warning is of great significance both to the coordination of ecological environment protection and tourism industry rapid development in tourism destination, and the sustainable and healthy development of regional social and economy. Firstly, based on the DPSIR model, the tourism ecological security early warning index system of Zhangjiajie was constructed from 5 aspects, which were driving force, pressure, state, impact and response. Then, by using the improved TOPSIS method, the tourism ecological security situation of Zhangjiajie from 2001 to 2014 was analyzed. Lastly, by using the grey GM (1,1) model, the tourism ecological security evolution trend of 2015-2020 was predicted. The results indicated that, on the whole, the close degree of Zhangjiajie's tourism ecological security showed a slightly upward trend during 2001-2014, the warning degree was the moderate warning. In terms of each subsystem, warning degree of the driving force system and the pressure system of Zhangjiajie's tourism ecological secu-rity were on the rise, which evolved from light warning to heavy warning; warning degree of the state system and the impact system had not changed so much, and had been in the moderate warning; warning degree of the response system was on the decline, which changed from huge warning to no warning during 2001-2014. According to the current development trend, the close degree of Zhangjiajie's tourism ecological security would rise further in 2015-2020, and the warning degree would turn from moderate warning into light warning, but the task of coordinating the relationship between tourism development and ecological construction and environmental protection would be still arduous.

49 CFR 234.211 - Security of warning system apparatus.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Security of warning system apparatus. 234.211 Section 234.211 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....211 Security of warning system apparatus. Highway-rail grade crossing warning system apparatus shall...

49 CFR 234.211 - Security of warning system apparatus.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Security of warning system apparatus. 234.211 Section 234.211 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....211 Security of warning system apparatus. Highway-rail grade crossing warning system apparatus shall...

49 CFR 234.211 - Security of warning system apparatus.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Security of warning system apparatus. 234.211 Section 234.211 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....211 Security of warning system apparatus. Highway-rail grade crossing warning system apparatus shall...

49 CFR 234.211 - Security of warning system apparatus.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Security of warning system apparatus. 234.211... Maintenance, Inspection, and Testing Maintenance Standards § 234.211 Security of warning system apparatus. Highway-rail grade crossing warning system apparatus shall be secured against unauthorized entry. ...

49 CFR 234.211 - Security of warning system apparatus.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Security of warning system apparatus. 234.211... Maintenance, Inspection, and Testing Maintenance Standards § 234.211 Security of warning system apparatus. Highway-rail grade crossing warning system apparatus shall be secured against unauthorized entry. ...

Earth observations taken during STS-77 mission

NASA Image and Video Library

1996-05-28

STS077-715-037 (19-29 May 1996) --- According to NASA scientists, Ruapehu, on New Zealand?s North Island, is one of the most active volcanoes in the South Pacific. Prior to the flight, crew members scheduled this site as one of their photographic targets. The volcano endured a significant eruption in late September, 1995. This view is the first image of the crater region since that eruption. Since then, numerous landslides and secondary explosions in the summit area has produced changes. In this view, recent mudflows extend from the summit region and down the mountain flank which is in the shadow. Ruapehu is also one of New Zealand?s high points - the mountain supports a glacier and permanent ice fields, and volcanic activity necessarily involves mixing hot volcanic products with snow and ice. Recent activity has produced destructive lahars (mudslides which are slurries of volcanic material with ice and water) downslope. A hazard warning to skiers is still in effect.

MAFALDA: An early warning modeling tool to forecast volcanic ash dispersal and deposition

NASA Astrophysics Data System (ADS)

Barsotti, S.; Nannipieri, L.; Neri, A.

2008-12-01

Forecasting the dispersal of ash from explosive volcanoes is a scientific challenge to modern volcanology. It also represents a fundamental step in mitigating the potential impact of volcanic ash on urban areas and transport routes near explosive volcanoes. To this end we developed a Web-based early warning modeling tool named MAFALDA (Modeling and Forecasting Ash Loading and Dispersal in the Atmosphere) able to quantitatively forecast ash concentrations in the air and on the ground. The main features of MAFALDA are the usage of (1) a dispersal model, named VOL-CALPUFF, that couples the column ascent phase with the ash cloud transport and (2) high-resolution weather forecasting data, the capability to run and merge multiple scenarios, and the Web-based structure of the procedure that makes it suitable as an early warning tool. MAFALDA produces plots for a detailed analysis of ash cloud dynamics and ground deposition, as well as synthetic 2-D maps of areas potentially affected by dangerous concentrations of ash. A first application of MAFALDA to the long-lasting weak plumes produced at Mt. Etna (Italy) is presented. A similar tool can be useful to civil protection authorities and volcanic observatories in reducing the impact of the eruptive events. MAFALDA can be accessed at http://mafalda.pi.ingv.it.

14 CFR 135.153 - Ground proximity warning system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Ground proximity warning system. 135.153... Equipment § 135.153 Ground proximity warning system. (a) No person may operate a turbine-powered airplane... equipped with an approved ground proximity warning system. (b) [Reserved] (c) For a system required by this...

14 CFR 135.153 - Ground proximity warning system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Ground proximity warning system. 135.153... Equipment § 135.153 Ground proximity warning system. (a) No person may operate a turbine-powered airplane... equipped with an approved ground proximity warning system. (b) [Reserved] (c) For a system required by this...

Conduit Wall Failure as a Trigger for Transition From Strombolian to Phreatomagmatic Explosive Activity in the Cova de Paúl Crater Eruption on Santo Antão, Cape Verde Islands

NASA Astrophysics Data System (ADS)

Tarff, R. W.; Day, S. J.

2011-12-01

Episodes of hazardous phreatomagmatic explosive activity, including Surtseyan activity, occur within otherwise less dangerous effusive to mildly explosive magmatic eruptions at high-elevation vents on many oceanic island volcanoes. The water driving these explosions is sourced from freshwater aquifers within the volcanic edifices. Understanding volcanic and geophysical precursors to, and mechanisms of, the (frequently abrupt) transitions to explosive activity is required as a basis for effective warning and mitigation of the resulting hazards. Here we describe near-vent deposits around the large Cova de Paúl crater on the island of Santo Antão, Cape Verde Islands, which provide some insights into a transition from mild magmatic to violently explosive phreatomagmatic activity in one such eruption. This pre-historic but well-preserved crater formed in a single eruption that produced extensive low-temperature, lithic-rich phreatomagmatic pyroclastic flows and surge deposits; these are interbedded in proximal outcrops with airfall breccia and ash beds containing varying proportions of lithic and juvenile clasts, pointing to a series of climactic explosions within an extended period of milder explosive activity of broadly Surtseyan type. Prior to the transition to phreatomagmatic activity, the eruption had been characterized by mild Strombolian activity that produced scoria and spatter deposits of broadly tephritic composition. The Strombolian deposits contain a distinct population of strongly banded, low-vesicularity angular clasts with strongly prolate vesicles and a notably glassy appearance. These became markedly larger and more abundant just below the transition to the phreatomagmatic deposits. Comparisons of these clasts with the Strombolian scoria suggest that they are fragments of flow-banded chilled margins from the walls of the eruptive conduit. Thermal shattering of these margins to produce the angular glassy clasts may record the onset of groundwater flow into the conduit, leading to the phreatomagmatic explosive phase of the eruption. Fragmentation of the conduit wall and ingress of groundwater would likely have been accompanied by seismic swarms consisting of high-frequency fracture events and episodes of harmonic tremor, pointing to a potential geophysical signature of the onset of phreatomagmatic explosive activity in comparable future eruptions on Santo Antão and other oceanic islands.

Enhanced early warning system impact on nursing practice: A phenomenological study.

PubMed

Burns, Kathleen A; Reber, Tracey; Theodore, Karen; Welch, Brenda; Roy, Debra; Siedlecki, Sandra L

2018-05-01

To determine how an enhanced early warning system has an impact on nursing practice. Early warning systems score physiologic measures and alert nurses to subtle changes in patient condition. Critics of early warning systems have expressed concern that nurses would rely on a score rather than assessment skills and critical thinking to determine the need for intervention. Enhancing early warning systems with innovative technology is still in its infancy, so the impact of an enhanced early warning system on nursing behaviours or practice has not yet been studied. Phenomenological design. Scripted, semistructured interviews were conducted in September 2015 with 25 medical/surgical nurses who used the enhanced early warning system. Data were analysed using thematic analysis techniques (coding and bracketing). Emerging themes were examined for relationships and a model describing the enhanced early warning system experience was developed. Nurses identified awareness leading to investigation and ease of prioritization as the enhanced early warning system's most important impact on their nursing practice. There was also an impact on organizational culture, with nurses reporting improved communication, increased collaboration, increased accountability and proactive responses to early changes in patient condition. Rather than hinder critical thinking, as many early warning systems' critics claim, nurses in this study found that the enhanced early warning system increased their awareness of changes in a patient's condition, resulting in earlier response and reassessment times. It also had an impact on the organization by improving communication and collaboration and supporting a culture of proactive rather than reactive response to early signs of deterioration. © 2017 John Wiley & Sons Ltd.

Seismic tremor signals from Bárðarbunga, Grímsvötn and other glacier covered volcanoes in Iceland's Vatnajökull ice cap

NASA Astrophysics Data System (ADS)

Vogfjörd, Kristin S.; Eibl, Eva; Bean, Chris; Roberts, Matthew; Ófeigsson, Benedikt; Jóhannesson, Tómas

2016-04-01

Many of Iceland's most active volcanoes, like Grímsvötn and Bárðarbunga are located under glaciers giving rise to a range of volcanic hazards having both local and cross-border effects on humans, infrastructures and aviation. Volcanic eruptions under ice can lead to explosive hydromagmatic volcanism and generate small to catastrophic subglacial floods that may take hours to days to emerge from the glacier edge. Unrest in subglacial hydrothermal systems and the draining of subglacial meltwater can also lead to flood hazards. These processes and magma-ice interactions in general, generate seismic tremor signals that are commonly observed on seismic systems during volcanic unrest and/or eruptions. The tremor signals exhibit certain characteristics in frequency content, amplitude and behavior with time, but their characteristics overlap. Ability to discriminate between the different processes in real-time or near-real time can support early eruption and flood warnings and help mitigate their detrimental effects. One of the goals set forth in the FUTUREVOLC volcano supersite project was in fact to understand and discriminate between the different types of seismic tremor recorded at subglacial volcanoes. In that pursuit, the seismic network was expanded into the Vatnajökull glacier with four permanent stations on rock and in the ice, in addition to three seismic arrays installed at the ice margin, to enable location and possible tracking of the tremor sources. To track subglacial floods with better resolution three GPS receivers were also installed on the ice, one in an ice cauldron above the Skaftárkatlar geothermal melting area and two down glacier, above the track of the expected subglacial flood. During FUTUREVOLC this infrastructure has recorded all the types of process expected: Magmatic dyke intrusion and propagation from Bárðarbunga, subaerial fissure eruption of that magma at Holuhraun, two subglacial floods, one small and one large, draining from the Skaftárkatlar area, a small flood from Grímsvötn and a small hydrothermal explosion at Kverkfjöll volcano. During the Bárðarbunga dyke propagation under the ice several sequences of tremor were observed, some particularly energetic. Examination of these signals in relation to the advancing dyke intrusion shows that they occurred when the migrating seismicity moved through the areas that later developed cauldrons on the ice surface, indicating increased melting at the bedrock-ice interface and possible magma-ice interaction. The subglacial flood from the Eastern Skaftár cauldron geothermal area, generated a strong tremor signal as well as small ice quakes recorded on near-by stations. Continuous real-time transmission of the GPS signal from inside the cauldron enabled near-real time processing and webcasting of the subsiding cauldron and thus early warning of the oncoming flood and its expected size. The signals recorded above the subglacial track also showed the glacier uplifting and advancing as the flood peak passed underneath. These observations allowed joint interpretation of the seismic single stations and array signals with the GPS signals. Results from the different processes will be presented and explained.

14 CFR 91.223 - Terrain awareness and warning system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Terrain awareness and warning system. 91..., and Certificate Requirements § 91.223 Terrain awareness and warning system. (a) Airplanes manufactured... seat, unless that airplane is equipped with an approved terrain awareness and warning system that as a...

14 CFR 135.154 - Terrain awareness and warning system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Terrain awareness and warning system. 135... Aircraft and Equipment § 135.154 Terrain awareness and warning system. (a) Airplanes manufactured after... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

49 CFR 234.257 - Warning system operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Warning system operation. 234.257 Section 234.257..., Inspection, and Testing Inspections and Tests § 234.257 Warning system operation. (a) Each highway-rail crossing warning system shall be tested to determine that it functions as intended when it is placed in...

14 CFR 121.354 - Terrain awareness and warning system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Terrain awareness and warning system. 121... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 135.154 - Terrain awareness and warning system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Terrain awareness and warning system. 135... Aircraft and Equipment § 135.154 Terrain awareness and warning system. (a) Airplanes manufactured after... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

49 CFR 234.257 - Warning system operation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Warning system operation. 234.257 Section 234.257..., Inspection, and Testing Inspections and Tests § 234.257 Warning system operation. (a) Each highway-rail crossing warning system shall be tested to determine that it functions as intended when it is placed in...

14 CFR 135.154 - Terrain awareness and warning system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Terrain awareness and warning system. 135... Aircraft and Equipment § 135.154 Terrain awareness and warning system. (a) Airplanes manufactured after... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 91.223 - Terrain awareness and warning system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Terrain awareness and warning system. 91..., and Certificate Requirements § 91.223 Terrain awareness and warning system. (a) Airplanes manufactured... seat, unless that airplane is equipped with an approved terrain awareness and warning system that as a...

14 CFR 135.154 - Terrain awareness and warning system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Terrain awareness and warning system. 135... Aircraft and Equipment § 135.154 Terrain awareness and warning system. (a) Airplanes manufactured after... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 91.223 - Terrain awareness and warning system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Terrain awareness and warning system. 91..., and Certificate Requirements § 91.223 Terrain awareness and warning system. (a) Airplanes manufactured... seat, unless that airplane is equipped with an approved terrain awareness and warning system that as a...

14 CFR 91.223 - Terrain awareness and warning system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Terrain awareness and warning system. 91..., and Certificate Requirements § 91.223 Terrain awareness and warning system. (a) Airplanes manufactured... seat, unless that airplane is equipped with an approved terrain awareness and warning system that as a...

49 CFR 234.225 - Activation of warning system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Activation of warning system. 234.225 Section 234... Maintenance, Inspection, and Testing Maintenance Standards § 234.225 Activation of warning system. A highway-rail grade crossing warning system shall be maintained to activate in accordance with the design of the...

14 CFR 121.354 - Terrain awareness and warning system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Terrain awareness and warning system. 121... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 121.354 - Terrain awareness and warning system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Terrain awareness and warning system. 121... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 91.223 - Terrain awareness and warning system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Terrain awareness and warning system. 91..., and Certificate Requirements § 91.223 Terrain awareness and warning system. (a) Airplanes manufactured... seat, unless that airplane is equipped with an approved terrain awareness and warning system that as a...

49 CFR 234.225 - Activation of warning system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Activation of warning system. 234.225 Section 234... Maintenance, Inspection, and Testing Maintenance Standards § 234.225 Activation of warning system. A highway-rail grade crossing warning system shall be maintained to activate in accordance with the design of the...

14 CFR 121.354 - Terrain awareness and warning system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Terrain awareness and warning system. 121... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 135.154 - Terrain awareness and warning system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Terrain awareness and warning system. 135... Aircraft and Equipment § 135.154 Terrain awareness and warning system. (a) Airplanes manufactured after... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

14 CFR 121.354 - Terrain awareness and warning system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Terrain awareness and warning system. 121... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No... awareness and warning system that meets the requirements for Class A equipment in Technical Standard Order...

FOGO-2014: Monitoring the Fogo 2014 Eruption, Cape Verde

NASA Astrophysics Data System (ADS)

Fernandes, Rui; Faria, Bruno

2015-04-01

Fogo volcano, located in the Cape Verde Archipelago offshore Western Africa, is a complete stratovolcano system that was created by the Cape Verde hotspot, forming the island of Fogo. The top (Pico do Fogo) reaches ~2830m above sea level, and raises ~1100m above Chã das Caldeiras, an almost flat circular area with approximately 10 kilometres in the north-south direction and 7 kilometres in the east-west direction. Chã das Caldeiras, surrounded towards the West by the ~1000m high Bordeira rampart, has been inhabited since the early 20th Century, because it is one of the most productive agricultural areas in this semi-arid country. Fogo volcano erupted on November 23, 2014 (~10:00UTC) on a subsidiary vent of the main cone, after 19 years of inactivity. C4G (Collaboratory for Geosciences), a distributed research infrastructure created in 2014 in the framework of the Portuguese Roadmap for Strategic Research Infrastructures, immediately offered support to the Cape Verdean authorities, with the goal of complementing the permanent geophysical monitoring network operated in Fogo island by INMG, the Cape Verdean Meteorological and Geophysical Institute. This permanent network is composed of seven seismographic stations and three tiltmeter stations, and the data is transmitted in real time to the INMG geophysical laboratory in São Vicente Island, where it is analysed on a routine basis. Pre-eruptive activity started to be detected by the permanent monitoring network on October 2014, with earthquakes occurring at depths larger than 15 km. These events led to a first volcanic warning to the Cape Verdean Civil Protection Agency. On November 22 several volcano-tectonic earthquakes were recorded at shallow depths, indicating shallow fracturing. On the basis of this activity, INMG issued a formal alert of an impending eruption to the Civil Protection Agency, ~24 hours before the onset of the eruption. Volcanic tremor and clear tiltmeter signals were recorded about one hour before the eruption began. The Copernicus Emergency Management Service was also activated and several maps of lava flows advance and general site information were produced, based on Earth Observation, to facilitate crisis management. The eruption caused no casualties or personal injuries. The lava expelled by the current eruption (still active at the time of submission, January 6, 2015, but declining) destroyed the two main villages in the caldera (~1000 inhabitants), previously evacuated, and covered vast areas of agricultural land, causing very large economic losses and an uncertain future of the local populations. The C4G team installed a network of seven cGNSS receivers and nine seismometers, distributed in Fogo Island. The operation of the equipment started on 28th November 2014, and will continue until the end of January 2015. The mission also included a new detailed gravimetric survey of the island, the acquisition of geological samples, and the analysis of the air quality during the eruption. We present here a detailed description of the monitoring efforts carried out during the eruption as well as initial results of the analysis of the data collected. This monitoring effort carried out at the request and in collaboration with INMG, was made possible by an emergency financial support provided by Fundação para a Ciência e Tecnologia, Portugal.

Exploring the Role of Social Memory of Floods for Designing Flood Early Warning Operations

NASA Astrophysics Data System (ADS)

Girons Lopez, Marc; Di Baldassarre, Giuliano; Grabs, Thomas; Halldin, Sven; Seibert, Jan

2016-04-01

Early warning systems are an important tool for natural disaster mitigation practices, especially for flooding events. Warnings rely on near-future forecasts to provide time to take preventive actions before a flood occurs, thus reducing potential losses. However, on top of the technical capacities, successful warnings require an efficient coordination and communication among a range of different actors and stakeholders. The complexity of integrating the technical and social spheres of warning systems has, however, resulted in system designs neglecting a number of important aspects such as social awareness of floods thus leading to suboptimal results. A better understanding of the interactions and feedbacks among the different elements of early warning systems is therefore needed to improve their efficiency and therefore social resilience. When designing an early warning system two important decisions need to be made regarding (i) the hazard magnitude at and from which a warning should be issued and (ii) the degree of confidence required for issuing a warning. The first decision is usually taken based on the social vulnerability and climatic variability while the second one is related to the performance (i.e. accuracy) of the forecasting tools. Consequently, by estimating the vulnerability and the accuracy of the forecasts, these two variables can be optimized to minimize the costs and losses. Important parameters with a strong influence on the efficiency of warning systems such as social awareness are however not considered in their design. In this study we present a theoretical exploration of the impact of social awareness on the design of early warning systems. For this purpose we use a definition of social memory of flood events as a proxy for flood risk awareness and test its effect on the optimization of the warning system design variables. Understanding the impact of social awareness on warning system design is important to make more robust warnings that can better adapt to different social settings and more efficiently reduce vulnerability.

Ground-based weather radar remote sensing of volcanic ash explosive eruptions

NASA Astrophysics Data System (ADS)

Marzano, F. S.; Marchiotto, S.; Barbieri, S.; Giuliani, G.; Textor, C.; Schneider, D. J.

2009-04-01

The explosive eruptions of active volcanoes with a consequent formation of ash clouds represent a severe threat in several regions of the urbanized world. During a Plinian or a sub-Plinian eruption the injection of large amounts of fine and coarse rock fragments and corrosive gases into the troposphere and lower stratosphere is usually followed by a long lasting ashfall which can cause a variety of damages. Volcanic ash clouds are an increasing hazard to aviation safety because of growing air traffic volumes that use more efficient and susceptible jet engines. Real-time and areal monitoring of a volcano eruption, in terms of its intensity and dynamics, is not always possible by conventional visual inspections, especially during worse visibility periods which are quite common during eruption activity. Remote sensing techniques both from ground and from space represent unique tools to be exploited. In this respect, microwave weather radars can gather three-dimensional information of atmospheric scattering volumes up several hundreds of kilometers, in all weather conditions, at a fairly high spatial resolution (less than a kilometer) and with a repetition cycle of few minutes. Ground-based radar systems represent one of the best methods for determining the height and volume of volcanic eruption clouds. Single-polarization Doppler radars can measure horizontally-polarized power echo and Doppler shift from which ash content and radial velocity can be, in principle, extracted. In spite of these potentials, there are still several open issues about microwave weather radar capabilities to detect and quantitatively retrieve ash cloud parameters. A major issue is related to the aggregation of volcanic ash particles within the eruption column of explosive eruptions which has been observed at many volcanoes. It influences the residence time of ash in the atmosphere and the radiative properties of the "umbrella" cloud. Numerical experiments are helpful to explore processes occurring in the eruption column. In this study we use the plume model ATHAM (Active Tracer High Resolution Atmospheric Model) to investigate, in both time and space, processes leading to particle aggregation in the eruption column. In this work a set of numerical simulations of radar reflectivity is performed with the ATHAM model, under the same experimental conditions except for the initial size distribution, i.e. varying the radii of average mass of the two particle dimension modes. A sensitivity analysis is carried out to evaluate the possible impact of aggregate particles on microwave radar reflectivity. It is shown how dimension, composition, temperature and mass concentration are the main characteristics of eruptive cloud particles that contribute to determine different radar reflectivity responses. In order to evaluate Rayleigh scattering approximation accuracy, the ATHAM simulations of radar reflectivity are used to compare in a detailed way the Mie and Rayleigh scattering regimes at S-, C- and X-band. The relationship between radar reflectivity factor and ash concentration has been statistically derived for the various particle classes by applying a new radar reflectivity microphysical model, which was developed starting from results of numerical experiments performed with plume model ATHAM. The ash retrieval physical-statistical algorithm is based on the backscattering microphysical model of volcanic cloud particles, used within a Bayesian classification and optimal regression algorithm. In order to illustrate the potential of this microwave active remote sensing technique, the case study of the eruption of Augustine volcano in Alaska in January 2006 is described. This event was the first time that a significant volcanic eruption was observed within the nominal range of a WSR-88D. The radar data, in conjunction with pilot reports, proved to be crucial in analyzing the height and movement of volcanic ash clouds during and immediately following each eruptive event. This data greatly aided National Weather Service meteorologists in the issuance of timely and accurate warning and advisory products to aviation, public, and marine interests. An application of the retrieval technique has been shown, taking into consideration the eruption of the Augustine volcano. Volume scan data from the NEXRAD WSR-88D S-band radar, which are located 190 km from the volcano vent, are processed to identify and estimate the particles concentration in an automatic fashion. The evolution of the Augustine Vulcanian eruption is discussed in terms of radar measurements products, pointing out the unique features, the current limitations and future improvements of radar remote sensing of volcanic plumes.

Incorporating Real-time Earthquake Information into Large Enrollment Natural Disaster Course Learning

NASA Astrophysics Data System (ADS)

Furlong, K. P.; Benz, H.; Hayes, G. P.; Villasenor, A.

2010-12-01

Although most would agree that the occurrence of natural disaster events such as earthquakes, volcanic eruptions, and floods can provide effective learning opportunities for natural hazards-based courses, implementing compelling materials into the large-enrollment classroom environment can be difficult. These natural hazard events derive much of their learning potential from their real-time nature, and in the modern 24/7 news-cycle where all but the most devastating events are quickly out of the public eye, the shelf life for an event is quite limited. To maximize the learning potential of these events requires that both authoritative information be available and course materials be generated as the event unfolds. Although many events such as hurricanes, flooding, and volcanic eruptions provide some precursory warnings, and thus one can prepare background materials to place the main event into context, earthquakes present a particularly confounding situation of providing no warning, but where context is critical to student learning. Attempting to implement real-time materials into large enrollment classes faces the additional hindrance of limited internet access (for students) in most lecture classrooms. In Earth 101 Natural Disasters: Hollywood vs Reality, taught as a large enrollment (150+ students) general education course at Penn State, we are collaborating with the USGS’s National Earthquake Information Center (NEIC) to develop efficient means to incorporate their real-time products into learning activities in the lecture hall environment. Over time (and numerous events) we have developed a template for presenting USGS-produced real-time information in lecture mode. The event-specific materials can be quickly incorporated and updated, along with key contextual materials, to provide students with up-to-the-minute current information. In addition, we have also developed in-class activities, such as student determination of population exposure to severe ground shaking (i.e. simulating the USGS PAGER product), tsunami warning calculations, and building damage analyses that allow the students to participate in realistic hazard analyses as the event unfolds. Examples of these templates and activities will be presented. Key to the successful implementation of real-time materials is sufficient flexibility and adaptability in the course syllabus.

Windshear warning aerospatiale approach

NASA Technical Reports Server (NTRS)

Bonafe, J. L.

1988-01-01

Vugraphs and transcribed remarks of a presentation on Aerospatiale's approach to windshear warning systems are given. Information is given on low altitude wind shear probability, wind shear warning models and warning system false alarms.

Popocatepetl

NASA Technical Reports Server (NTRS)

2002-01-01

Located about 40 miles (65 km) southeast of Mexico City, Popocatepetl roared back to life on December 18, 2000, spewing red hot rocks, ash, and smoke high into the air over the Valley of Mexico. Concerned that there may be even more massive eruptions to follow, or perhaps mudslides from the summit's melting snow and ice, Mexican authorities asked nearby residents to evacuate the region. The last major eruption of Popocatepetl (pronounced poh-poh-kah-TEH-peh-til) occurred in 800 A.D., in which vast amounts of lava and ash from the volcano completely filled many of the surrounding valleys. Since then, there have been at least five moderate eruptions, two of which occurred in the 1900s. Toward the end of 2000, scientists warned there were signs of activity within the volcano as pressure within a dome of lava at its base continued to build, which eventually led to the moderate eruption on December 18. This true-color image of Popocatepetl was acquired on January 4, 1999, by the Enhanced Thematic Mapper Plus (ETM+) aboard NASA's Landsat 7 satellite. Even from this two-dimensional perspective, you get a sense of the volcano's impressive slopes as it towers some 17,930 feet (5,465 meters) above the surrounding landscape. Snow and ice encircle the summit (whitish pixels), at the top of which the volcano's crater can be seen clearly. Surveying the larger surrounding region, there is ample evidence of human agriculture to feed the more than 20 million people who live in the greater Mexico City region (to the north). Image courtesy Ron Beck, EROS Data Center

14 CFR 23.703 - Takeoff warning system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... takeoff. The warning must continue until— (1) The configuration is changed to allow safe takeoff, or (2... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Takeoff warning system. 23.703 Section 23... Control Systems § 23.703 Takeoff warning system. For all airplanes with a maximum weight more than 6,000...

Distress detection, location, and communications using advanced space technology

NASA Technical Reports Server (NTRS)

Sivertson, W. E., Jr.

1977-01-01

This paper briefly introduces a concept for low-cost, global, day-night, all-weather disaster warning and assistance. Evolving, advanced space technology with passive radio frequency reflectors in conjunction with an imaging synthetic aperture radar is employed to detect, identify, locate, and provide passive communication with earth users in distress. This concept evolved from a broad NASA research on new global search and rescue techniques. Appropriate airborne radar test results from this research are reviewed and related to potential disaster applications. The analysis indicates the approach has promise for disaster communications relative to floods, droughts, earthquakes, volcanic eruptions, and severe storms.

Acquiring Comprehensive Observations using an Integrated Sensorweb for Early Warning

NASA Technical Reports Server (NTRS)

Habib, Shahid; Ambrose, Steve

2006-01-01

As an integrated observing strategy, the concept of sensorweb for Earth observations is appealing in many aspects. For instance, by increasing the spatial and temporal coverage of observations from space and other vantage points, one can eventually aid in increasing the accuracy of the atmospheric models which are precursor to hurricane track prediction, volcanic eruption forecast, and trajectory path of transcontinental transport of dust, harmful nuclear and chemical plumes. In reality, there is little analysis'available in terms of benefits, costs and optimized set of sensors needed to make these necessary observations. This is a complex problem that must be carefully studied and balanced over many boundaries such as science, defense, early warning security, and surveillance. Simplistically, the sensorweb concept from the technological point of view alone has a great appeal in the defense, early warning and security applications. In fact, it can be relatively less expensive in per unit cost as opposed to building and deploying it for the scientific use. However, overall observing approach should not be singled out and aligned somewhat . orthogonally to serve a particular need. On the other hand, the sensorweb should be designed and deployed to serve multiple subject areas and customers simultaneously; and can behave as directed measuring systems for both science and operational entities. Sensorweb can be designed to act as expert systems, and/or also provide a dedicated integrated surveillance network. Today, there is no system in the world that is fully integrated in terms of reporting timely multiple hazards warnings, computing the lass of life and property damage estimates, and is also designed to cater to everyone's needs. It is not an easier problem to undertake and more so is not practically solvable. At this time due to some recent events in the world, the scientific community, social scientists, and operational agencies are more cognizant and getting together to address such colossal problems. Increasing our knowledge of the home planet, via amplified set of observations, is certainly a right step in a right direction. Furthermore, this is a pre-requisite in understanding multiple hazard phenomena's. This paper examines various sensorweb options and observing architectures that can be useful specifically in addressing some of these complex issues. The ultimate goal is to serve the society by providing potential natural hazards information to the decision makers in the most expeditious manner so they can prepare themselves to mitigate potential risks to human life, livestock and property.

Acquiring Comprehensive Observations using an integrated Sensorweb for Early Warning

NASA Technical Reports Server (NTRS)

Habib, Shahid; Ambrose, Steve

2006-01-01

As an integrated observing strategy, the concept of sensorweb for Earth observations is appealing in many aspects. For instance, by increasing the spatial and temporal coverage of observations from space and other vantage points, one can eventually aid in increasing the accuracy of the atmospheric models which are precursor to hurricane track prediction, volcanic eruption forecast, and trajectory path of transcontinental transport of dust, harmful nuclear and chemical plumes. In reality, there is little analysis'available in terms of benefits, costs and optimized set of sensors needed to make these necessary observations. This is a complex problem that must be carefully studied and balanced over many boundaries such as science, defense, early warning, security, and surveillance. Simplistically, the sensorweb concept from the technological point of view alone has a great appeal in the defense, early warning and security applications. In fact, it can be relatively less expensive in per unit cost as opposed to building and deploying it for the scientific use. However, overall observing approach should not be singled out and aligned somewhat orthogonally to serve a particular need. On the other hand, the sensorweb should be designed and deployed to serve multiple subject areas and customers simultaneously; and can behave as directed measuring systems for both science and operational entities. Sensorweb can be designed to act as expert systems, and/or also provide a dedicated integrated surveillance network. Today, there is no system in the world that is fully integrated in terms of reporting timely multiple hazards warnings, computing the loss of life and property damage estimates, and is also designed to cater to everyone's needs. It is not an easier problem to undertake and more so is not practically solvable. At this time due to some recent events in the world, the scientific community, social scientists, and operational agencies are more cognizant and getting together to address such colossal problems. Increasing our knowledge of the home planet, via amplified set of observations, is certainly a right step in a right direction. Furthermore, this is a pre-requisite in understanding multiple hazard phenomena's. This paper examines various sensorweb options and observing architectures that can be useful specifically in addressing some of these complex issues. The ultimate goal is to serve the society by providing potential natural hazards information to the decision makers in the most expeditious manner so they can prepare themselves to mitigate potential risks to human life, livestock and property.

Analysis and design of the ultraviolet warning optical system based on interference imaging

NASA Astrophysics Data System (ADS)

Wang, Wen-cong; Hu, Hui-jun; Jin, Dong-dong; Chu, Xin-bo; Shi, Yu-feng; Song, Juan; Liu, Jin-sheng; Xiao, Ting; Shao, Si-pei

2017-10-01

Ultraviolet warning technology is one of the important methods for missile warning. It provides a very effective way to detect the target for missile approaching alarm. With the development of modern technology, especially the development of information technology at high speed, the ultraviolet early warning system plays an increasingly important role. Compared to infrared warning, the ultraviolet warning has high efficiency and low false alarm rate. In the modern warfare, how to detect the threats earlier, prevent and reduce the attack of precision-guided missile has become a new challenge of missile warning technology. Because the ultraviolet warning technology has high environmental adaptability, the low false alarm rate, small volume and other advantages, in the military field applications it has been developed rapidly. For the ultraviolet warning system, the optimal working waveband is 250 nm 280 nm (Solar Blind UV) due to the strong absorption of ozone layer. According to current application demands for solar blind ultraviolet detection and warning, this paper proposes ultraviolet warning optical system based on interference imaging, which covers solar blind ultraviolet (250nm-280nm) and dual field. This structure includes a primary optical system, an ultraviolet reflector array, an ultraviolet imaging system and an ultraviolet interference imaging system. It makes use of an ultraviolet beam-splitter to achieve the separation of two optical systems. According to the detector and the corresponding application needs of two visual field of the optical system, the calculation and optical system design were completed. After the design, the MTF of the two optical system is more than 0.8@39lp/mm.A single pixel energy concentration is greater than 80%.

On the importance of risk knowledge for an end-to-end tsunami early warning system

NASA Astrophysics Data System (ADS)

Post, Joachim; Strunz, Günter; Riedlinger, Torsten; Mück, Matthias; Wegscheider, Stephanie; Zosseder, Kai; Steinmetz, Tilmann; Gebert, Niklas; Anwar, Herryal

2010-05-01

Warning systems commonly use information provided by networks of sensors able to monitor and detect impending disasters, aggregate and condense these information to provide reliable information to a decision maker whether to warn or not, disseminates the warning message and provide this information to people at risk. Ultimate aim is to enable those in danger to make decisions (e.g. initiate protective actions for buildings) and to take action to safe their lives. This involves very complex issues when considering all four elements of early warning systems (UNISDR-PPEW), namely (1) risk knowledge, (2) monitoring and warning service, (3) dissemination and communication, (4) response capability with the ultimate aim to gain as much time as possible to empower individuals and communities to act in an appropriate manner to reduce injury, loss of life, damage to property and the environment and loss of livelihoods. Commonly most warning systems feature strengths and main attention on the technical/structural dimension (monitoring & warning service, dissemination tools) with weaknesses and less attention on social/cultural dimension (e.g. human response capabilities, defined warning chain to and knowing what to do by the people). Also, the use of risk knowledge in early warning most often is treated in a theoretical manner (knowing that it is somehow important), yet less in an operational, practical sense. Risk assessments and risk maps help to motivate people, prioritise early warning system needs and guide preparations for response and disaster prevention activities. Beyond this risk knowledge can be seen as a tie between national level early warning and community level reaction schemes. This presentation focuses on results, key findings and lessons-learnt related to tsunami risk assessment in the context of early warning within the GITEWS (German-Indonesian Tsunami Early Warning) project. Here a novel methodology reflecting risk information needs in the early warning context has been worked out. The generated results contribute significantly in the fields of (1) warning decision and warning levels, (2) warning dissemination and warning message content, (3) early warning chain planning, (4) increasing response capabilities and protective systems, (5) emergency relief and (6) enhancing communities' awareness and preparedness towards tsunami threats. Additionally examples will be given on the potentials of an operational use of risk information in early warning systems as first experiences exist for the tsunami early warning center in Jakarta, Indonesia. Beside this the importance of linking national level early warning information with tsunami risk information available at the local level (e.g. linking warning message information on expected intensity with respective tsunami hazard zone maps at community level for effective evacuation) will be demonstrated through experiences gained in three pilot areas in Indonesia. The presentation seeks to provide new insights on benefits using risk information in early warning and will provide further evidence that practical use of risk information is an important and indispensable component of end-to-end early warning.

Calderas and magma reservoirs

NASA Astrophysics Data System (ADS)

Cashman, Katharine V.; Giordano, Guido

2014-11-01

Large caldera-forming eruptions have long been a focus of both petrological and volcanological studies; petrologists have used the eruptive products to probe conditions of magma storage (and thus processes that drive magma evolution), while volcanologists have used them to study the conditions under which large volumes of magma are transported to, and emplaced on, the Earth's surface. Traditionally, both groups have worked on the assumption that eruptible magma is stored within a single long-lived melt body. Over the past decade, however, advances in analytical techniques have provided new views of magma storage regions, many of which provide evidence of multiple melt lenses feeding a single eruption, and/or rapid pre-eruptive assembly of large volumes of melt. These new petrological views of magmatic systems have not yet been fully integrated into volcanological perspectives of caldera-forming eruptions. Here we explore the implications of complex magma reservoir configurations for eruption dynamics and caldera formation. We first examine mafic systems, where stacked-sill models have long been invoked but which rarely produce explosive eruptions. An exception is the 2010 eruption of Eyjafjallajökull volcano, Iceland, where seismic and petrologic data show that multiple sills at different depths fed a multi-phase (explosive and effusive) eruption. Extension of this concept to larger mafic caldera-forming systems suggests a mechanism to explain many of their unusual features, including their protracted explosivity, spatially variable compositions and pronounced intra-eruptive pauses. We then review studies of more common intermediate and silicic caldera-forming systems to examine inferred conditions of magma storage, time scales of melt accumulation, eruption triggers, eruption dynamics and caldera collapse. By compiling data from large and small, and crystal-rich and crystal-poor, events, we compare eruptions that are well explained by simple evacuation of a zoned magma chamber (termed the Standard Model by Gualda and Ghiorso, 2013) to eruptions that are better explained by tapping multiple, rather than single, melt lenses stored within a largely crystalline mush (which we term complex magma reservoirs). We then discuss the implications of magma storage within complex, rather than simple, reservoirs for identifying magmatic systems with the potential to produce large eruptions, and for monitoring eruption progress under conditions where successive melt lenses may be tapped. We conclude that emerging views of complex magma reservoir configurations provide exciting opportunities for re-examining volcanological concepts of caldera-forming systems.

Triggering of Solar Magnetic Eruptions on Various Size Scales Alphonse Sterling

NASA Technical Reports Server (NTRS)

Sterling, A.C.

2010-01-01

A solar eruption that produces a coronal mass ejection (CME) together with a flare is driven by the eruption of a closed-loop magnetic arcade that has a sheared-field core. Before eruption, the sheared core envelops a polarity inversion line along which cool filament material may reside. The sheared-core arcade erupts when there is a breakdown in the balance between the confining downward-directed magnetic tension of the overall arcade field and the upward-directed force of the pent-up magnetic pressure of the sheared field in the core of the arcade. What triggers the breakdown in this balance in favor of the upward-directed force is still an unsettled question. We consider several eruption examples, using imaging data from the SoHO, TRACE and Hinode satellites, and other sources, along with information about the magnetic field of the erupting regions. In several cases, observations of large-scale eruptions, where the magnetic neutral line spans few x 10,000 km, are consistent with magnetic flux cancellation being the trigger to the eruption's onset, even though the amount of flux canceled is only few percent of the total magnetic flux of the erupting region. In several other cases, an initial compact (small size-scale) eruption occurs embedded inside of a larger closed magnetic loop system, so that the smaller eruption destabilizes and causes the eruption of the much larger system. In this way, small-scale eruptive events can result in eruption of much larger-scale systems.

RECURRENT NOVAE IN M31

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

Shafter, A. W.; Henze, M.; Rector, T. A.

2015-02-01

The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova (RN) candidates. To pass the initial screen and qualify as a RN candidate, two or more eruptions were required to be coincident within 0.′1, although this criterion was relaxed to 0.′15 for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential RN systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent, the original plates and published images of the relevant eruptions havemore » been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as RNe, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be RNe, with an additional 4 systems (8 eruptions) being possibly recurrent. It is estimated that ∼4% of the nova eruptions seen in M31 over the past century are associated with RNe. A Monte Carlo analysis shows that the discovery efficiency for RNe may be as low as 10% that for novae in general, suggesting that as many as one in three nova eruptions observed in M31 arise from progenitor systems having recurrence times ≲100 yr. For plausible system parameters, it appears unlikely that RNe can provide a significant channel for the production of Type Ia supernovae.« less

Volcano early warning system based on MSG-SEVIRI multispectral data

NASA Astrophysics Data System (ADS)

Ganci, Gaetana; Vicari, Annamaria; Del Negro, Ciro

2010-05-01

Spaceborne remote sensing of high-temperature volcanic features offers an excellent opportunity to monitor the onset and development of new eruptive activity. Particularly, images with lower spatial but higher temporal resolution from meteorological satellites have been proved to be a sound instrument for continuous monitoring of volcanic activity, even though the relevant volcanic characteristics are much smaller than the nominal pixel size. The launch of Spinning Enhanced Visible and Infrared Imager (SEVIRI), on August 2002, onboard the geosynchronous platforms MSG1 and MSG2, has opened a new perspective for near real-time volcano monitoring by providing images at 15 minutes interval. Indeed, in spite of the low spatial resolution (3 km2 at nadir), the high frequency of observations afforded by the MSG SEVIRI was recently applied both for forest fire detection and for the monitoring of effusive volcanoes in Europe and Africa. Our Laboratory of Technologies (TecnoLab) at INGV-CT has been developing methods and know-how for the automated acquisition and management of MSG SEVIRI data. To provide a basis for real-time response during eruptive events, we designed and developed the automated system called HOTSAT. Our algorithm takes advantages from both spectral and spatial comparisons. Firstly, we use an adaptive thresholding procedure based on the computation of the spatial standard deviation derived from the immediately neighboring of each pixel to detect "potential" hot pixels. Secondly, it is required to further assess as true or false hotspot detections base on other thresholds test derived from the SEVIRI middle infrared (MIR, 3.9 μm) brightness temperatures taking into account its statistic behavior. Following these procedures, all the computations are based on dynamic thresholds reducing the number of false alarm due to atmospheric conditions. Our algorithm allows also the derivation of radiative power at all "hot" pixels. This is carried out using the MIR radiance method introduced by Wooster et al. [2003] for forest fires. It's based on an approximation of the Plank's Law as a power law. No assumption is made on the thermal structure of the pixel. The radiant flux, i.e. the fire radiative power, is proportional to the calibrated radiance associated to the hot part of the pixel computed as the difference between the observed hotspot pixel radiance in the SEVIRI MIR channel and the background radiance that would have been observed at the same location in the absence of thermal anomalies. The HOTSAT early warning system based on SEVIRI multispectral data is now suitable to be employed in an operational system of volcano monitoring. To validate and test the system some real cases on Mt Etna are presented.

Emergency Warning Systems. Part 2. Warning Systems - Evaluation Guidelines.

DTIC Science & Technology

1983-07-01

ELEMENT. PROJECT. TASK AREA A WORK UNIT NUMBERS PRC Voorhees Work Unit 2234G 1500 Planning Research Drive McLean, Virginia 22102 ___ 11. CONTROLLING ...different from Controlling Office) IS. SECURITY CLASS. (of this report) Unclassified 15a. DECLASSIFICATION/DOWNGRADING SCHEDULE 16. DISTRIBUTION...systems that control these warning systems are discussed. Test results of several warning systems are included along with a discussion of sound

Assessing the performance of regional landslide early warning models: the EDuMaP method

NASA Astrophysics Data System (ADS)

Calvello, M.; Piciullo, L.

2016-01-01

A schematic of the components of regional early warning systems for rainfall-induced landslides is herein proposed, based on a clear distinction between warning models and warning systems. According to this framework an early warning system comprises a warning model as well as a monitoring and warning strategy, a communication strategy and an emergency plan. The paper proposes the evaluation of regional landslide warning models by means of an original approach, called the "event, duration matrix, performance" (EDuMaP) method, comprising three successive steps: identification and analysis of the events, i.e., landslide events and warning events derived from available landslides and warnings databases; definition and computation of a duration matrix, whose elements report the time associated with the occurrence of landslide events in relation to the occurrence of warning events, in their respective classes; evaluation of the early warning model performance by means of performance criteria and indicators applied to the duration matrix. During the first step the analyst identifies and classifies the landslide and warning events, according to their spatial and temporal characteristics, by means of a number of model parameters. In the second step, the analyst computes a time-based duration matrix with a number of rows and columns equal to the number of classes defined for the warning and landslide events, respectively. In the third step, the analyst computes a series of model performance indicators derived from a set of performance criteria, which need to be defined by considering, once again, the features of the warning model. The applicability, potentialities and limitations of the EDuMaP method are tested and discussed using real landslides and warning data from the municipal early warning system operating in Rio de Janeiro (Brazil).

Systems and Sensors for Debris-flow Monitoring and Warning

PubMed Central

Arattano, Massimo; Marchi, Lorenzo

2008-01-01

Debris flows are a type of mass movement that occurs in mountain torrents. They consist of a high concentration of solid material in water that flows as a wave with a steep front. Debris flows can be considered a phenomenon intermediate between landslides and water floods. They are amongst the most hazardous natural processes in mountainous regions and may occur under different climatic conditions. Their destructiveness is due to different factors: their capability of transporting and depositing huge amounts of solid materials, which may also reach large sizes (boulders of several cubic meters are commonly transported by debris flows), their steep fronts, which may reach several meters of height and also their high velocities. The implementation of both structural and non-structural control measures is often required when debris flows endanger routes, urban areas and other infrastructures. Sensor networks for debris-flow monitoring and warning play an important role amongst non-structural measures intended to reduce debris-flow risk. In particular, debris flow warning systems can be subdivided into two main classes: advance warning and event warning systems. These two classes employ different types of sensors. Advance warning systems are based on monitoring causative hydrometeorological processes (typically rainfall) and aim to issue a warning before a possible debris flow is triggered. Event warning systems are based on detecting debris flows when these processes are in progress. They have a much smaller lead time than advance warning ones but are also less prone to false alarms. Advance warning for debris flows employs sensors and techniques typical of meteorology and hydrology, including measuring rainfall by means of rain gauges and weather radar and monitoring water discharge in headwater streams. Event warning systems use different types of sensors, encompassing ultrasonic or radar gauges, ground vibration sensors, videocameras, avalanche pendulums, photocells, trip wires etc. Event warning systems for debris flows have a strong linkage with debris-flow monitoring that is carried out for research purposes: the same sensors are often used for both monitoring and warning, although warning systems have higher requirements of robustness than monitoring systems. The paper presents a description of the sensors employed for debris-flow monitoring and event warning systems, with attention given to advantages and drawbacks of different types of sensors. PMID:27879828

The perception of volcanic risk in Kona communities from Mauna Loa and Hualālai volcanoes, Hawai‵i

NASA Astrophysics Data System (ADS)

Gregg, C. E.; Houghton, B. F.; Johnston, D. M.; Paton, D.; Swanson, D. A.

2004-02-01

Volcanic hazards in Kona (i.e. the western side of the island of Hawai‵i) stem primarily from Mauna Loa and Hualālai volcanoes. The former has erupted 39 times since 1832. Lava flows were emplaced in Kona during seven of these eruptions and last impacted Kona in 1950. Hualālai last erupted in ca. 1800. Society's proximity to potential eruptive sources and the potential for relatively fast-moving lava flows, coupled with relatively long time intervals since the last eruptions in Kona, are the underlying stimuli for this study of risk perception. Target populations were high-school students and adults ( n=462). Using these data, we discuss threat knowledge as an influence on risk perception, and perception as a driving mechanism for preparedness. Threat knowledge and perception of risk were found to be low to moderate. On average, fewer than two-thirds of the residents were aware of the most recent eruptions that impacted Kona, and a minority felt that Mauna Loa and Hualālai could ever erupt again. Furthermore, only about one-third were aware that lava flows could reach the coast in Kona in less than 3 h. Lava flows and ash fall were perceived to be among the least likely hazards to affect the respondent's community within the next 10 years, whereas vog (volcanic smog) was ranked the most likely. Less than 18% identified volcanic hazards as amongst the most likely hazards to affect them at home, school, or work. Not surprisingly, individual preparedness measures were found on average to be limited to simple tasks of value in frequently occurring domestic emergencies, whereas measures specific to infrequent hazard events such as volcanic eruptions were seldom adopted. Furthermore, our data show that respondents exhibit an 'unrealistic optimism bias' and infer that responsibility for community preparedness for future eruptions primarily rests with officials. We infer that these respondents may be less likely to attend to hazard information, react to warnings as directed, and undertake preparedness measures than other populations who perceive responsibility to lie with themselves. There are significant differences in hazard awareness and risk perception between students and adults, between subpopulations representing local areas, and between varying ethnicities. We conclude that long time intervals since damaging lava flows have occurred in Kona have contributed to lower levels of awareness and risk perceptions of the threat from lava flows, and that the on-going eruption at Kīlauea has facilitated greater awareness and perception of risk of vog but not of other volcanic hazards. Low levels of preparedness may be explained by low perceptions of threat and risk and perhaps by the lack of a clear motivation or incentive to seek new modes of adjustment.

Experimental calibration of Phreatic and Hydrothermal Explosions: A case study on Lake Okaro, New Zealand

NASA Astrophysics Data System (ADS)

Foote, L. C.; Scheu, B.; kennedy, B.; Gravley, D.; Dingwell, D. B.

2011-12-01

Phreatic and hydrothermal eruptions, the most common on earth, frequently lead to magmatic eruptions. They often occur with little or no warning, representing a significant hazard. These eruptions occur over a range of temperature and pressure, and within widely differing rock types. Additionally, these eruptions may be triggered by earthquakes or landslides . Regardless of the trigger, they occur when hydrothermal/supercritical fluid rapidly flashes to steam due either to a heating or a decompression. Despite the frequency of these eruptions, previous studies have largely been focused exclusively on either the physical characteristics of the eruptions or experimental modelling of the trigger processes, with very few combining the two. Here, a new experimental procedure has been developed to model phreatic fragmentation based on the shock-tube experiments of magmatic fragmentation introduced by Alidibirov & Dingwell (1996). This technique uses water-saturated samples, producing fragmentation from a combination of argon gas overpressure and steam flashing, within the vesicles. By integrating measurements of the physical characteristics such as porosity, permeability and mineralogy in the analysis of the results of these experiments a model of phreatic fragmentation is proposed, to aid in future hazard modelling. The phreatic explosion crater forming Lake Okaro, within the Taupo Volcanic Zone of New Zealand was used as a case study. The eruption was triggered within the Rangitaiki Ignimbrite, which served as the sample material for these experiments. In order to evaluate the effects of alteration, both original, unaltered material and hydrothermally altered samples were analysed. As fragmentation is driven by gas overpressure/steam expansion within vesicles, porosity plays a critical role. For these samples average porosity values are 24 and 40% respectively. Experimental conditions were chosen primarily to reflect the conditions of the study location but also to study the effect of water saturation on the fragmentation behavior. Thus experiments were run at both room temperature and 300°C, and from 4 to 15 MPa. Pressure sensors were used to record the speed of fragmentation and fragments were recovered in order to determine grain-size distributions. First analyses of the fragmentation speed reveal no significant difference between dry and saturated samples; (14 - 42 m/s depending on applied energy). In contrast, the results of the grain size analysis show a clear shift to smaller grain sizes with saturated samples (independent of pressure or sample type) possibly reflecting the more efficient conversion of energy involved in phreatic eruptions most likely in combination with a strength reduction of the samples due to water weakening effects. We provide herewith a first parameterisation of conditions for phreatic and hydrothermal eruptions and offer an explanation for the reduction in grain size associated with phreatic eruptions.

The perception of volcanic risk in Kona communities from Mauna Loa and Hualālai volcanoes, Hawai'i

USGS Publications Warehouse

Gregg, Chris E.; Houghton, Bruce F.; Johnston, David M.; Paton, Douglas; Swanson, D.A.

2004-01-01

Volcanic hazards in Kona (i.e. the western side of the island of Hawai'i) stem primarily from Mauna Loa and Huala??lai volcanoes. The former has erupted 39 times since 1832. Lava flows were emplaced in Kona during seven of these eruptions and last impacted Kona in 1950. Huala??lai last erupted in ca. 1800. Society's proximity to potential eruptive sources and the potential for relatively fast-moving lava flows, coupled with relatively long time intervals since the last eruptions in Kona, are the underlying stimuli for this study of risk perception. Target populations were high-school students and adults ( n =462). Using these data, we discuss threat knowledge as an influence on risk perception, and perception as a driving mechanism for preparedness. Threat knowledge and perception of risk were found to be low to moderate. On average, fewer than two-thirds of the residents were aware of the most recent eruptions that impacted Kona, and a minority felt that Mauna Loa and Huala??lai could ever erupt again. Furthermore, only about one-third were aware that lava flows could reach the coast in Kona in less than 3 h. Lava flows and ash fall were perceived to be among the least likely hazards to affect the respondent's community within the next 10 years, whereas vog (volcanic smog) was ranked the most likely. Less than 18% identified volcanic hazards as amongst the most likely hazards to affect them at home, school, or work. Not surprisingly, individual preparedness measures were found on average to be limited to simple tasks of value in frequently occurring domestic emergencies, whereas measures specific to infrequent hazard events such as volcanic eruptions were seldom adopted. Furthermore, our data show that respondents exhibit an 'unrealistic optimism bias' and infer that responsibility for community preparedness for future eruptions primarily rests with officials. We infer that these respondents may be less likely to attend to hazard information, react to warnings as directed, and undertake preparedness measures than other populations who perceive responsibility to lie with themselves. There are significant differences in hazard awareness and risk perception between students and adults, between subpopulations representing local areas, and between varying ethnicities. We conclude that long time intervals since damaging lava flows have occurred in Kona have contributed to lower levels of awareness and risk perceptions of the threat from lava flows, and that the on-going eruption at Ki??lauea has facilitated greater awareness and perception of risk of vog but not of other volcanic hazards. Low levels of preparedness may be explained by low perceptions of threat and risk and perhaps by the lack of a clear motivation or incentive to seek new modes of adjustment. ?? 2003 Published by Elsevier B.V.

30 CFR 75.1103-3 - Automatic fire sensor and warning device systems; minimum requirements; general.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-3 Automatic fire sensor and warning device systems; minimum requirements; general. Automatic fire sensor and warning device systems installed in belt haulageways of...

30 CFR 75.1103-3 - Automatic fire sensor and warning device systems; minimum requirements; general.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-3 Automatic fire sensor and warning device systems; minimum requirements; general. Automatic fire sensor and warning device systems installed in belt haulageways of...

30 CFR 75.1103-3 - Automatic fire sensor and warning device systems; minimum requirements; general.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-3 Automatic fire sensor and warning device systems; minimum requirements; general. Automatic fire sensor and warning device systems installed in belt haulageways of...

30 CFR 75.1103-3 - Automatic fire sensor and warning device systems; minimum requirements; general.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-3 Automatic fire sensor and warning device systems; minimum requirements; general. Automatic fire sensor and warning device systems installed in belt haulageways of...

The Trend of Voluntary Warnings in Electronic Nicotine Delivery System Magazine Advertisements.

PubMed

Shang, Ce; Chaloupka, Frank J

2017-01-10

Some manufacturers of electronic nicotine delivery systems (ENDS) voluntarily carried health warnings in their advertisements. This study examined these voluntary warnings in magazine ads and plotted their trends between 2012 and early 2015. ENDS magazine ads were obtained through Kantar media and warnings were collected from the Chicago Public Library or the Trinkets and Trash surveillance system. The prevalence of voluntary warnings, warnings with the specific capitalized word "WARNING", and MarkTen warnings were examined after being weighted using factors related to exposure between January 2012 and March 2015. Five brands (MarkTen, NJOY, MISTIC, and some Blu) carried warnings during the study period. The prevalence of warnings post 2012 that contained a description of nicotine did not significantly increase until the launch of MarkTen, which also happened several months before April 2014 when the U.S. food and drug administration (FDA) published its proposed deeming rule. In addition, none of these warnings met the criteria required by the FDA in the final rules. Voluntary warnings, particularly MarkTen warnings, significantly increased in ENDS magazine ads between 2014 and 2015. It is important to monitor how ENDS manufacturers will comply with the FDA regulation related to warnings and how this regulation will ultimately impact ENDS risk perceptions and use.

Early Warning System Implementation Guide: For Use with the National High School Center's Early Warning System Tool v2.0

ERIC Educational Resources Information Center

Therriault, Susan Bowles; Heppen, Jessica; O'Cummings, Mindee; Fryer, Lindsay; Johnson, Amy

2010-01-01

This Early Warning System (EWS) Implementation Guide is a supporting document for schools and districts that are implementing the National High School Center's Early Warning System (EWS) Tool v2.0. Developed by the National High School Center at the American Institutes for Research (AIR), the guide and tool support the establishment and…

From 3D to 4D seismic tomography at El Hierro Island (Canary Islands, Spain)

NASA Astrophysics Data System (ADS)

Garcia-Yeguas, A.; Koulakov, I.; Jakovlev, A.; Ibáñez, J. M.

2012-04-01

In this work we are going to show the advantages of a dynamic tomography 4D, versus a static image 3D related with a volcanic reactivation and eruption at El Hierro island (Canary Islands, Spain). In this process a high number of earthquakes before and during the eruptive processes have been registered. We are going to show a 3D image as an average of the velocity structure and then the characteristics and physical properties on the medium, including the presence or not of magma. This image will be complemented with its evolution along the time, observing its volcanic dynamic and its influence over the medium properties, including its power as an important element on early warnings protocols. After more than forty years of quiet at Canary Islands, since 1971 with Teneguía eruption at La Palma Island, and more than 200 years on El Hierro Island (The last eruption known at El Hierro took place in 1793, volcán de Lomo Negro), on 19th July on 2011 the Spanish seismic national network, administered by IGN (Instituto Geográfico Nacional), detected an increase of local seismic activity below El Hierro island (Canary Islands, Spain). Since this moment an intense swarm took place, with more than 11000 events, until 11th December, with magnitudes (MLg) from 0.2 to 4.4. In this period two eruptive processes have been declared in front of the South coast of El Hierro island, and they have not finished yet. This seismic swarm has allowed carrying out a 3D seismic tomography, using P and S waves traveltimes. It has showed a low velocity from the North to the South. On the other hand, we have performed a 4D seismic tomography, taking the events occurred at different intervals of time. We can observe the evolution of the negative anomaly along the time, from the North to the South, where has taken place La Restinga submarine eruption. 4D seismic tomography is an innovative and powerful tool able to show the evolution in time of a volcanic process.

Implementing Obstetric Early Warning Systems.

PubMed

Friedman, Alexander M; Campbell, Mary L; Kline, Carolyn R; Wiesner, Suzanne; D'Alton, Mary E; Shields, Laurence E

2018-04-01

Severe maternal morbidity and mortality are often preventable and obstetric early warning systems that alert care providers of potential impending critical illness may improve maternal safety. While literature on outcomes and test characteristics of maternal early warning systems is evolving, there is limited guidance on implementation. Given current interest in early warning systems and their potential role in care, the 2017 Society for Maternal-Fetal Medicine (SMFM) Annual Meeting dedicated a session to exploring early warning implementation across a wide range of hospital settings. This manuscript reports on key points from this session. While implementation experiences varied based on factors specific to individual sites, common themes relevant to all hospitals presenting were identified. Successful implementation of early warnings systems requires administrative and leadership support, dedication of resources, improved coordination between nurses, providers, and ancillary staff, optimization of information technology, effective education, evaluation of and change in hospital culture and practices, and support in provider decision-making. Evolving data on outcomes on early warning systems suggest that maternal risk may be reduced. To effectively reduce maternal, risk early warning systems that capture deterioration from a broad range of conditions may be required in addition to bundles tailored to specific conditions such as hemorrhage, thromboembolism, and hypertension.

Technology-Based Early Warning Systems for Bipolar Disorder: A Conceptual Framework

PubMed Central

Torous, John; Thompson, Wesley

2016-01-01

Recognition and timely action around “warning signs” of illness exacerbation is central to the self-management of bipolar disorder. Due to its heterogeneity and fluctuating course, passive and active mobile technologies have been increasingly evaluated as adjunctive or standalone tools to predict and prevent risk of worsening of course in bipolar disorder. As predictive analytics approaches to big data from mobile health (mHealth) applications and ancillary sensors advance, it is likely that early warning systems will increasingly become available to patients. Such systems could reduce the amount of time spent experiencing symptoms and diminish the immense disability experienced by people with bipolar disorder. However, in addition to the challenges in validating such systems, we argue that early warning systems may not be without harms. Probabilistic warnings may be delivered to individuals who may not be able to interpret the warning, have limited information about what behaviors to change, or are unprepared to or cannot feasibly act due to time or logistic constraints. We propose five essential elements for early warning systems and provide a conceptual framework for designing, incorporating stakeholder input, and validating early warning systems for bipolar disorder with a focus on pragmatic considerations. PMID:27604265

Proximal pyroclastic deposits from the 1989-1990 eruption of Redoubt Volcano, Alaska - stratigraphy, distribution, and physical characteristics

USGS Publications Warehouse

Gardner, C.A.; Neal, C.A.; Waitt, R.B.; Janda, R.J.

1994-01-01

More than 20 eruptive events during the 1989-1990 eruption of Redoubt Volcano emplaced a complex sequence of lithic pyroclastic-flow, -surge, -fall, ice-diamict, and lahar deposits mainly on the north side of the volcano. The deposits record the changing eruption dynamics from initial gas-rich vent-clearing explosions to episodic gas-poor lava-dome extrusions and failures. The repeated dome failures produced lithic pyroclastic flows that mixed with snow and glacial ice to generate lahars that were channelled off Drift glacier into the Drift River valley. Some of the dome failures occurred without precursory seismic warning and appeared to result solely from gravitational instability. Material from the disrupted lava domes avalanched down a steep, partly ice-filled canyon incised on the north flank of the volcano and came to rest on the heavily crevassed surface of the piedmont lobe of Drift glacier. Most dome-collapse events resulted in single, monolithologic, massive to reversely graded, medium- to coarse-grained, sandy pyroclastic-flow deposits containing abundant dense dome clasts. These deposits vary in thickness, grain size, and texture depending on distance from the vent and local topography; deposits are finer and better sorted down flow, thinner and finer on hummocks, and thicker and coarser where ponded in channels cut through the glacial ice. The initial vent-clearing explosions emplaced unusual deposits of glacial ice, snow, and rock in a frozen matrix on the north and south flanks of the volcano. Similar deposits were described at Nevado del Ruiz, Columbia and have probably been emplaced at other snow-and-ice-clad volcanoes, but poor preservation makes them difficult to recognize in the geologic record. In a like fashion, most deposits from the 1989-1990 eruption of Redoubt Volcano may be difficult to recognize and interpret in the future because they were emplaced in an environment where glacio-fluvial processes dominate and quickly obscure the primary depositional record. ?? 1994.

Observed activation status of lane departure warning and forward collision warning of Honda vehicles at dealership service centers.

PubMed

Reagan, Ian J; McCartt, Anne T

2016-11-16

There are little objective data on whether drivers with lane departure warning and forward collision warning systems actually use them, but self-report data indicate that lane departure warning may be used less and viewed less favorably than forward collision warning. The current study assessed whether the systems were turned on when drivers brought their vehicles to dealership service stations and whether the observational protocol is a feasible method for collecting similar data on various manufacturers' systems. Observations of 2013-2015 Honda Accords, 2014-2015 Odysseys, and 2015 CR-Vs occurred at 2 U.S. Honda dealerships for approximately 4 weeks during Summer 2015. Of the 265 vehicles observed to have the 2 systems, 87 (32.8%) had lane departure warning turned on. Accords were associated with a 66% increase in the likelihood that lane departure warning was turned on compared with Odysseys, but the rate was still only about 40% in Accords. In contrast, forward collision warning was turned on in all but one of the observed vehicles. Observations found that the activation rate was much higher for forward collision warning than lane departure warning. The observation method worked well and appears feasible for extending to other manufacturers.

30 CFR 75.1103-8 - Automatic fire sensor and warning device systems; examination and test requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-8 Automatic fire sensor and warning device systems; examination and test requirements. (a) Automatic fire sensor and warning device systems shall be examined at...

30 CFR 75.1103-8 - Automatic fire sensor and warning device systems; examination and test requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-8 Automatic fire sensor and warning device systems; examination and test requirements. (a) Automatic fire sensor and warning device systems shall be examined at...

30 CFR 75.1103-8 - Automatic fire sensor and warning device systems; examination and test requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-8 Automatic fire sensor and warning device systems; examination and test requirements. (a) Automatic fire sensor and warning device systems shall be examined at...

30 CFR 75.1103-8 - Automatic fire sensor and warning device systems; examination and test requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-8 Automatic fire sensor and warning device systems; examination and test requirements. (a) Automatic fire sensor and warning device systems shall be examined at...

30 CFR 75.1103-8 - Automatic fire sensor and warning device systems; examination and test requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-8 Automatic fire sensor and warning device systems; examination and test requirements. (a) Automatic fire sensor and warning device systems shall be examined at...

Petrological evidence for non-linear increase of magmatic intrusion rates before eruption at open vent mafic volcanoe

NASA Astrophysics Data System (ADS)

Ruth, D. C. S.; Costa Rodriguez, F.

2015-12-01

The most active volcanoes on earth erupt in a yearly to decadal time scales, typically erupt mafic magmas and are open-vent systems with prominent degassing plumes (e.g. Mayon, Arenal, Llaima, Etna). Here we investigate the plumbing systems, dynamics, and processes that drive eruptions at these systems. These are key questions for improving hazard evaluation, and better understanding the unrest associated with these types of volcanoes. The petrology and geochemistry from six historical eruptions (1947-2006) of Mayon volcano (Philippines) shows that all lavas are basaltic andesite with phenocrysts of plagioclase + orthopyroxene (Opx) + clinopyroxene. Opx crystals show a variety of compositions and zoning patterns (reverse, normal or complex) with Mg# (= 100 *Mg/[Mg+Fe]) varying from 67 to 81. The simplest interpretation is that the low Mg# parts of the crystals resided on an upper crustal and crystal rich reservoir that was intruded by more primitive magmas from which the high Mg# parts of the crystals grew. Modelling Mg-Fe diffusion in Opx shows that times since magma injection and eruption range from a few days up to 3.5 years in all of the investigated eruptions. The longest diffusion times are shorter than the repose times between the eruptions, which implies that crystal recycling between eruptive events is negligible. This is a surprising result that shows that for each eruption a different part of the evolved crystal-rich plumbing system is activated. This can be due to random intrusion location or an irreversibility of the plumbing system that prevents multiple eruptions from the same crystal-rich part. Moreover, we find that the number of intrusions markedly increases before each eruption in a non-linear manner. Such an increased rate of intrusions with time might reflect non-linear rheological properties of the crystal-rich system, of the enclosing rocks, or the non-linear evolution of crystal-melt reaction-dissolution fronts during magma intrusions.

76 FR 35327 - Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-17

... stabilizer takeoff warning switches, and corrective actions if necessary. This AD was prompted by reports that the warning horn did not sound during the takeoff warning system test of the S132 ``nose up stab takeoff warning switch.'' We are issuing this AD to detect and correct a takeoff warning system switch...

75 FR 55691 - Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-14

... takeoff warning switches, and corrective actions if necessary. This proposed AD results from reports that the warning horn did not sound during the takeoff warning system test of the S132 ``nose up stab takeoff warning switch.'' We are proposing this AD to detect and correct a takeoff warning system switch...

Advanced driver assistance systems: Using multimodal redundant warnings to enhance road safety.

PubMed

Biondi, Francesco; Strayer, David L; Rossi, Riccardo; Gastaldi, Massimiliano; Mulatti, Claudio

2017-01-01

This study investigated whether multimodal redundant warnings presented by advanced assistance systems reduce brake response times. Warnings presented by assistance systems are designed to assist drivers by informing them that evasive driving maneuvers are needed in order to avoid a potential accident. If these warnings are poorly designed, they may distract drivers, slow their responses, and reduce road safety. In two experiments, participants drove a simulated vehicle equipped with a forward collision avoidance system. Auditory, vibrotactile, and multimodal warnings were presented when the time to collision was shorter than five seconds. The effects of these warnings were investigated with participants performing a concurrent cell phone conversation (Exp. 1) or driving in high-density traffic (Exp. 2). Braking times and subjective workload were measured. Multimodal redundant warnings elicited faster braking reaction times. These warnings were found to be effective even when talking on a cell phone (Exp. 1) or driving in dense traffic (Exp. 2). Multimodal warnings produced higher ratings of urgency, but ratings of frustration did not increase compared to other warnings. Findings obtained in these two experiments are important given that faster braking responses may reduce the potential for a collision. Copyright © 2016 Elsevier Ltd. All rights reserved.

Probabilistic short-term forecasting of eruption rate at Kīlauea Volcano using a physics-based model

NASA Astrophysics Data System (ADS)

Anderson, K. R.

2016-12-01

Deterministic models of volcanic eruptions yield predictions of future activity conditioned on uncertainty in the current state of the system. Physics-based eruption models are well-suited for deterministic forecasting as they can relate magma physics with a wide range of observations. Yet, physics-based eruption forecasting is strongly limited by an inadequate understanding of volcanic systems, and the need for eruption models to be computationally tractable. At Kīlauea Volcano, Hawaii, episodic depressurization-pressurization cycles of the magma system generate correlated, quasi-exponential variations in ground deformation and surface height of the active summit lava lake. Deflations are associated with reductions in eruption rate, or even brief eruptive pauses, and thus partly control lava flow advance rates and associated hazard. Because of the relatively well-understood nature of Kīlauea's shallow magma plumbing system, and because more than 600 of these events have been recorded to date, they offer a unique opportunity to refine a physics-based effusive eruption forecasting approach and apply it to lava eruption rates over short (hours to days) time periods. A simple physical model of the volcano ascribes observed data to temporary reductions in magma supply to an elastic reservoir filled with compressible magma. This model can be used to predict the evolution of an ongoing event, but because the mechanism that triggers events is unknown, event durations are modeled stochastically from previous observations. A Bayesian approach incorporates diverse data sets and prior information to simultaneously estimate uncertain model parameters and future states of the system. Forecasts take the form of probability distributions for eruption rate or cumulative erupted volume at some future time. Results demonstrate the significant uncertainties that still remain even for short-term eruption forecasting at a well-monitored volcano - but also the value of a physics-based, mixed deterministic-probabilistic eruption forecasting approach in reducing and quantifying these uncertainties.

Recent Progress of Solar Weather Forecasting at Naoc

NASA Astrophysics Data System (ADS)

He, Han; Wang, Huaning; Du, Zhanle; Zhang, Liyun; Huang, Xin; Yan, Yan; Fan, Yuliang; Zhu, Xiaoshuai; Guo, Xiaobo; Dai, Xinghua

The history of solar weather forecasting services at National Astronomical Observatories, Chinese Academy of Sciences (NAOC) can be traced back to 1960s. Nowadays, NAOC is the headquarters of the Regional Warning Center of China (RWC-China), which is one of the members of the International Space Environment Service (ISES). NAOC is responsible for exchanging data, information and space weather forecasts of RWC-China with other RWCs. The solar weather forecasting services at NAOC cover short-term prediction (within two or three days), medium-term prediction (within several weeks), and long-term prediction (in time scale of solar cycle) of solar activities. Most efforts of the short-term prediction research are concentrated on the solar eruptive phenomena, such as flares, coronal mass ejections (CMEs) and solar proton events, which are the key driving sources of strong space weather disturbances. Based on the high quality observation data of the latest space-based and ground-based solar telescopes and with the help of artificial intelligence techniques, new numerical models with quantitative analyses and physical consideration are being developed for the predictions of solar eruptive events. The 3-D computer simulation technology is being introduced for the operational solar weather service platform to visualize the monitoring of solar activities, the running of the prediction models, as well as the presenting of the forecasting results. A new generation operational solar weather monitoring and forecasting system is expected to be constructed in the near future at NAOC.

A systematic approach to advanced cockpit warning systems for air transport operations: Line pilot preferences

NASA Technical Reports Server (NTRS)

Williams, D. H.; Simpson, C. A.

1976-01-01

Line pilots (fifty captains, first officers, and flight engineers) from 8 different airlines were administered a structured questionnaire relating to future warning system design and solutions to current warning system problems. This was followed by a semantic differential to obtain a factor analysis of 18 different cockpit warning signals on scales such as informative/distracting, annoying/soothing. Half the pilots received a demonstration of the experimental text and voice synthesizer warning systems before answering the questionnaire and the semantic differential. A control group answered the questionnaire and the semantic differential first, thus providing a check for the stability of pilot preferences with and without actual exposure to experimental systems. Generally, the preference data obtained revealed much consistency and strong agreement among line pilots concerning advance cockpit warning system design.

The Trend of Voluntary Warnings in Electronic Nicotine Delivery System Magazine Advertisements

PubMed Central

Shang, Ce; Chaloupka, Frank J.

2017-01-01

Some manufacturers of electronic nicotine delivery systems (ENDS) voluntarily carried health warnings in their advertisements. This study examined these voluntary warnings in magazine ads and plotted their trends between 2012 and early 2015. ENDS magazine ads were obtained through Kantar media and warnings were collected from the Chicago Public Library or the Trinkets and Trash surveillance system. The prevalence of voluntary warnings, warnings with the specific capitalized word “WARNING”, and MarkTen warnings were examined after being weighted using factors related to exposure between January 2012 and March 2015. Five brands (MarkTen, NJOY, MISTIC, and some Blu) carried warnings during the study period. The prevalence of warnings post 2012 that contained a description of nicotine did not significantly increase until the launch of MarkTen, which also happened several months before April 2014 when the U.S. food and drug administration (FDA) published its proposed deeming rule. In addition, none of these warnings met the criteria required by the FDA in the final rules. Voluntary warnings, particularly MarkTen warnings, significantly increased in ENDS magazine ads between 2014 and 2015. It is important to monitor how ENDS manufacturers will comply with the FDA regulation related to warnings and how this regulation will ultimately impact ENDS risk perceptions and use. PMID:28075420

People-centred landslide early warning systems in the context of risk management

NASA Astrophysics Data System (ADS)

Haß, S.; Asch, K.; Fernandez-Steeger, T.; Arnhardt, C.

2009-04-01

In the current hazard research people-centred warning becomes more and more important, because different types of organizations and groups have to be involved in the warning process. This fact has to be taken into account when developing early warning systems. The effectiveness of early warning depends not only on technical capabilities but also on the preparedness of decision makers and their immediate response on how to act in case of emergency. Hence early warning systems have to be regarded in the context of an integrated and holistic risk management. Disaster Risk Reduction (DRR) measures include people-centred, timely and understandable warning. Further responsible authorities have to be identified in advance and standards for risk communication have to be established. Up to now, hazard and risk assessment for geohazards focuses on the development of inventory, susceptibility, hazard and risk maps. But often, especially in Europe, there are no institutional structures for managing geohazards and in addition there is a lack of an authority that is legally obliged to alarm on landslides at national or regional level. One of the main characteristics within the warning process for natural hazards e.g. in Germany is the split of responsibility between scientific authorities (wissenschaftliche Fachbehörde) and enforcement authorities (Vollzugsbehörde). The scientific authority provides the experts who define the methods and measures for monitoring and evaluate the hazard level. The main focus is the acquisition and evaluation of data and subsequently the distribution of information. The enforcement authority issues official warnings about dangerous natural phenomena. Hence the information chain in the context of early warning ranges over two different institutions, the forecast service and the warning service. But there doesn't exist a framework for warning processes in terms of landslides as yet. The concept for managing natural disasters is often reduced to hazard assessment and emergency response. Great importance is attached to the scientific understanding of hazards and protective structures, while analysis of socio-economic impacts and risk assessment are not considered enough. The reduction of vulnerability has to be taken into greater account. Also the information needs of different stakeholders have to be identified at an early stage and should be integrated in the development of early warning systems. The content of the warning message must be simple, understandable and should cover instructions on how to react. Further the timeliness of the messages has to be guarented. In this context the aim of the landslide monitoring and early warning system SLEWS (Sensor Based Landslide Early Warning System) is to integrate the above mentioned aspects of a holistic disaster and risk management. The technology of spatial data infrastructures and web services provides the use of multiple communication channels within an early warning system. Thus people-centred early warning messages and information about slope stability can be sent in nearly real-time. It has to be underlined that the technological information process is just one element of an effective warning system. Moreover the warning system has also to be considered as a social system and has to make allowance to socio-economic and gender aspects : «[...] Develop early warning systems that are people centered, in particular systems whose warnings are timely and understandable to those at risk, which take into account the demographic, gender, cultural and livelihood characteristics of the target audiences, including guidance on how to act upon warnings, and that support effective operations by disaster managers and other decision makers » (Hyogo Framework, 2005) References : UNITED NATIONS INTERNATIONAL STRATEGY FOR DISASTER REDUCTION SECRETARIAT (UNISDR) (2006): Developing early warning systems: a checklist, Third international conference on early warning (EWC III): from concept to action: 27-29 March 2006, Bonn, Germany. Geneva, Switzerland: International Strategy for Disaster Reduction. WORLD CONFERENCE ON DISASTER REDUCTION (2005) : Report of the World Conference on Disaster Reduction: Kobe, Hyogo, Japan, 18-22 January 2005. Geneva, Switzerland, Secretariat, World Conference on Disaster Reduction. INTER-AGENCY SECRETARIAT OF THE ISDR & GLOBAL PLATFORM FOR DISASTER RISK REDUCTION (2007): Disaster risk reduction: 2007 global review. Geneva, UN, ISDR.

Assessing the performance of regional landslide early warning models: the EDuMaP method

NASA Astrophysics Data System (ADS)

Calvello, M.; Piciullo, L.

2015-10-01

The paper proposes the evaluation of the technical performance of a regional landslide early warning system by means of an original approach, called EDuMaP method, comprising three successive steps: identification and analysis of the Events (E), i.e. landslide events and warning events derived from available landslides and warnings databases; definition and computation of a Duration Matrix (DuMa), whose elements report the time associated with the occurrence of landslide events in relation to the occurrence of warning events, in their respective classes; evaluation of the early warning model Performance (P) by means of performance criteria and indicators applied to the duration matrix. During the first step, the analyst takes into account the features of the warning model by means of ten input parameters, which are used to identify and classify landslide and warning events according to their spatial and temporal characteristics. In the second step, the analyst computes a time-based duration matrix having a number of rows and columns equal to the number of classes defined for the warning and landslide events, respectively. In the third step, the analyst computes a series of model performance indicators derived from a set of performance criteria, which need to be defined by considering, once again, the features of the warning model. The proposed method is based on a framework clearly distinguishing between local and regional landslide early warning systems as well as among correlation laws, warning models and warning systems. The applicability, potentialities and limitations of the EDuMaP method are tested and discussed using real landslides and warnings data from the municipal early warning system operating in Rio de Janeiro (Brazil).

A novel approach to estimate the eruptive potential and probability in open conduit volcanoes

PubMed Central

De Gregorio, Sofia; Camarda, Marco

2016-01-01

In open conduit volcanoes, volatile-rich magma continuously enters into the feeding system nevertheless the eruptive activity occurs intermittently. From a practical perspective, the continuous steady input of magma in the feeding system is not able to produce eruptive events alone, but rather surplus of magma inputs are required to trigger the eruptive activity. The greater the amount of surplus of magma within the feeding system, the higher is the eruptive probability.Despite this observation, eruptive potential evaluations are commonly based on the regular magma supply, and in eruptive probability evaluations, generally any magma input has the same weight. Conversely, herein we present a novel approach based on the quantification of surplus of magma progressively intruded in the feeding system. To quantify the surplus of magma, we suggest to process temporal series of measurable parameters linked to the magma supply. We successfully performed a practical application on Mt Etna using the soil CO2 flux recorded over ten years. PMID:27456812

A novel approach to estimate the eruptive potential and probability in open conduit volcanoes.

PubMed

De Gregorio, Sofia; Camarda, Marco

2016-07-26

In open conduit volcanoes, volatile-rich magma continuously enters into the feeding system nevertheless the eruptive activity occurs intermittently. From a practical perspective, the continuous steady input of magma in the feeding system is not able to produce eruptive events alone, but rather surplus of magma inputs are required to trigger the eruptive activity. The greater the amount of surplus of magma within the feeding system, the higher is the eruptive probability.Despite this observation, eruptive potential evaluations are commonly based on the regular magma supply, and in eruptive probability evaluations, generally any magma input has the same weight. Conversely, herein we present a novel approach based on the quantification of surplus of magma progressively intruded in the feeding system. To quantify the surplus of magma, we suggest to process temporal series of measurable parameters linked to the magma supply. We successfully performed a practical application on Mt Etna using the soil CO2 flux recorded over ten years.

Magma plumbing for the 2014-2015 Holuhraun eruption, Iceland

NASA Astrophysics Data System (ADS)

Geiger, Harri; Mattsson, Tobias; Deegan, Frances M.; Troll, Valentin R.; Burchardt, Steffi; Gudmundsson, Ólafur; Tryggvason, Ari; Krumbholz, Michael; Harris, Chris

2016-08-01

The 2014-2015 Holuhraun eruption on Iceland was located within the Askja fissure swarm but was accompanied by caldera subsidence in the Bárðarbunga central volcano 45 km to the southwest. Geophysical monitoring of the eruption identified a seismic swarm that migrated from Bárðarbunga to the Holuhraun eruption site over the course of two weeks. In order to better understand this lateral connection between Bárðarbunga and Holuhraun, we present mineral textures and compositions, mineral-melt-equilibrium calculations, whole rock and trace element data, and oxygen isotope ratios for selected Holuhraun samples. The Holuhraun lavas are compositionally similar to recorded historical eruptions from the Bárðarbunga volcanic system but are distinct from the historical eruption products of the nearby Askja system. Thermobarometry calculations indicate a polybaric magma plumbing system for the Holuhraun eruption, wherein clinopyroxene and plagioclase crystallized at average depths of ˜17 km and ˜5 km, respectively. Crystal resorption textures and oxygen isotope variations imply that this multilevel plumbing system facilitated magma mixing and assimilation of low-δ18O Icelandic crust prior to eruption. In conjunction with the existing geophysical evidence for lateral migration, our results support a model of initial vertical magma ascent within the Bárðarbunga plumbing system followed by lateral transport of aggregated magma batches within the upper crust to the Holuhraun eruption site.

Design of vehicle intelligent anti-collision warning system

NASA Astrophysics Data System (ADS)

Xu, Yangyang; Wang, Ying

2018-05-01

This paper mainly designs a low cost, high-accuracy, micro-miniaturization, and digital display and acousto-optic alarm features of the vehicle intelligent anti-collision warning system that based on MCU AT89C51. The vehicle intelligent anti-collision warning system includes forward anti-collision warning system, auto parking systems and reversing anti-collision radar system. It mainly develops on the basis of ultrasonic distance measurement, its performance is reliable, thus the driving safety is greatly improved and the parking security and efficiency enhance enormously.

Anatomy of Historical Tsunamis: Lessons Learned for Tsunami Warning

NASA Astrophysics Data System (ADS)

Igarashi, Y.; Kong, L.; Yamamoto, M.; McCreery, C. S.

2011-11-01

Tsunamis are high-impact disasters that can cause death and destruction locally within a few minutes of their occurrence and across oceans hours, even up to a day, afterward. Efforts to establish tsunami warning systems to protect life and property began in the Pacific after the 1946 Aleutian Islands tsunami caused casualties in Hawaii. Seismic and sea level data were used by a central control center to evaluate tsunamigenic potential and then issue alerts and warnings. The ensuing events of 1952, 1957, and 1960 tested the new system, which continued to expand and evolve from a United States system to an international system in 1965. The Tsunami Warning System in the Pacific (ITSU) steadily improved through the decades as more stations became available in real and near-real time through better communications technology and greater bandwidth. New analysis techniques, coupled with more data of higher quality, resulted in better detection, greater solution accuracy, and more reliable warnings, but limitations still exist in constraining the source and in accurately predicting propagation of the wave from source to shore. Tsunami event data collected over the last two decades through international tsunami science surveys have led to more realistic models for source generation and inundation, and within the warning centers, real-time tsunami wave forecasting will become a reality in the near future. The tsunami warning system is an international cooperative effort amongst countries supported by global and national monitoring networks and dedicated tsunami warning centers; the research community has contributed to the system by advancing and improving its analysis tools. Lessons learned from the earliest tsunamis provided the backbone for the present system, but despite 45 years of experience, the 2004 Indian Ocean tsunami reminded us that tsunamis strike and kill everywhere, not just in the Pacific. Today, a global intergovernmental tsunami warning system is coordinated under the United Nations. This paper reviews historical tsunamis, their warning activities, and their sea level records to highlight lessons learned with the focus on how these insights have helped to drive further development of tsunami warning systems and their tsunami warning centers. While the international systems do well for teletsunamis, faster detection, more accurate evaluations, and widespread timely alerts are still the goals, and challenges still remain to achieving early warning against the more frequent and destructive local tsunamis.

Triggering of solar magnetic eruptions on various size scales

NASA Astrophysics Data System (ADS)

Sterling, Alphonse

A solar eruption that produces a coronal mass ejection (CME) together with a flare is driven by the eruption of a closed-loop magnetic arcade that has a sheared-field core. Before eruption, the sheared core envelops a polarity inversion line along which cool filament material may reside. The sheared-core arcade erupts when there is a breakdown in the balance between the confining downward-directed magnetic tension of the overall arcade field and the upward-directed force of the pent-up magnetic pressure of the sheared field in the core of the arcade. What triggers the breakdown in this balance in favor of the upward-directed force is still an unsettled question. We consider several eruption examples, using imaging data from the SoHO, TRACE and Hinode satellites, and other sources, along with information about the magnetic field of the erupting regions. In several cases, observations of large-scale eruptions, where the magnetic neutral line spans ˜ few ×10,000 km, are consistent with magnetic flux cancelation being the trigger to the eruption's onset, even though the amount of flux canceled is only ˜ few percent of the total magnetic flux of the erupting region. In several other cases, an initial compact (small size-scale) eruption occurs embedded inside of a larger closed magnetic loop system, so that the smaller eruption destabilizes and causes the eruption of the much larger system. In this way, small-scale eruptive events can result in eruption of much larger-scale systems. This work was funded by NASA's Science Mission Directorate thought the Living With a Star Targeted Research and Technology Program, the Supporting Research and Program, and the Hinode project.

Processes Influencing the Timing and Volume of Eruptions From the Youngest Supervolcano on Earth

NASA Astrophysics Data System (ADS)

Wilson, C. J. N.; Barker, S. J.; Morgan, D. J.; Rowland, J. V.; Schipper, I.

2015-12-01

In their stratigraphic records, silicic caldera volcanoes display wide ranges of eruptive styles and volumes. However, relationships between frequency and magnitude are often complex, and the forecasting of future activity is inherently problematic. Taupo volcano, New Zealand, provides a unique opportunity to investigate eruptive histories from a hyperactive, large silicic magmatic system with eruptive volumes that span 3-4 orders of magnitude, and show no clear relationships with the repose period. Taupo hosted the world's most recent supereruption at 25.4 ka, which discharged 530 km3 of magma in the episodic 10-phase Oruanui event. Only 5 kyr later, Taupo revived, with 3 dacitic eruptions from 21.5-17 ka and 25 rhyolite eruptions from 12-1.7 ka. Here we use trends in whole rock, glass and mineral chemistry to show how the magma system reestablished following the Oruanui event, and to consider what processes influence the state of the modern volcano. The post-Oruanui dacites reflect the first products of the rebuilding silicic magma system, as most of the Oruanui mush was reconfigured or significantly modified in composition following thermal fluxing accompanying post-caldera collapse readjustment. Compositional variations within the younger rhyolites at <12 ka reflect fine-scale temporal changes in mineral phase stability, closely linked to the development, stabilization and maturation of a new silicic mush system. For the most recent eruptions, the system underwent destabilization, resulting in increased volumes of melt extraction from the silicic mush. Orthopyroxene Fe-Mg diffusion timescales indicate that the onset of rapid heating and priming of the silicic mush occurred <100 years prior to the <2.15 ka eruptions, with subsequent melt accumulation occurring in only decades. The largest post-Oruanui eruption at 232 AD culminated from elevated mafic magma supply to the silicic mush pile, rapid melt accumulation and high differential tectonic stress build up, leading to one of the largest and most violent Holocene eruptions globally. The latest eruptions of Taupo highlight the multiple controls on the timing of eruptions, and demonstrate how the magmatic system can rapidly change behavior to generate large eruptible melt bodies on timescales of direct relevance to humans and monitoring initiatives.

Understanding the environmental impacts of large fissure eruptions: Aerosol and gas emissions from the 2014-2015 Holuhraun eruption (Iceland)

NASA Astrophysics Data System (ADS)

Ilyinskaya, Evgenia; Schmidt, Anja; Mather, Tamsin A.; Pope, Francis D.; Witham, Claire; Baxter, Peter; Jóhannsson, Thorsteinn; Pfeffer, Melissa; Barsotti, Sara; Singh, Ajit; Sanderson, Paul; Bergsson, Baldur; McCormick Kilbride, Brendan; Donovan, Amy; Peters, Nial; Oppenheimer, Clive; Edmonds, Marie

2017-08-01

The 2014-2015 Holuhraun eruption in Iceland, emitted ∼11 Tg of SO2 into the troposphere over 6 months, and caused one of the most intense and widespread volcanogenic air pollution events in centuries. This study provides a number of source terms for characterisation of plumes in large fissure eruptions, in Iceland and elsewhere. We characterised the chemistry of aerosol particle matter (PM) and gas in the Holuhraun plume, and its evolution as the plume dispersed, both via measurements and modelling. The plume was sampled at the eruptive vent, and in two populated areas in Iceland. The plume caused repeated air pollution events, exceeding hourly air quality standards (350 μg/m3) for SO2 on 88 occasions in Reykjahlíð town (100 km distance), and 34 occasions in Reykjavík capital area (250 km distance). Average daily concentration of volcanogenic PM sulphate exceeded 5 μg/m3 on 30 days in Reykjavík capital area, which is the maximum concentration measured during non-eruptive background interval. There are currently no established air quality standards for sulphate. Combining the results from direct sampling and dispersion modelling, we identified two types of plume impacting the downwind populated areas. The first type was characterised by high concentrations of both SO2 and S-bearing PM, with a high Sgas/SPM mass ratio (SO2(g)/SO42-(PM) > 10). The second type had a low Sgas/SPM ratio (<10). We suggest that this second type was a mature plume where sulphur had undergone significant gas-to-aerosol conversion in the atmosphere. Both types of plume were rich in fine aerosol (predominantly PM1 and PM2.5), sulphate (on average ∼90% of the PM mass) and various trace species, including heavy metals. The fine size of the volcanic PM mass (75-80% in PM2.5), and the high environmental lability of its chemical components have potential adverse implications for environmental and health impacts. However, only the dispersion of volcanic SO2 was forecast in public warnings and operationally monitored during the eruption. We make a recommendation that sulphur gas-to-aerosol conversion processes, and a sufficiently large model domain to contain the transport of a tropospheric plume on the timescale of days be utilized for public health and environmental impact forecasting in future eruptions in Iceland and elsewhere in the world.

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Operating characteristics of warning system... Maintenance Standards § 234.205 Operating characteristics of warning system apparatus. Operating... system shall be maintained in accordance with the limits within which the system is designed to operate. ...

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Operating characteristics of warning system... Maintenance Standards § 234.205 Operating characteristics of warning system apparatus. Operating... system shall be maintained in accordance with the limits within which the system is designed to operate. ...

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Operating characteristics of warning system... Maintenance Standards § 234.205 Operating characteristics of warning system apparatus. Operating... system shall be maintained in accordance with the limits within which the system is designed to operate. ...

49 CFR 234.259 - Warning time.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 12 months and when the warning system is modified because of a change in train speeds. Electronic... 49 Transportation 4 2014-10-01 2014-10-01 false Warning time. 234.259 Section 234.259... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.259 Warning...

49 CFR 234.259 - Warning time.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 12 months and when the warning system is modified because of a change in train speeds. Electronic... 49 Transportation 4 2012-10-01 2012-10-01 false Warning time. 234.259 Section 234.259... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.259 Warning...

49 CFR 234.259 - Warning time.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 12 months and when the warning system is modified because of a change in train speeds. Electronic... 49 Transportation 4 2013-10-01 2013-10-01 false Warning time. 234.259 Section 234.259... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.259 Warning...

Rapid assembly and rejuvenation of a large silicic magmatic system: Insights from mineral diffusive profiles in the Kidnappers and Rocky Hill deposits, New Zealand

NASA Astrophysics Data System (ADS)

Cooper, George F.; Morgan, Daniel J.; Wilson, Colin J. N.

2017-09-01

The timescales over which magmas in large silicic systems are reactivated, assembled and stored remains a fundamental question in volcanology. To address this question, we study timescales from Fe-Mg interdiffusion in orthopyroxenes and Ti diffusion in quartz from the caldera-forming 1200 km3 Kidnappers and 200 km3 Rocky Hill eruptions from the Mangakino volcanic centre (Taupo Volcanic Zone, New Zealand). The two eruptions came from the same source area, have indistinguishable 40Ar/39Ar ages (∼1.0 Ma) and zircon U-Pb age spectra, but their respective deposits are separated by a short period of erosion. Compositions of pumice, glass and mineral species in the collective eruption deposits define multiple melt dominant bodies but indicate that these shared a common magmatic mush zone. Diffusion timescales from both eruptions are used to build on chemical and textural crystal signatures and interpret both the crystal growth histories and the timing of magma accumulation. Fe-Mg interdiffusion profiles in orthopyroxenes imply that the three melt-dominant bodies, established through extraction of melt and crystals from the common source, were generated within 600 years and with peak accumulation rates within 100 years of each eruption. In addition, a less-evolved melt interacted with the Kidnappers magma, beginning ∼30 years prior to and peaking within 3 years of the eruption. This interaction did not directly trigger the eruption, but may have primed the magmatic system. Orthopyroxene crystals with the same zoning patterns from the Kidnappers and Rocky Hill pumices yield consistently different diffusion timescales, suggesting a time break between the eruptions of ∼20 years (from core-rim zones) to ∼10 years (outer rim zones). Diffusion of Ti in quartz reveals similarly short timescales and magmatic residence times of <30 years, suggesting quartz is only recording the last period of crystallization within the final eruptible melt. Accumulation of the eruptible magma for these two, closely successive eruptions was accomplished over centuries to decades, in contrast to the gestation time of the magmatic system of ∼200 kyr, as indicated by zircon age patterns. The magmatic system was able to recover after the Kidnappers eruption in only ∼10-20 years to accumulate enough eruptible melt and crystals for a second ∼ 200 km3 eruption. Our data support concepts of large silicic systems being stored as long-lived crystal mushes, with eruptible melts generated over extraordinarily short timescales prior to eruption.

Recent Progress in Understanding Natural-Hazards-Generated TEC Perturbations: Measurements and Modeling Results

NASA Astrophysics Data System (ADS)

Komjathy, A.; Yang, Y. M.; Meng, X.; Verkhoglyadova, O. P.; Mannucci, A. J.; Langley, R. B.

2015-12-01

Natural hazards, including earthquakes, volcanic eruptions, and tsunamis, have been significant threats to humans throughout recorded history. The Global Positioning System satellites have become primary sensors to measure signatures associated with such natural hazards. These signatures typically include GPS-derived seismic deformation measurements, co-seismic vertical displacements, and real-time GPS-derived ocean buoy positioning estimates. Another way to use GPS observables is to compute the ionospheric total electron content (TEC) to measure and monitor post-seismic ionospheric disturbances caused by earthquakes, volcanic eruptions, and tsunamis. Research at the University of New Brunswick (UNB) laid the foundations to model the three-dimensional ionosphere at NASA's Jet Propulsion Laboratory by ingesting ground- and space-based GPS measurements into the state-of-the-art Global Assimilative Ionosphere Modeling (GAIM) software. As an outcome of the UNB and NASA research, new and innovative GPS applications have been invented including the use of ionospheric measurements to detect tiny fluctuations in the GPS signals between the spacecraft and GPS receivers caused by natural hazards occurring on or near the Earth's surface.We will show examples for early detection of natural hazards generated ionospheric signatures using ground-based and space-borne GPS receivers. We will also discuss recent results from the U.S. Real-time Earthquake Analysis for Disaster Mitigation Network (READI) exercises utilizing our algorithms. By studying the propagation properties of ionospheric perturbations generated by natural hazards along with applying sophisticated first-principles physics-based modeling, we are on track to develop new technologies that can potentially save human lives and minimize property damage. It is also expected that ionospheric monitoring of TEC perturbations might become an integral part of existing natural hazards warning systems.

Landslide risk mitigation by means of early warning systems

NASA Astrophysics Data System (ADS)

Calvello, Michele

2017-04-01

Among the many options available to mitigate landslide risk, early warning systems may be used where, in specific circumstances, the risk to life increases above tolerable levels. A coherent framework to classify and analyse landslide early warning systems (LEWS) is herein presented. Once the objectives of an early warning strategy are defined depending on the scale of analysis and the type of landslides to address, the process of designing and managing a LEWS should synergically employ technical and social skills. A classification scheme for the main components of LEWSs is proposed for weather-induced landslides. The scheme is based on a clear distinction among: i) the landslide model, i.e. a functional relationship between weather characteristics and landslide events considering the geotechnical, geomorphological and hydro-geological characterization of the area as well as an adequate monitoring strategy; ii) the warning model, i.e. the landslide model plus procedures to define the warning events and to issue the warnings; iii) the warning system, i.e. the warning model plus warning dissemination procedures, communication and education tools, strategies for community involvement and emergency plans. Each component of a LEWS is related to a number of actors involved with their deployment, operational activities and management. For instance, communication and education, community involvement and emergency plans are all significantly influenced by people's risk perception and by operational aspects system managers need to address in cooperation with scientists.

Early prediction of eruption site using lightning location data: An operational real-time system in Iceland

NASA Astrophysics Data System (ADS)

Arason, Þórður; Bjornsson, Halldór; Nína Petersen, Guðrún

2013-04-01

Eruption of subglacial volcanoes may lead to catastrophic floods and thus early determination of the exact eruption site may be critical to civil protection evacuation plans. A system is being developed that automatically monitors and analyses volcanic lightning in Iceland. The system predicts the eruption site location from mean lightning locations, taking into account upper level wind. In estimating mean lightning locations, outliers are automatically omitted. A simple wind correction is performed based on the vector wind at the 500 hPa pressure level in the latest radiosonde from Keflavík airport. The system automatically creates a web page with maps and tables showing individual lightning locations and mean locations with and without wind corrections along with estimates of uncetainty. A dormant automatic monitoring system, waiting for a rare event, potentially for several years, is quite susceptible to degeneration during the waiting period, e.g. due to computer or other IT-system upgrades. However, ordinary weather thunderstorms in Iceland should initiate special monitoring and automatic analysis of this system in the same fashion as during a volcanic eruption. Such ordinary weather thunderstorm events will be used to observe anomalies and malfunctions in the system. The essential elements of this system will be described. An example is presented of how the system would have worked during the first hours of the Grímsvötn 2011 eruption. In that case the exact eruption site, within the Grímsvötn caldera, was first known about 15 hours into the eruption.

The social impacts of the heat-health watch/warning system in Phoenix, Arizona: assessing the perceived risk and response of the public.

PubMed

Kalkstein, Adam J; Sheridan, Scott C

2007-10-01

Heat is the leading weather-related killer in the United States. Although previous research suggests that social influences affect human responses to natural disaster warnings, no studies have examined the social impacts of heat or heat warnings on a population. Here, 201 surveys were distributed in Metropolitan Phoenix to determine the social impacts of the heat warning system, or more specifically, to gauge risk perception and warning response. Consistent with previous research, increased risk perception of heat results in increased response to a warning. Different social factors such as sex, race, age, and income all play an important role in determining whether or not people will respond to a warning. In particular, there is a strong sense of perceived risk to the heat among Hispanics which translates to increased response when heat warnings are issued. Based on these findings, suggestions are presented to help improve the Phoenix Heat Warning System.

Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica

NASA Astrophysics Data System (ADS)

de Moor, J. M.; Aiuppa, A.; Pacheco, J.; Avard, G.; Kern, C.; Liuzzo, M.; Martínez, M.; Giudice, G.; Fischer, T. P.

2016-05-01

Volcanic eruptions involving interaction with water are amongst the most violent and unpredictable geologic phenomena on Earth. Phreatic eruptions are exceptionally difficult to forecast by traditional geophysical techniques. Here we report on short-term precursory variations in gas emissions related to phreatic blasts at Poás volcano, Costa Rica, as measured with an in situ multiple gas analyzer that was deployed at the edge of the erupting lake. Gas emitted from this hyper-acid crater lake approaches magmatic values of SO2/CO2 1-6 days prior to eruption. The SO2 flux derived from magmatic degassing through the lake is measureable by differential optical absorption spectrometry (sporadic campaign measurements), which allows us to constrain lake gas output and input for the major gas species during eruptive and non-eruptive periods. We can further calculate power supply to the hydrothermal system using volatile mass balance and thermodynamics, which indicates that the magmatic heat flux into the shallow hydrothermal system increases from ∼27 MW during quiescence to ∼59 MW during periods of phreatic events. These transient pulses of gas and heat from the deeper magmatic system generate both phreatic eruptions and the observed short-term changes in gas composition, because at high gas flux scrubbing of sulfur by the hydrothermal system is both kinetically and thermodynamically inhibited whereas CO2 gas is always essentially inert in hyperacid conditions. Thus, the SO2/CO2 of lake emissions approaches magmatic values as gas and power supply to the sub-limnic hydrothermal system increase, vaporizing fluids and priming the hydrothermal system for eruption. Our results suggest that high-frequency real-time gas monitoring could provide useful short-term eruptive precursors at volcanoes prone to phreatic explosions.

Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica

USGS Publications Warehouse

de Moor, Maarten; Aiuppa, Alessandro; Pacheco, Javier; Avard, Geoffroy; Kern, Christoph; Liuzzo, Marco; Martinez, Maria; Giudice, Gaetano; Fischer, Tobias P.

2016-01-01

Volcanic eruptions involving interaction with water are amongst the most violent and unpredictable geologic phenomena on Earth. Phreatic eruptions are exceptionally difficult to forecast by traditional geophysical techniques. Here we report on short-term precursory variations in gas emissions related to phreatic blasts at Poás volcano, Costa Rica, as measured with an in situ multiple gas analyzer that was deployed at the edge of the erupting lake. Gas emitted from this hyper-acid crater lake approaches magmatic values of SO2/CO2 1–6 days prior to eruption. The SO2 flux derived from magmatic degassing through the lake is measureable by differential optical absorption spectrometry (sporadic campaign measurements), which allows us to constrain lake gas output and input for the major gas species during eruptive and non-eruptive periods. We can further calculate power supply to the hydrothermal system using volatile mass balance and thermodynamics, which indicates that the magmatic heat flux into the shallow hydrothermal system increases from ∼27 MW during quiescence to ∼59 MW during periods of phreatic events. These transient pulses of gas and heat from the deeper magmatic system generate both phreatic eruptions and the observed short-term changes in gas composition, because at high gas flux scrubbing of sulfur by the hydrothermal system is both kinetically and thermodynamically inhibited whereas CO2gas is always essentially inert in hyperacid conditions. Thus, the SO2/CO2 of lake emissions approaches magmatic values as gas and power supply to the sub-limnic hydrothermal system increase, vaporizing fluids and priming the hydrothermal system for eruption. Our results suggest that high-frequency real-time gas monitoring could provide useful short-term eruptive precursors at volcanoes prone to phreatic explosions.

Ballistic Missile Early Warning System Clear Air Force Station, ...

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

Ballistic Missile Early Warning System - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

The VIDA Framework as an Education Tool: Leveraging Volcanology Data for Educational Purposes

NASA Astrophysics Data System (ADS)

Faied, D.; Sanchez, A.

2009-04-01

The VIDA Framework as an Education Tool: Leveraging Volcanology Data for Educational Purposes Dohy Faied, Aurora Sanchez (on behalf of SSP08 VAPOR Project Team) While numerous global initiatives exist to address the potential hazards posed by volcanic eruption events and assess impacts from a civil security viewpoint, there does not yet exist a single, unified, international system of early warning and hazard tracking for eruptions. Numerous gaps exist in the risk reduction cycle, from data collection, to data processing, and finally dissemination of salient information to relevant parties. As part of the 2008 International Space University's Space Studies Program, a detailed gap analysis of the state of volcano disaster risk reduction was undertaken, and this paper presents the principal results. This gap analysis considered current sensor technologies, data processing algorithms, and utilization of data products by various international organizations. Recommendations for strategies to minimize or eliminate certain gaps are also provided. In the effort to address the gaps, a framework evolved at system level. This framework, known as VIDA, is a tool to develop user requirements for civil security in hazardous contexts, and a candidate system concept for a detailed design phase. While the basic intention of VIDA is to support disaster risk reduction efforts, there are several methods of leveraging raw science data to support education across a wide demographic. Basic geophysical data could be used to educate school children about the characteristics of volcanoes, satellite mappings could support informed growth and development of societies in at-risk areas, and raw sensor data could contribute to a wide range of university-level research projects. Satellite maps, basic geophysical data, and raw sensor data are combined and accessible in a way that allows the relationships between these data types to be explored and used in a training environment. Such a resource naturally lends itself to research efforts in the subject but also research in operational tools, system architecture, and human/machine interaction in civil protection or emergency scenarios.

Distress detection, location, and communications using advanced space technology. [satellite-borne synthetic aperture radar

NASA Technical Reports Server (NTRS)

Sivertson, W. E., Jr.

1977-01-01

This paper briefly introduces a concept for low-cost, global, day-night, all-weather disaster warning and assistance. Evolving, advanced space technology with passive radio frequency reflectors in conjunction with an imaging synthetic aperture radar is employed to detect, identify, locate, and provide passive communication with earth users in distress. This concept evolved from a broad NASA research on new global search and rescue techniques. Appropriate airborne radar test results from this research are reviewed and related to potential disaster applications. The analysis indicates the approach has promise for disaster communications relative to floods, droughts, earthquakes, volcanic eruptions, and severe storms.

Managing Risks? Early Warning Systems for Climate Change

NASA Astrophysics Data System (ADS)

Sitati, A. M.; Zommers, Z. A.; Habilov, M.

2014-12-01

Early warning systems are a tool with which to minimize risks posed by climate related hazards. Although great strides have been made in developing early warning systems most deal with one hazard, only provide short-term warnings and do not reach the most vulnerable. This presentation will review research results of the United Nations Environment Programme's CLIM-WARN project. The project seeks to identify how governments can better communicate risks by designing multi-hazard early warning systems that deliver actionable warnings across timescales. Household surveys and focus group discussions were conducted in 36 communities in Kenya, Ghana and Burkina Faso in order to identify relevant climate related hazards, current response strategies and early warning needs. Preliminary results show significant variability in both risks and needs within and between countries. For instance, floods are more frequent in rural western parts of Kenya. Droughts are frequent in the north while populations in urban areas face a range of hazards - floods, droughts, disease outbreaks - that sometimes occur simultaneously. The majority of the rural population, especially women, the disabled and the elderly, do not have access to modern media such as radio, television, or internet. While 55% of rural populace never watches television, 64% of urban respondents watch television on a daily basis. Communities have different concepts of how to design warning systems. It will be a challenge for national governments to create systems that accommodate such diversity yet provide standard quality of service to all. There is a need for flexible and forward-looking early warning systems that deliver broader information about risks. Information disseminated through the system could not only include details of hazards, but also long-term adaptation options, general education, and health information, thus increasingly both capabilities and response options.

An intelligent IoT emergency vehicle warning system using RFID and Wi-Fi technologies for emergency medical services.

PubMed

Lai, Yeong-Lin; Chou, Yung-Hua; Chang, Li-Chih

2018-01-01

Collisions between emergency vehicles for emergency medical services (EMS) and public road users have been a serious problem, impacting on the safety of road users, emergency medical technicians (EMTs), and the patients on board. The aim of this study is to develop a novel intelligent emergency vehicle warning system for EMS applications. The intelligent emergency vehicle warning system is developed by Internet of Things (IoT), radio-frequency identification (RFID), and Wi-Fi technologies. The system consists of three major parts: a system trigger tag, an RFID system in an emergency vehicle, and an RFID system at an intersection. The RFID system either in an emergency vehicle or at an intersection contains a controller, an ultrahigh-frequency (UHF) RFID reader module, a Wi-Fi module, and a 2.4-GHz antenna. In addition, a UHF ID antenna is especially designed for the RFID system in an emergency vehicle. The IoT system provides real-time visual warning at an intersection and siren warning from an emergency vehicle in order to effectively inform road users about an emergency vehicle approaching. The developed intelligent IoT emergency vehicle warning system demonstrates the capabilities of real-time visual and siren warnings for EMS safety.

Early identification systems for emerging foodborne hazards.

PubMed

Marvin, H J P; Kleter, G A; Prandini, A; Dekkers, S; Bolton, D J

2009-05-01

This paper provides a non-exhausting overview of early warning systems for emerging foodborne hazards that are operating in the various places in the world. Special attention is given to endpoint-focussed early warning systems (i.e. ECDC, ISIS and GPHIN) and hazard-focussed early warning systems (i.e. FVO, RASFF and OIE) and their merit to successfully identify a food safety problem in an early stage is discussed. Besides these early warning systems which are based on monitoring of either disease symptoms or hazards, also early warning systems and/or activities that intend to predict the occurrence of a food safety hazard in its very beginning of development or before that are described. Examples are trend analysis, horizon scanning, early warning systems for mycotoxins in maize and/or wheat and information exchange networks (e.g. OIE and GIEWS). Furthermore, recent initiatives that aim to develop predictive early warning systems based on the holistic principle are discussed. The assumption of the researchers applying this principle is that developments outside the food production chain that are either directly or indirectly related to the development of a particular food safety hazard may also provide valuable information to predict the development of this hazard.

Alaskan Air Defense and Early Warning Systems Clear Air ...

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

Alaskan Air Defense and Early Warning Systems - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

Effectiveness of a Forward Collision Warning System in simple and in dual task from an electrophysiological perspective.

PubMed

Bueno, Mercedes; Fort, Alexandra; Francois, Mathilde; Ndiaye, Daniel; Deleurence, Philippe; Fabrigoule, Colette

2013-04-29

Forward Collision Warning Systems (FCWS) are expected to assist drivers; however, it is not completely clear whether these systems are of benefit to distracted drivers as much as they are to undistracted drivers. This study aims at investigating further the analysis of the effectiveness of a surrogate FCWS according to the attentional state of participants. In this experiment electrophysiological and behavioural data were recording while participants were required to drive in a simple car simulator and to react to the braking of the lead vehicle which could be announced by a warning system. The effectiveness of this warning system was evaluated when drivers were distracted or not by a secondary cognitive task. In a previous study, the warning signal was not completely effective likely due to the presence of another predictor of the forthcoming braking which competes with the warning. By eliminating this secondary predictor in the present study, the results confirmed the negative effect of the secondary task and revealed the expected effectiveness of the warning system at behavioural and electrophysiological levels. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Geyser preplay and eruption in a laboratory model with a bubble trap

NASA Astrophysics Data System (ADS)

Adelstein, Esther; Tran, Aaron; Saez, Carolina Muñoz; Shteinberg, Alexander; Manga, Michael

2014-09-01

We present visual observations and temperature measurements from a laboratory model of a geyser. Our model incorporates a bubble trap, a zone in which vapor can accumulate in the geyser's subsurface plumbing, in a vertical conduit connected to a basal chamber. Analogous features have been identified at several natural geysers. We observe three types of eruptions: 1) rising bubbles eject a small volume of liquid in a weak spout (small eruption); 2) boiling occurs in the conduit above the bubble trap (medium eruption); and 3) boiling occurs in the conduit and chamber (large eruption). In the last two cases, boiling in the conduit causes a rapid hydrostatic pressure drop that allows for the rise and eruption of liquid water in a vigorous spout. Boiling initiates at depth rather than propagating downward from the surface. In a single eruption cycle, multiple small eruptions precede every medium and large eruption. At least one eruption cycle that culminates in a medium eruption (i.e., a quiescent period followed by a series of small eruptions leading up to a medium eruption) precedes every eruption cycle that culminates in a large eruption. We find that the transfer of fluid with high enthalpy to the upper conduit during small and medium eruptions is necessary to heat the upper conduit and prepare the system for the full boiling required for a large eruption. The placement of the bubble trap midway up the conduit allows for more efficient heating of the upper conduit. Our model provides insight into the influence of conduit geometry on eruption style and the importance of heat transfer by smaller events in preparing the geyser system for eruption.

30 CFR 75.1103-4 - Automatic fire sensor and warning device systems; installation; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-4 Automatic fire sensor and warning device systems; installation; minimum requirements. (a) Effective December 31, 2009, automatic fire sensor and warning device...

30 CFR 75.1103-4 - Automatic fire sensor and warning device systems; installation; minimum requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic fire sensor and warning device...-UNDERGROUND COAL MINES Fire Protection § 75.1103-4 Automatic fire sensor and warning device systems; installation; minimum requirements. (a) Effective December 31, 2009, automatic fire sensor and warning device...

14 CFR 121.360 - Ground proximity warning-glide slope deviation alerting system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... person may operate a turbine-powered airplane unless it is equipped with a ground proximity warning... system incorporates a Mode 4 flap warning inhibition control; and (2) An outline of all input sources... turbine-powered airplane unless it is equipped with a ground proximity warning/glide slope deviation...

14 CFR 121.360 - Ground proximity warning-glide slope deviation alerting system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... person may operate a turbine-powered airplane unless it is equipped with a ground proximity warning... system incorporates a Mode 4 flap warning inhibition control; and (2) An outline of all input sources... turbine-powered airplane unless it is equipped with a ground proximity warning/glide slope deviation...

A SDMS Model: Early Warning Coordination Centres

NASA Astrophysics Data System (ADS)

Santos-Reyes, Jaime

2010-05-01

Following the tsunami disaster in 2004, the General Secretary of the United Nations (UN) Kofi Annan called for a global early warning system for all hazards and for all communities. He also requested the ISDR (International Strategy fort Disaster Reduction) and its UN partners to conduct a global survey of capacities, gaps and opportunities in relation to early warning systems. The produced report, "Global survey of Early Warning Systems", concluded that there are many gaps and shortcomings and that much progress has been made on early warning systems and great capabilities are available around the world. However, it may be argued that an early warning system (EWS) may not be enough to prevent fatalities due to a natural hazard; i.e., it should be seen as part of a ‘wider' or total system. Furthermore, an EWS may work very well when assessed individually but it is not clear whether it will contribute to accomplish the purpose of the ‘total disaster management system'; i.e., to prevent fatalities. For instance, a regional EWS may only work if it is well co-ordinated with the local warning and emergency response systems that ensure that the warning is received, communicated and acted upon by the potentially affected communities. It may be argued that without these local measures being in place, a regional EWS will have little impact in saving lives. Researchers argued that unless people are warned in remote areas, the technology is useless; for instance McGuire [5] argues that: "I have no doubt that the technical element of the warning system will work very well,"…"But there has to be an effective and efficient communications cascade from the warning centre to the fisherman on the beach and his family and the bar owners." Similarly, McFadden [6] states that: "There's no point in spending all the money on a fancy monitoring and a fancy analysis system unless we can make sure the infrastructure for the broadcast system is there,"… "That's going to require a lot of work. If it's a tsunami, you've got to get it down to the last Joe on the beach. This is the stuff that is really very hard." Given the above, the paper argues that there is a need for a systemic approach to early warning centres. Systemic means looking upon things as a system; systemic means seeing pattern and inter-relationship within a complex whole; i.e., to see events as products of the working of a system. System may be defined as a whole which is made of parts and relationships. Given this, ‘failure' may be seen as the product of a system and, within that, see death/injury/property loss etc. as results of the working of systems. This paper proposes a preliminary model of ‘early warning coordination centres' (EWCC); it should be highlighted that an EWCC is a subsystem of the Systemic Disaster Management System (SDMS) model.

Volvo and Infiniti drivers' experiences with select crash avoidance technologies.

PubMed

Braitman, Keli A; McCartt, Anne T; Zuby, David S; Singer, Jeremiah

2010-06-01

Vehicle-based crash avoidance systems can potentially reduce crashes, but success depends on driver acceptance and understanding. This study gauged driver use, experience, and acceptance among early adopters of select technologies. Telephone interviews were conducted in early 2009 with 380 owners of Volvo vehicles equipped with forward collision warning with autobrake, lane departure warning, side-view assist, and/or active bi-xenon headlights and 485 owners of Infiniti vehicles with lane departure warning/prevention. Most owners kept systems turned on most of the time, especially forward collision warning with autobrake and side-view assist. The exception was lane departure prevention; many owners were unaware they had it, and the system must be activated each time the vehicle is started. Most owners reported being safer with the technologies and would want them again on their next vehicles. Perceived false or unnecessary warnings were fairly common, particularly with side-view assist. Some systems were annoying, especially lane departure warning. Many owners reported safer driving behaviors such as greater use of turn signals (lane departure warning), increased following distance (forward collision warning), and checking side mirrors more frequently (side-view assist), but some reported driving faster at night (active headlights). Despite some unnecessary or annoying warnings, most Volvo and Infiniti owners use crash avoidance systems most of the time. Among early adopters, the first requirement of effective warning systems (that owners use the technology) seems largely met. Systems requiring activation by drivers for each trip are used less often. Owner experience with the latest technologies from other automobile manufacturers should be studied, as well as for vehicles on which technologies are standard (versus optional) equipment. The effectiveness of technologies in preventing and mitigating crashes and injuries, and user acceptance of interfaces, should be examined as more vehicles with advanced technologies penetrate the fleet.

The effectiveness of physiologically based early warning or track and trigger systems after triage in adult patients presenting to emergency departments: a systematic review.

PubMed

Wuytack, Francesca; Meskell, Pauline; Conway, Aislinn; McDaid, Fiona; Santesso, Nancy; Hickey, Fergal G; Gillespie, Paddy; Raymakers, Adam J N; Smith, Valerie; Devane, Declan

2017-12-06

Changes to physiological parameters precede deterioration of ill patients. Early warning and track and trigger systems (TTS) use routine physiological measurements with pre-specified thresholds to identify deteriorating patients and trigger appropriate and timely escalation of care. Patients presenting to the emergency department (ED) are undiagnosed, undifferentiated and of varying acuity, yet the effectiveness and cost-effectiveness of using early warning systems and TTS in this setting is unclear. We aimed to systematically review the evidence on the use, development/validation, clinical effectiveness and cost-effectiveness of physiologically based early warning systems and TTS for the detection of deterioration in adult patients presenting to EDs. We searched for any study design in scientific databases and grey literature resources up to March 2016. Two reviewers independently screened results and conducted quality assessment. One reviewer extracted data with independent verification of 50% by a second reviewer. Only information available in English was included. Due to the heterogeneity of reporting across studies, results were synthesised narratively and in evidence tables. We identified 6397 citations of which 47 studies and 1 clinical trial registration were included. Although early warning systems are increasingly used in EDs, compliance varies. One non-randomised controlled trial found that using an early warning system in the ED may lead to a change in patient management but may not reduce adverse events; however, this is uncertain, considering the very low quality of evidence. Twenty-eight different early warning systems were developed/validated in 36 studies. There is relatively good evidence on the predictive ability of certain early warning systems on mortality and ICU/hospital admission. No health economic data were identified. Early warning systems seem to predict adverse outcomes in adult patients of varying acuity presenting to the ED but there is a lack of high quality comparative studies to examine the effect of using early warning systems on patient outcomes. Such studies should include health economics assessments.

Monitoring diffuse He degassing from the summit crater of Pico do Fogo volcano, Cape Verde

NASA Astrophysics Data System (ADS)

Alonso, Mar; Dionis, Samara; Fernandes, Paulo; Melián, Gladys; Asensio-Ramos, María; Padilla, Germán D.; Hernández, Pedro A.; Pérez, Nemesio M.; Silva, Sonia

2017-04-01

Fogo (476km2) is one of the Sotavento islands of Cape Verde archipelago. The main geomorphological feature is the presence of a 9 km wide caldera hosting one of the world's most active volcanoes, Pico do Fogo (2829 m.a.s.l.), with the last eruption occurring on November 2014. Pico do Fogo volcano is characterized by the existence of a fumarolic field situated NW inside the summit crater and composed by low- and high-temperature gas discharges (90 to above 200oC respectively) with widespread sulfur precipitates at the surface, typical of hydrothermal alteration. As part of the geochemical monitoring program for the volcanic surveillance of Fogo volcano, twelve surveys of diffuse Helium (He) emission through the surface of the crater have been performed since 2008. He emission has been measured because it is considered as an excellent geochemical indicator (Pogorsky and Quirt 1981) due to its geochemical properties. Recent results clearly show the importance of helium emission studies for the prediction of major volcanic events and the importance of continuous monitoring of this gas in active volcanic regions (Padrón et al. 2013). Soil He emission rates were measured always at the same 63 sampling sites distributed inside the crater and covering an area of 0.142km2. At each measurement site, soil gas was collected in 10 cc glass vials with a hypodermic syringe by inserting to 40 cm depth a 50 cm stainless probe and later analyzed for He content by a quadrupole mass spectrometer Pfeiffer Omnistar 422. Diffusive and convective emission values were estimated at each sampling site following the Fick and Darcy's laws. The He emission rate through the crater was estimated after making the spatial interpolation maps using sequential Gaussian simulation. The average emission rate during these eight years of study is 3.3 kg d-1. The emission rate showed an important increase (up to 5.7 kg d-1) eight months before the 2014 eruption onset. During the eruptive period the crater released the highest value (up to 8 kg d-1), followed by a decrease after the eruption. The last emission value was measured in October 2016 and represents the lowest value of the series (1 kg d-1). This data suggest that monitoring of He degassing rate in volcanic areas is an excellent warning geochemical precursory signal for volcanic unrest. This work demonstrates and reinforces the importance of performing helium emission studies as an important promising volcano monitoring technique that might help to detect early warning signals of volcanic unrest in oceanic volcanic islands.

A Sustainable Early Warning System for Climate Change Impacts on Water Quality Management

NASA Astrophysics Data System (ADS)

Lee, T.; Tung, C.; Chung, N.

2007-12-01

In this era of rapid social and technological change leading to interesting life complexity and environmental displacement, both positive and negative effects among ecosystems call for a balance in which there are impacts by climate changes. Early warning systems for climate change impacts are necessary in order to allow society as a whole to properly and usefully assimilate the masses of new information and knowledge. Therefore, our research addresses to build up a sustainable early warning mechanism. The main goal is to mitigate the cumulative impacts on the environment of climate change and enhance adaptive capacities. An effective early warning system has been proven for protection. However, there is a problem that estimate future climate changes would be faced with high uncertainty. In general, take estimations for climate change impacts would use the data from General Circulation Models and take the analysis as the Intergovernmental Panel on Climate Change declared. We follow the course of the method for analyzing climate change impacts and attempt to accomplish the sustainable early warning system for water quality management. Climate changes impact not only on individual situation but on short-term variation and long-term gradually changes. This kind characteristic should adopt the suitable warning system for long-term formulation and short- term operation. To continue the on-going research of the long-term early warning system for climate change impacts on water quality management, the short-term early warning system is established by using local observation data for reappraising the warning issue. The combination of long-term and short-term system can provide more circumstantial details. In Taiwan, a number of studies have revealed that climate change impacts on water quality, especially in arid period, the concentration of biological oxygen demand may turn into worse. Rapid population growth would also inflict injury on its assimilative capacity to degenerate. To concern about those items, the sustainable early warning system is established and the initiative fall into the following categories: considering the implications for policies, applying adaptive strategies and informing the new climate changes. By setting up the framework of early warning system expectantly can defend stream area from impacts damaging and in sure the sustainable development.

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2010 CFR

2010-10-01

... apparatus. 234.205 Section 234.205 Transportation Other Regulations Relating to Transportation (Continued... characteristics of warning system apparatus. Operating characteristics of electromagnetic, electronic, or electrical apparatus of each highway-rail crossing warning system shall be maintained in accordance with the...

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2011 CFR

2011-10-01

... apparatus. 234.205 Section 234.205 Transportation Other Regulations Relating to Transportation (Continued... characteristics of warning system apparatus. Operating characteristics of electromagnetic, electronic, or electrical apparatus of each highway-rail crossing warning system shall be maintained in accordance with the...

Is More Better? - Night Vision Enhancement System's Pedestrian Warning Modes and Older Drivers.

PubMed

Brown, Timothy; He, Yefei; Roe, Cheryl; Schnell, Thomas

2010-01-01

Pedestrian fatalities as a result of vehicle collisions are much more likely to happen at night than during day time. Poor visibility due to darkness is believed to be one of the causes for the higher vehicle collision rate at night. Existing studies have shown that night vision enhancement systems (NVES) may improve recognition distance, but may increase drivers' workload. The use of automatic warnings (AW) may help minimize workload, improve performance, and increase safety. In this study, we used a driving simulator to examine performance differences of a NVES with six different configurations of warning cues, including: visual, auditory, tactile, auditory and visual, tactile and visual, and no warning. Older drivers between the ages of 65 and 74 participated in the study. An analysis based on the distance to pedestrian threat at the onset of braking response revealed that tactile and auditory warnings performed the best, while visual warnings performed the worst. When tactile or auditory warnings were presented in combination with visual warning, their effectiveness decreased. This result demonstrated that, contrary to general sense regarding warning systems, multi-modal warnings involving visual cues degraded the effectiveness of NVES for older drivers.

Time-to-impact estimation in passive missile warning systems

NASA Astrophysics Data System (ADS)

Şahıngıl, Mehmet Cihan

2017-05-01

A missile warning system can detect the incoming missile threat(s) and automatically cue the other Electronic Attack (EA) systems in the suit, such as Directed Infrared Counter Measure (DIRCM) system and/or Counter Measure Dispensing System (CMDS). Most missile warning systems are currently based on passive sensor technology operating in either Solar Blind Ultraviolet (SBUV) or Midwave Infrared (MWIR) bands on which there is an intensive emission from the exhaust plume of the threatening missile. Although passive missile warning systems have some clear advantages over pulse-Doppler radar (PDR) based active missile warning systems, they show poorer performance in terms of time-to-impact (TTI) estimation which is critical for optimizing the countermeasures and also "passive kill assessment". In this paper, we consider this problem, namely, TTI estimation from passive measurements and present a TTI estimation scheme which can be used in passive missile warning systems. Our problem formulation is based on Extended Kalman Filter (EKF). The algorithm uses the area parameter of the threat plume which is derived from the used image frame.

Air quality early-warning system for cities in China

NASA Astrophysics Data System (ADS)

Xu, Yunzhen; Yang, Wendong; Wang, Jianzhou

2017-01-01

Air pollution has become a serious issue in many developing countries, especially in China, and could generate adverse effects on human beings. Air quality early-warning systems play an increasingly significant role in regulatory plans that reduce and control emissions of air pollutants and inform the public in advance when harmful air pollution is foreseen. However, building a robust early-warning system that will improve the ability of early-warning is not only a challenge but also a critical issue for the entire society. Relevant research is still poor in China and cannot always satisfy the growing requirements of regulatory planning, despite the issue's significance. Therefore, in this paper, a hybrid air quality early-warning system was successfully developed, composed of forecasting and evaluation. First, a hybrid forecasting model was proposed as an important part of this system based on the theory of "decomposition and ensemble" and combined with the advanced data processing technique, support vector machine, the latest bio-inspired optimization algorithm and the leave-one-out strategy for deciding weights. Afterwards, to intensify the research, fuzzy evaluation was performed, which also plays an indispensable role in the early-warning system. The forecasting model and fuzzy evaluation approaches are complementary. Case studies using daily air pollution concentrations of six air pollutants from three cities in China (i.e., Taiyuan, Harbin and Chongqing) are used as examples to evaluate the efficiency and effectiveness of the developed air quality early-warning system. Experimental results demonstrate that both the accuracy and the effectiveness of the developed system are greatly superior for air quality early warning. Furthermore, the application of forecasting and evaluation enables the informative and effective quantification of future air quality, offering a significant advantage, and can be employed to develop rapid air quality early-warning systems.

Geochemical and textural constraints on degassing processes in sub-Plinian eruptions: case-study of the Greenish Pumice eruption of Mount Somma-Vesuvius

NASA Astrophysics Data System (ADS)

Zdanowicz, G.; Boudon, G.; Balcone-Boissard, H.; Cioni, R.; Mundula, F.; Orsi, G.; Civetta, L.; Agrinier, P.

2018-04-01

Plinian eruptions are characterized by high intensity and an overall steady character, and result in a stable convective column. The main processes controlling the dynamics of such steady and stable plume systems have been extensively investigated. Conversely, sub-Plinian eruptions are unsteady, as recorded by the large variability of the products and deposits. Our knowledge of the processes creating this unsteadiness on various timescales remains limited, and still requires more observations as well as theoretical and experimental investigation. Here, we focus on the sub-Plinian eruption of the Greenish Pumice (GP, 19,265 ± 105 BP), Mt. Somma-Vesuvius (Italy). On the basis of coupled geochemical and textural analyses of samples from the well-established stratigraphy of the GP deposits, we investigate volatiles (H2O, CO2, F, Cl) to better constrain the unsteady sub-Plinian eruptive style. This allows us to carry out a detailed study of the degassing processes in relation to the eruption dynamics. We find that degassing by open-system processes generally dominates throughout the entire eruption, but alternates with episodes of closed-system degassing. The fluctuating degassing regimes, responsible for the variable magma ascent rate within the conduit, are also responsible for the eruptive column instability. Volatile behavior is well correlated with textural heterogeneities of the eruptive products. Both reflect higher conduit heterogeneity than for Plinian eruptions, where we find a higher horizontal gradient in magma ascent velocity due to a smaller conduit diameter.

75 FR 48620 - Airworthiness Directives; The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-11

... operations. This proposed AD results from a design change in the cabin altitude warning system that would... warning system that would address the identified unsafe condition(s), and that once this design change was... altitude warning and takeoff configuration warning lights. The activation includes changing the wiring in...

Lights and siren: a review of emergency vehicle warning systems.

PubMed

De Lorenzo, R A; Eilers, M A

1991-12-01

Emergency medical services providers routinely respond to emergencies using lights and siren. This practice is not without risk of collision. Audible and visual warning devices and vehicle markings are integral to efficient negotiation of traffic and reduction of collision risk. An understanding of warning system characteristics is necessary to implement appropriate guidelines for prehospital transportation systems. The pertinent literature on emergency vehicle warning systems is reviewed, with emphasis on potential health hazards associated with these techniques. Important findings inferred from the literature are 1) red flashing lights alone may not be as effective as other color combinations, 2) there are no data to support a seizure risk with strobe lights, 3) lime-yellow is probably superior to traditional emergency vehicle colors, 4) the siren is an extremely limited warning device, and 5) exposure to siren noise can cause hearing loss. Emergency physicians must ensure that emergency medical services transportation systems consider the pertinent literature on emergency vehicle warning systems.

Assessing the likelihood of volcanic eruption through analysis of volcanotectonic earthquake fault plane solutions

NASA Astrophysics Data System (ADS)

Roman, D. C.; Neuberg, J.; Luckett, R. R.

2006-08-01

Episodes of volcanic unrest do not always lead to an eruption. Many of the commonly monitored signals of volcanic unrest, including surface deformation and increased degassing, can reflect perturbations to a deeper magma storage system, and may persist for years without accompanying eruptive activity. Signals of volcanic unrest can also persist following the end of an eruption. Furthermore, the most reliable eruption precursor, the occurrence of low-frequency seismicity, appears to reflect very shallow processes and typically precedes eruptions by only hours to days. Thus, the identification of measurable and unambiguous indicators that are sensitive to changes in the mid-level conduit system during an intermediate stage of magma ascent is of critical importance to the field of volcano monitoring. Here, using data from the ongoing eruption of the Soufrière Hills Volcano, Montserrat, we show that ˜90° changes in the orientation of double-couple fault-plane solutions for high-frequency 'volcanotectonic' (VT) earthquakes reflect pressurization of the mid-level conduit system prior to eruption and may precede the onset of eruptive episodes by weeks to months. Our results demonstrate that, once the characteristic stress field response to magma ascent at a given volcano is established, a relatively simple analysis of VT fault-plane solutions may be used to make intermediate-term assessments of the likelihood of future eruptive activity.

GOSAT/TANSO-FTS Measurement of Volcanic and Geothermal CO2 Emissions

NASA Astrophysics Data System (ADS)

Schwandner, Florian M.; Carn, Simon A.; Newhall, Christopher G.

2010-05-01

Approximately one tenth of the Earth's human population lives in direct reach of volcanic hazards. Being able to provide sufficiently early and scientifically sound warning is a key to volcanic hazard mitigation. Quantitative time-series monitoring of volcanic CO2 emissions will likely play a key role in such early warning activities in the future. Impending volcanic eruptions or any potentially disastrous activity that involves movement of magma in the subsurface, is often preceded by an early increase of CO2 emissions. Conventionally, volcanic CO2 monitoring is done either in campaigns of soil emission measurements (grid of one-time measuring points) that are labor intensive and slow, or by ground-based remote FTIR measurements in emission plumes. These methods are not easily available at all sites of potential activity and prohibitively costly to employ on a large number of volcanoes. In addition, both of these ground-based approaches pose a significant risk to the workers conducting these measurements. Some aircraft-based measurements have been conducted as well in the past, however these are limited by the usually meager funding situation of individual observatories, the hazard such flights pose to equipment and crew, and by the inaccessibility of parts of the plume due to ash hazards. The core motivation for this study is therefore to develop a method for volcanic CO2 monitoring from space that will provide sufficient coverage, resolution, and data quality for an application to quantitative time series monitoring and correlation with other available datasets, from a safe distance and with potentially global reach. In summary, the purpose of the proposed research is to quantify volcanic CO2 emissions using satellite-borne observations. Quantitative estimates will be useful for warning of impending volcanic eruptions, and assessing the contribution of volcanic CO2 to global GHG. Our approach encompasses method development and testing for the detection of volcanic CO2 anomalies using GOSAT and correlation with Aura/OMI, AIRS, and ASTER determined SO2 fluxes and ground based monitoring of CO2 and other geophysical and geochemical parameters. This will provide the ground work for future higher spatial resolution satellite missions. This is a joint effort from two GOSAT-IBUKI data application projects: "Satellite-Borne Quantification of Carbon Dioxide Emissions from Volcanoes and Geothermal Areas" (PI Schwandner), and "Application of GOSAT/TANSO-FTS to the Measurement of Volcanic CO2 Emissions" (PI Carn).

USGS research on geohazards of the North Pacific: past, present, and future

NASA Astrophysics Data System (ADS)

McNutt, M. K.; Eichelberger, J. C.

2012-12-01

The disastrous earthquakes and tsunamis of Sumatra in 2004 and Tohoku in 2011 have driven re-examination of where and how such events occur. Particular focus is on the North Pacific. Of the top 30 earthquakes recorded instrumentally worldwide, 50% occurred along the line of subduction from the Kuril Islands to the southern Alaska mainland. This region has seen monstrous volcanic eruptions (Katmai-Novarupta, 1912), destructive tsunamis (Severo-Kurilsk, 1952), and one of Earth's largest instrumentally-recorded earthquakes (M9.2 Alaska, 1964). Only the modest populations in these frontier towns half a century ago kept losses to a minimum. Impact of any natural disaster to population, vital infrastructure, and sea and air transportation would be magnified today. While USGS had a presence in Alaska for more than a century, the great Alaska earthquake of 1964 ushered in the first understanding of the area's risks. This was the first mega-thrust earthquake properly interpreted as such, and led to re-examination of the 1960 Chilean event. All modern conceptions of mega-thrust earthquakes and tsunamis derive some heritage from USGS research following the 1964 event. The discovery of oil in the Alaska Arctic prompted building a pipeline from the north slope of Alaska to the ice-free port of Valdez. The USGS identified risks from crossing permafrost and active faults. Accurate characterization of these hazards informed innovative designs that kept the pipeline from rupturing due to ground instability or during the M7.9 Denali earthquake of 2002. As a large state with few roads, air travel is common in Alaska. The frequent ash eruptions of volcanoes in the populous Cook Inlet basin became a serious issue, highlighted by the near-crash of a large passenger jet in 1989. In response, the USGS and its partners developed and deployed efficient seismic networks on remote volcanoes and initiated regular satellite surveillance for early warning of ash eruptions. Close collaboration developed with Russian colleagues to jointly monitor volcanoes under the international air routes that traverse the region. Impacts from eruptions on the ground have been more limited than on aviation. But because it was sited before an awareness of geohazards, the Drift River Oil Terminal has been inundated by large lahars from Redoubt in 1990 and 2009, endangering large oil storage tanks. Eruption warnings from the USGS and its partners aided the terminal's crew, and no lives were lost. The Cook Inlet Regional Citizens Advisory Council recently called for replacing the facility with an underwater pipeline within five years. The USGS is now beginning an investigation of the paleo-tsunami record of the Aleutian Islands and, with partners, marine studies aimed at understanding the cause of Aleutian subduction's propensity for the most extreme of events. We are implementing a new ash transport model that will for the first time provide ash fallout forecasts. And we look forward to enhancing our partnership with Russian colleagues through sharing of data and best practices in order to mitigate disaster risk to all communities of the North Pacific.

Kamchatkan Volcanic Eruption Response Team (KVERT), Russia: preventing the danger of volcanic eruptions to aviation.

NASA Astrophysics Data System (ADS)

Girina, O.; Neal, Ch.

2012-04-01

The Kamchatkan Volcanic Eruption Response Team (KVERT) has been a collaborative project of scientists from the Institute of Volcanology and Seismology, the Kamchatka Branch of Geophysical Surveys, and the Alaska Volcano Observatory (IVS, KB GS and AVO). The purpose of KVERT is to reduce the risk of costly, damaging, and possibly deadly encounters of aircraft with volcanic ash clouds. To reduce this risk, KVERT collects all possible volcanic information and issues eruption alerts to aviation and other emergency officials. KVERT was founded by Institute of Volcanic Geology and Geochemistry FED RAS in 1993 (in 2004, IVGG merged with the Institute of Volcanology to become IVS). KVERT analyzes volcano monitoring data (seismic, satellite, visual and video, and pilot reports), assigns the Aviation Color Code, and issues reports on eruptive activity and unrest at Kamchatkan (since 1993) and Northern Kurile (since 2003) volcanoes. KVERT receives seismic monitoring data from KB GS (the Laboratory for Seismic and Volcanic Activity). KB GS maintains telemetered seismic stations to investigate 11 of the most active volcanoes in Kamchatka. Data are received around the clock and analysts evaluate data each day for every monitored volcano. Satellite data are provided from several sources to KVERT. AVO conducts satellite analysis of the Kuriles, Kamchatka, and Alaska as part of it daily monitoring and sends the interpretation to KVERT staff. KVERT interprets MODIS and MTSAT images and processes AVHRR data to look for evidence of volcanic ash and thermal anomalies. KVERT obtains visual volcanic information from volcanologist's field trips, web-cameras that monitor Klyuchevskoy (established in 2000), Sheveluch (2002), Bezymianny (2003), Koryaksky (2009), Avachinsky (2009), Kizimen (2011), and Gorely (2011) volcanoes, and pilots. KVERT staff work closely with staff of AVO, AMC (Airport Meteorological Center) at Yelizovo Airport and the Tokyo Volcanic Ash Advisory Center (VAAC), the Anchorage VAAC, the Washington VAAC, the Montreal VAAC, and the Darwin VAAC to release timely eruption warnings. Urgent information is sent by email to government agencies, aviation services, and scientists (>300 users) located throughout the North Pacific region. KVERT staff also notify AMC and other emergency agencies in Kamchatka by telephone. VONA/KVERT Information Releases (VONA - Volcano Observatory Notice for Aviation) are formal written notifications that are sent by email to these same users to announce Aviation Color Code changes and significant changes in activity. These statements are posted on the KVERT (http://www.kscnet.ru/ivs/kvert/) and the AVO (http://www.avo.alaska.edu) web site. During the period of 2009-2011, eruptions of 6 of Kamchatkan volcanoes were potentially dangerous for aviation: three significant events occurred at Bezymianny (2009, 2010 and 2011), one protracted eruption at Klyuchevskoy (from 2009 till 2010), three short events at Koryaksky (2009) and an ongoing explosive-effusive eruption at Kizimen (2010-2012). Eruptions of Karymsky and Sheveluch volcanoes have continued essentially uninterrupted throughout the period 2009-2011 and have also posed a hazard to aviation intermittently. Very strong explosive eruption of Sheveluch occurred on October 27-28, 2010.

Multiple Attribute Evaluation of Auditory Warning Signals for In-Vehicle Crash Avoidance Warning Systems

DOT National Transportation Integrated Search

1995-11-01

This research was directed at optimizing the auditory warnings that may be used in future crash avoidance warning applications. There is a need to standardize such warnings, so that they retain immediacy of meaning across various vehicles, situations...

Toward an integrative spatiotemporal architecture of the magma plumbing system leading to systematic Plinian eruption at Montagne Pelée Martinique (Lesser Antilles)

NASA Astrophysics Data System (ADS)

Boudon, G.; Balcone-Boissard, H.; Lyonnet, E.; Morgan, D. J.

2017-12-01

The dynamic of crustal magma reservoir may be at the origin of pressure/temperature variations that may trigger magma ascent and eruption. These changes can be registered during crystal growth and can probably produce at the surface geophysical or/and geochemical signals that could be registered by monitoring network, constituting precursory signals. For volcanoes where the plumbing system is well established in terms of volume and depth for a given cycle, repetitive eruptions of the same order of magnitude and involving similar magma composition may occur. It was the case for Montagne Pelée (Martinique, Lesser Antilles), sadly known for the 1902 lava dome-forming eruption that killed 30 000 inhabitants, and that produce repetitive Plinian eruptions in the last 15 ky. Are the perturbations in the dynamic of the magma storage identical for all these eruptions and is the timescale between these perturbations and the eruptions in the same order of magnitude? In the last decade, intracristalline diffusion modelling has been increasingly used to constrain timescale of magmatic processes. Recently this kind of investigations has been coupled to a petrological model of the magma storage region to better wholly describe its behaviour through a Crystal System Analysis (CSA) approach. Here we aim at constraining the pre-eruptive dynamic of the reservoir giving birth to the Plinian eruptions at Montagne Pelée. Precisely we attempt to identify the processes at the origin of the eruptions and the timescale between this process and the eruption. By studying the last five Plinian eruptions of this volcano the question of the systematic occurrence of one process at the same time prior eruption will be discussed. To achieve this goal we performed a detailed petrological description of the eruptive products of the first Plinian phase of these eruptions to build a CSA tree through EPMA and SEM analyses, coupled to Fe-Mg diffusion modelling in orthopyroxenes to retrieve timescale between the perturbation identified in the reservoir and the eruption. We thus highlight that: i) the perturbation event is not systematically the same through all eruptions; ii) the timescale that separate this event from the eruptions is in the order of 4-6 months, significantly shorter that what was up to now estimated for large silicic eruptions.

Geology, tectonics, and the 2002-2003 eruption of the Semeru volcano, Indonesia: Interpreted from high-spatial resolution satellite imagery

NASA Astrophysics Data System (ADS)

Solikhin, Akhmad; Thouret, Jean-Claude; Gupta, Avijit; Harris, Andy J. L.; Liew, Soo Chin

2012-02-01

The paper illustrates the application of high-spatial resolution satellite images in interpreting volcanic structures and eruption impacts in the Tengger-Semeru massif in east Java, Indonesia. We use high-spatial resolution images (IKONOS and SPOT 5) and aerial photos in order to analyze the structures of Semeru volcano and map the deposits. Geological and tectonic mapping is based on two DEMs and on the interpretation of aerial photos and four SPOT and IKONOS optical satellite images acquired between 1996 and 2002. We also compared two thermal Surface Kinetic Temperature ASTER images before and after the 2002-2003 eruption in order to delineate and evaluate the impacts of the pyroclastic density currents. Semeru's principal structural features are probably due to the tectonic setting of the volcano. A structural map of the Tengger-Semeru massif shows four groups of faults orientated N40, N160, N75, and N105 to N140. Conspicuous structures, such as the SE-trending horseshoe-shaped scar on Semeru's summit cone, coincide with the N160-trending faults. The direction of minor scars on the east flank parallels the first and second groups of faults. The Semeru composite cone hosts the currently active Jonggring-Seloko vent. This is located on, and buttressed against, the Mahameru edifice at the head of a large scar that may reflect a failure plane at shallow depth. Dipping 35° towards the SE, this failure plane may correspond to a weak basal layer of weathered volcaniclastic rocks of Tertiary age. We suggest that the deformation pattern of Semeru and its large scar may be induced by flank spreading over the weak basal layer of the volcano. It is therefore necessary to consider the potential for flank and summit collapse in the future. The last major eruption took place in December 2002-January 2003, and involved emplacement of block-and-ash flows. We have used the 2003 ASTER Surface Kinetic Temperature image to map the 2002-2003 pyroclastic density current deposits. We have also compared two 10 m-pixel images acquired before and after the event to describe the extent and impact of an estimated volume of 5.45 × 10 6 m 3 of block-and-ash flow deposits. An ash-rich pyroclastic surge escaped from one of the valley-confined block-and ash flows at 5 to 8 km distance from the crater and swept across the forest and tilled land on the SW side of the Bang River Valley. Downvalley, the temperature of the pyroclastic surge decreased and a mud-rich deposit coated the banks of the Bang River Valley. Thus, hazard mitigation at Semeru should combine: (1) continuous monitoring of the eruptive activity through an early-warning system, and (2) continuous remote sensing of the morphological changes in the drainage system due to the impact of frequent pyroclastic density currents and lahars.

Study on warning radius of diffuse reflection laser warning based on fish-eye lens

NASA Astrophysics Data System (ADS)

Chen, Bolin; Zhang, Weian

2013-09-01

The diffuse reflection type of omni-directional laser warning based on fish-eye lens is becoming more and more important. As one of the key parameters of warning system, the warning radius should be put into investigation emphatically. The paper firstly theoretically analyzes the energy detected by single pixel of FPA detector in the system under complicated environment. Then the least energy detectable by each single pixel of the system is computed in terms of detector sensitivity, system noise, and minimum SNR. Subsequently, by comparison between the energy detected by single pixel and the least detectable energy, the warning radius is deduced from Torrance-Sparrow five-parameter semiempirical statistic model. Finally, a field experiment was developed to validate the computational results. It has been found that the warning radius has a close relationship with BRDF parameters of the irradiated target, propagation distance, angle of incidence, and detector sensitivity, etc. Furthermore, an important fact is shown that the experimental values of warning radius are always less than that of theoretical ones, due to such factors as the optical aberration of fish-eye lens, the transmissivity of narrowband filter, and the packing ratio of detector.

Connected motorcycle crash warning interfaces.

DOT National Transportation Integrated Search

2016-01-15

Crash warning systems have been deployed in the high-end vehicle market segment for some time and are trickling down to additional motor vehicle industry segments each year. The motorcycle segment, however, has no deployed crash warning system to dat...

Light vehicle forward-looking, rear-end collision warning system performance guidelines

DOT National Transportation Integrated Search

1998-05-01

This document presents performance guidelines for forward-looking, rear-end collision warning systems (abbreviated FCW) for improving vehicular safety by preventing or mitigating vehicular rear-end collisions through driver notification or warning. T...

Multiple Attribute Evaluation Of Auditory Warning Signals For In-Vehicle Crash Avoidance Warning Systems, Technical Report

DOT National Transportation Integrated Search

1995-11-01

THIS RESEARCH WAS DIRECTED AT OPTIMIZING THE AUDITORY WARNINGS THAT MAY BE USED IN FUTURE CRASH AVOIDANCE WARNING APPLICATIONS. THERE IS A NEED TO STANDARDIZE SUCH WARNINGS, SO THAT THEY RETAIN IMMEDIACY OF MEANING ACROSS VARIOUS VEHICLES, SITUATIONS...

49 CFR 234.259 - Warning time.

Code of Federal Regulations, 2011 CFR

2011-10-01

... modified because of a change in train speeds. Electronic devices that accurately determine actual warning... 49 Transportation 4 2011-10-01 2011-10-01 false Warning time. 234.259 Section 234.259..., Inspection, and Testing Inspections and Tests § 234.259 Warning time. Each crossing warning system shall be...

49 CFR 234.259 - Warning time.

Code of Federal Regulations, 2010 CFR

2010-10-01

... modified because of a change in train speeds. Electronic devices that accurately determine actual warning... 49 Transportation 4 2010-10-01 2010-10-01 false Warning time. 234.259 Section 234.259..., Inspection, and Testing Inspections and Tests § 234.259 Warning time. Each crossing warning system shall be...

78 FR 36817 - Proposed Agency Information Collection Activities; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-19

...) accidents resulting from warning system failures can be reduced. Motorists lose faith in warning systems... greater risk of an accident is present when a warning system fails to activate as a train approaches a... device malfunctions. With this information, FRA is able to correlate accident data and equipment...

Real-Time Target Motion Animation for Missile Warning System Testing

DTIC Science & Technology

2006-04-01

T. Perkins, R. Sundberg, J. Cordell, Z. Tun , and M. Owen, Real-time Target Motion Animation for Missile Warning System Testing, Proc. SPIE Vol 6208...Z39-18 Real-time target motion animation for missile warning system testing Timothy Perkins*a, Robert Sundberga, John Cordellb, Zaw Tunb, Mark

14 CFR 91.1415 - CAMP: Mechanical reliability reports.

Code of Federal Regulations, 2013 CFR

2013-01-01

... failure, malfunction, or defect in an aircraft concerning— (1) Fires during flight and whether the related fire-warning system functioned properly; (2) Fires during flight not protected by related fire-warning system; (3) False fire-warning during flight; (4) An exhaust system that causes damage during flight to...

14 CFR 91.1415 - CAMP: Mechanical reliability reports.

Code of Federal Regulations, 2011 CFR

2011-01-01

... failure, malfunction, or defect in an aircraft concerning— (1) Fires during flight and whether the related fire-warning system functioned properly; (2) Fires during flight not protected by related fire-warning system; (3) False fire-warning during flight; (4) An exhaust system that causes damage during flight to...

On a Possible Unified Scaling Law for Volcanic Eruption Durations

PubMed Central

Cannavò, Flavio; Nunnari, Giuseppe

2016-01-01

Volcanoes constitute dissipative systems with many degrees of freedom. Their eruptions are the result of complex processes that involve interacting chemical-physical systems. At present, due to the complexity of involved phenomena and to the lack of precise measurements, both analytical and numerical models are unable to simultaneously include the main processes involved in eruptions thus making forecasts of volcanic dynamics rather unreliable. On the other hand, accurate forecasts of some eruption parameters, such as the duration, could be a key factor in natural hazard estimation and mitigation. Analyzing a large database with most of all the known volcanic eruptions, we have determined that the duration of eruptions seems to be described by a universal distribution which characterizes eruption duration dynamics. In particular, this paper presents a plausible global power-law distribution of durations of volcanic eruptions that holds worldwide for different volcanic environments. We also introduce a new, simple and realistic pipe model that can follow the same found empirical distribution. Since the proposed model belongs to the family of the self-organized systems it may support the hypothesis that simple mechanisms can lead naturally to the emergent complexity in volcanic behaviour. PMID:26926425

On a Possible Unified Scaling Law for Volcanic Eruption Durations.

PubMed

Cannavò, Flavio; Nunnari, Giuseppe

2016-03-01

Volcanoes constitute dissipative systems with many degrees of freedom. Their eruptions are the result of complex processes that involve interacting chemical-physical systems. At present, due to the complexity of involved phenomena and to the lack of precise measurements, both analytical and numerical models are unable to simultaneously include the main processes involved in eruptions thus making forecasts of volcanic dynamics rather unreliable. On the other hand, accurate forecasts of some eruption parameters, such as the duration, could be a key factor in natural hazard estimation and mitigation. Analyzing a large database with most of all the known volcanic eruptions, we have determined that the duration of eruptions seems to be described by a universal distribution which characterizes eruption duration dynamics. In particular, this paper presents a plausible global power-law distribution of durations of volcanic eruptions that holds worldwide for different volcanic environments. We also introduce a new, simple and realistic pipe model that can follow the same found empirical distribution. Since the proposed model belongs to the family of the self-organized systems it may support the hypothesis that simple mechanisms can lead naturally to the emergent complexity in volcanic behaviour.

ERUPTING FILAMENTS WITH LARGE ENCLOSING FLUX TUBES AS SOURCES OF HIGH-MASS THREE-PART CMEs, AND ERUPTING FILAMENTS IN THE ABSENCE OF ENCLOSING FLUX TUBES AS SOURCES OF LOW-MASS UNSTRUCTURED CMEs

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

Hutton, Joe; Morgan, Huw, E-mail: joh9@aber.ac.uk

2015-11-01

The 3-part appearance of many coronal mass ejections (CMEs) arising from erupting filaments emerges from a large magnetic flux tube structure, consistent with the form of the erupting filament system. Other CMEs arising from erupting filaments lack a clear 3-part structure and reasons for this have not been researched in detail. This paper aims to further establish the link between CME structure and the structure of the erupting filament system and to investigate whether CMEs which lack a 3-part structure have different eruption characteristics. A survey is made of 221 near-limb filament eruptions observed from 2013 May 03 to 2014more » June 30 by Extreme UltraViolet (EUV) imagers and coronagraphs. Ninety-two filament eruptions are associated with 3-part structured CMEs, 41 eruptions are associated with unstructured CMEs. The remaining 88 are categorized as failed eruptions. For 34% of the 3-part CMEs, processing applied to EUV images reveals the erupting front edge is a pre-existing loop structure surrounding the filament, which subsequently erupts with the filament to form the leading bright front edge of the CME. This connection is confirmed by a flux-rope density model. Furthermore, the unstructured CMEs have a narrower distribution of mass compared to structured CMEs, with total mass comparable to the mass of 3-part CME cores. This study supports the interpretation of 3-part CME leading fronts as the outer boundaries of a large pre-existing flux tube. Unstructured (non 3-part) CMEs are a different family to structured CMEs, arising from the eruption of filaments which are compact flux tubes in the absence of a large system of enclosing closed field.« less

How do I know if I’ve improved my continental scale flood early warning system?

NASA Astrophysics Data System (ADS)

Cloke, Hannah L.; Pappenberger, Florian; Smith, Paul J.; Wetterhall, Fredrik

2017-04-01

Flood early warning systems mitigate damages and loss of life and are an economically efficient way of enhancing disaster resilience. The use of continental scale flood early warning systems is rapidly growing. The European Flood Awareness System (EFAS) is a pan-European flood early warning system forced by a multi-model ensemble of numerical weather predictions. Responses to scientific and technical changes can be complex in these computationally expensive continental scale systems, and improvements need to be tested by evaluating runs of the whole system. It is demonstrated here that forecast skill is not correlated with the value of warnings. In order to tell if the system has been improved an evaluation strategy is required that considers both forecast skill and warning value. The combination of a multi-forcing ensemble of EFAS flood forecasts is evaluated with a new skill-value strategy. The full multi-forcing ensemble is recommended for operational forecasting, but, there are spatial variations in the optimal forecast combination. Results indicate that optimizing forecasts based on value rather than skill alters the optimal forcing combination and the forecast performance. Also indicated is that model diversity and ensemble size are both important in achieving best overall performance. The use of several evaluation measures that consider both skill and value is strongly recommended when considering improvements to early warning systems.

Lane change warning threshold based on driver perception characteristics.

PubMed

Wang, Chang; Sun, Qinyu; Fu, Rui; Li, Zhen; Zhang, Qiong

2018-08-01

Lane Change Warning system (LCW) is exploited to alleviate driver workload and improve the safety performance of lane changes. Depending on the secure threshold, the lane change warning system could transmit caution to drivers. Although the system possesses substantial benefits, it may perturb the conventional operating of the driver and affect driver judgment if the warning threshold does not conform to the driver perception of safety. Therefore, it is essential to establish an appropriate warning threshold to enhance the accuracy rate and acceptability of the lane change warning system. This research aims to identify the threshold that conforms to the driver perception of the ability to safely change lanes with a rear vehicle fast approaching. We propose a theoretical warning model of lane change based on a safe minimum distance and deceleration of the rear vehicle. For the purpose of acquiring the different safety levels of lane changes, 30 licensed drivers are recruited and we obtain the extreme moments represented by driver perception characteristics from a Front Extremity Test and a Rear Extremity Test implemented on the freeway. The required deceleration of the rear vehicle corresponding to the extreme time is calculated according to the proposed model. In light of discrepancies in the deceleration in these extremity experiments, we determine two levels of a hierarchical warning system. The purpose of the primary warning is to remind drivers of the existence of potentially dangerous vehicles and the second warning is used to warn the driver to stop changing lanes immediately. We use the signal detection theory to analyze the data. Ultimately, we confirm that the first deceleration threshold is 1.5 m/s 2 and the second deceleration threshold is 2.7 m/s 2 . The findings provide the basis for the algorithm design of LCW and enhance the acceptability of the intelligent system. Copyright © 2018 Elsevier Ltd. All rights reserved.

Early warning system for Douglas-fir tussock moth outbreaks in the Western United States.

Treesearch

Gary E. Daterman; John M. Wenz; Katharine A. Sheehan

2004-01-01

The Early Warning System is a pheromone-based trapping system used to detect outbreaks of Douglas-fir tussock moth (DFTM, Orgyia pseudotsugata) in the western United States. Millions of acres are susceptible to DFTM defoliation, but Early Warning System monitoring focuses attention only on the relatively limited areas where outbreaks may be...

77 FR 19055 - Morgan Olson, LLC, Receipt of Petition for Decision of Inconsequential Noncompliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-29

... noncompliance is that the affected vehicles do not contain a primary door latch system or door closure warning... for either a primary door latch system or door closure warning system applied only to its vehicles... latched position. Nor are these vehicles equipped with a door closure warning system. Rule text: Paragraph...

On the use of Bayesian decision theory for issuing natural hazard warnings

NASA Astrophysics Data System (ADS)

Economou, T.; Stephenson, D. B.; Rougier, J. C.; Neal, R. A.; Mylne, K. R.

2016-10-01

Warnings for natural hazards improve societal resilience and are a good example of decision-making under uncertainty. A warning system is only useful if well defined and thus understood by stakeholders. However, most operational warning systems are heuristic: not formally or transparently defined. Bayesian decision theory provides a framework for issuing warnings under uncertainty but has not been fully exploited. Here, a decision theoretic framework is proposed for hazard warnings. The framework allows any number of warning levels and future states of nature, and a mathematical model for constructing the necessary loss functions for both generic and specific end-users is described. The approach is illustrated using one-day ahead warnings of daily severe precipitation over the UK, and compared to the current decision tool used by the UK Met Office. A probability model is proposed to predict precipitation, given ensemble forecast information, and loss functions are constructed for two generic stakeholders: an end-user and a forecaster. Results show that the Met Office tool issues fewer high-level warnings compared with our system for the generic end-user, suggesting the former may not be suitable for risk averse end-users. In addition, raw ensemble forecasts are shown to be unreliable and result in higher losses from warnings.

On the use of Bayesian decision theory for issuing natural hazard warnings.

PubMed

Economou, T; Stephenson, D B; Rougier, J C; Neal, R A; Mylne, K R

2016-10-01

Warnings for natural hazards improve societal resilience and are a good example of decision-making under uncertainty. A warning system is only useful if well defined and thus understood by stakeholders. However, most operational warning systems are heuristic: not formally or transparently defined. Bayesian decision theory provides a framework for issuing warnings under uncertainty but has not been fully exploited. Here, a decision theoretic framework is proposed for hazard warnings. The framework allows any number of warning levels and future states of nature, and a mathematical model for constructing the necessary loss functions for both generic and specific end-users is described. The approach is illustrated using one-day ahead warnings of daily severe precipitation over the UK, and compared to the current decision tool used by the UK Met Office. A probability model is proposed to predict precipitation, given ensemble forecast information, and loss functions are constructed for two generic stakeholders: an end-user and a forecaster. Results show that the Met Office tool issues fewer high-level warnings compared with our system for the generic end-user, suggesting the former may not be suitable for risk averse end-users. In addition, raw ensemble forecasts are shown to be unreliable and result in higher losses from warnings.

On the use of Bayesian decision theory for issuing natural hazard warnings

PubMed Central

Stephenson, D. B.; Rougier, J. C.; Neal, R. A.; Mylne, K. R.

2016-01-01

Warnings for natural hazards improve societal resilience and are a good example of decision-making under uncertainty. A warning system is only useful if well defined and thus understood by stakeholders. However, most operational warning systems are heuristic: not formally or transparently defined. Bayesian decision theory provides a framework for issuing warnings under uncertainty but has not been fully exploited. Here, a decision theoretic framework is proposed for hazard warnings. The framework allows any number of warning levels and future states of nature, and a mathematical model for constructing the necessary loss functions for both generic and specific end-users is described. The approach is illustrated using one-day ahead warnings of daily severe precipitation over the UK, and compared to the current decision tool used by the UK Met Office. A probability model is proposed to predict precipitation, given ensemble forecast information, and loss functions are constructed for two generic stakeholders: an end-user and a forecaster. Results show that the Met Office tool issues fewer high-level warnings compared with our system for the generic end-user, suggesting the former may not be suitable for risk averse end-users. In addition, raw ensemble forecasts are shown to be unreliable and result in higher losses from warnings. PMID:27843399

A Method to Increase Drivers' Trust in Collision Warning Systems Based on Reliability Information of Sensor

NASA Astrophysics Data System (ADS)

Tsutsumi, Shigeyoshi; Wada, Takahiro; Akita, Tokihiko; Doi, Shun'ichi

Driver's workload tends to be increased during driving under complicated traffic environments like a lane change. In such cases, rear collision warning is effective for reduction of cognitive workload. On the other hand, it is pointed out that false alarm or missing alarm caused by sensor errors leads to decrease of driver' s trust in the warning system and it can result in low efficiency of the system. Suppose that reliability information of the sensor is provided in real-time. In this paper, we propose a new warning method to increase driver' s trust in the system even with low sensor reliability utilizing the sensor reliability information. The effectiveness of the warning methods is shown by driving simulator experiments.

Dynamics of gas-driven eruptions: Experimental simulations using CO2-H2O-polymer system

NASA Astrophysics Data System (ADS)

Zhang, Youxue; Sturtevant, B.; Stolper, E. M.

1997-02-01

We report exploratory experiments simulating gas-driven eruptions using the CO2-H2O system at room temperature as an analog of natural eruptive systems. The experimental apparatus consists of a test cell and a large tank. Initially, up to 1.0 wt% of CO2 is dissolved in liquid water under a pressure of up to 735 kPa in the test cell. The experiment is initiated by suddenly reducing the pressure of the test cell to a typical tank pressure of 10 kPa. The following are the main results: (1) The style of the process depends on the decompression ratio. There is a threshold decompression ratio above which rapid eruption occurs. (2) During rapid eruption, there is always fragmentation at the liquid-vapor interface. Fragmentation may also occur in the flow interior. (3) Initially, the top of the erupting column ascends at a constant acceleration (instead of constant velocity). (4) Average bubble radius grows as t2/3. (5) When viscosity is 20 times that of pure water or greater, a static foam may be stable after expansion to 97% vesicularity. The experiments provide several insights into natural gas-driven eruptions, including (1) the interplay between bubble growth and ascent of the erupting column must be considered for realistic modeling of bubble growth during gas-driven eruptions, (2) buoyant rise of the bubbly magma is not necessary during an explosive volcanic eruption, and (3) CO2-driven limnic eruptions can be explosive. The violence increases with the initial CO2 content dissolved in water.

ShakeAlert—An earthquake early warning system for the United States west coast

USGS Publications Warehouse

Burkett, Erin R.; Given, Douglas D.; Jones, Lucile M.

2014-08-29

Earthquake early warning systems use earthquake science and the technology of monitoring systems to alert devices and people when shaking waves generated by an earthquake are expected to arrive at their location. The seconds to minutes of advance warning can allow people and systems to take actions to protect life and property from destructive shaking. The U.S. Geological Survey (USGS), in collaboration with several partners, has been working to develop an early warning system for the United States. ShakeAlert, a system currently under development, is designed to cover the West Coast States of California, Oregon, and Washington.

Diffuse CO_{2} degassing monitoring of the oceanic active volcanic island of El Hierro, Canary Islands, Spain

NASA Astrophysics Data System (ADS)

Hernández, Pedro A.; Norrie, Janice; Withoos, Yannick; García-Merino, Marta; Melián, Gladys; Padrón, Eleazar; Barrancos, José; Padilla, Germán; Rodríguez, Fátima; Pérez, Nemesio M.

2017-04-01

Even during repose periods, volcanoes release large amounts of gases from both visible (fumaroles, solfataras, plumes) and non-visible emanations (diffuse degassing). In the last 20 years, there has been considerable interest in the study of diffuse degassing as a powerful tool in volcano monitoring programs, particularly in those volcanic areas where there are no visible volcanic-hydrothermal gas emissions. Historically, soil gas and diffuse degassing surveys in volcanic environments have focused mainly on CO2 because it is, after water vapor, the most abundant gas dissolved in magma. As CO2 travels upward by advective-diffusive transport mechanisms and manifests itself at the surface, changes in its flux pattern over time provide important information for monitoring volcanic and seismic activity. Since 1998, diffuse CO2 emission has been monitored at El Hierro Island, the smallest and south westernmost island of the Canarian archipelago with an area of 278 km2. As no visible emanations occur at the surface environment of El Hierro, diffuse degassing studies have become the most useful geochemical tool to monitor the volcanic activity in this volcanic island. The island experienced a volcano-seismic unrest that began in July 2011, characterized by the location of a large number of relatively small earthquakes (M<2.5) beneath El Hierro at depths between 8 and 15 km. On October 12, 2011, a submarine eruption was confirmed during the afternoon of October 12, 2011 by visual observations off the coast of El Hierro, about 2 km south of the small village of La Restinga in the southernmost part of the island. During the pre-eruptive and eruptive periods, the time series of the diffuse CO2 emission released by the whole island experienced two significant increases. The first started almost 2 weeks before the onset of the submarine eruption, reflecting a clear geochemical anomaly in CO2 emission, most likely due to increasing release of deep seated magmatic gases to the surface. The second one, between October 24 and November 27, 2011, before the most energetic seismic events of the volcanic-seismic unrest (Melián et al., 2014. J. Geophys. Res. Solid Earth, 119, 6976-6991). The highest CO2 degassing rate measured in the last three years (1684 t/d) was observed during a seismo-volcanic unrest. This value decreased until close to background value (˜422 t/d, Melián et al., 2014) contemporaneously with the decline of the seismic activity during the first half of 2013. The last diffuse CO2 degassing survey was carried out in the summer of 2016, showing a emission rate of 854 t/d. Discrete surveys of diffuse CO2 emission have provided important information to optimize the early warning system in the volcano monitoring programs of El Hierro and to monitor the evolution of an ongoing volcanic eruption, even though is a submarine eruption.

Mass transfer processes in a post eruption hydrothermal system: Parameterisation of microgravity changes at Te Maari craters, New Zealand

NASA Astrophysics Data System (ADS)

Miller, Craig A.; Currenti, Gilda; Hamling, Ian; Williams-Jones, Glyn

2018-05-01

Fluid transfer and ground deformation at hydrothermal systems occur both as a precursor to, or as a result of, an eruption. Typically studies focus on pre-eruption changes to understand the likelihood of unrest leading to eruption; however, monitoring post-eruption changes is important for tracking the return of the system towards background activity. Here we describe processes occurring in a hydrothermal system following the 2012 eruption of Upper Te Maari crater on Mt Tongariro, New Zealand, from observations of microgravity change and deformation. Our aim is to assess the post-eruption recovery of the system, to provide a baseline for long-term monitoring. Residual microgravity anomalies of up to 92 ± 11 μGal per year are accompanied by up to 0.037 ± 0.01 m subsidence. We model microgravity changes using analytic solutions to determine the most likely geometry and source location. A multiobjective inversion tests whether the gravity change models are consistent with the observed deformation. We conclude that the source of subsidence is separate from the location of mass addition. From this unusual combination of observations, we develop a conceptual model of fluid transfer within a condensate layer, occurring in response to eruption-driven pressure changes. We find that depressurisation drives the evacuation of pore fluid, either exiting the system completely as vapour through newly created vents and fumaroles, or migrating to shallower levels where it accumulates in empty pore space, resulting in positive gravity changes. Evacuated pores then collapse, causing subsidence. In addition we find that significant mass addition occurs from influx of meteoric fluids through the fractured hydrothermal seal. Long-term combined microgravity and deformation monitoring will allow us to track the resealing and re-pressurisation of the hydrothermal system and assess what hazard it presents to thousands of hikers who annually traverse the volcano, within 2 km of the eruption site.

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

NASA Astrophysics Data System (ADS)

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

2010-05-01

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

Evolution of tsunami warning systems and products.

PubMed

Bernard, Eddie; Titov, Vasily

2015-10-28

Each year, about 60 000 people and $4 billion (US$) in assets are exposed to the global tsunami hazard. Accurate and reliable tsunami warning systems have been shown to provide a significant defence for this flooding hazard. However, the evolution of warning systems has been influenced by two processes: deadly tsunamis and available technology. In this paper, we explore the evolution of science and technology used in tsunami warning systems, the evolution of their products using warning technologies, and offer suggestions for a new generation of warning products, aimed at the flooding nature of the hazard, to reduce future tsunami impacts on society. We conclude that coastal communities would be well served by receiving three standardized, accurate, real-time tsunami warning products, namely (i) tsunami energy estimate, (ii) flooding maps and (iii) tsunami-induced harbour current maps to minimize the impact of tsunamis. Such information would arm communities with vital flooding guidance for evacuations and port operations. The advantage of global standardized flooding products delivered in a common format is efficiency and accuracy, which leads to effectiveness in promoting tsunami resilience at the community level. © 2015 The Authors.

Evolution of tsunami warning systems and products

PubMed Central

Bernard, Eddie; Titov, Vasily

2015-01-01

Each year, about 60 000 people and $4 billion (US$) in assets are exposed to the global tsunami hazard. Accurate and reliable tsunami warning systems have been shown to provide a significant defence for this flooding hazard. However, the evolution of warning systems has been influenced by two processes: deadly tsunamis and available technology. In this paper, we explore the evolution of science and technology used in tsunami warning systems, the evolution of their products using warning technologies, and offer suggestions for a new generation of warning products, aimed at the flooding nature of the hazard, to reduce future tsunami impacts on society. We conclude that coastal communities would be well served by receiving three standardized, accurate, real-time tsunami warning products, namely (i) tsunami energy estimate, (ii) flooding maps and (iii) tsunami-induced harbour current maps to minimize the impact of tsunamis. Such information would arm communities with vital flooding guidance for evacuations and port operations. The advantage of global standardized flooding products delivered in a common format is efficiency and accuracy, which leads to effectiveness in promoting tsunami resilience at the community level. PMID:26392620

Connecting Coronal Mass Ejections to Their Solar Active Region Sources: Combining Results from the HELCATS and FLARECAST Projects

NASA Astrophysics Data System (ADS)

Murray, Sophie A.; Guerra, Jordan A.; Zucca, Pietro; Park, Sung-Hong; Carley, Eoin P.; Gallagher, Peter T.; Vilmer, Nicole; Bothmer, Volker

2018-04-01

Coronal mass ejections (CMEs) and other solar eruptive phenomena can be physically linked by combining data from a multitude of ground-based and space-based instruments alongside models; however, this can be challenging for automated operational systems. The EU Framework Package 7 HELCATS project provides catalogues of CME observations and properties from the Heliospheric Imagers on board the two NASA/STEREO spacecraft in order to track the evolution of CMEs in the inner heliosphere. From the main HICAT catalogue of over 2,000 CME detections, an automated algorithm has been developed to connect the CMEs observed by STEREO to any corresponding solar flares and active-region (AR) sources on the solar surface. CME kinematic properties, such as speed and angular width, are compared with AR magnetic field properties, such as magnetic flux, area, and neutral line characteristics. The resulting LOWCAT catalogue is also compared to the extensive AR property database created by the EU Horizon 2020 FLARECAST project, which provides more complex magnetic field parameters derived from vector magnetograms. Initial statistical analysis has been undertaken on the new data to provide insight into the link between flare and CME events, and characteristics of eruptive ARs. Warning thresholds determined from analysis of the evolution of these parameters is shown to be a useful output for operational space weather purposes. Parameters of particular interest for further analysis include total unsigned flux, vertical current, and current helicity. The automated method developed to create the LOWCAT catalogue may also be useful for future efforts to develop operational CME forecasting.

Interactions and interconnectivity of neighboring volcanic systems in southern Japan (Kyūshū)

NASA Astrophysics Data System (ADS)

Brothelande, E.; Amelung, F.; Zhang, Y.

2016-12-01

The global volcanic eruption record contains about 60 volcano pairs that erupted the same day and 30 pairs that erupted within 3 days. However, neighboring volcano interactions are still poorly understood, in mafic as well as in felsic systems. Here, we use GPS time series of Japan's Aira caldera and Kirishima volcanic system (andesitic systems) to search for interactions between the two neighboring plumbing systems. Aira caldera (17 km x 23 km), also known as Kagoshima Bay, was formed by a massive eruption about 22,000 years ago and is often considered as the world's most active caldera volcano. The center of the caldera is occupied by Sakurajima volcano, a volcanic island that emerged about 13,000 years ago. Today, the caldera hosts more than 1 million people living along the shore and in the city of Kagoshima. The Kirishima volcanoes are a group of 18 eruption cones located 20 km north of Aira caldera. An eruption, the largest in more than 50 years, occurred in 2011 at Shinmoe-dake volcano. The magmatic system of Kirishima volcano was considered to be independent of Aira caldera, but our preliminary results suggest that this may not be the case: it seems that subtle uplift of the Aira caldera occurring during at least the first decade of this century ceased with the 2011 eruption of the Kirishima system. Using deformation data and finite element modeling, we explore possible interactions between magma reservoirs at depth.

Methods for the evaluation of alternative disaster warning systems. Executive summary

NASA Technical Reports Server (NTRS)

Agnew, C. E.; Anderson, R. J., Jr.; Lanen, W. N.

1977-01-01

Methods for estimating the economic costs and benefits of the transmission-reception and reception-action segments of a disaster warning system (DWS) are described. Methods were identified for the evaluation of the transmission and reception portions of alternative disaster warning systems. Example analyses using the methods identified were performed.

30 CFR 75.1101-10 - Water sprinkler systems; fire warning devices at belt drives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Water sprinkler systems; fire warning devices..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-10 Water sprinkler systems; fire warning devices at belt drives. Each water sprinkler...

30 CFR 75.1101-10 - Water sprinkler systems; fire warning devices at belt drives.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Water sprinkler systems; fire warning devices..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-10 Water sprinkler systems; fire warning devices at belt drives. Each water sprinkler...

30 CFR 75.1101-10 - Water sprinkler systems; fire warning devices at belt drives.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Water sprinkler systems; fire warning devices..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-10 Water sprinkler systems; fire warning devices at belt drives. Each water sprinkler...

30 CFR 75.1101-10 - Water sprinkler systems; fire warning devices at belt drives.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Water sprinkler systems; fire warning devices..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-10 Water sprinkler systems; fire warning devices at belt drives. Each water sprinkler...

30 CFR 75.1101-10 - Water sprinkler systems; fire warning devices at belt drives.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Water sprinkler systems; fire warning devices..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-10 Water sprinkler systems; fire warning devices at belt drives. Each water sprinkler...

77 FR 5058 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Automatic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

... for OMB Review; Comment Request; Automatic Fire Sensor and Warning Devices Systems; Examination and..., ``Automatic Fire Sensor and Warning Devices Systems,'' to the Office of Management and Budget (OMB) for review... and warning device systems are maintained and calibrated in order to function properly at all times...

Grain size and shape analysis of the AD 1226 tephra layer, Reykjanes volcanic system

NASA Astrophysics Data System (ADS)

Ösp Magnúsdóttir, Agnes; Höskuldsson, Ármann; Larsen, Guðrún; Tumi Guðmunsson, Magnús; Sigurgeirsson, Magnús Á.

2014-05-01

Recent explosive eruptions in Iceland have drawn attention to long range tephra transport in the atmosphere. In Iceland tephra forming explosion eruptions are frequent, due to abundance of water. However, the volcanism on the island is principally basaltic. Volcanism along the Reykjanes Peninsula is divided into five distinct volcanic systems. Volcano-tectonic activity within these systems is periodic, with recurrence intervals in the range of 1 ka. Last volcano-tectonic sequence began around AD 940, shortly after settlement of Iceland, and lasted through AD 1340. During this period activity was characterized by basaltic fissure eruptions. Furthermore, this activity period on the Reykjanes peninsula began within the eastern most volcanic system and gradually moved towards the west across the peninsula. The 1226 eruption was a basaltic fissure eruption with in the Reykjanes volcanic system. The eruption began on land and gradually progressed towards the SW until the volcanic fissure extended into the sea. Water-magma interaction changed the eruption from effusive into explosive forming the largest tephra layer on the peninsula. Due to its close proximity to the Keflavik international airport and that of the capital of Iceland it is important to get an insight into, the characteristics, generation and distribution of such tephra deposits. In this eruption the tephra produced had an approximate volume of 0.1 km3 and covered an area of some 3500 km2 within the 0.5 cm isopach. Total grain size distribution of this tephra layer will be presented along with analysis of principal grain shapes of the finer portion of the tephra layer as a function of distance from the source. The tephra grain size is dominated by particles finer than 1 millimeter with an almost complete absence of large grains independent of distance from the source. Comprehensive understanding of the characteristics of tephra generated in this eruption can help us to understand hazards posed by future eruptions of similar nature in the area.

30 CFR 75.1103-5 - Automatic fire warning devices; actions and response.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic fire warning devices; actions and... Protection § 75.1103-5 Automatic fire warning devices; actions and response. (a) When the carbon monoxide... fire sensor and warning device systems shall provide an effective warning signal at the following...

30 CFR 75.1103-5 - Automatic fire warning devices; actions and response.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic fire warning devices; actions and... Protection § 75.1103-5 Automatic fire warning devices; actions and response. (a) When the carbon monoxide... fire sensor and warning device systems shall provide an effective warning signal at the following...

Should We Enhance the Observing Systems or Improve Coordination Among the Operating Agencies: What is Needed the Most for Security--A Philosophical Discussion

NASA Technical Reports Server (NTRS)

Habib, Shahid

2006-01-01

As an integrated observing strategy, the concept of sensorweb for Earth observations is appealing in many aspects. For instance, by increasing the spatial and temporal coverage of observations from space and other vantage points, one can eventually aid in increasing the accuracy of the atmospheric models which are precursor to hurricane track prediction, volcanic eruption forecast, and trajectory path of transcontinental transport of dust, harmful nuclear and chemical plumes. In reality, there is little analysis available in terms of benefits, costs and optimized set of sensors needed to make these necessary observations. This is a complex problem that must be carefully studied and balanced over many boundaries such as science, defense, early warning, security, and surveillance. Simplistically, the sensorweb concept from the technological point of view alone has a great appeal in the defense, early warning and security applications. In fact, it can be relatively less expensive in per unit cost as opposed to building and deploying it for the scientific use. However, overall observing approach should not be singled out and aligned somewhat orthogonally to serve a particular need. On the other hand, the sensorweb should be designed and deployed to serve multiple subject areas and customers simultaneously; and can behave as directed measuring systems for both science and operational entities. Sensorweb can be designed to act as expert systems, and/or also provide a dedicated integrated surveillance network. Today, there is no system in the world that is fully integrated in terms of reporting timely multiple hazards warnings, computing the loss of life and property damage estimates, and is also designed to cater to everyone's needs. It is not an easier problem to undertake and more so is not practically solvable. At this time due to some recent events in the world, the scientific community, social scientists, and operational agencies are more cognizant and getting together to address such colossal problems. Increasing our knowledge of the home planet, via amplified set of observations, is certainly a right step in a right direction. Furthermore, this is a pre-requisite in understanding multiple hazard phenomenas. This paper examines various sensorweb options and observing architectures that can be useful specifically in addressing some of these complex issues. The ultimate goal is to serve the society by providing potential natural hazards information to the decision makers in the most expeditious manner so they can prepare themselves to mitigate potential risks to human life, livestock and property.

Automated Safety Warning Controller (ASWC) Phase I - Proof of Concept

DOT National Transportation Integrated Search

2010-07-07

Automated warning systems are not a new concept within the transportation community. There are several projects on the state highway that use the concept of a roadway sensor initiating some type of motorist warning. To date, all of these systems are ...

Truck monitoring and warning systems for freeway-to-freeway connections

DOT National Transportation Integrated Search

1999-10-01

This research focuses on the development and evaluation of a truck monitoring and warning (TM&W) system for detecting high, long, fast trucks at freeway-to-freeway connections and activating displays to warn the truck drivers of potential hazards as ...

Environment Agency England flood warning systems

NASA Astrophysics Data System (ADS)

Strong, Chris; Walters, Mark; Haynes, Elizabeth; Dobson, Peter

2015-04-01

Context In England around 5 million homes are at risk of flooding. We invest significantly in flood prevention and management schemes but we can never prevent all flooding. Early alerting systems are fundamental to helping us reduce the impacts of flooding. The Environment Agency has had the responsibility for flood warning since 1996. In 2006 we invested in a new dissemination system that would send direct messages to pre-identified recipients via a range of channels. Since then we have continuously improved the system and service we offer. In 2010 we introduced an 'opt-out' service where we pre-registered landline numbers in flood risk areas, significantly increasing the customer base. The service has performed exceptionally well under intense flood conditions. Over a period of 3 days in December 2013, when England was experiencing an east coast storm surge, the system sent nearly 350,000 telephone messages, 85,000 emails and 70,000 text messages, with a peak call rate of around 37,000 per hour and 100% availability. The Floodline Warnings Direct (FWD) System FWD provides warnings in advance of flooding so that people at risk and responders can take action to minimise the impact of the flood. Warnings are sent via telephone, fax, text message, pager or e-mail to over 1.1 million properties located within flood risk areas in England. Triggers for issuing alerts and warnings include attained and forecast river levels and rainfall in some rapidly responding locations. There are three levels of warning: Flood Alert, Flood Warning and Severe Flood Warning, and a stand down message. The warnings can be updated to include relevant information to help inform those at risk. Working with our current provider Fujitsu, the system is under a programme of continuous improvement including expanding the 'opt-out' service to mobile phone numbers registered to at risk addresses, allowing mobile registration to the system for people 'on the move' and providing access to registration via third parties. The 'Future Flood Warning System' Our research shows that people want more choice on how they access and receive warnings. Many want a service tailored to their own risk, rather than that of their community. They also want more information about the forecast and the situation to that they can make decisions personal to their circumstances. Our future flood warning system will build upon the success of our existing service and will aim to: • provide our customers with a more flexible and personalised self-service approach which caters for the diverse range of user needs • alert people wherever they are, not just in properties • be flexible enough to respond to user feedback to make improvements and utilise new technology as it becomes available • provide real-time visualisation of system performance, to assist our flood response • capture greater levels of information from the recipients of our warnings • be efficient for operators of the system and utilise automation where relevant • take a risk based approach to resilience to provide the highest level of reliability when needed at a reduced cost

Some human factors issues in the development and evaluation of cockpit alerting and warning systems

NASA Technical Reports Server (NTRS)

Randle, R. J., Jr.; Larsen, W. E.; Williams, D. H.

1980-01-01

A set of general guidelines for evaluating a newly developed cockpit alerting and warning system in terms of human factors issues are provided. Although the discussion centers around a general methodology, it is made specifically to the issues involved in alerting systems. An overall statement of the current operational problem is presented. Human factors problems with reference to existing alerting and warning systems are described. The methodology for proceeding through system development to system test is discussed. The differences between traditional human factors laboratory evaluations and those required for evaluation of complex man-machine systems under development are emphasized. Performance evaluation in the alerting and warning subsystem using a hypothetical sample system is explained.

Operation of a real-time warning system for debris flows in the San Francisco bay area, California

USGS Publications Warehouse

Wilson, Raymond C.; Mark, Robert K.; Barbato, Gary; ,

1993-01-01

The United States Geological Survey (USGS) and the National Weather Service (NWS) have developed an operational warning system for debris flows during severe rainstorms in the San Francisco Bay region. The NWS makes quantitative forecasts of precipitation from storm systems approaching the Bay area and coordinates a regional network of radio-telemetered rain gages. The USGS has formulated thresholds for the intensity and duration of rainfall required to initiate debris flows. The first successful public warnings were issued during a severe storm sequence in February 1986. Continued operation of the warning system since 1986 has provided valuable working experience in rainfall forecasting and monitoring, refined rainfall thresholds, and streamlined procedures for issuing public warnings. Advisory statements issued since 1986 are summarized.

An Envelope Based Feedback Control System for Earthquake Early Warning: Reality Check Algorithm

NASA Astrophysics Data System (ADS)

Heaton, T. H.; Karakus, G.; Beck, J. L.

2016-12-01

Earthquake early warning systems are, in general, designed to be open loop control systems in such a way that the output, i.e., the warning messages, only depend on the input, i.e., recorded ground motions, up to the moment when the message is issued in real-time. We propose an algorithm, which is called Reality Check Algorithm (RCA), which would assess the accuracy of issued warning messages, and then feed the outcome of the assessment back into the system. Then, the system would modify its messages if necessary. That is, we are proposing to convert earthquake early warning systems into feedback control systems by integrating them with RCA. RCA works by continuously monitoring and comparing the observed ground motions' envelopes to the predicted envelopes of Virtual Seismologist (Cua 2005). Accuracy of magnitude and location (both spatial and temporal) estimations of the system are assessed separately by probabilistic classification models, which are trained by a Sparse Bayesian Learning technique called Automatic Relevance Determination prior.

Meteotsunamis, destructive tsunami-like waves: from observations and simulations towards a warning system (MESSI)

NASA Astrophysics Data System (ADS)

Sepic, Jadranka; Vilibic, Ivica

2016-04-01

Atmospherically-generated tsunami-like waves, also known as meteotsunamis, pose a severe threat for exposed coastlines. Although not as destructive as ordinary tsunamis, several meters high meteotsunami waves can bring destruction, cause loss of human lives and raise panic. For that reason, MESSI, an integrative meteotsunami research & warning project, has been developed and will be presented herein. The project has a threefold base: (1) research of atmosphere-ocean interaction with focus on (i) source processes in the atmosphere, (ii) energy transfer to the ocean and (iii) along-propagation growth of meteotsunami waves; (2) estimation of meteotsunami occurrence rates in past, present and future climate, and mapping of meteotsunami hazard; (3) construction of a meteotsunami warning system prototype, with the latter being the main objective of the project. Due to a great frequency of meteotsunamis and its complex bathymetry which varies from the shallow shelf in the north towards deep pits in the south, with a number of funnel-shaped bays and harbours substantially amplifying incoming tsunami-like waves, the Adriatic, northernmost of the Mediterranean seas, has been chosen as an ideal area for realization of the MESSI project and implementation of the warning system. This warning system will however be designed to allow for a wider applicability and easy-to-accomplish transfer to other endangered locations. The architecture of the warning system will integrate several components: (1) real-time measurements of key oceanographic and atmospheric parameters, (2) coupled atmospheric-ocean models run in real time (warning) mode, and (3) semi-automatic procedures and protocols for warning of civil protection, local authorities and public. The effectiveness of the warning system will be tested over the historic events.

The Eruption Forecasting Information System: Volcanic Eruption Forecasting Using Databases

NASA Astrophysics Data System (ADS)

Ogburn, S. E.; Harpel, C. J.; Pesicek, J. D.; Wellik, J.

2016-12-01

Forecasting eruptions, including the onset size, duration, location, and impacts, is vital for hazard assessment and risk mitigation. The Eruption Forecasting Information System (EFIS) project is a new initiative of the US Geological Survey-USAID Volcano Disaster Assistance Program (VDAP) and will advance VDAP's ability to forecast the outcome of volcanic unrest. The project supports probability estimation for eruption forecasting by creating databases useful for pattern recognition, identifying monitoring data thresholds beyond which eruptive probabilities increase, and for answering common forecasting questions. A major component of the project is a global relational database, which contains multiple modules designed to aid in the construction of probabilistic event trees and to answer common questions that arise during volcanic crises. The primary module contains chronologies of volcanic unrest. This module allows us to query eruption chronologies, monitoring data, descriptive information, operational data, and eruptive phases alongside other global databases, such as WOVOdat and the Global Volcanism Program. The EFIS database is in the early stages of development and population; thus, this contribution also is a request for feedback from the community. Preliminary data are already benefitting several research areas. For example, VDAP provided a forecast of the likely remaining eruption duration for Sinabung volcano, Indonesia, using global data taken from similar volcanoes in the DomeHaz database module, in combination with local monitoring time-series data. In addition, EFIS seismologists used a beta-statistic test and empirically-derived thresholds to identify distal volcano-tectonic earthquake anomalies preceding Alaska volcanic eruptions during 1990-2015 to retrospectively evaluate Alaska Volcano Observatory eruption precursors. This has identified important considerations for selecting analog volcanoes for global data analysis, such as differences between closed and open system volcanoes.

Eye movement and brake reactions to real world brake-capacity forward collision warnings--a naturalistic driving study.

PubMed

Wege, Claudia; Will, Sebastian; Victor, Trent

2013-09-01

The purpose of this field operational test study is to assess visual attention allocation and brake reactions in response to a brake-capacity forward collision warning (B-FCW), which is designed similarly to all forward collision warnings on the market for trucks. Truck drivers' reactions immediately after the warning (threat-period) as well as a few seconds after the warning (post-threat-recovery-period) are analyzed, both with and without taking into consideration the predictability of an event and driver distraction. A B-FCW system interface should immediately direct visual attention toward the threat and allow the driver to make a quick decision about whether or not to brake. To investigate eye movement reactions, we analyzed glances 30s before and 15s after 60 naturally occurring collision warning events. The B-FCW events were extracted from the Volvo euroFOT database, which contains data from 30 Volvo trucks driving for approximately 40000 h for four million kilometers. Statistical analyses show that a B-FCW leads to immediate attention allocation toward the roadway and drivers hit the brake. In addition to this intended effect during the threat-period, a rather unexpected effect within the post-threat-recovery-period was discovered in unpredictable events and events with distracted drivers. A few seconds after a warning is issued, eye movements are directed away from the road toward the warning source in the instrument cluster. This potentially indicates that the driver is seeking to understand the circumstances of the warning. Potential reasons for this are discussed: properties relating to the termination of the warning information, the position of the visual and/or audio warning, the conspicuity of the warning, the duration of the warning, and the modality of the warning. The present results are particularly valuable because all on-market collision warning systems in trucks (and almost all in cars) involve visual warnings positioned in the instrument cluster like the one in this study. Acknowledging the fact that human machine interface (HMI)-design is challenging, the conclusions lead the way toward HMI design recommendations for collision warning systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

77 FR 5616 - Proposed Technical Standard Order (TSO)-C151c, Terrain Awareness and Warning System (TAWS)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-03

... (TSO)-C151c, Terrain Awareness and Warning System (TAWS) ACTION: Notice of availability and request for... second draft of Technical Standard Order (TSO)- C151c, Terrain Awareness and Warning System. Comments received from the initial June 2011 release, resulted in changes to the proposed document significant...

30 CFR 75.1103-3 - Automatic fire sensor and warning device systems; minimum requirements; general.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic fire sensor and warning device systems; minimum requirements; general. 75.1103-3 Section 75.1103-3 Mineral Resources MINE SAFETY AND...-UNDERGROUND COAL MINES Fire Protection § 75.1103-3 Automatic fire sensor and warning device systems; minimum...

Patterns of volcanotectonic seismicity and stress during the ongoing eruption of the Soufrière Hills Volcano, Montserrat (1995-2007)

USGS Publications Warehouse

Roman, D.C.; De Angelis, S.; Latchman, J.L.; White, Rickie

2008-01-01

The ongoing eruption of the Soufrière Hills Volcano, Montserrat, has been accompanied throughout by varying levels of high-frequency, ‘volcanotectonic’ (VT), seismicity. These earthquakes reflect the brittle response of the host rock to stresses generated within the magmatic system and thus reveal interesting and useful information about the structure of the volcanic conduit system and processes occurring within it. In general, systematic changes in the rate, location, and fault-plane solutions of VT earthquakes correspond to changes in the volcano's behavior, and indicate that the main conduit for the eruption is a dike or system of dikes trending NE–SW and centered beneath the eruptive vent. To date, the eruption has comprised three extrusive phases, separated by two ~ 1–2 year-long periods of residual activity. Prior to the start of each extrusive phase, VT earthquakes with fault-plane solution p-axes oriented perpendicular to inferred regional maximum compression dominate the data set, consistent with stresses induced by the inflation of the mid-level conduit system. ~ 90°-rotated VT fault-plane solutions are also observed preceding a change in eruption style from effusive to explosive in 1997. While increases in the rate of VT earthquakes precede eruption phase onsets, high rates of VT seismicity are also observed during the first period of residual activity and in this case appear to reflect the relaxation of host rock following withdrawal of magma from the mid-crustal system. Most VT earthquakes are located directly beneath the eruptive vent, although two ‘distal VT clusters’ were observed during the first six months of the eruption (late 1995–early 1996). Both of these distal clusters likely resulted from stresses generated during the establishment of the main conduit system.

Evaluation of a Road-Departure Crash Warning System.

DOT National Transportation Integrated Search

2007-12-31

This report presents the results of an independent evaluation of the Road-Departure Crash Warning System (RDCW), which is designed to warn drivers when they are drifting out of their lane or about to enter a curve at an unsafe speed. The RDCW lateral...

Truck monitoring and warning systems for freeway-to-freeway connections : summary

DOT National Transportation Integrated Search

1999-10-01

This project focuses on the development and evaluation of a truck monitoring and warning (TM&W) system for detecting high, long, fast trucks at freeway-to-freeway connections and activating displays to warn the truck drivers of potential hazards as t...

A Study on Management Standards and Manual of Water supply system for the response of Mt. Baekdu Volcanic Eruption in South Korea

NASA Astrophysics Data System (ADS)

Lee, G.; Jee, Y.; Kim, J.

2013-12-01

Korea is regarded as a safety area from the volcanic disaster, however, the countermeasures for Mt. Baekdu volcanic eruption has been discussed because the possibility of the volcanic eruption had been heightened and various experimental results show risk of Mt. Baekdu volcanic eruption. The purpose of study is to establish management standards and manual for water supply system through the analysis of the volcanic ash effect to the water supply systems. In this study, similar case study for the water supply system to the volcanic ash damage had been investigated. Present status of water supply system and response manual for water supply systems also had been investigated. And then problems of present response manual using had been estimated. As the result, damage according to Mt. Baekdu volcanic eruption on the water supply system could be forecasted. And the direction of management standard and response manual has been established. Acknowledgments This research was supported by a grant [NEMA-BAEKDUSAN-2012-2-2] from the Volcanic Disaster Preparedness Research Center sponsored by National Emergency Management Agency of Korea.

Networking of Icelandic Earth Infrastructures - Natural laboratories and Volcano Supersites

NASA Astrophysics Data System (ADS)

Vogfjörd, K. S.; Sigmundsson, F.; Hjaltadóttir, S.; Björnsson, H.; Arason, Ø.; Hreinsdóttir, S.; Kjartansson, E.; Sigbjörnsson, R.; Halldórsson, B.; Valsson, G.

2012-04-01

The back-bone of Icelandic geoscientific research infrastructure is the country's permanent monitoring networks, which have been built up to monitor seismic and volcanic hazard and deformation of the Earth's surface. The networks are mainly focussed around the plate boundary in Iceland, particularly the two seismic zones, where earthquakes of up to M7.3 have occurred in centuries past, and the rift zones with over 30 active volcanic systems where a large number of powerful eruptions have occurred, including highly explosive ones. The main observational systems are seismic, strong motion, GPS and bore-hole strain networks, with the addition of more recent systems like hydrological stations, permanent and portable radars, ash-particle counters and gas monitoring systems. Most of the networks are owned by a handful of Icelandic institutions, but some are operated in collaboration with international institutions and universities. The networks have been in operation for years to decades and have recorded large volumes of research quality data. The main Icelandic infrastructures will be networked in the European Plate Observing System (EPOS). The plate boundary in the South Iceland seismic zone (SISZ) with its book-shelf tectonics and repeating major earthquakes sequences of up to M7 events, has the potential to be defined a natural laboratory within EPOS. Work towards integrating multidisciplinary data and technologies from the monitoring infrastructures in the SISZ with other fault regions has started in the FP7 project NERA, under the heading of Networking of Near-Fault Observatories. The purpose is to make research-quality data from near-fault observatories available to the research community, as well as to promote transfer of knowledge and techical know-how between the different observatories of Europe, in order to create a network of fault-monitoring networks. The seismic and strong-motion systems in the SISZ are also, to some degree, being networked nationally to strengthen their early warning capabilities. In response to the far-reaching dispersion of ash from the 2010 Eyjafjallajökull eruption and subsequent disturbance to European air-space, the instrumentation of the Icelandic volcano observatory was greatly improved in number and capability to better monitor sub-surface volcanic processes as well as the air-borne products of eruptions. This infrastructure will also be networked with other European volcano observatories in EPOS. Finally the Icelandic EPOS team, together with other European collaborators, has responded to an FP7 call for the establishment of an Icelandic volcano supersite, where land- and space-based data will be made available to researchers and hazard managers, in line with the implementation plan of the GEO. The focus of the Icelandic volcano supersite are the active volcanoes in Iceland's Eastern volcanic zone.

Development and validation of a weather-based warning system to advise fungicide applications to control dollar spot on turfgrass.

PubMed

Smith, D L; Kerns, J P; Walker, N R; Payne, A F; Horvath, B; Inguagiato, J C; Kaminski, J E; Tomaso-Peterson, M; Koch, P L

2018-01-01

Dollar spot is one of the most common diseases of golf course turfgrass and numerous fungicide applications are often required to provide adequate control. Weather-based disease warning systems have been developed to more accurately time fungicide applications; however, they tend to be ineffective and are not currently in widespread use. The primary objective of this research was to develop a new weather-based disease warning system to more accurately advise fungicide applications to control dollar spot activity across a broad geographic and climactic range. The new dollar spot warning system was developed from data collected at field sites in Madison, WI and Stillwater, OK in 2008 and warning system validation sites were established in Madison, WI, Stillwater, OK, Knoxville, TN, State College, PA, Starkville, MS, and Storrs, CT between 2011 and 2016. A meta-analysis of all site-years was conducted and the most effective warning system for dollar spot development consisted of a five-day moving average of relative humidity and average daily temperature. Using this model the highest effective probability that provided dollar spot control similar to that of a calendar-based program across the numerous sites and years was 20%. Additional analysis found that the 20% spray threshold provided comparable control to the calendar-based program while reducing fungicide usage by up to 30%, though further refinement may be needed as practitioners implement this warning system in a range of environments not tested here. The weather-based dollar spot warning system presented here will likely become an important tool for implementing precision disease management strategies for future turfgrass managers, especially as financial and regulatory pressures increase the need to reduce pesticide usage on golf course turfgrass.

Development and validation of a weather-based warning system to advise fungicide applications to control dollar spot on turfgrass

PubMed Central

Smith, D. L.; Kerns, J. P.; Walker, N. R.; Payne, A. F.; Horvath, B.; Inguagiato, J. C.; Kaminski, J. E.; Tomaso-Peterson, M.

2018-01-01

Dollar spot is one of the most common diseases of golf course turfgrass and numerous fungicide applications are often required to provide adequate control. Weather-based disease warning systems have been developed to more accurately time fungicide applications; however, they tend to be ineffective and are not currently in widespread use. The primary objective of this research was to develop a new weather-based disease warning system to more accurately advise fungicide applications to control dollar spot activity across a broad geographic and climactic range. The new dollar spot warning system was developed from data collected at field sites in Madison, WI and Stillwater, OK in 2008 and warning system validation sites were established in Madison, WI, Stillwater, OK, Knoxville, TN, State College, PA, Starkville, MS, and Storrs, CT between 2011 and 2016. A meta-analysis of all site-years was conducted and the most effective warning system for dollar spot development consisted of a five-day moving average of relative humidity and average daily temperature. Using this model the highest effective probability that provided dollar spot control similar to that of a calendar-based program across the numerous sites and years was 20%. Additional analysis found that the 20% spray threshold provided comparable control to the calendar-based program while reducing fungicide usage by up to 30%, though further refinement may be needed as practitioners implement this warning system in a range of environments not tested here. The weather-based dollar spot warning system presented here will likely become an important tool for implementing precision disease management strategies for future turfgrass managers, especially as financial and regulatory pressures increase the need to reduce pesticide usage on golf course turfgrass. PMID:29522560

Seismo-acoustic evidence for an avalanche driven phreatic eruption through a beheaded hydrothermal system: An example from the 2012 Tongariro eruption

USGS Publications Warehouse

Jolly, A.D.; Jousset, P.; Lyons, J.J.; Carniel, R.; Fournier, R.; Fry, B.; Miller, C.

2016-01-01

The 6 August 2012 Te Maari eruption comprises a complex eruption sequence including multiple eruption pulses, a debris avalanche that propagated ~ 2 km from the vent, and the formation of a 500 m long, arcuate chasm, located ~ 300 m from the main eruption vent. The eruption included 6 distinct impulses that were coherent across a local infrasound network marking the eruption onset at 11:52:18 (all times UTC). An eruption energy release of ~ 3 × 1012 J was calculated using a body wave equation for radiated seismic energy. A similar calculation based on the infrasound record, shows that ~ 90% of the acoustic energy was released from three impulses at onset times 11:52:20 (~ 20% of total eruption energy), 11:52:27 (~ 50%), and 11:52:31 (~ 20%). These energy impulses may coincide with eyewitness accounts describing an initial eastward directed blast, followed by a westward directed blast, and a final vertical blast. Pre-eruption seismic activity includes numerous small unlocatable micro-earthquakes that began at 11:46:50. Two larger high frequency earthquakes were recorded at 11:49:06 and 11:49:21 followed directly by a third earthquake at 11:50:17. The first event was located within the scarp based on an arrival time location from good first P arrival times and probably represents the onset of the debris avalanche. The third event was a tornillo, characterised by a 0.8 Hz single frequency resonance, and has a resonator attenuation factor of Q ~ 40, consistent with a bubbly fluid filled resonator. This contrasts with a similar tornillo event occurring 2.5 weeks earlier having Q ~ 250–1000, consistent with a dusty gas charged resonator. We surmise from pre-eruption seismicity, and the observed attenuation change, that the debris avalanche resulted from the influx of fluids into the hydrothermal system, causing destabilisation and failure. The beheaded hydrothermal system may have then caused depressurisation frothing of the remaining gas charged system leading to the onset of explosive activity.

New ground-based lidar enables volcanic CO2 flux measurements.

PubMed

Aiuppa, Alessandro; Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Nuvoli, Marcello; Chiodini, Giovanni; Minopoli, Carmine; Tamburello, Giancarlo

2015-09-01

There have been substantial advances in the ability to monitor the activity of hazardous volcanoes in recent decades. However, obtaining early warning of eruptions remains challenging, because the patterns and consequences of volcanic unrests are both complex and nonlinear. Measuring volcanic gases has long been a key aspect of volcano monitoring since these mobile fluids should reach the surface long before the magma. There has been considerable progress in methods for remote and in-situ gas sensing, but measuring the flux of volcanic CO2-the most reliable gas precursor to an eruption-has remained a challenge. Here we report on the first direct quantitative measurements of the volcanic CO2 flux using a newly designed differential absorption lidar (DIAL), which were performed at the restless Campi Flegrei volcano. We show that DIAL makes it possible to remotely obtain volcanic CO2 flux time series with a high temporal resolution (tens of minutes) and accuracy (<30%). The ability of this lidar to remotely sense volcanic CO2 represents a major step forward in volcano monitoring, and will contribute improved volcanic CO2 flux inventories. Our results also demonstrate the unusually strong degassing behavior of Campi Flegrei fumaroles in the current ongoing state of unrest.

Effect of audio in-vehicle red light-running warning message on driving behavior based on a driving simulator experiment.

PubMed

Yan, Xuedong; Liu, Yang; Xu, Yongcun

2015-01-01

Drivers' incorrect decisions of crossing signalized intersections at the onset of the yellow change may lead to red light running (RLR), and RLR crashes result in substantial numbers of severe injuries and property damage. In recent years, some Intelligent Transport System (ITS) concepts have focused on reducing RLR by alerting drivers that they are about to violate the signal. The objective of this study is to conduct an experimental investigation on the effectiveness of the red light violation warning system using a voice message. In this study, the prototype concept of the RLR audio warning system was modeled and tested in a high-fidelity driving simulator. According to the concept, when a vehicle is approaching an intersection at the onset of yellow and the time to the intersection is longer than the yellow interval, the in-vehicle warning system can activate the following audio message "The red light is impending. Please decelerate!" The intent of the warning design is to encourage drivers who cannot clear an intersection during the yellow change interval to stop at the intersection. The experimental results showed that the warning message could decrease red light running violations by 84.3 percent. Based on the logistic regression analyses, drivers without a warning were about 86 times more likely to make go decisions at the onset of yellow and about 15 times more likely to run red lights than those with a warning. Additionally, it was found that the audio warning message could significantly reduce RLR severity because the RLR drivers' red-entry times without a warning were longer than those with a warning. This driving simulator study showed a promising effect of the audio in-vehicle warning message on reducing RLR violations and crashes. It is worthwhile to further develop the proposed technology in field applications.

Criteria for evaluating the condition of a tropical cyclone warning system.

PubMed

Parker, D

1999-09-01

This paper evaluates the condition (i.e. health) of a tropical cyclone warning system (TCWS) during a 'quiet period' between infrequent intense cyclones. Capacity to make pre-disaster evaluations is important--disaster warning systems need to be in sound condition before, not after, disaster. The research--part of the UK's International Decade of Natural Disaster Reduction Flagship Programme--focuses upon an evaluatory method first used on flood warning systems. The Criteria-development Matrix comprises social, organisational and institutional criteria by which a TCWS may be assessed using a five-stage development scale. This method is used to evaluate Mauritius's TCWS using in-depth interview data. Ways to enhance the method and apply it to other disaster warning systems are discussed. The TCWS in Mauritius is a relatively sound one from which others can learn. Weaknesses requiring attention for Mauritius's TCWS to progress to an advanced level of development are identified.

Understanding the eruption mechanisms of the explosive Bellecombe Eruptions on Piton de la Fournaise, La Réunion

NASA Astrophysics Data System (ADS)

Morgan, K.; Ort, M. H.; Di Muro, A.; Parnell, R. A.; Huff, W. D.

2017-12-01

Piton de la Fournaise (PdF) is an active basaltic volcano on La Réunion island. The Bellecombe Tephra was deposited from at least three unusually explosive eruptions between 3000-5000 ka. The Bellecombe eruptions were interpreted recently to have been due to rapid depressurization of the hydrothermal system when a deep fracture opened after lateral, seaward-directed sliding of the eastern flank, late in a large effusive eruption. This project tests this hypothesis by physically, mineralogically, and chemically characterizing the Bellecombe Tephra to look for evidence of the involvement of the PdF hydrothermal system in the eruptions and understand where the eruptions initiated. The Bellecombe tephra consists of three units separated by incipient soils. Both the Upper and Lower Bellecombe deposits are mostly medium to very fine ash. Lower Bellecombe deposits, from the first two eruptions, are mostly beds of glassy ash containing minor lithic grains and olivine crystals. Hydrothermal minerals, mostly smectite, are present in a few Lower Bellecombe beds. Since these minerals are only present in some beds, the smectite formed before deposition rather than as a product of surficial alteration. The Upper Bellecombe deposits record a third eruption and vary between clast-supported crystal- and lithic-rich lapilli beds and ash beds with abundant ash pellets. The crystals are mostly olivine, with lesser pyroxene and plagioclase and sparse hydrothermal quartz. Gabbro and oceanite clasts are abundant and trachytic pumice rare in these deposits. Hydrothermal minerals are common in most Upper Bellecombe beds. The presence of smectite in some of the Lower Bellecombe beds suggests these deposits came from a system below 200 ºC. Clays in the Upper Bellecombe beds - smectite and mixed layer R0 illite/smectite - imply a system at 40-140 ºC. The hydrothermal system was involved, but might not have been the primary impetus for these eruptions, since hydrothermal minerals are not present in all of the beds, but we find no evidence of high temperatures. The lower Bellecombe vent was near the active summit whereas the Upper Bellecombe vent was from a previously more active area, and this may be reflected in the temperatures of the hydrothermal system. The abundant olivine crystals confirm a relation to a large effusive oceanite eruption.

An electrophysiological study of the impact of a Forward Collision Warning System in a simulator driving task.

PubMed

Bueno, Mercedes; Fabrigoule, Colette; Deleurence, Philippe; Ndiaye, Daniel; Fort, Alexandra

2012-08-27

Driver distraction has been identified as the most important contributing factor in rear-end collisions. In this context, Forward Collision Warning Systems (FCWS) have been developed specifically to warn drivers of potential rear-end collisions. The main objective of this work is to evaluate the impact of a surrogate FCWS and of its reliability according to the driver's attentional state by recording both behavioral and electrophysiological data. Participants drove following a lead motorcycle in a simplified simulator with or without a warning system which gave forewarning of the preceding vehicle braking. Participants had to perform this driving task either alone (simple task) or simultaneously with a secondary cognitive task (dual task). Behavioral and electrophysiological data contributed to revealing a positive effect of the warning system. Participants were faster in detecting the brake light when the system was perfect or imperfect, and the time and attentional resources allocation required for processing the target at higher cognitive level were reduced when the system was completely reliable. When both tasks were performed simultaneously, warning effectiveness was considerably affected at both performance and neural levels; however, the analysis of the brain activity revealed fewer differences between distracted and undistracted drivers when using the warning system. These results show that electrophysiological data could be a valuable tool to complement behavioral data and to have a better understanding of how these systems impact the driver. Copyright © 2012 Elsevier B.V. All rights reserved.

Textural and geochemical constraints on eruptive style of the 79AD eruption at Vesuvius

NASA Astrophysics Data System (ADS)

Balcone-Boissard, Hélène; Boudon, Georges; Villemant, Benoît.

2010-05-01

The 79AD eruption of Vesuvius, also known as the "Pompeii eruption", is the reference for one of the explosive eruptive styles, the plinian-type eruption. The eruption involved H2O-rich phonolitic magmas and is commonly divided into three phases: an initial phreatomagmatic phase, followed by a plinian event which produced a thick pumice fallout deposit and a final phase that was dominated by numerous column-collapse events. During the plinian phase, a first white pumice fallout was produced from a high steady eruptive column, followed by a grey pumice fallout originated by an oscillatory eruptive column with several partial column collapse events. This study focuses on the pumice fallout deposits, sampled in a proximal thick section, at the Terzigno quarry, 6 km southeast of the present crater. In order to constrain the degassing processes and the eruptive dynamics, major element compositions, residual volatile contents (H2O, Cl) and textural characteristics (vesicularity and microcrystallinity) were studied. A previous study that we performed on the pre-eruptive Cl content has shown that Cl may be used as an indicator of magma saturation with Cl-rich fluids and of pre-eruptive pressures. Cl contents measured in melt inclusions show that only the white pumice and the upper part of the grey pumice magma were H2O saturated prior eruption. Large variations in residual volatile contents exist between the different eruptive units and textural features strongly differ between white and grey pumice clasts but also within the grey pumice clasts. The degassing processes were thus highly heterogeneous: the white pumice eruptive units represent a typical closed-system degassing evolution whereas the first grey pumice one, stored in the same pre-eruptive saturation conditions, follows a particular open-system degassing evolution. Here we propose a new model of the 79AD eruption where pre-eruptive conditions (H2O saturation, magma temperature and viscosity) are the critical parameters which determine the diversity of the syn-eruptive degassing processes and hence the eruptive dynamics. We suggest that the oscillatory regime that dominates the grey pumice eruptive phase is linked to the pre-eruptive water undersaturation of most part of the grey magma and to the time delays necessary for H2O exsolution.

The limits of earthquake early warning: Timeliness of ground motion estimates

USGS Publications Warehouse

Minson, Sarah E.; Meier, Men-Andrin; Baltay, Annemarie S.; Hanks, Thomas C.; Cochran, Elizabeth S.

2018-01-01

The basic physics of earthquakes is such that strong ground motion cannot be expected from an earthquake unless the earthquake itself is very close or has grown to be very large. We use simple seismological relationships to calculate the minimum time that must elapse before such ground motion can be expected at a distance from the earthquake, assuming that the earthquake magnitude is not predictable. Earthquake early warning (EEW) systems are in operation or development for many regions around the world, with the goal of providing enough warning of incoming ground shaking to allow people and automated systems to take protective actions to mitigate losses. However, the question of how much warning time is physically possible for specified levels of ground motion has not been addressed. We consider a zero-latency EEW system to determine possible warning times a user could receive in an ideal case. In this case, the only limitation on warning time is the time required for the earthquake to evolve and the time for strong ground motion to arrive at a user’s location. We find that users who wish to be alerted at lower ground motion thresholds will receive more robust warnings with longer average warning times than users who receive warnings for higher ground motion thresholds. EEW systems have the greatest potential benefit for users willing to take action at relatively low ground motion thresholds, whereas users who set relatively high thresholds for taking action are less likely to receive timely and actionable information.

The limits of earthquake early warning: Timeliness of ground motion estimates

PubMed Central

Hanks, Thomas C.

2018-01-01

The basic physics of earthquakes is such that strong ground motion cannot be expected from an earthquake unless the earthquake itself is very close or has grown to be very large. We use simple seismological relationships to calculate the minimum time that must elapse before such ground motion can be expected at a distance from the earthquake, assuming that the earthquake magnitude is not predictable. Earthquake early warning (EEW) systems are in operation or development for many regions around the world, with the goal of providing enough warning of incoming ground shaking to allow people and automated systems to take protective actions to mitigate losses. However, the question of how much warning time is physically possible for specified levels of ground motion has not been addressed. We consider a zero-latency EEW system to determine possible warning times a user could receive in an ideal case. In this case, the only limitation on warning time is the time required for the earthquake to evolve and the time for strong ground motion to arrive at a user’s location. We find that users who wish to be alerted at lower ground motion thresholds will receive more robust warnings with longer average warning times than users who receive warnings for higher ground motion thresholds. EEW systems have the greatest potential benefit for users willing to take action at relatively low ground motion thresholds, whereas users who set relatively high thresholds for taking action are less likely to receive timely and actionable information. PMID:29750190

Magma ascent and lava flow emplacement rates during the 2011 Axial Seamount eruption based on CO2 degassing

NASA Astrophysics Data System (ADS)

Jones, M. R.; Soule, S. A.; Gonnermann, H. M.; Le Roux, V.; Clague, D. A.

2018-07-01

Quantitative metrics for eruption rates at mid-ocean ridges (MORs) would improve our understanding of the structure and formation of the uppermost oceanic crust and would provide a means to link volcanic processes with the conditions of the underlying magmatic system. However, these metrics remain elusive because no MOR eruptions have been directly observed. The possibility of disequilibrium degassing in mid-ocean ridge basalts (MORB), due to high eruptive depressurization rates, makes the analysis of volatile concentrations in MORB glass a promising method for evaluating eruption rates. In this study, we estimate magma ascent and lava flow emplacement rates during the 2011 eruption of Axial Seamount based on numerical modeling of diffusion-controlled bubble growth and new measurements of dissolved volatiles, vesicularity, and vesicle size distributions in erupted basalts. This dataset provides a unique view of the variability in magma ascent (∼0.02-1.2 m/s) and lava flow rates (∼0.1-0.7 m/s) during a submarine MOR eruption based on 50 samples collected from a >10 km long fissure system and three individual lava flow lobes. Samples from the 2011 eruption display an unprecedented range in dissolved CO2 concentrations, nearly spanning the full range observed on the global MOR system. The variable vesicularity and dissolved CO2 concentrations in these samples can be explained by differences in the extent of degassing, dictated by flow lengths and velocities during both vertical ascent and horizontal flow along the seafloor. Our results document, for the first time, the variability in magma ascent rates during a submarine eruption (∼0.02-1.2 m/s), which spans the global range previously proposed based on CO2 degassing. The slowest ascent rates are associated with hummocky flows while faster ascent rates produce channelized sheet flows. This study corroborates degassing-based models for eruption rates using comparisons with independent methods and documents the relationship between eruption dynamics, magma ascent rates, and the morphology of eruptive products. Globally, this approach allows interrogation of the processes that govern mid-ocean ridge eruptions and influence the formation of the oceanic crust.

Radio disturbance warning issuance system

NASA Technical Reports Server (NTRS)

Maeda, R.; Inuki, H.

1979-01-01

A radio disturbance warning issuance system was introduced in the Hiraiso Branch of the Radio Research Laboratories in 1972 to reconstruct the current radio disturbance warning service as a social information service. A description of the new ideas which were experimentally systematized by means of an electronic computer is presented.

Non-invasive, home-based electroencephalography hypoglycaemia warning system for personal monitoring using skin surface electrodes: a single-case feasibility study.

PubMed

Clewett, Christopher J; Langley, Phillip; Bateson, Anthony D; Asghar, Aziz; Wilkinson, Antony J

2016-03-01

Hypoglycaemia unawareness is a common condition associated with increased risk of severe hypoglycaemia. The purpose of the authors' study was to develop a simple to use, home-based and non-invasive hypoglycaemia warning system based on electroencephalography (EEG), and to demonstrate its use in a single-case feasibility study. A participant with type 1 diabetes forms a single-person case study where blood sugar levels and EEG were recorded. EEG was recorded using skin surface electrodes placed behind the ear located within the T3 region by the participant in the home. EEG was analysed retrospectively to develop an algorithm which would trigger a warning if EEG changes associated with hypoglycaemia onset were detected. All hypoglycaemia events were detected by the EEG hypoglycaemia warning algorithm. Warnings were triggered with blood glucose concentration levels at or below 4.2 mmol/l in this participant and no warnings were issued when in euglycaemia. The feasibility of a non-invasive EEG-based hypoglycaemia warning system for personal monitoring in the home has been demonstrated in a single case study. The results suggest that further studies are warranted to evaluate the system prospectively in a larger group of participants.

Urban Flood Prevention and Early Warning System in Jinan City

NASA Astrophysics Data System (ADS)

Feng, Shiyuan; Li, Qingguo

2018-06-01

The system construction of urban flood control and disaster reduction in China is facing pressure and challenge from new urban water disaster. Under the circumstances that it is difficult to build high standards of flood protection engineering measures in urban areas, it is particularly important to carry out urban flood early warning. In Jinan City, a representative inland area, based on the index system of early warning of flood in Jinan urban area, the method of fuzzy comprehensive evaluation was adopted to evaluate the level of early warning. Based on the cumulative rainfall of 3 hours, the CAflood simulation results based on cellular automaton model of urban flooding were used as evaluation indexes to realize the accuracy and integration of urban flood control early warning.

How does a collision warning system shape driver's brake response time? The influence of expectancy and automation complacency on real-life emergency braking.

PubMed

Ruscio, Daniele; Ciceri, Maria Rita; Biassoni, Federica

2015-04-01

Brake Reaction Time (BRT) is an important parameter for road safety. Previous research has shown that drivers' expectations can impact RT when facing hazardous situations, but driving with advanced driver assistance systems, can change the way BRT are considered. The interaction with a collision warning system can help faster more efficient responses, but at the same time can require a monitoring task and evaluation process that may lead to automation complacency. The aims of the present study are to test in a real-life setting whether automation compliancy can be generated by a collision warning system and what component of expectancy can impact the different tasks involved in an assisted BRT process. More specifically four component of expectancy were investigated: presence/absence of anticipatory information, previous direct experience, reliability of the device, and predictability of the hazard determined by repeated use of the warning system. Results supply indication on perception time and mental elaboration of the collision warning system alerts. In particular reliable warning quickened the decision making process, misleading warnings generated automation complacency slowing visual search for hazard detection, lack of directed experienced slowed the overall response while unexpected failure of the device lead to inattentional blindness and potential pseudo-accidents with surprise obstacle intrusion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Feasibility study of using satellites for a disaster warning system

NASA Technical Reports Server (NTRS)

1973-01-01

The development of requirements for the Disaster Warning System (DWS) was investigated in relation to the National Weather Service. Conceptual communication traffic flow patterns for the future of the NWS are studied to determine the impact of the DWS on the MWS. The planned warning systems, and satellite communications are discussed along with data collection, and communication services.

75 FR 33666 - Parts and Accessories Necessary for Safe Operation; Applications for an Exemption From Con-Way...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-14

...), and Iteris, Inc. (Iteris) regarding the placement of lane departure warning system sensors at the top... mounting of the lane departure warning system sensors near the top of the windshield, and within the swept... departure warning system would be used to alert a driver when he or she unintentionally drifts out of their...

UNAVCO Real-Time GNSS Positioning: High-Precision Static and Kinematic Testing of the Next Generation GNSS network.

NASA Astrophysics Data System (ADS)

Berglund, H. T.; Hodgkinson, K. M.; Blume, F.; Mencin, D.; Phillips, D. A.; Meertens, C. M.; Mattioli, G. S.

2014-12-01

The GAGE Facility, managed by UNAVCO, operates a real-time GNSS (RT-GNSS) network of ~450 stations. The majority of the streaming stations are part of the EarthScope Plate Boundary Observatory (PBO). Following community input from a real-time GNSS data products and formats meeting hosted by UNAVCO in Spring of 2011, UNAVCO now provides real-time PPP positions, and network solutions where practical, for all available stations using Trimble's PIVOT RTX server software and TrackRT. The UNAVCO real-time system has the potential to enhance our understanding of earthquakes, seismic wave propagation, volcanic eruptions, magmatic intrusions, movement of ice, landslides, and the dynamics of the atmosphere. Beyond the ever increasing applications in science and engineering, RT-GNSS has the potential to provide early warning of hazards to emergency managers, utilities, other infrastructure managers, first responders and others. Upgrades to the network include eight Trimble NetR9 GNSS receivers with GLONASS and receiver-based RTX capabilities and sixteen new co-located MEMS based accelerometers. These new capabilities will allow integration of GNSS and strong motion data to produce broad-spectrum waveforms improving Earthquake Early Warning systems. Controlled outdoor kinematic and static experiments provide a useful method for evaluating and comparing real-time systems. UNAVCO has developed a portable low-cost antenna actuator to characterize the kinematic performance of receiver- and server-based real-time positioning algorithms and identify system limitations. We have performed tests using controlled 1-d antenna motions and will present comparisons between these and other post-processed kinematic algorithms including GIPSY-OASIS and TRACK. In addition to kinematic testing, long-term static testing of Trimble's RTX service is ongoing at UNAVCO and will be used to characterize the stability of the position time-series produced by RTX. In addition, with the goal of characterizing stability and improving software and higher level products based on real-time and high frequency GNSS time series, we present an overview of the UNAVCO RT-GPS system, a comparison of the UNAVCO generated real-time, static and community data products, and an overview of available common data sets.

The Lusi eruption and implications for understanding fossil piercement structures in sedimentary basins

NASA Astrophysics Data System (ADS)

Svensen, Henrik; Mazzini, Adriano; Planke, Sverre; Hadi, Soffian

2016-04-01

The Lusi eruption started in northeast Java, Indonesia, on May 29th 2006, and it has been erupting rocks, mud, water, and gas ever since. We have been doing field work and research on Lusi ever since the eruption commenced. This work was initially motivated from studying the initiation of a mud volcano. However, the longevity of the eruption has made it possible to describe and monitor the lifespan of this unique piercement structure. . One of the first-order questions regarding the eruption is how it should be classified and if there are any other modern or fossil analogues that can place Lusi in a relevant geological context. During the initial stages of eruption, Lusi was classified as a mud volcano, but following geochemical studies the eruption did not show the typical CH4-dominated gas composition of other mud volcanoes and the temperature was also too high. Moreover, mud volcano eruptions normally last a few days, but Lusi never stopped during the past decade. In particular, the crater fluid geochemistry suggests a connection to the neighboring volcanic complex. Lusi represent a sedimentary hosted hydrothermal system. This opens up new possibilities for understanding fossil hydrothermal systems in sedimentary basins, such as hydrothermal vent complexes and breccia-pipes found in sedimentary basins affected by the formation of Large igneous provinces. We will present examples from the Karoo Basin (South Africa) and the Vøring Basin (offshore Norway) and discuss how Lusi can be used to refine existing formation models. Finally, by comparing Lusi to fossil hydrothermal systems we may get insight into the processes operating at depth where the Lusi system interacts with the igneous rocks of the neighbouring volcanic arc.

Mt. Ruapehu, New Zealand

NASA Image and Video Library

2017-12-08

All around the world, people live in places where the threat of natural disaster is high. On the North Island of New Zealand, the Mount Ruapehu volcano is just such a threat. A towering, active stratovolcano (the classic cone-shaped volcano), snow-capped Ruapehu Volcano is pictured in this enhanced-color image. The image is made from topography data collected by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000, and imagery collected by the Landsat satellite on October 23, 2002. Ruapehu is one of New Zealand’s most active volcanoes, with ten eruptions since 1861. The eruptions aren’t the only threat from the volcano, however. Among the most serious threats is a volcanic mudflow called a lahar. In between eruptions, a lake forms in the volcano’s caldera from melting snow. If a previous eruption has deposited a dam of ash, rocks and mud in the lake’s natural overflow point, then the lake becomes dangerously full, held back only by the temporary dam. In this scene, the lake is nestled among the ridges at the top of the volcano. Eventually, the dam gives way and a massive flow of mud and debris churns down the mountain toward farmland and towns below. Scientists estimate that Ruapehu has experienced 60 lahars in the last 150 years. A devastating lahar in 1953 killed more than 150 people, who died when a passenger train plunged into a ravine when a railroad bridge was taken out by the lahar. The flank of the volcano below the lake is deeply carved by the path of previous lahars; the gouge can be seen just left of image center. Currently scientists in the region are predicting that the lake will overflow in a lahar sometime in the next year. There is great controversy about how to deal with the threat. News reports from the region indicate that the government is planning to invest in a high-tech warning system that will alert those who might be affected well in advance of any catastrophic release. Others feel that the government should combat the threat through engineering at the top of the mountain, for example, by undertaking a controlled release of the lake. Credit Landsat data provided courtesy of the University of Maryland Global Land Cover Facility Landsat processing by Laura Rocchio, Landsat Project Science Office SRTM 3-arcsecond elevation data courtesy of SRTM Team NASA/JPL/NIMA Visualization created by Earth Observatory staff. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Is More Better? — Night Vision Enhancement System’s Pedestrian Warning Modes and Older Drivers

PubMed Central

Brown, Timothy; He, Yefei; Roe, Cheryl; Schnell, Thomas

2010-01-01

Pedestrian fatalities as a result of vehicle collisions are much more likely to happen at night than during day time. Poor visibility due to darkness is believed to be one of the causes for the higher vehicle collision rate at night. Existing studies have shown that night vision enhancement systems (NVES) may improve recognition distance, but may increase drivers’ workload. The use of automatic warnings (AW) may help minimize workload, improve performance, and increase safety. In this study, we used a driving simulator to examine performance differences of a NVES with six different configurations of warning cues, including: visual, auditory, tactile, auditory and visual, tactile and visual, and no warning. Older drivers between the ages of 65 and 74 participated in the study. An analysis based on the distance to pedestrian threat at the onset of braking response revealed that tactile and auditory warnings performed the best, while visual warnings performed the worst. When tactile or auditory warnings were presented in combination with visual warning, their effectiveness decreased. This result demonstrated that, contrary to general sense regarding warning systems, multi-modal warnings involving visual cues degraded the effectiveness of NVES for older drivers. PMID:21050616

AN/ALQ-135 tail warning system follow-on operational test and evaluation

NASA Astrophysics Data System (ADS)

Jenkins, V. M.

1981-11-01

This is a study of the reliability and maintainability of the tail warning system (TWS) AN/ALQ-153. This TWS is a solid state pulsed Doppler radar designed to provide warning and initiate countermeasures against threats attacking from the tail of B-52G/H aircraft.

76 FR 32367 - Agency Information Collection Activities, Proposed Collection; Comment Request; Integrated Public...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-06

...; Integrated Public Alert and Warning Systems (IPAWS) Inventory AGENCY: Federal Emergency Management Agency... proposed revision of the information collection concerning public alert and warning systems at the Federal... evaluation and assessment of existing public alert and warning resources and their integration with the...

76 FR 54245 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, Integrated...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-31

... Request, Integrated Public Alert and Warning Systems (IPAWS) Inventory AGENCY: Federal Emergency... system to alert and warn the American people in situations of war, terrorist attack, natural disaster, or... inventory of public alert and warning resources, capabilities, and the degree of integration at the Federal...

Test track and driving simulator evaluations of warnings to prevent right-angle crashes at signalized intersections

DOT National Transportation Integrated Search

2008-10-01

Two experiments (simulator and test track) were conducted to validate the concept of a system designed to warn potential victims of a likely red-light violator. The warning system uses sensors to detect vehicles that are unlikely to stop at red traff...

Reduced cooling following future volcanic eruptions

NASA Astrophysics Data System (ADS)

Hopcroft, Peter O.; Kandlbauer, Jessy; Valdes, Paul J.; Sparks, R. Stephen J.

2017-11-01

Volcanic eruptions are an important influence on decadal to centennial climate variability. Large eruptions lead to the formation of a stratospheric sulphate aerosol layer which can cause short-term global cooling. This response is modulated by feedback processes in the earth system, but the influence from future warming has not been assessed before. Using earth system model simulations we find that the eruption-induced cooling is significantly weaker in the future state. This is predominantly due to an increase in planetary albedo caused by increased tropospheric aerosol loading with a contribution from associated changes in cloud properties. The increased albedo of the troposphere reduces the effective volcanic aerosol radiative forcing. Reduced sea-ice coverage and hence feedbacks also contribute over high-latitudes, and an enhanced winter warming signal emerges in the future eruption ensemble. These findings show that the eruption response is a complex function of the environmental conditions, which has implications for the role of eruptions in climate variability in the future and potentially in the past.

40 CFR 205.173-3 - Warning statement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Warning statement. 205.173-3 Section... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.173-3 Warning... of that category the manufacturer distributes into commerce: Warning: This product should be checked...

40 CFR 205.173-3 - Warning statement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Warning statement. 205.173-3 Section... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.173-3 Warning... of that category the manufacturer distributes into commerce: Warning: This product should be checked...

40 CFR 205.173-3 - Warning statement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Warning statement. 205.173-3 Section... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.173-3 Warning... of that category the manufacturer distributes into commerce: Warning: This product should be checked...

40 CFR 205.173-3 - Warning statement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Warning statement. 205.173-3 Section... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.173-3 Warning... of that category the manufacturer distributes into commerce: Warning: This product should be checked...

40 CFR 205.173-3 - Warning statement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Warning statement. 205.173-3 Section... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.173-3 Warning... of that category the manufacturer distributes into commerce: Warning: This product should be checked...

Are Avellino (4365 cal BP) and Pompeii twin plinian eruptions? Pre-eruptive constraints and degassing history

NASA Astrophysics Data System (ADS)

Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît.; Ucciani, Guillaume; Cioni, Raffaello

2010-05-01

Somma-Vesuvius activity started 35 ky ago and is characterized by numerous eruptions of variable composition and eruptive style, sometimes interrupted by long periods of unrest. The main explosive eruptions are represented by four plinian eruptions: Pomici di Base eruption (22 cal ky), Mercato (~8900 cal BP), Avellino (4365 cal BP) and Pompeii (79 AD). The 79 AD eruption embodies the most famous eruption since it's responsible of the destruction of Pompeii and Herculanum and it's the first described eruption. The Avellino eruption represents the last plinian event that preceded the Pompeii eruption. The eruptive sequence is similar to the 79 AD plinian eruption, with an opening phase preceding a main plinian fallout activity which ended by a phreatomagmatic phase. The fallout deposit displays a sharp colour contrast from white to grey pumice, corresponding to a magma composition evolution. We focus our study on the main fallout deposit that we sampled in detail in the Traianello quarry, 9 km North-North East of the crater, to investigate the degassing processes during the eruption, using volatile content and textural observations. Density and vesicularity measurements were obtained on a minimum of 100 pumice clasts sampled in 10 stratigraphic levels in the fallout deposit. On the basis of the density distribution, bulk geochemical data, point analytical measurements on glasses (melt inclusions and residual glass) and textural observations were obtained simultaneously on a minimum of 5 pumice clasts per eruptive unit. The glass composition, in particular the Na/K ratio, evolves from Na-rich phonolite for white pumices to a more K-rich phonolite for grey pumices. The pre-eruptive conditions are constrained by systematic Cl measurements in melt inclusions and matrix glass of pumice clasts. The entire magma was saturated relative to sub-critical fluids (a Cl-rich H2O vapour phase and a brine), with a Cl melt content buffered at ~6000 ppm, and a mean pre-eruptive H2O content depending of the magma composition. Most of the pumices of the different eruptive units show that H2O degassing during the eruption followed a typical closed-system evolution as expected for plinian eruption. Contrary to H2O, Cl was not efficiently degassed during the plinian phase of the eruption: the matrix glass composition remains close to the pre-eruptive content. Compared to the 79AD eruption the degassing processes showed by the whole Avellino plinian phase is more homogeneous and similar to the white pumice phase of the Pompeii eruption whereas the open-system degassing mode identified from the grey pumices of the 79AD eruption is not represented during the Avellino eruption.

Towards a certification process for tsunami early warning systems

NASA Astrophysics Data System (ADS)

Löwe, Peter; Wächter, Jochen; Hammitzsch, Martin

2013-04-01

The natural disaster of the Boxing Day Tsunami of 2004 was followed by an information catastrophe. Crucial early warning information could not be delivered to the communities under imminent threat, resulting in over 240,000 casualties in 14 countries. This tragedy sparked the development of a new generation of integrated modular Tsunami Early Warning Systems (TEWS). While significant advances were accomplished in the past years, recent events, like the Chile 2010 and the Tohoku 2011 tsunami demonstrate that the key technical challenge for Tsunami Early Warning research on the supranational scale still lies in the timely issuing of status information and reliable early warning messages in a proven workflow. A second challenge stems from the main objective of the Intergovernmental Oceanographic Commission of UNESCO (IOC) Tsunami Programme, the integration of national TEWS towards ocean-wide networks: Each of the increasing number of integrated Tsunami Early Warning Centres has to cope with the continuing evolution of sensors, hardware and software while having to maintain reliable inter-center information exchange services. To avoid future information catastrophes, the performance of all components, ranging from individual sensors, to Warning Centers within their particular end-to-end Warning System Environments, and up to federated Systems of Tsunami Warning Systems has to be regularly validated against defined criteria. Since 2004, GFZ German Research Centre for Geosciences (GFZ) has built up expertise in the field of TEWS. Within GFZ, the Centre for GeoInformation Technology (CeGIT) has focused its work on the geoinformatics aspects of TEWS in two projects already, being the German Indonesian Tsunami Early Warning System (GITEWS) and the Distant Early Warning System (DEWS). This activity is continued in the TRIDEC project (Collaborative, Complex, and Critical Decision Processes in Evolving Crises) funded under the European Union's seventh Framework Programme (FP7). TRIDEC focuses on real-time intelligent information management in Earth management and its long-term application: The technical development is based on mature system architecture models and industry standards. The use of standards already applies to the operation of individual TRIDEC reference installations and their interlinking into an integrated service infrastructure for supranational warning services. This is a first step towards best practices and service lifecycles for Early Warning Centre IT service management, including Service Level Agreements (SLA) and Service Certification. While on a global scale the integration of TEWS progresses towards Systems of Systems (SoS), there is still an absence of accredited and reliable certifications for national TEWS or regional Tsunami Early Warning Systems of Systems (TEWSoS). Concepts for TEWS operations have already been published under the guidance of the IOC, and can now be complemented by the recent research advances concerning SoS architecture. Combined with feedback from the real world, such as the NEAMwave 2012 Tsunami exercise in the Mediterranean, this can serve as a starting point to formulate initial requirements for TEWS and TEWSoS certification: Certification activities will cover the establishment of new TEWS and TEWSoS, and also both maintenance and enhancement of existing TEWS/TEWSoS. While the IOC is expected to take a central role in the development of the certification strategy, it remains to be defined which bodies will actually conduct the certification process. Certification requirements and results are likely to become a valuable information source for various target groups, ranging from national policy decision makers, government agency planners, national and local government preparedness officials, TWC staff members, Disaster Responders, the media and the insurance industry.

Big data managing in a landslide early warning system: experience from a ground-based interferometric radar application

NASA Astrophysics Data System (ADS)

Intrieri, Emanuele; Bardi, Federica; Fanti, Riccardo; Gigli, Giovanni; Fidolini, Francesco; Casagli, Nicola; Costanzo, Sandra; Raffo, Antonio; Di Massa, Giuseppe; Capparelli, Giovanna; Versace, Pasquale

2017-10-01

A big challenge in terms or landslide risk mitigation is represented by increasing the resiliency of society exposed to the risk. Among the possible strategies with which to reach this goal, there is the implementation of early warning systems. This paper describes a procedure to improve early warning activities in areas affected by high landslide risk, such as those classified as critical infrastructures for their central role in society. This research is part of the project LEWIS (Landslides Early Warning Integrated System): An Integrated System for Landslide Monitoring, Early Warning and Risk Mitigation along Lifelines. LEWIS is composed of a susceptibility assessment methodology providing information for single points and areal monitoring systems, a data transmission network and a data collecting and processing center (DCPC), where readings from all monitoring systems and mathematical models converge and which sets the basis for warning and intervention activities. The aim of this paper is to show how logistic issues linked to advanced monitoring techniques, such as big data transfer and storing, can be dealt with compatibly with an early warning system. Therefore, we focus on the interaction between an areal monitoring tool (a ground-based interferometric radar) and the DCPC. By converting complex data into ASCII strings and through appropriate data cropping and average, and by implementing an algorithm for line-of-sight correction, we managed to reduce the data daily output without compromising the capability for performing.

Early warning signals of regime shifts in coupled human–environment systems

PubMed Central

Bauch, Chris T.; Sigdel, Ram; Pharaon, Joe; Anand, Madhur

2016-01-01

In complex systems, a critical transition is a shift in a system’s dynamical regime from its current state to a strongly contrasting state as external conditions move beyond a tipping point. These transitions are often preceded by characteristic early warning signals such as increased system variability. However, early warning signals in complex, coupled human–environment systems (HESs) remain little studied. Here, we compare critical transitions and their early warning signals in a coupled HES model to an equivalent environment model uncoupled from the human system. We parameterize the HES model, using social and ecological data from old-growth forests in Oregon. We find that the coupled HES exhibits a richer variety of dynamics and regime shifts than the uncoupled environment system. Moreover, the early warning signals in the coupled HES can be ambiguous, heralding either an era of ecosystem conservationism or collapse of both forest ecosystems and conservationism. The presence of human feedback in the coupled HES can also mitigate the early warning signal, making it more difficult to detect the oncoming regime shift. We furthermore show how the coupled HES can be “doomed to criticality”: Strategic human interactions cause the system to remain perpetually in the vicinity of a collapse threshold, as humans become complacent when the resource seems protected but respond rapidly when it is under immediate threat. We conclude that the opportunities, benefits, and challenges of modeling regime shifts and early warning signals in coupled HESs merit further research. PMID:27815533

Punctuated Evolution of Volcanology: An Observatory Perspective

NASA Astrophysics Data System (ADS)

Burton, W. C.; Eichelberger, J. C.

2010-12-01

Volcanology from the perspective of crisis prediction and response-the primary function of volcano observatories-is influenced both by steady technological advances and singular events that lead to rapid changes in methodology and procedure. The former can be extrapolated somewhat, while the latter are surprises or shocks. Predictable advances include the conversion from analog to digital systems and the exponential growth of computing capacity and data storage. Surprises include eruptions such as 1980 Mount St Helens, 1985 Nevado del Ruiz, 1989-1990 Redoubt, 1991 Pinatubo, and 2010 Eyjafjallajokull; the opening of GPS to civilian applications, and the advent of an open Russia. Mount St Helens switched the rationale for volcanology in the USGS from geothermal energy to volcano hazards, Ruiz and Pinatubo emphasized the need for international cooperation for effective early warning, Redoubt launched the effort to monitor even remote volcanoes for purposes of aviation safety, and Eyjafjallajokull hammered home the need for improved ash-dispersion and engine-tolerance models; better GPS led to a revolution in volcano geodesy, and the new Russian Federation sparked an Alaska-Kamchatka scientific exchange. The pattern has been that major funding increases for volcano hazards occur after these unpredictable events, which suddenly expose a gap in capabilities, rather than out of a calculated need to exploit technological advances or meet a future goal of risk mitigation. It is up to the observatory and national volcano hazard program to leverage these sudden funding increases into a long-term, sustainable business model that incorporates both the steadily increasing costs of staff and new technology and prepares for the next volcano crisis. Elements of the future will also include the immediate availability on the internet of all publically-funded volcano data, and subscribable, sophisticated hazard alert systems that run computational, fluid dynamic eruption models. These models will be coupled with risk assessments in which the parameters are adjusted to an emerging situation, while accessing global eruption databases in order to construct eruption event trees with statistically sound probabilities. Design of these alert systems will necessarily require the joint input of scientists and emergency management leaders. All of this can be visualized now, and programs such as VHub, WOVOdat, and NVEWS are working towards its eventual reality. Technological advances will make possible in a crisis the tapping of a global pool of expertise, which may have the effect of diminishing the importance of observatories as physical entities-however, familiarity with the nearby, monitored volcanoes and impacted populations will always require their presence. What is also clear about the future is that there must be more international communication and cooperation. We do this quite well scientifically, but not so well in terms of observatory operations or best practices. While parallel paths can be stimulating through diversity and competition, there is no need for every national program to separately invent the wheel. Changes will also need to be made in institutional expectations of scientists, which currently overemphasize solitary achievement at the expense of community efforts.

Crystallization Conditions at Cascade and Other Arc Volcanoes: The Role of Recharge, and Ultimate, Proximal and Immediate Causes of Eruption

NASA Astrophysics Data System (ADS)

Putirka, K. D.

2016-12-01

A number of hypotheses have been offered to explain why volcanoes erupt. These include magma mixing, mafic recharge, or partial crystallization, any of which can drive parts or all of a system to vapor saturation, and so add to a magma's buoyancy. Age dates indicate long pre-eruption storage times for felsic magmas erupted at arcs, indicating that mafic recharge magmas, which can reinvigorate such systems, is a possible eruption trigger. However, plutonic systems reveal numerous recharge events that have no obvious ties to eruption (Coint et al. 2013; Putirka et al. 2014). And crystallization conditions at some arc systems support the implicit view, that recharge might be a necessary, but not a sufficient condition for eruption. At several Cascade volcanoes, Cpx and Amp crystals record coolings of 100-300oC. The Cpx grains derive exclusively from mafic enclaves, while Amp grains derive from both host and enclave materials. These considerable coolings call for a time lag following recharge, and indicate that vapor saturation is a proximal, although not necessarily an immediate cause of eruption. But we cannot discount recharge altogether. At the Cascades and at other arcs, Cpx crystalizes throughout the middle and upper crust, mostly from the surface down to 15 km. And high Fo olivine grains provide evidence for very hot magmas that intrude the upper mantle and lower crust, and possibly the middle crust, if hydrous. Volcanic pathways thus clearly extend into the middle crust, and at times, well below the Moho. It is unclear to what extent these deep pathways are hydraulically connected to the surface, or the role of deep-seated processes in initiating or sustaining eruptions. Progress in understanding these pathways, and triggering mechanisms, requires our differentiating "ultimate", "proximal" and "immediate" causes, and determining which of various magmatic processes provide necessary or sufficient conditions for eruption.

Earth Observations taken by the Expedition 13 crew

NASA Image and Video Library

2006-08-14

ISS013-E-66488 (14 Aug. 2006) --- Ash cloud from Ubinas Volcano, Peru is featured in this image photographed by an Expedition 13 crewmember on the International Space Station (ISS). Subduction of the Nazca tectonic plate along the western coast of South America forms the high Peruvian Andes, and also produces magma feeding a chain of historically active volcanoes along the western front of the mountains. The most active of these volcanoes in Peru is Ubinas. A typical steep-sided stratovolcano comprised primarily of layers of silica-rich lava flows, it has a summit elevation of 5,672 meters. The volcanic cone appears distinctively truncated or flat-topped in profile -- the result of a relatively small eruption that evacuated a magma reservoir near the summit. Following removal of the magma, the summit material collapsed downwards to form the current 1.4 kilometer-wide summit caldera. This oblique image (looking at an angle from the ISS) captures an ash cloud first observed on satellite imagery at 11:00 GMT on Aug. 14, 2006; this image was acquired one hour and 45 minutes later. The ash cloud resulted in the issuing of an aviation hazard warning by the Buenos Aires Volcanic Ash Advisory Center. Modern activity at Ubinas is characterized by these minor to moderate explosive eruptions of ash and larger pumice - a volcanic rock characterized by low density and high proportion of gas bubbles formed as the explosively-erupted parent lava cools during its transit through the air. These materials blanket the volcanic cone and surrounding area, giving this image an overall gray appearance. Shadowing of the western flank of Ubinas throws several lava flows into sharp relief, and highlights the steep slopes at the flow fronts -- a common characteristic of silica-rich, thick, and slow-moving lavas. NASA researchers note that the most recent major eruption of Ubinas occurred in 1969, however the historical record of activity extends back to the 16th century.

Eruptive pattern classification on Mount Etna (Sicily) and Piton de la Fournaise (La Réunion)

NASA Astrophysics Data System (ADS)

Falsaperla, Susanna; Langer, Horst; Ferrazzini, Valérie

2016-04-01

In the framework of the European MEDiterrranean Supersite Volcanoes (MED­SUV) project, Mt. Etna (Italy) and Piton de la Fournaise (La Réunion) were chosen as "European Supersite Demonstrator" and test site, respectively, to promote the transfer and implementation of efficient tools for the identification of impending volcanic activity. Both are "open-conduit volcanoes", forming ideal sites for the test and validation of innovative concepts, which can contribute to minimize volcanic hazard. One of the aims of the MED-SUV project was the development of software for machine learning applicable to data processing for early-warning purposes. Near-real time classification of continuous seismic data stream has been carried out in the control room of INGV Osservatorio Etneo since 2010. Subsequently, automatic alert procedures were activated. In the light of the excellent results for the 24/7 surveillance of Etna, we examine the portability of tools developed in the framework of the project when applied to seismic data recorded at Piton de la Fournaise. In the present application to data recorded at Piton de la Fournaise, the classifier aims at highlighting changes in the frequency content of the background seismic signal heralding the activation of the volcanic source and the imminent eruption. We describe the preliminary results of this test on a set of data of nearly two years starting on January 2014. This period follows three years of inactivity and deflation of the volcano and marks a renewal of the volcano activity with inflation, deep seismicity (-7km bsl) and five eruptions with fountains and lava flows that lasted from a few hours to more than two months. We discuss here the necessary tuning for the implementation of the software to the new dataset analyzed. We also propose a comparison with the results of pattern classification regarding recent eruptive activity at Etna.

Towards Operational Meteotsunami Early Warning System: the Adriatic Project MESSI

NASA Astrophysics Data System (ADS)

Vilibic, I.; Sepic, J.; Denamiel, C. L.; Mihanovic, H.; Muslim, S.; Tudor, M.; Ivankovic, D.; Jelavic, D.; Kovacevic, V.; Masce, T.; Dadic, V.; Gacic, M.; Horvath, K.; Monserrat, S.; Rabinovich, A.; Telisman-Prtenjak, M.

2017-12-01

A number of destructive meteotsunamis - atmospherically-driven long ocean waves in a tsunami frequency band - occurred during the last decade through the world oceans. Owing to significant damage caused by these meteotsunamis, several scientific groups (occasionally in collaboration with public offices) have started developing meteotsunami warning systems. Creation of one such system has been initialized in the late 2015 within the MESSI (Meteotsunamis, destructive long ocean waves in the tsunami frequency band: from observations and simulations towards a warning system) project. Main goal of this project is to build a prototype of a meteotsunami warning system for the eastern Adriatic coast. The system will be based on real-time measurements, operational atmosphere and ocean modeling and real time decision-making process. Envisioned MESSI meteotsunami warning system consists of three modules: (1) synoptic warning module, which will use established correlation between forecasted synoptic fields and high-frequency sea level oscillations to provide qualitative meteotsunami forecasts for up to a week in advance, (2) probabilistic premodeling prediction module, which will use operational WRF-ROMS-ADCIRC modeling system and compare the forecast with an atlas of presimulations to get the probabilistic meteotsunami forecast for up to three days in advance, and (3) real-time module, which is based on real time tracking of properties of air pressure disturbance (amplitude, speed, direction, period, ...) and their real-time comparison with the atlas of meteotsunami simulations. System will be tested on recent meteotsunami events which were recorded in the MESSI area shortly after the operational meteotsunami network installation. Albeit complex, such a multilevel warning system has a potential to be adapted to most meteotsunami hot spots, simply by tuning the system parameters to the available atmospheric and ocean data.

Monitoring volcanic thermal activity by Robust Satellite Techniques: achievements and perspectives

NASA Astrophysics Data System (ADS)

Tramutoli, V.; Marchese, F.; Mazzeo, G.; Pergola, N.

2009-12-01

Satellite data have been increasingly used in last decades to study active volcanoes and to monitor thermal activity variation in space-time domain. Several satellite techniques and original methods have been developed and tested, devoted to hotspot detection and thermal monitoring. Among them, a multi-temporal approach, named RST (Robust Satellite Techniques), has shown high performances in detecting hotspots, with a low false positive rate under different observational and atmospheric conditions, providing also a potential toward low-level thermal anomalies which may announce incoming eruptions. As the RST scheme is intrinsically exportable on different geographic areas and satellite sensors, it has been applied and tested on a number of volcanoes and in different environmental conditions. This work presents major results and outcomes of studies carried out on Etna and Stromboli (Italy), Merapi (Java Indonesia), Asamayama (Japan), Jebel Al Tair (Yemen) by using different satellite systems and sensors (e.g. NOAA-AVHRR, EOS-MODIS, MSG-SEVIRI). Performances on hotspot detection, early warning and real-time monitoring, together with capabilities in possible thermal precursor identification, will be presented and discussed.

Joint NOAA/NWS/USGS prototype debris flow warning system for recently burned areas in Southern California

USGS Publications Warehouse

Restrepo, P.; Jorgensen, D.P.; Cannon, S.H.; Costa, J.; Laber, J.; Major, J.; Martner, B.; Purpura, J.; Werner, K.

2008-01-01

Debris flows, also known as mudslides, are composed gravity-driven mixtures of sediment and water that travel through steep channels, over open hillslopes, and the like. Addressing this issue, US Geological Survey (USGS) and NOAA have established a debris-flow warning system that has the ability to monitor and forecast precipitation and issue timely weather hazard warning. In 2005, this joint NOAA-USGS prototype debris-flow warning system was issued in Southern California and as a result, it has provided valuable information to emergency managers in affected communities.

El Cobreloa: A geyser with two distinct eruption styles

NASA Astrophysics Data System (ADS)

Namiki, Atsuko; Muñoz-Saez, Carolina; Manga, Michael

2014-08-01

We performed field measurements at a geyser nicknamed "El Cobreloa," located in the El Tatio Geyser Field, Northern Andes, Chile. The El Cobreloa geyser has two distinct eruption styles: minor eruptions and more energetic and long-lived major eruptions. Minor eruptions splash hot water intermittently over an approximately 4 min time period. Major eruptions begin with an eruption style similar to minor eruptions, but then transition to a voluminous liquid water-dominated eruption, and finally end with energetic steam discharge that continues for approximately 1 h. We calculated eruption intervals by visual observations, acoustic measurements, and ground temperature measurements and found that each eruption style has a regular interval: 4 h and 40 min for major eruptions and ˜14 min for minor eruptions. Eruptions of El Cobreloa and geochemical measurements suggest interaction of three water sources. The geyser reservoir, connected to the surface by a conduit, is recharged by a deep, hot aquifer. More deeply derived magmatic fluids heat the reservoir. Boiling in the reservoir releases steam and hot liquid water to the overlying conduit, causing minor eruptions, and heating the water in the conduit. Eventually the water in the conduit becomes warm enough to boil, leading to a steam-dominated eruption that empties the conduit. The conduit is then recharged by a shallow, colder aquifer, and the eruption cycle begins anew. We develop a model for minor eruptions which heat the water in the conduit. El Cobreloa provides insight into how small eruptions prepare the geyser system for large eruptions.

Modelling fluid flow in clastic eruptions: application to the Lusi mud eruption.

NASA Astrophysics Data System (ADS)

Collignon, Marine; Schmid, Daniel W.; Galerne, Christophe; Lupi, Matteo; Mazzini, Adriano

2017-04-01

Clastic eruptions involve the rapid ascension of clasts together with fluids, gas and/or liquid phases that may deform and brecciate the host rocks. These fluids transport the resulting mixture, called mud breccia, to the surface. Such eruptions are often associated with geological structures such as mud volcanoes, hydrothermal vent complexes and more generally piercement structures. They involve various processes, acting over a wide range of scales which makes them a complex and challenging, multi-phase system to model. Although piercement structures have been widely studied and discussed, only few attempts have been made to model the dynamics of such clastic eruptions. The ongoing Lusi mud eruption, in the East Java back-arc basin, which began in May 2006, is probably the most spectacular clastic eruption. Lusi's eruptive behaviour has been extensively studied over the past decade and thus represents a unique opportunity to better understand the dynamics driving clastic eruptions, including fossil clastic systems. We use both analytical formulations and numerical models to simulate Lusi's eruptive dynamics and to investigate simple relationships between the mud breccia properties (density, viscosity, gas and clast content) and the volumetric flow rate. Our results show that the conduit radius of such piercement system cannot exceeds a few meters at depth, and that clasts, if not densely packed, will not affect the flow rate when they are smaller than a fifth of the conduit size. Using published data for the annual gas fluxes at Lusi, we infer a maximal depth at which exsolution starts. This occurs between 1800 m and 3200 m deep for the methane and between 750 m and 1000 m for the carbon dioxide.

Design of a reliable and operational landslide early warning system at regional scale

NASA Astrophysics Data System (ADS)

Calvello, Michele; Piciullo, Luca; Gariano, Stefano Luigi; Melillo, Massimo; Brunetti, Maria Teresa; Peruccacci, Silvia; Guzzetti, Fausto

2017-04-01

Landslide early warning systems at regional scale are used to warn authorities, civil protection personnel and the population about the occurrence of rainfall-induced landslides over wide areas, typically through the prediction and measurement of meteorological variables. A warning model for these systems must include a regional correlation law and a decision algorithm. A regional correlation law can be defined as a functional relationship between rainfall and landslides; it is typically based on thresholds of rainfall indicators (e.g., cumulated rainfall, rainfall duration) related to different exceedance probabilities of landslide occurrence. A decision algorithm can be defined as a set of assumptions and procedures linking rainfall thresholds to warning levels. The design and the employment of an operational and reliable early warning system for rainfall-induced landslides at regional scale depend on the identification of a reliable correlation law as well as on the definition of a suitable decision algorithm. Herein, a five-step process chain addressing both issues and based on rainfall thresholds is proposed; the procedure is tested in a landslide-prone area of the Campania region in southern Italy. To this purpose, a database of 96 shallow landslides triggered by rainfall in the period 2003-2010 and rainfall data gathered from 58 rain gauges are used. First, a set of rainfall thresholds are defined applying a frequentist method to reconstructed rainfall conditions triggering landslides in the test area. In the second step, several thresholds at different exceedance probabilities are evaluated, and different percentile combinations are selected for the activation of three warning levels. Subsequently, within steps three and four, the issuing of warning levels is based on the comparison, over time and for each combination, between the measured rainfall and the pre-defined warning level thresholds. Finally, the optimal percentile combination to be employed in the regional early warning system is selected evaluating the model performance in terms of success and error indicators by means of the "event, duration matrix, performance" (EDuMaP) method.

Multiparametric Geophysical Signature of Vulcanian Explosions

NASA Astrophysics Data System (ADS)

Gottsmann, J.; de Angelis, S.; Fournier, N.; van Camp, M. J.; Sacks, S. I.; Linde, A. T.; Ripepe, M.

2010-12-01

Extrusion of viscous magma leading to lava dome-formation is a common phenomenon at arc volcanoes recently demonstrated at Mount St. Helens (USA), Chaiten (Chile), and SoufriËre Hills Volcano (British West Indies). The growth of lava domes is frequently accompanied by vigorous eruptions, commonly referred to as Vulcanian-style, characterized by sequences of short-lived (tens of seconds to tens of minutes) explosive pulses, reflecting the violent explosive nature of arc volcanism. Vulcanian eruptions represent a significant hazard, and an understanding of their dynamics is vital for risk mitigation. While eruption parameters have been mostly constrained from observational evidence, as well as from petrological, theoretical, and experimental studies, our understanding on the physics of the subsurface processes leading to Vulcanian eruptions is incomplete. We present and interpret a unique set of multi-parameter geophysical data gathered during two Vulcanian eruptions in July and December, 2008 at SoufriËre Hills Volcano from seismic, geodetic, infrasound, barometric, and gravimetric instrumentation. These events document the spectrum of Vulcanian eruptions in terms of their explosivity and nature of erupted products. Our analysis documents a pronounced difference in the geophysical signature of the two events associated with priming timescales and eruption triggering suggesting distinct differences in the mechanics involved. The July eruption has a signature related to shallow conduit dynamics including gradual system destabilisation, syn-eruptive decompression of the conduit by magma fragmentation, conduit emptying and expulsion of juvenile pumice. In contrast, sudden pressurisation of the entire plumbing system including the magma chambers resulted in dome carapace failure, a violent cannon-like explosion, propagation of a shock wave and pronounced ballistic ejection of dome fragments. We demonstrate that with lead times of between one and six minutes to the explosions the geophysical signature is indicative of the style of eruption priming, the dynamics of the ensuing eruption, and the nature of the erupted material. Our study conclusively demonstrates the extraordinary value of integrated multi-parameter systems for monitoring operations, in particular at volcanoes characterized by phases of continuous dome growth interspersed by vigorous, often unexpected, explosive activity.

The reconnaissance and early-warning optical system design for dual field of space-based "solar blind ultraviolet"

NASA Astrophysics Data System (ADS)

Wang, Wen-cong; Jin, Dong-dong; Shao, Fei; Hu, Hui-jun; Shi, Yu-feng; Song, Juan; Zhang, Yu-tu; Yong, Liu

2016-07-01

With the development of modern technology, especially the development of information technology at high speed, the ultraviolet early warning system plays an increasingly important role. In the modern warfare, how to detect the threats earlier, prevent and reduce the attack of precision-guided missile has become a new challenge. Because the ultraviolet warning technology has high environmental adaptability, the low false alarm rate, small volume and other advantages, in the military field applications it has been developed rapidly. According to current application demands for solar blind ultraviolet detection and warning, this paper proposes a reconnaissance and early-warning optical system, which covers solar blind ultraviolet (250nm-280nm) and dual field. This structure takes advantage of a narrow field of view and long focal length optical system to achieve the target object detection, uses wide-field and short focal length optical system to achieve early warning of the target object. It makes use of an ultraviolet beam-splitter to achieve the separation of two optical systems. According to the detector and the corresponding application needs of two visual field of the optical system, the calculation and optical system design were completed. After the design, the MTF of the two optical system is more than 0.8@39lp/mm. A single pixel energy concentration is greater than 80%.

The Warning System in Disaster Situations: A Selective Analysis.

DTIC Science & Technology

DISASTERS, *WARNING SYSTEMS), CIVIL DEFENSE, SOCIAL PSYCHOLOGY, REACTION(PSYCHOLOGY), FACTOR ANALYSIS, CLASSIFICATION, STATISTICAL DATA, TIME ... MANAGEMENT PLANNING AND CONTROL, DAMAGE, CONTROL SYSTEMS, THREAT EVALUATION, DECISION MAKING, DATA PROCESSING, COMMUNICATION SYSTEMS, NUCLEAR EXPLOSIONS

Tracing Magmatic Degassing Timescales at Soufrière Hills Volcano using Short-Lived Uranium Series Isotopes

NASA Astrophysics Data System (ADS)

Turner, S.; McGee, L. E.; Handley, H. K.; Reagan, M. K.; Turner, M. B.; Berlo, K.; Barclay, J.; Sparks, R. S. J.

2016-12-01

Soufrière Hills Volcano, on the Caribbean island of Montserrat, is one of the most intensively studied and constantly monitored volcanic systems in the world. Since 1995, the island has seen five phases of eruption, interspersed with periods of quiescence of varying length. The last eruptive phase ended in 2010, and the current period of quiescence is the longest since 1995. Mafic recharge is thought to contribute volatiles which may lead to system overpressure and trigger a volcanic eruption. At Soufrière Hills Volcano, enclaves of mafic material are a notable feature within the andesitic dome collapse material from all five eruptive phases and have been the focus of several recent petrogenetic studies, meaning that they are extremely well-characterised. We present a 210Pb-226Ra isotope data of enclave-andesite pairs from all five recent eruption phases of Soufrière Hills to investigate the timescale on which volatile transfer occurs prior to eruptions. 210Pb-226Ra disequilibria is a powerful tool in tracing gas movement within recently erupted (<100 years) volcanic material, as one of the intermediary daughters involved in the chain (222Rn) is released in the gas phase of magmas. Subsequent deficits or excesses of 210Pb over 226Ra provide information on whether gas transfer occurred over a short time-frame or if gas fluxing from a mafic magma was maintained for some time previous to each eruption. This vital information may elucidate whether the system is recharging and preparing for a new eruptive phase or draining its current magma supply thus diminishing the possibility of further, explosive eruptions. Preliminary results suggest that gas fluxing from mafic magma was particularly effective in the first two eruptive phases, supporting the mafic-trigger hypothesis. However, we observe a possible change in this behaviour from phase 3 onwards. We complement these time-sensitive geochemical data with comparison to high resolution monitoring data with the hope that the coupling of these two techniques may aid in predicting how the system is likely to behave in the future.

49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the vehicle's service brake system. The warning signal must meet the applicable requirements of... September 1, 1975, must meet the brake system indicator lamp requirements of FMVSS No. 571.105 (S5.3..., must have a warning signal which operates before or upon application of the brakes in the event of a...

Volcanic Eruptions of the EPR and Ridge Axis Segmentation: An Interdisciplinary View

NASA Astrophysics Data System (ADS)

White, S.; Soule, S. A.; Tolstoy, M.; Waldhauser, F.; Rubin, K.

2008-12-01

The eruption of the EPR in 2005-06 provides an ideal window into the relationship between fine-scale segmentation of the ridge axis and individual eruptive episodes. Lava flow mapping of the eruption by visual and acoustic images, precise dates on multiple eruptive units, stress information from seismicity, long-term records of hydrothermal activity, and well known segment boundaries illustrate the relationships between eruptions and segmentation of mid-ocean ridges. Lava flows emerged from several sections of the axial summit trough (AST) during the eruption, presumably from en echelon fissures between 9 45'N and 9 57'N. Each en echelon fissure is a 4th order segment, and the overall area matches the 3rd Order segment between ~9 45'N and ~9 58'N. Within the eruption, the primary eruptive fissure jumped east by 600 m at 9 53'N, and ran along an inward facing fault scarp, although limited lava effusion also extended northward along the axial fissure. A zone of high seismicity connects the normal fault bounding the eastern fissure eruption with the main locus of eruption on the ridge axis to the south, suggesting that the offset eruption may have occurred in response to stress buildup on this fault. Radiometric ages indicate that the entire along-axis extent of the eruptive fissures activated initially, but that volcanic activity focused to a single fourth-order segment within 1-3 months. Previously indentified breaks in the AST and its overall outline were largely unchanged by the eruption. These observations support the hypothesis that fourth-order segments are offsets controlled by the mechanics of dike emplacement, whereas third-order segments represent discrete volcanic systems. Dike segmentation may be controlled by variations in underlying ridge structure or the magma reservoir. Hydrothermal systems disrupted as far south as 9 37'N may be responding to cracking due to stress interaction or share a common deeper magmatic source. Comparisons between the 1991 EPR eruption at the same site, and several mapped southern EPR eruptions, the 10 45'N EPR eruption in ca. 2003 all show similar relationships to segmentation

Volcanism in Iceland in historical time: Volcano types, eruption styles and eruptive history

NASA Astrophysics Data System (ADS)

Thordarson, T.; Larsen, G.

2007-01-01

The large-scale volcanic lineaments in Iceland are an axial zone, which is delineated by the Reykjanes, West and North Volcanic Zones (RVZ, WVZ, NVZ) and the East Volcanic Zone (EVZ), which is growing in length by propagation to the southwest through pre-existing crust. These zones are connected across central Iceland by the Mid-Iceland Belt (MIB). Other volcanically active areas are the two intraplate belts of Öræfajökull (ÖVB) and Snæfellsnes (SVB). The principal structure of the volcanic zones are the 30 volcanic systems, where 12 are comprised of a fissure swarm and a central volcano, 7 of a central volcano, 9 of a fissure swarm and a central domain, and 2 are typified by a central domain alone. Volcanism in Iceland is unusually diverse for an oceanic island because of special geological and climatological circumstances. It features nearly all volcano types and eruption styles known on Earth. The first order grouping of volcanoes is in accordance with recurrence of eruptions on the same vent system and is divided into central volcanoes (polygenetic) and basalt volcanoes (monogenetic). The basalt volcanoes are categorized further in accordance with vent geometry (circular or linear), type of vent accumulation, characteristic style of eruption and volcanic environment (i.e. subaerial, subglacial, submarine). Eruptions are broadly grouped into effusive eruptions where >95% of the erupted magma is lava, explosive eruptions if >95% of the erupted magma is tephra (volume calculated as dense rock equivalent, DRE), and mixed eruptions if the ratio of lava to tephra occupy the range in between these two end-members. Although basaltic volcanism dominates, the activity in historical time (i.e. last 11 centuries) features expulsion of basalt, andesite, dacite and rhyolite magmas that have produced effusive eruptions of Hawaiian and flood lava magnitudes, mixed eruptions featuring phases of Strombolian to Plinian intensities, and explosive phreatomagmatic and magmatic eruptions spanning almost the entire intensity scale; from Surtseyan to Phreatoplinian in case of "wet" eruptions and Strombolian to Plinian in terms of "dry" eruptions. In historical time the magma volume extruded by individual eruptions ranges from ˜1 m 3 to ˜20 km 3 DRE, reflecting variable magma compositions, effusion rates and eruption durations. All together 205 eruptive events have been identified in historical time by detailed mapping and dating of events along with extensive research on documentation of eruptions in historical chronicles. Of these 205 events, 192 represent individual eruptions and 13 are classified as "Fires", which include two or more eruptions defining an episode of volcanic activity that lasts for months to years. Of the 159 eruptions verified by identification of their products 124 are explosive, effusive eruptions are 14 and mixed eruptions are 21. Eruptions listed as reported-only are 33. Eight of the Fires are predominantly effusive and the remaining five include explosive activity that produced extensive tephra layers. The record indicates an average of 20-25 eruptions per century in Iceland, but eruption frequency has varied on time scale of decades. An apparent stepwise increase in eruption frequency is observed over the last 1100 years that reflects improved documentation of eruptive events with time. About 80% of the verified eruptions took place on the EVZ where the four most active volcanic systems (Grímsvötn, Bárdarbunga-Veidivötn, Hekla and Katla) are located and 9%, 5%, 1% and 0.5% on the RVZ-WVZ, NVZ, ÖVB, and SVB, respectively. Source volcano for ˜4.5% of the eruptions is not known. Magma productivity over 1100 years equals about 87 km 3 DRE with basaltic magma accounting for about 79% and intermediate and acid magma accounting for 16% and 5%, respectively. Productivity is by far highest on the EVZ where 71 km 3 (˜82%) were erupted, with three flood lava eruptions accounting for more than one half of that volume. RVZ-WVZ accounts for 13% of the magma and the NWZ and the intraplate belts for 2.5% each. Collectively the axial zone (RVZ, WVZ, NVZ) has only erupted 15-16% of total magma volume in the last 1130 years.

75 FR 26269 - Draft Programmatic Environmental Assessment for the Integrated Public Alert and Warning Program's...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

...] Draft Programmatic Environmental Assessment for the Integrated Public Alert and Warning Program's... from construction- related actions taken under the Integrated Public Alert and Warning Program (IPAWS... Order 13407, Public Alert and Warning System, by providing robust and survivable power generation, fuel...

Impact of social preparedness on flood early warning systems

NASA Astrophysics Data System (ADS)

Girons Lopez, M.; Di Baldassarre, G.; Seibert, J.

2017-01-01

Flood early warning systems play a major role in the disaster risk reduction paradigm as cost-effective methods to mitigate flood disaster damage. The connections and feedbacks between the hydrological and social spheres of early warning systems are increasingly being considered as key aspects for successful flood mitigation. The behavior of the public and first responders during flood situations, determined by their preparedness, is heavily influenced by many behavioral traits such as perceived benefits, risk awareness, or even denial. In this study, we use the recency of flood experiences as a proxy for social preparedness to assess its impact on the efficiency of flood early warning systems through a simple stylized model and implemented this model using a simple mathematical description. The main findings, which are based on synthetic data, point to the importance of social preparedness for flood loss mitigation, especially in circumstances where the technical forecasting and warning capabilities are limited. Furthermore, we found that efforts to promote and preserve social preparedness may help to reduce disaster-induced losses by almost one half. The findings provide important insights into the role of social preparedness that may help guide decision-making in the field of flood early warning systems.

14 CFR 23.703 - Takeoff warning system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.703 Takeoff warning system. For commuter category airplanes, unless it can be shown...

14 CFR 23.703 - Takeoff warning system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.703 Takeoff warning system. For commuter category airplanes, unless it can be shown...

An integrated earthquake early warning system and its performance at schools in Taiwan

NASA Astrophysics Data System (ADS)

Wu, Bing-Ru; Hsiao, Nai-Chi; Lin, Pei-Yang; Hsu, Ting-Yu; Chen, Chiou-Yun; Huang, Shieh-Kung; Chiang, Hung-Wei

2017-01-01

An earthquake early warning (EEW) system with integration of regional and onsite approaches was installed at nine demonstration stations in several districts of Taiwan for taking advantages of both approaches. The system performance was evaluated by a 3-year experiment at schools, which experienced five major earthquakes during this period. The blind zone of warning was effectively reduced by the integrated EEW system. The predicted intensities from EEW demonstration stations showed acceptable accuracy compared to field observations. The operation experience from an earthquake event proved that students could calmly carry out correct action before the seismic wave arrived using some warning time provided by the EEW system. Through successful operation in practice, the integrated EEW system was verified as an effective tool for disaster prevention at schools.

Forests and Phenology: Designing the Early Warning System to Understand Forest Change

NASA Astrophysics Data System (ADS)

Pierce, T.; Phillips, M. B.; Hargrove, W. W.; Dobson, G.; Hicks, J.; Hutchins, M.; Lichtenstein, K.

2010-12-01

Vegetative phenology is the study of plant development and changes with the seasons, such as the greening-up and browning-down of forests, and how these events are influenced by variations in climate. A National Phenology Data Set, based on Moderate Resolution Imaging Spectroradiometer satellite images covering 2002 through 2009, is now available from work by NASA, the US Forest Service, and Oak Ridge National Laboratory. This new data set provides an easily interpretable product useful for detecting changes to the landscape due to long-term factors such as climate change, as well as finding areas affected by short-term forest threats such as insects or disease. The Early Warning System (EWS) is a toolset being developed by the US Forest Service and the University of North Carolina-Asheville to support distribution and use of the National Phenology Data Set. The Early Warning System will help research scientists, US Forest Service personnel, forest and natural resources managers, decision makers, and the public in the use of phenology data to better understand unexpected change within our nation’s forests. These changes could have multiple natural sources such as insects, disease, or storm damage, or may be due to human-induced events, like thinning, harvest, forest conversion to agriculture, or residential and commercial use. The primary goal of the Early Warning System is to provide a seamless integration between monitoring, detection, early warning and prediction of these forest disturbances as observed through phenological data. The system consists of PC and web-based components that are structured to support four user stages of increasing knowledge and data sophistication. Building Literacy: This stage of the Early Warning System educates potential users about the system, why the system should be used, and the fundamentals about the data the system uses. The channels for this education include a website, interactive tutorials, pamphlets, and other technology transfer methodologies. Achieving Context and Meaning: To provide deeper meaning and knowledge about the Early Warning System to users, this stage of the Early Warning System provides more information about specific examples of disturbances seen in the phenological data, as well the spatial and temporal context to these disturbances. The main components of this stage are specific case studies of forest disturbances. Accessing Data: This component of the Early Warning System includes products for research scientists, the aerial detection survey sketch mapper community, and others who will access and analyze the Early Warning System and phenological data. Products and data will be available through online GIS mashups and WMS and KML downloads. Utilizing Services: The final stage of the Early Warning System supports the analysis of phenological data and serves the results to those end users, including forest managers, the forest industry, and the public, who need to locate past, present, and potential forest disturbances. The main components of this stage include data-driven web tools, automated analysis processes, and end user training programs.

A national survey of obstetric early warning systems in the United Kingdom: five years on.

PubMed

Isaacs, R A; Wee, M Y K; Bick, D E; Beake, S; Sheppard, Z A; Thomas, S; Hundley, V; Smith, G B; van Teijlingen, E; Thomas, P W

2014-07-01

The Confidential Enquiries into Maternal Deaths in the UK have recommended obstetric early warning systems for early identification of clinical deterioration to reduce maternal morbidity and mortality. This survey explored early warning systems currently used by maternity units in the UK. An electronic questionnaire was sent to all 205 lead obstetric anaesthetists under the auspices of the Obstetric Anaesthetists' Association, generating 130 (63%) responses. All respondents reported use of an obstetric early warning system, compared with 19% in a similar survey in 2007. Respondents agreed that the six most important physiological parameters to record were respiratory rate, heart rate, temperature, systolic and diastolic blood pressure and oxygen saturation. One hundred and eighteen (91%) lead anaesthetists agreed that early warning systems helped to prevent obstetric morbidity. Staffing pressures were perceived as the greatest barrier to their use, and improved audit, education and training for healthcare professionals were identified as priority areas. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

Mauna Loa--history, hazards and risk of living with the world's largest volcano

USGS Publications Warehouse

Trusdell, Frank A.

2012-01-01

Mauna Loa on the Island Hawaiʻi is the world’s largest volcano. People residing on its flanks face many hazards that come with living on or near an active volcano, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and local tsunami (giant seawaves). The County of Hawaiʻi (Island of Hawaiʻi) is the fastest growing County in the State of Hawaii. Its expanding population and increasing development mean that risk from volcano hazards will continue to grow. U.S. Geological Survey (USGS) scientists at the Hawaiian Volcano Observatory (HVO) closely monitor and study Mauna Loa Volcano to enable timely warning of hazardous activity and help protect lives and property.

[Evaluation and analysis of monitoring and early warning functions of the occupational disease reporting system in China].

PubMed

Zhu, Xiaojun; Li, Tao; Liu, Mengxuan

2015-06-01

To evaluate the monitoring and early warning functions of the occupational disease reporting system right now in China, and to analyze their influencing factors. An improved audit tool (ODIT) was used to score the monitoring and early warning functions with a total score of 10. The nine indices were completeness of information on the reporting form, coverage of the reporting system, accessibility of criteria or guidelines for diagnosis, education and training for physicians, completeness of the reporting system, statistical methods, investigation of special cases, release of monitoring information, and release of early warning information. According to the evaluation, the occupational disease reporting system in China had a score of 5.5 in monitoring existing occupational diseases with a low score for release of monitoring information; the reporting system had a score of 6.5 in early warning of newly occurring occupational diseases with low scores for education and training for physicians as well as completeness of the reporting system. The occupational disease reporting system in China still does not have full function in monitoring and early warning. It is the education and participation of physicians from general hospitals in the diagnosis and treatment of occupational diseases and suspected occupational diseases that need to be enhanced. In addition, the problem of monitoring the incidence of occupational diseases needs to be solved as soon as possible.

Deep fluid transfer evidenced by surface deformation during the 2014-2015 unrest at Piton de la Fournaise volcano

NASA Astrophysics Data System (ADS)

Peltier, Aline; Beauducel, François; Villeneuve, Nicolas; Ferrazzini, Valérie; Di Muro, Andrea; Aiuppa, Alessandro; Derrien, Allan; Jourde, Kevin; Taisne, Benoit

2016-07-01

Identifying the onset of volcano unrest and providing an unequivocal identification of volcano reawakening remain challenging problems in volcanology. At Piton de la Fournaise, renewal of eruptive activity in 2014-2015, after 41 months of quiescence and deflation, was associated with long-term continuous edifice inflation measured by GNSS. Inflation started on June 9, 2014, and its rate progressively increased through 2015. Inflation onset was rapidly followed by an eruption on June 20-21, 2014, showing that volcano reactivation can be extremely fast, even after long non-eruptive phases. This short-lived eruption involved a shallow source (1.3-1.9 km depth below the summit). The inflation that followed, and eruptions in 2015, involved a larger depth range of fluid accumulation, constrained by inverse modeling at ca. 3.9 to 1.2-1.7 km depth. This time evolution reveals that volcano reawakening was associated with continuous pressurization of the shallowest parts of its plumbing system, triggered by progressive upwards transfer of magma from greater depth. A deep magma pulse occurred in mid-April 2015 and was associated with deep seismicity (3 to 9.5 km depth) and CO2 enrichment in fluids emitted by summit fumaroles. From this date, ground deformation accelerated and the output rates of eruptions increased, culminating in the long-lasting, large-volume, August-October eruption ( 36 Mm3). This evolution suggests that deep magma/fluid transfer through an open conduit system first provoked the expulsion of the top of the plumbing system in June 2014, and then induced the progressive vertical transfer of the entire plumbing system down to 9 km (four eruptions in 2015). The new sustained feeding of the volcano was also at the origin of the hydrothermal system perturbation and the acceleration of the eastern flank motion, which favor lateral dike propagation and the occurrence of frequent and increasingly large eruptions. Our results highlight the fast and progressive way in which basaltic magmatic systems can wake up.

The 2012-2014 eruptive cycle of Copahue Volcano, Southern Andes. Magmatic-Hydrothermal system interaction and manifestations.

NASA Astrophysics Data System (ADS)

Morales, Sergio; Alarcón, Alex; Basualto, Daniel; Bengoa, Cintia; Bertín, Daniel; Cardona, Carlos; Córdova, Maria; Franco, Luis; Gil, Fernando; Hernandez, Erasmo; Lara, Luis; Lazo, Jonathan; Mardones, Cristian; Medina, Roxana; Peña, Paola; Quijada, Jonathan; San Martín, Juan; Valderrama, Oscar

2015-04-01

Copahue Volcano (COPV), in Southern Andes of Chile, is an andesitic-basaltic stratovolcano, which is located on the western margin of Caviahue Caldera. The COPV have a NE-trending fissure with 9 aligned vents, being El Agrio the main currently active vent, with ca. 400 m in diameter. The COPV is placed into an extensive hydrothermal system which has modulated its recent 2012-2014 eruptive activity, with small phreatic to phreatomagmatic eruptions and isolated weak strombolian episodes and formation of crater lakes inside the main crater. Since 2012, the Southern Andes Volcano Observatory (OVDAS) carried out the real-time monitoring with seismic broadband stations, GPS, infrasound sensors and webcams. In this work, we report pre, sin, and post-eruptive seismic activity of the last two main eruptions (Dec, 2012 and Oct, 2014) both with different seismic precursors and superficial activity, showing the second one a particularly appearance of seismic quiescence episodes preceding explosive activity, as an indicator of interaction between magmatic-hydrothermal systems. The first episode, in late 2012, was characterized by a low frequency (0.3-0.4 Hz and 1.0-1.5 Hz) continuous tremor which increased gradually from background noise level amplitude to values of reduced displacement (DR), close to 50 cm2 at the peak of the eruption, reaching an eruptive column of ~1.5 km height. After few months of recording low energy seismicity, a sequence of low frequency, repetitive and low energy seismic events arose, with a frequency of occurrence up to 300 events/hour. Also, the VLP earthquakes were added to the record probably associated with magma intrusion into a deep magmatic chamber during all stages of eruptive process, joined to the record of VT seismicity during the same period, which is located throughout the Caviahue Caldera area. Both kind of seismic patterns were again recorded in October 2014, being the precursor of the new eruptive cycle at this time as well as the deformation of the volcanic edifice detected by GPS network. In this new eruptive process, the record of tremor was followed by particular seismic quiescence, as precursors of explosive activity which evolved from low acoustic energy signals toward more energetic signals with impulsive first arrivals and strong attenuation, joined to night incandescence in the main vent without evident juvenile material ejected, which could be associated to the temporal depression of the hydrothermal system located in the volcano system. The recent eruptive episode at Copahue Volcano is a good example of the complex temporal evolution of the interaction between magmatic and hydrothermal systems.

Early warning system for aftershocks

USGS Publications Warehouse

Bakun, W.H.; Fischer, F.G.; Jensen, E.G.; VanSchaack, J.

1994-01-01

A prototype early warning system to provide San Francisco and Oakland, California a few tens-of-seconds warning of incoming strong ground shaking from already-occurred M ≧ 3.7 aftershocks of the magnitude 7.1 17 October 1989 Loma Prieta earthquake was operational on 28 October 1989. The prototype system consisted of four components: ground motion sensors in the epicentral area, a central receiver, a radio repeater, and radio receivers. One of the radio receivers was deployed at the California Department of Transportation (CALTRANS) headquarters at the damaged Cypress Street section of the I-880 freeway in Oakland, California on 28 October 1989 and provided about 20 sec of warning before shaking from the M 4.5 Loma Prieta aftershock that occurred on 2 November 1989 at 0550 UTC. In its first 6 months of operation, the system generated triggers for all 12 M > 3.7 aftershocks for which trigger documentation is preserved, did not trigger on any M ≦ 3.6 aftershocks, and produced one false trigger as a result of a now-corrected single point of failure design flaw. Because the prototype system demonstrated that potentially useful warnings of strong shaking from aftershocks are feasible, the USGS has completed a portable early warning system for aftershocks that can be deployed anywhere.

Hydrologic ensembles based on convection-permitting precipitation nowcasts for flash flood warnings

NASA Astrophysics Data System (ADS)

Demargne, Julie; Javelle, Pierre; Organde, Didier; de Saint Aubin, Céline; Ramos, Maria-Helena

2017-04-01

In order to better anticipate flash flood events and provide timely warnings to communities at risk, the French national service in charge of flood forecasting (SCHAPI) is implementing a national flash flood warning system for small-to-medium ungauged basins. Based on a discharge-threshold flood warning method called AIGA (Javelle et al. 2014), the current version of the system runs a simplified hourly distributed hydrologic model with operational radar-gauge QPE grids from Météo-France at a 1-km2 resolution every 15 minutes. This produces real-time peak discharge estimates along the river network, which are subsequently compared to regionalized flood frequency estimates to provide warnings according to the AIGA-estimated return period of the ongoing event. To further extend the effective warning lead time while accounting for hydrometeorological uncertainties, the flash flood warning system is being enhanced to include Météo-France's AROME-NWC high-resolution precipitation nowcasts as time-lagged ensembles and multiple sets of hydrological regionalized parameters. The operational deterministic precipitation forecasts, from the nowcasting version of the AROME convection-permitting model (Auger et al. 2015), were provided at a 2.5-km resolution for a 6-hr forecast horizon for 9 significant rain events from September 2014 to June 2016. The time-lagged approach is a practical choice of accounting for the atmospheric forecast uncertainty when no extensive forecast archive is available for statistical modelling. The evaluation on 781 French basins showed significant improvements in terms of flash flood event detection and effective warning lead-time, compared to warnings from the current AIGA setup (without any future precipitation). We also discuss how to effectively communicate verification information to help determine decision-relevant warning thresholds for flood magnitude and probability. Javelle, P., Demargne, J., Defrance, D., Arnaud, P., 2014. Evaluating flash flood warnings at ungauged locations using post-event surveys: a case study with the AIGA warning system. Hydrological Sciences Journal, doi: 10.1080/02626667.2014.923970 Auger, L., Dupont, O., Hagelin, S., Brousseau, P., Brovelli, P., 2015. AROME-NWC: a new nowcasting tool based on an operational mesoscale forecasting system. Quarterly Journal of the Royal Meteorological Society, 141: 1603-1611, doi:10.1002/qj.2463

Applying Advanced and Existing Sensors in Dealing with Potential Natural Disasters

NASA Technical Reports Server (NTRS)

Habib, Shahid

2006-01-01

As an integrated observing strategy, the concept of sensorweb for Earth observations is appealing in many aspects. For instance, by increasing the spatial and temporal coverage of observations from space and other vantage points, one can eventually aid in increasing the accuracy of the atmospheric models which are precursor to hurricane track prediction, volcanic eruption forecast, and trajectory path of transcontinental transport of dust, harmful nuclear and chemical plumes. In reality, there is little analysis available in terms of benefits, costs and optimized set of sensors needed to make these necessary observations. This is a complex problem that must be carefully studied and balanced over many boundaries such as science, defense, early warning, security, and surveillance. Simplistically, the sensorweb concept from the technological point of view alone has a great appeal in the defense, early warning and security applications. In fact, it can be relatively less expensive in per unit cost as opposed to building and deploying it for the scientific use. However, overall observing approach should not be singled out and aligned somewhat orthogonally to serve a particular need. On the other hand, the sensorweb should be designed and deployed to serve multiple subject areas and customers simultaneously; and can behave as directed measuring systems for both science and operational entities. Sensorweb can be designed to act as expert systems, and/or also provide a dedicated integrated surveillance network. Today, there is no system in the world that is fully integrated in terms of reporting timely multiple hazards warnings, computing the loss of life and property damage estimates, and is also designed to cater to everyone s needs. It is not an easier problem to undertake and more so is not practically solvable. At this time due to some recent events in the world, the scientific community, social scientists, and operational agencies are more cognizant and getting together to address such colossal problems. Increasing our knowledge of the home planet, via amplified set of observations, is certainly a right step in a right direction. Furthermore, this is a prerequisite in understanding multiple hazard phenomena's. This paper examines various sensorweb options and observing architectures that can be useful specifically in addressing some of these complex issues. The ultimate goal is to serve the society by providing potential natural hazards information to the decision makers in the most expeditious manner so they can prepare themselves to mitigate potential risks to human life, livestock and property.

14 CFR 23.703 - Takeoff warning system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.703 Takeoff warning system. Link to an amendment published at 76 FR 75757, December 2...

14 CFR 23.703 - Takeoff warning system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.703 Takeoff warning system. For all airplanes with a maximum weight more than 6,000...

A first Event-tree for the Bárðarbunga volcanic system (Iceland): from the volcanic crisis in 2014 towards a tool for hazard assessment

NASA Astrophysics Data System (ADS)

Barsotti, Sara; Tumi Gudmundsson, Magnús; Jónsdottir, Kristín; Vogfjörd, Kristín; Larsen, Gudrun; Oddsson, Björn

2015-04-01

Bárdarbunga volcano is part of a large volcanic system that had its last confirmed eruption before the present unrest in 1910. This system is partially covered by ice within the Vatnajökull glacier and it extends further to the NNE as well as to SW. Based on historical data, its eruptive activity has been predominantly characterized by explosive eruptions, originating beneath the glacier, and important effusive eruptions in the ice-free part of the system itself. The largest explosive eruptions took place on the southern side of the fissure system in AD 1477 producing about 10 km3 of tephra. Due to the extension and location of this volcanic system, the range of potential eruptive scenarios and associated hazards is quite wide. Indeed, it includes: inundation, due to glacial outburst; tephra fallout, due to ash-rich plume generated by magma-water interaction; abundant volcanic gas release; and lava flows. Most importantly these phenomena are not mutually exclusive and might happen simultaneously, creating the premise for a wide spatial and temporal impact. During the ongoing volcanic crisis at Bárdarbunga, which started on 16 August, 2014, the Icelandic Meteorological Office, together with the University of Iceland and Icelandic Civil Protection started a common effort of drawing, day-by-day, the potential evolution of the ongoing rifting event and, based on the newest data from the monitoring networks, updated and more refined scenarios have been identified. Indeed, this volcanic crisis created the occasion for pushing forward the creation of the first Event-tree for the Bárðarbunga volcanic system. We adopted the approach suggested by Newhall and Pallister (2014) and a preliminary ET made of nine nodes has been constructed. After the two initial nodes (restless and genesis) the ET continues with the identification of the location of aperture of future eruptive vents. Due to the complex structure of the system and historical eruptions, this third node (location) is split into four sub-ETs corresponding to: caldera, ice-covered fissure, ice-free fissure toward the North and ice-free fissure toward the South. This subdivision is needed because different hazards will impact different parts of the country, e.g. eruption sources located in parts of the system belonging to different water catchments will trigger glacial outbursts that will inundate different areas in the lowland. Once the source location has been identified, defining outcome, phenomena, size, duration and sectors are then the following steps. The outcomes include effusive lava flows, pure sub-glacial eruptions (with no aerial component), phreatomagmatic basaltic explosive eruptions, to mixed eruptions. Once the phenomena are listed, the sizes are identified as functions of the hazards themselves, for example the sizes may refer to the extrusion rate in case of lava flow and to the volume in case of flood. This way to proceed is mostly due to the need to include a wide range of phenomena that might occur at the same time and that need to be treated separately. A tentative estimation of likelihoods at each branch has been done mostly based on past eruptive events and historical evidence. This is the first step towards the setup of a long-range hazard assessment tool.

Early prediction of eruption site using lightning location data: Estimates of accuracy during past eruptions

NASA Astrophysics Data System (ADS)

Nína Petersen, Guðrún; Arason, Þórður; Bjornsson, Halldór

2013-04-01

Eruption of subglacial volcanoes may lead to catastrophic floods and therefore early determination of the exact eruption site may be critical to civil protection evacuation plans. Poor visibility due to weather or darkness often inhibit positive identification of exact eruption location for many hours. However, because of the proximity and abundance of water in powerful subglacial volcanic eruptions, they are probably always accompanied by early lightning activity in the volcanic column. Lightning location systems, designed for weather thunderstorm monitoring, based on remote detection of electromagnetic waves from lightning, can provide valuable real-time information on location of eruption site. Important aspect of such remote detection is its independence of weather, apart from thunderstorms close to the volcano. Individual lightning strikes can be 5-10 km in length and are sometimes tilted and to the side of the volcanic column. This adds to the lightning location uncertainty, which is often a few km. Furthermore, the volcanic column may be swayed by the local wind to one side. Therefore, location of a single lightning can be misleading but by calculating average location of many lightning strikes and applying wind correction a more accurate eruption site location can be obtained. In an effort to assess the expected accuracy, the average lightning locations during the past five volcanic eruptions in Iceland (1998-2011) were compared to the exact site of the eruption vent. Simultaneous weather thunderstorms might have complicated this analysis, but there were no signs of ordinary thunderstorms in Iceland during these eruptions. To identify a suitable wind correction, the vector wind at the 500 hPa pressure level (5-6 km altitude) was compared to mean lightning locations during the eruptions. The essential elements of a system, which predicts the eruption site during the first hour(s) of an eruption, will be described.

The 2011 eruption of Nabro volcano, Eritrea: perspectives on magmatic processes from melt inclusions

NASA Astrophysics Data System (ADS)

Donovan, Amy; Blundy, Jon; Oppenheimer, Clive; Buisman, Iris

2018-01-01

The 2011 eruption of Nabro volcano, Eritrea, produced one of the largest volcanic sulphur inputs to the atmosphere since the 1991 eruption of Mt. Pinatubo, yet has received comparatively little scientific attention. Nabro forms part of an off-axis alignment, broadly perpendicular to the Afar Rift, and has a history of large-magnitude explosive silicic eruptions, as well as smaller more mafic ones. Here, we present and analyse extensive petrological data obtained from samples of trachybasaltic tephra erupted during the 2011 eruption to assess the pre-eruptive magma storage system and explain the large sulphur emission. We show that the eruption involved two texturally distinct batches of magma, one of which was more primitive and richer in sulphur than the other, which was higher in water (up to 2.5 wt%). Modelling of the degassing and crystallisation histories demonstrates that the more primitive magma rose rapidly from depth and experienced degassing crystallisation, while the other experienced isobaric cooling in the crust at around 5 km depth. Interaction between the two batches occurred shortly before the eruption. The eruption itself was likely triggered by recharge-induced destabilisation of vertically extensive mush zone under the volcano. This could potentially account for the large volume of sulphur released. Some of the melt inclusions are volatile undersaturated, and suggest that the original water content of the magma was around 1.3 wt%, which is relatively high for an intraplate setting, but consistent with seismic studies of the Afar plume. This eruption was smaller than some geological eruptions at Nabro, but provides important insights into the plumbing systems and dynamics of off-axis volcanoes in Afar.

Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano.

PubMed

Druitt, T H; Costa, F; Deloule, E; Dungan, M; Scaillet, B

2012-02-01

Caldera-forming volcanic eruptions are low-frequency, high-impact events capable of discharging tens to thousands of cubic kilometres of magma explosively on timescales of hours to days, with devastating effects on local and global scales. Because no such eruption has been monitored during its long build-up phase, the precursor phenomena are not well understood. Geophysical signals obtained during recent episodes of unrest at calderas such as Yellowstone, USA, and Campi Flegrei, Italy, are difficult to interpret, and the conditions necessary for large eruptions are poorly constrained. Here we present a study of pre-eruptive magmatic processes and their timescales using chemically zoned crystals from the 'Minoan' caldera-forming eruption of Santorini volcano, Greece, which occurred in the late 1600s BC. The results provide insights into how rapidly large silicic systems may pass from a quiescent state to one on the edge of eruption. Despite the large volume of erupted magma (40-60 cubic kilometres), and the 18,000-year gestation period between the Minoan eruption and the previous major eruption, most crystals in the Minoan magma record processes that occurred less than about 100 years before the eruption. Recharge of the magma reservoir by large volumes of silicic magma (and some mafic magma) occurred during the century before eruption, and mixing between different silicic magma batches was still taking place during the final months. Final assembly of large silicic magma reservoirs may occur on timescales that are geologically very short by comparison with the preceding repose period, with major growth phases immediately before eruption. These observations have implications for the monitoring of long-dormant, but potentially active, caldera systems.

Electronic rumble strip

NASA Astrophysics Data System (ADS)

Stauffer, Donald R.; Lenz, James

1997-02-01

Single vehicle run-off-road accidents are responsible for significant numbers of injuries and fatalities, and significant property damage. This fact spurs interest in warning systems to alert drivers that vehicles are drifting towards the edge of the road, and that a run-off road accident is imminent. An early attempt at such a warning system is the use of machined grooves on the shoulder to create a rumble strip. Such a system only provides warning, however, as the vehicle actually leaves the traffic lane. More desirable is a system that warns in anticipation of such departure. Honeywell has under development a magnetic lateral guidance system that couples a sensitive magnetoresistive transducer with a magnetic traffic marking tape being developed by 3M. While this development was initially undertaken for use in automated highways, or for special tasks such as guiding snowplow owners, the system can provide an effective, all-weather warning system to provide alert of impending departure from the roadway. This electronic rumble strip is actually a simpler system than the baseline guidance system, and can monitor both distance from the traffic lane edge and the speed of approach to the edge with a low cost sensor.

Lessons from Hawaii: A Blessing in Disguise.

PubMed

Deitchman, Scott; Dallas, Cham E; Burkle, Frederick

2018-03-20

On January 13, 2018, Hawaii experienced an erroneous alert that falsely warned of an imminent ballistic missile strike. Rather than focus on the inconvenience caused by the false alert, we used reporting of the event to identify the missing elements that would characterize a system that could save lives by alerting and informing the public in a nuclear detonation. These include warnings that contain essential information rather than directing recipients to secondary sources; a system that issues alerts directly from federal agencies that will have the earliest warning; a robust multimodal alerting system that can deliver messages before and after the detonation; and swift activation of federal agencies immediately upon warning.

32 CFR 806b.27 - When to include a Privacy Act warning statement in publications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... include the Warning Statement when publications direct collection of the Social Security Number, or any part of the Social Security Number, from the individual. The warning statement will cite legal authority and when part of a record system, the Privacy Act system of records number and title. You can use...

32 CFR 806b.28 - Warning banners.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Warning banners. 806b.28 Section 806b.28... PROGRAM Privacy Act Notifications § 806b.28 Warning banners. Information systems that contain information... subject to the Privacy Act will have warning banners displayed on the first screen (at a minimum) to...

32 CFR 806b.28 - Warning banners.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Warning banners. 806b.28 Section 806b.28... PROGRAM Privacy Act Notifications § 806b.28 Warning banners. Information systems that contain information... subject to the Privacy Act will have warning banners displayed on the first screen (at a minimum) to...

32 CFR 806b.28 - Warning banners.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Warning banners. 806b.28 Section 806b.28... PROGRAM Privacy Act Notifications § 806b.28 Warning banners. Information systems that contain information... subject to the Privacy Act will have warning banners displayed on the first screen (at a minimum) to...

32 CFR 806b.28 - Warning banners.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Warning banners. 806b.28 Section 806b.28... PROGRAM Privacy Act Notifications § 806b.28 Warning banners. Information systems that contain information... subject to the Privacy Act will have warning banners displayed on the first screen (at a minimum) to...

32 CFR 806b.28 - Warning banners.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Warning banners. 806b.28 Section 806b.28... PROGRAM Privacy Act Notifications § 806b.28 Warning banners. Information systems that contain information... subject to the Privacy Act will have warning banners displayed on the first screen (at a minimum) to...

Safety Early Warning Research for Highway Construction Based on Case-Based Reasoning and Variable Fuzzy Sets

PubMed Central

Liu, Yan; Xu, Zhen-Jun

2013-01-01

As a high-risk subindustry involved in construction projects, highway construction safety has experienced major developments in the past 20 years, mainly due to the lack of safe early warnings in Chinese construction projects. By combining the current state of early warning technology with the requirements of the State Administration of Work Safety and using case-based reasoning (CBR), this paper expounds on the concept and flow of highway construction safety early warnings based on CBR. The present study provides solutions to three key issues, index selection, accident cause association analysis, and warning degree forecasting implementation, through the use of association rule mining, support vector machine classifiers, and variable fuzzy qualitative and quantitative change criterion modes, which fully cover the needs of safe early warning systems. Using a detailed description of the principles and advantages of each method and by proving the methods' effectiveness and ability to act together in safe early warning applications, effective means and intelligent technology for a safe highway construction early warning system are established. PMID:24191134

Safety early warning research for highway construction based on case-based reasoning and variable fuzzy sets.

PubMed

Liu, Yan; Yi, Ting-Hua; Xu, Zhen-Jun

2013-01-01

As a high-risk subindustry involved in construction projects, highway construction safety has experienced major developments in the past 20 years, mainly due to the lack of safe early warnings in Chinese construction projects. By combining the current state of early warning technology with the requirements of the State Administration of Work Safety and using case-based reasoning (CBR), this paper expounds on the concept and flow of highway construction safety early warnings based on CBR. The present study provides solutions to three key issues, index selection, accident cause association analysis, and warning degree forecasting implementation, through the use of association rule mining, support vector machine classifiers, and variable fuzzy qualitative and quantitative change criterion modes, which fully cover the needs of safe early warning systems. Using a detailed description of the principles and advantages of each method and by proving the methods' effectiveness and ability to act together in safe early warning applications, effective means and intelligent technology for a safe highway construction early warning system are established.

Precursory signals of the 2014-15 Fogo eruption (Cape Verde) detected by surface CO2 emission and heat flow observations

NASA Astrophysics Data System (ADS)

Pérez, Nemesio M.; Dionis, Samara; Fernandes, Paulo; Barrancos, José; Rodríguez, Fátima; Bandomo, Zuleyka; Hernández, Pedro A.; Melián, Gladys V.; Silva, Sónia; Padilla, Germán; Padrón, Eleazar; Cabral, Jeremias; Calvo, David; Asensio-Ramos, María; Pereira, José Manuel; Gonçalves, António A.; Barros, Inocencio; Semedo, Helio

2015-04-01

On November 23, 2014 a new eruption occurred at Fogo volcano (Cape Verde) after 19 years of the last eruptive event in 1995. In the case of the 1995 Fogo eruption, a volcano monitoring program for the volcanic surveillance of Fogo did not exist. On the contrary, a simple and multidisciplinary volcano monitoring program was initiated since 2007 to detect early warning signals of a new volcanic unrest such as the 2014-15 Fogo eruption. Diffuse CO2 emission surveys at the summit crater of Pico do Fogo volcano were periodically carried out from May 2007 to October 2014 to provide this multidisciplinary approach and to monitor potential volcanic activity changes. During this 7 year period, CO2 efflux ranged from non detectable (< 1.5 g m-2 d-1) up to relatively high (61.9 kg m-2 d-1) values. The observed average δ13C- CO2 values related to these diffuse CO2 emission surveys ranged from -22.1 to 1.6 ‰, and surface heat flux measurements, following the method of Dawson (1964), showed also a wide range of values from 0.1 to 460 W m-2. Areas with the highest observed CO2 efflux values were also characterized by a relatively high soil temperature and an intense surface hydrothermal alteration, which supports that degassing process is primary controlled by an advective mechanism generated by geothermal gradients (convection). Two periods of anomalous diffuse CO2 emission were observed between February 2009 to February 2010 and March to August 2014, respectively. Rest of surveys showed the lowest variability on diffuse CO2 emission, ranging from 23 to 186 t d-1 (average = 86 t d-1). The first anomalous period was characterized by a sharp increase on diffuse CO2 emission, suggesting the first magma intrusion beneath Pico do Fogo volcano. This observation is also supported by a significant change on the δ13C- CO2 signature from May 2009 (-10.2 ‰) to February 2010 (-6.1‰) of the diffuse CO2 degassing, indicating an enrichment on the magmatic CO2 component. On February 2010, the diffuse CO2 emission rate was 219 ± 36 t d-1 (Dionis et al., 2015). The second anomalous period started on March 2014, eight months before the 2014-15 Fogo eruption onset, and reached a relatively high value of 337 ± 119 t d-1 on August 30, 2014. It was likely caused by rising of magmatic gases from a second magma intrusion which ended on an eruption. Heat flow temporal evolution during the observation period also shows a quasi-continuous increase before the eruption onset, with the maximum observed heat flow (16.4 ± 3.4 MW) on March 2014. These geochemical and geophysical evidences are clearly precursory signals of the 2014-15 Fogo eruption. Dawson, G.B. (1964), N Z J Geol Geophys 7:155-171; Dionis S. et al. (2015), Bull. Volcanol., in press

Petrology of the 2004-2006 Mount St. Helens lava dome -- implications for magmatic plumbing and eruption triggering: Chapter 30 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

USGS Publications Warehouse

Pallister, John S.; Thornber, Carl R.; Cashman, Katharine V.; Clynne, Michael A.; Lowers, Heather; Mandeville, Charles W.; Brownfield, Isabelle K.; Meeker, Gregory P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

2008-01-01

The question of new versus residual magma has implications for the long-term eruptive behavior of Mount St. Helens, because arrival of a new batch of dacitic magma from the deep crust could herald the beginning of a new long-term cycle of eruptive activity. It is also important to our understanding of what triggered the eruption and its future course. Two hypotheses for triggering are considered: (1) top-down fracturing related to the shallow groundwater system and (2) an increase in reservoir pressure brought about by recent magmatic replenishment. With respect to the future course of the eruption, similarities between textures and character of eruption of the 2004-6 dome and the long-duration (greater than 100 years) pre-1980 summit dome, along with the low eruptive rate of the current eruption, suggest that the eruption could continue sluggishly or intermittently for years to come.

Volcano geodesy: Challenges and opportunities for the 21st century

USGS Publications Warehouse

Dzurisin, D.

2000-01-01

Intrusions of magma beneath volcanoes deform the surrounding rock and, if the intrusion is large enough, the overlying ground surface. Numerical models generally agree that, for most eruptions, subsurface volume changes are sufficient to produce measurable deformation at the surface. Studying this deformation can help to determine the location, volume, and shape of a subsurface magma body and thus to anticipate the onset and course of an eruption. This approach has been successfully applied at many restless volcanoes, especially basaltic shields and silicic calderas, using various geodetic techniques and sensors. However, its success at many intermediate-composition strato-volcanoes has been limited by generally long repose intervals, steep terrain, and structural influences that complicate the history and shape of surface deformation. These factors have made it difficult to adequately characterize deformation in space and time at many of the world's dangerous volcanoes. Recent technological advances promise to make this task easier by enabling the acquisition of geodetic data of high spatial and temporal resolution from Earth-orbiting satellites. Synthetic aperture radar interferometry (InSAR) can image ground deformation over large areas at metre-scale resolution over time-scales of a month to a few years. Global Positioning System (GPS) stations can provide continuous information on three-dimensional ground displacements at a network of key sites -information that is especially important during volcanic crises. By using InSAR to determine the shape of the displacement field and GPS to monitor temporal changes at key sites, scientists have a much better chance to capture geodetic signals that have so far been elusive at many volcanoes. This approach has the potential to provide longer-term warnings of impending volcanic activity than is possible with other monitoring techniques.

Local to global: a collaborative approach to volcanic risk assessment

NASA Astrophysics Data System (ADS)

Calder, Eliza; Loughlin, Sue; Barsotti, Sara; Bonadonna, Costanza; Jenkins, Susanna

2017-04-01

Volcanic risk assessments at all scales present challenges related to the multitude of volcanic hazards, data gaps (hazards and vulnerability in particular), model representation and resources. Volcanic hazards include lahars, pyroclastic density currents, lava flows, tephra fall, ballistics, gas dispersal and also earthquakes, debris avalanches, tsunamis and more ... they can occur in different combinations and interact in different ways throughout the unrest, eruption and post-eruption period. Volcanoes and volcanic hazards also interact with other natural hazards (e.g. intense rainfall). Currently many hazards assessments consider the hazards from a single volcano but at national to regional scales the potential impacts of multiple volcanoes over time become important. The hazards that have the greatest tendency to affect large areas up to global scale are those transported in the atmosphere: volcanic particles and gases. Volcanic ash dispersal has the greatest potential to directly or indirectly affect the largest number of people worldwide, it is currently the only volcanic hazard for which a global assessment exists. The quantitative framework used (primarily at a regional scale) considers the hazard at a given location from any volcano. Flow hazards such as lahars and floods can have devastating impacts tens of kilometres from a source volcano and lahars can be devastating decades after an eruption has ended. Quantitative assessment of impacts is increasingly undertaken after eruptions to identify thresholds for damage and reduced functionality. Some hazards such as lava flows could be considered binary (totally destructive) but others (e.g. ash fall) have varying degrees of impact. Such assessments are needed to enhance available impact and vulnerability data. Currently, most studies focus on physical vulnerability but there is a growing emphasis on social vulnerability showing that it is highly variable and dynamic with pre-eruption socio-economic conditions tending to influence longer term well-being and recovery. The volcanological community includes almost 100 Volcano Observatories worldwide, the official institutions responsible for monitoring volcanoes. They may be dedicated institutions, or operate from national institutions (geological surveys, universities, met agencies). They have a key role in early warning, forecasting and long term hazard assessment (often in the form of volcanic hazards maps). The complexity of volcanic systems means that once unrest begins there are multiple potential eruptive outcomes and short term forecasts can change rapidly. This local knowledge of individual volcanoes underpins hazard and risk assessments developed at national, regional and global scales. Combining this local expertise with the knowledge of the international research community (including interdisciplinary perspectives) creates a powerful partnership. A collaborative approach is therefore needed to develop effective volcanic risk assessments at regional to global scale. The World Organisation of Volcano Observatories is a Commission of IAVCEI, alongside other Commissions such as 'Hazard and Risk' (with an active working group on volcanic hazards maps) and the 'Cities and Volcanoes' Commission. The Global Volcano Model network is a collaborative initiative developing hazards and risk information at national to global scales, underpinned by local expertise. Partners include IAVCEI, Smithsonian Institution, International Volcanic Health Hazard Network, VHub and other initiatives and institutions.

A hazard-independent approach for the standardised multi-channel dissemination of warning messages

NASA Astrophysics Data System (ADS)

Esbri Palomares, M. A.; Hammitzsch, M.; Lendholt, M.

2012-04-01

The tsunami disaster affecting the Indian Ocean region on Christmas 2004 demonstrated very clearly the shortcomings in tsunami detection, public warning processes as well as intergovernmental warning message exchange in the Indian Ocean region. In that regard, early warning systems require that the dissemination of early warning messages has to be executed in way that ensures that the message delivery is timely; the message content is understandable, usable and accurate. To that end, diverse and multiple dissemination channels must be used to increase the chance of the messages reaching all affected persons in a hazard scenario. In addition to this, usage of internationally accepted standards for the warning dissemination such as the Common Alerting Protocol (CAP) and Emergency Data Exchange Language (EDXL) Distribution Element specified by the Organization for the Advancement of Structured Information Standards (OASIS) increase the interoperability among different warning systems enabling thus the concept of system-of-systems proposed by GEOSS. The project Distant Early Warning System (DEWS), co-funded by the European Commission under the 6th Framework Programme, aims at strengthening the early warning capacities by building an innovative generation of interoperable tsunami early warning systems based on the above mentioned concepts following a Service-oriented Architecture (SOA) approach. The project focuses on the downstream part of the hazard information processing where customized, user-tailored warning messages and alerts flow from the warning centre to the responsible authorities and/or the public with their different needs and responsibilities. The information logistics services within DEWS generate tailored EDXL-DE/CAP warning messages for each user that must receive the message according to their preferences, e.g., settings for language, interested areas, dissemination channels, etc.. However, the significant difference in the implementation and capabilities of different dissemination channels such as SMS, email and television, have bearing on the information processing required for delivery and consumption of a DEWS EDXL-DE/CAP message over each dissemination channel. These messages may include additional information in the form of maps, graphs, documents, sensor observations, etc. Therefore, the generated messages are pre-processed by channel adaptors in the information dissemination services converting it into a format that is suitable for end-to-end delivery over the dissemination channels without any semantic distortion. The approach followed by DEWS for disseminating warnings not only relies on traditional communication ways used by the already established early warnings such as the delivery of faxes and phone calls but takes into consideration the use of other broadly used communication channels such as SMS, email, narrowcast and broadcast television, instant messaging, Voice over IP, and radio. It also takes advantage of social media channels like RSS feeds, Facebook, Twitter, etc., enabling a multiplier effect, like in the case of radio and television, and thus allowing to create mash-ups by aggregating other sources of information to the original message. Finally, status information is also important in order to assess and understand whether the process of disseminating the warning to the message consumers has been successfully completed or the process failed at some point of the dissemination chain. To that end, CAP-based messages generated within the information dissemination services provide the semantics for those fields that are of interest within the context of reporting the warning dissemination status in DEWS.

Volcanic Eruptions and Climate: Outstanding Research Issues

NASA Astrophysics Data System (ADS)

Robock, Alan

2016-04-01

Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do volcanic eruptions change the probability of El Niño or La Niña in the years following the eruption? Are there decadal-scale oceanic responses that can provide long-term predictability? What was the contribution of volcanic eruptions to initiation and maintenance of the Little Ice Age? What are the observational needs for future volcanic eruptions that will help to improve forecasts, observe responses following volcanic eruptions, and better understand nucleation and growth of sulfate aerosols, which is important for evaluating suggestions for considering anthropogenic stratospheric clouds for climate engineering?

Kilauea's 5-9 March 2011 Kamoamoa fissure eruption and its relation to 30+ years of activity from Pu'u 'Ō'ō: Chapter 18

USGS Publications Warehouse

Orr, Tim R.; Poland, Michael P.; Patrick, Matthew R.; Thelen, Weston A.; Sutton, A.J.; Elias, Tamar; Thornber, Carl R.; Parcheta, Carolyn; Wooten, Kelly M.; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique

2015-01-01

Lava output from Kīlauea's long-lived East Rift Zone eruption, ongoing since 1983, began waning in 2010 and was coupled with uplift, increased seismicity, and rising lava levels at the volcano's summit and Pu‘u ‘Ō‘ō vent. These changes culminated in the four-day-long Kamoamoa fissure eruption on the East Rift Zone starting on 5 March 2011. About 2.7 × 106 m3 of lava erupted, accompanied by ˜15 cm of summit subsidence, draining of Kīlauea's summit lava lake, a 113 m drop of Pu‘u ‘Ō‘ō's crater floor, ˜3 m of East Rift Zone widening, and eruptive SO2 emissions averaging 8500 tonnes/day. Lava effusion resumed at Pu‘u ‘Ō‘ō shortly after the Kamoamoa eruption ended, marking the onset of a new period of East Rift Zone activity. Multiparameter monitoring before and during the Kamoamoa eruption suggests that it was driven by an imbalance between magma supplied to and erupted from Kīlauea's East Rift Zone and that eruptive output is affected by changes in the geometry of the rift zone plumbing system. These results imply that intrusions and eruptive changes during ongoing activity at Kīlauea may be anticipated from the geophysical, geological, and geochemical manifestations of magma supply and magma plumbing system geometry.

The Global Emergency Observation and Warning System

NASA Technical Reports Server (NTRS)

Bukley, Angelia P.; Mulqueen, John A.

1994-01-01

Based on an extensive characterization of natural hazards, and an evaluation of their impacts on humanity, a set of functional technical requirements for a global warning and relief system was developed. Since no technological breakthroughs are required to implement a global system capable of performing the functions required to provide sufficient information for prevention, preparedness, warning, and relief from natural disaster effects, a system is proposed which would combine the elements of remote sensing, data processing, information distribution, and communications support on a global scale for disaster mitigation.

From Rock to Magmatic Timescales in 25 Hours: Near-Real Time Petrological Volcanic Eruption Monitoring Tested with Basaltic Icelandic Tephras

NASA Astrophysics Data System (ADS)

Couperthwaite, F.; Morgan, D. J.; Thordarson, T.; Shea, T.; Harvey, J.

2016-12-01

Diffusion modeling of erupted crystals is routine for investigating pre-eruptive timescales within magma storage bodies and magma transport systems. The technique typically produces results some time after a volcanic eruption has commenced. This contribution employs a user-friendly, easy-to-use method for deployment in near-real time during an eruption, enabling rapid timescale assessment whilst retaining reliability. A `stress test' was undertaken to simulate analysis during an evolving eruption involving multiple tephra layers, to test method performance and assess the rapidity with which timescale data could be retrieved. The first tephra cycle was completely processed in 25 working hours, significantly faster than current traditional methods. Traditional limitations include slow data processing rates, the measurement of crystal orientations and sectioning angles, crystal shape uncertainties, and the possibilities of crystal growth and/or changing boundary conditions. These constraints have been considered for the new methodology with corrections applied at a crystal population level. Tephra samples from Vatnaöldur, Iceland were the study material for the stress test. 39 magmatic timescales from Mg-Fe interdiffusion across 25 olivine crystals were retrieved from the basal tephra layer representing eruption onset. Timescales range from 400 days to 160 days with olivine cores giving Forsterite (Fo) values of 82-84 and rim values 79 indicating a single olivine population showing normal zoning (Mg-rich core). The distribution of timescales is consistent with a single pulse of magma migrating from depth into a shallow system 1year before eruption onset. Magma arrival slows, then ceases by 5 months before eruption with no new magma entering the system in the days and weeks immediately before eruption. At the time of abstract submission, work is ongoing regarding the signals from later tephra units, but preliminary results indicate tapping of a source with longer crustal residence. Being able to retrieve this information within a day or so of the start of an eruption has exciting implications for eruption monitoring and hazard mitigation.

Comparison of proposed countermeasures for dilemma zone at signalized intersections based on cellular automata simulations.

PubMed

Wu, Yina; Abdel-Aty, Mohamed; Ding, Yaoxian; Jia, Bin; Shi, Qi; Yan, Xuedong

2018-07-01

The Type II dilemma zone describes the road segment to a signalized intersection where drivers have difficulties to decide either stop or go at the onset of yellow signal. Such phenomenon can result in an increased crash risk at signalized intersections. Different types of warning systems have been proposed to help drivers make decisions. Although the warning systems help to improve drivers' behavior, they also have several disadvantages such as increasing rear-end crashes or red-light running (RLR) violations. In this study, a new warning system called pavement marking with auxiliary countermeasure (PMAIC) is proposed to reduce the dilemma zone and enhance the traffic safety at signalized intersections. The proposed warning system integrates the pavement marking and flashing yellow system which can provide drivers with better suggestions about stop/go decisions based on their arriving time and speed. In order to evaluate the performance of the proposed warning system, this paper presents a cellular automata (CA) simulation study. The CA simulations are conducted for four different scenarios in total, including the typical intersection without warning system, the intersection with flashing green countermeasure, the intersection with pavement marking, and the intersection with the PMAIC warning system. Before the specific CA simulation analysis, a logistic regression model is calibrated based on field video data to predict drivers' general stop/go decisions. Also, the rules of vehicle movements in the CA models under the influence by different warning systems are proposed. The proxy indicators of rear-end crash and potential RLR violations were estimated and used to evaluate safety levels for the different scenarios. The simulation results showed that the PMAIC countermeasure consistently offered best performance to reduce rear-end crash and RLR violation. Meanwhile, the results indicate that the flashing-green countermeasure could not effectively reduce either rear-end crash risk or RLR violations. Also, it is found that the pavement-marking countermeasure has positive effects on reducing the rear-end risk while it may increase the probability of RLR violation. Lastly, the implementation of the proposed warning system is discussed with the consideration of connected-vehicle technology. It is expected that the dilemma zone issues can be efficiently addressed if the proposed countermeasure can be employed within connected vehicle technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geologic map of the northeast flank of Mauna Loa volcano, Island of Hawai'i, Hawaii

USGS Publications Warehouse

Trusdell, Frank A.; Lockwood, John P.

2017-05-01

SummaryMauna Loa, the largest volcano on Earth, has erupted 33 times since written descriptions became available in 1832. Some eruptions were preceded by only brief seismic unrest, while others followed several months to a year of increased seismicity.The majority of the eruptions of Mauna Loa began in the summit area (>12,000-ft elevation; Lockwood and Lipman, 1987); yet the Northeast Rift Zone (NERZ) was the source of eight flank eruptions since 1843 (table 1). This zone extends from the 13,680-ft-high summit towards Hilo (population ~60,000), the second largest city in the State of Hawaii. Although most of the source vents are farther than 30 km away, the 1880 flow from one of the vents extends into Hilo, nearly reaching Hilo Bay. The city is built entirely on flows erupted from the NERZ, most older than that erupted in 1843.Once underway, Mauna Loa's eruptions can produce lava flows that reach the sea in less than 24 hours, severing roads and utilities in their path. For example, lava flows erupted from the Southwest Rift Zone (SWRZ) in 1950 advanced at an average rate of 9.3 km per hour, and all three lobes reached the ocean within approximately 24 hours (Finch and Macdonald, 1953). The flows near the eruptive vents must have traveled even faster.In terms of eruption frequency, pre-eruption warning, and rapid flow emplacement, Mauna Loa poses an enormous volcanic-hazard threat to the Island of Hawai‘i. By documenting past activity and by alerting the public and local government officials of our findings, we can anticipate the volcanic hazards and substantially mitigate the risks associated with an eruption of this massive edifice.From the geologic record, we can deduce several generalized facts about the geologic history of the NERZ. The middle to the uppermost section of the rift zone were more active in the past 4,000 years than the lower part, perhaps due to buttressing of the lower east rift zone by Mauna Kea and Kīlauea volcanoes. The historical flows that erupted on the north flank of the rift zone, which is more vulnerable to inundation, advanced toward Hilo. Lockwood (1990) noted that the vents of historical activity are migrating to the south. The volcano appears to have a self-regulating mechanism that evenly distributes long-term activity across its flanks. The geologic record also supports this notion; the time prior to the historical period (Age Group 1, orange units, pre-A.D. 1843–1,000 yr B.P.; see map sheet 2) is dominated by activity on the south side of the NERZ.The NERZ trends N. 65° E. and is about 40 km long and 2–4 km wide, narrowing at the summit caldera. It becomes diffuse (6–7 km wide) at its down-rift terminus, at the approximately 3,400-ft elevation. Its constructional crest is marked by low spatter ramparts and by spatter cones as high as 60 m. Subparallel eruptive fissures and ground cracks cut vent deposits and flows in and near the rift crest. Lava typically flows to the north, east, or south, depending on vent location relative to the rift crest.Encompassing 1,140 km2 of the northeast flank of Mauna Loa from the 10,880-ft elevation to sea level, the map covers the area from Hilo to Volcano on the east and includes the rift zone from Puu Ulaula quadrangle in the southwest to Hilo in the northeast. The distribution of 105 eruptive units (flows)—separated into 15 age groups ranging from more than 30,000 years B.P. to A.D. 1984—are shown, as well as the relations of volcanic and surficial sedimentary deposits. This map incorporates previously reported work published in generalized small-scale maps (Lockwood and Lipman, 1987; Buchanan-Banks, 1993; Lockwood, 1995; and Wolfe and Morris, 1996).

Development of structural health monitoring and early warning system for reinforced concrete system

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

Iranata, Data, E-mail: iranata-data@yahoo.com, E-mail: data@ce.its.ac.id; Wahyuni, Endah; Murtiadi, Suryawan

Many buildings have been damaged due to earthquakes that occurred recently in Indonesia. The main cause of the damage is the large deformation of the building structural component cannot accommodate properly. Therefore, it is necessary to develop the Structural Health Monitoring System (SHMS) to measure precisely the deformation of the building structural component in the real time conditions. This paper presents the development of SHMS for reinforced concrete structural system. This monitoring system is based on deformation component such as strain of reinforcement bar, concrete strain, and displacement of reinforced concrete component. Since the deformation component has exceeded the limitmore » value, the warning message can be sent to the building occupies. This warning message has also can be performed as early warning system of the reinforced concrete structural system. The warning message can also be sent via Short Message Service (SMS) through the Global System for Mobile Communications (GSM) network. Hence, the SHMS should be integrated with internet modem to connect with GSM network. Additionally, the SHMS program is verified with experimental study of simply supported reinforced concrete beam. Verification results show that the SHMS has good agreement with experimental results.« less

Video Games in Volcanic Hazard Communications: Methods & Issues

NASA Astrophysics Data System (ADS)

Mani, Lara; Cole, Paul; Stewart, Iain

2016-04-01

Educational outreach plays a vital role in improving the resilience of vulnerable populations at risk from natural disasters. Currently, that activity is undertaken in many guises including the distribution of leaflets and posters, maps, presentations, education sessions and through radio and TV broadcasts. Such tried-and-tested communication modes generally target traditional stakeholder groups, but it is becoming increasingly important to engage with the new generation of learners who, due to advancements in technology, obtain information in ways different to their predecessors. That new generation is defined by a technological way of life and it remains a challenge to keep them motivated. On the eastern Caribbean island of St. Vincent, the La Soufriere Volcano lies in quiescence since the last eruption in 1979. Since then, an entire generation - over 56% of the population (Worldbank, 2015) - has little or no direct experience of a volcanic eruption. The island experiences, more frequently, other hazards (hurricanes, flooding, earthquakes landsliding), such that disaster preparedness measures give less priority to volcanic threats, which are deemed to pose less of a risk. With no accurate predictions to warn of the next eruption, it is especially important to educate residents about the potential of future volcanic hazards on the island, and to motivate them to prepare to mitigate their risk. This research critically examines the application of video games in supporting and enhancing existing public education and outreach programmes for volcanic hazards. St. Vincent's Volcano is a computer game designed to improve awareness and knowledge of the eruptive phenomena from La Soufriere that could pose a threat to residents. Within an interactive and immersive environment, players become acquainted with a 3D model of St. Vincent together with an overlay of the established volcanic hazard map (Robertson, 2005). Players are able to view visualisations of two historical eruptions (1902 &1979), which are reproduced based on historical data and personal accounts of the eruptions. Through a series of interactive scenes, each of the principal hazardous phenomena associated with La Soufriere - pyroclastic flows & surges, ash fall and lahars - are visualised and explained. The game concludes with a quiz in which players are required to answer questions are based on information provided throughout the game. The St. Vincent's Volcano game was trialled in St. Vincent during a volcano awareness education week in April 2015. The presentation will share reflections on how this type of interactive tool can be tested and implemented, and explore the issues and challenges with using video games in a dynamic environment.

Improving tsunami warning systems with remote sensing and geographical information system input.

PubMed

Wang, Jin-Feng; Li, Lian-Fa

2008-12-01

An optimal and integrative tsunami warning system is introduced that takes full advantage of remote sensing and geographical information systems (GIS) in monitoring, forecasting, detection, loss evaluation, and relief management for tsunamis. Using the primary impact zone in Banda Aceh, Indonesia as the pilot area, we conducted three simulations that showed that while the December 26, 2004 Indian Ocean tsunami claimed about 300,000 lives because there was no tsunami warning system at all, it is possible that only about 15,000 lives could have been lost if the area had used a tsunami warning system like that currently in use in the Pacific Ocean. The simulations further calculated that the death toll could have been about 3,000 deaths if there had been a disaster system further optimized with full use of remote sensing and GIS, although the number of badly damaged or destroyed houses (29,545) could have likely remained unchanged.

Flood and landslide warning based on rainfall thresholds and soil moisture indexes: the HEWS (Hydrohazards Early Warning System) for Sicily

NASA Astrophysics Data System (ADS)

Brigandì, Giuseppina; Tito Aronica, Giuseppe; Bonaccorso, Brunella; Gueli, Roberto; Basile, Giuseppe

2017-09-01

The main focus of the paper is to present a flood and landslide early warning system, named HEWS (Hydrohazards Early Warning System), specifically developed for the Civil Protection Department of Sicily, based on the combined use of rainfall thresholds, soil moisture modelling and quantitative precipitation forecast (QPF). The warning system is referred to 9 different Alert Zones in which Sicily has been divided into and based on a threshold system of three different increasing critical levels: ordinary, moderate and high. In this system, for early flood warning, a Soil Moisture Accounting (SMA) model provides daily soil moisture conditions, which allow to select a specific set of three rainfall thresholds, one for each critical level considered, to be used for issue the alert bulletin. Wetness indexes, representative of the soil moisture conditions of a catchment, are calculated using a simple, spatially-lumped rainfall-streamflow model, based on the SCS-CN method, and on the unit hydrograph approach, that require daily observed and/or predicted rainfall, and temperature data as input. For the calibration of this model daily continuous time series of rainfall, streamflow and air temperature data are used. An event based lumped rainfall-runoff model has been, instead, used for the derivation of the rainfall thresholds for each catchment in Sicily characterised by an area larger than 50 km2. In particular, a Kinematic Instantaneous Unit Hydrograph based lumped rainfall-runoff model with the SCS-CN routine for net rainfall was developed for this purpose. For rainfall-induced shallow landslide warning, empirical rainfall thresholds provided by Gariano et al. (2015) have been included in the system. They were derived on an empirical basis starting from a catalogue of 265 shallow landslides in Sicily in the period 2002-2012. Finally, Delft-FEWS operational forecasting platform has been applied to link input data, SMA model and rainfall threshold models to produce warning on a daily basis for the entire region.

Brake reactions of distracted drivers to pedestrian Forward Collision Warning systems.

PubMed

Lubbe, Nils

2017-06-01

Forward Collision Warning (FCW) can be effective in directing driver attention towards a conflict and thereby aid in preventing or mitigating collisions. FCW systems aiming at pedestrian protection have been introduced onto the market, yet an assessment of their safety benefits depends on the accurate modeling of driver reactions when the system is activated. This study contributes by quantifying brake reaction time and brake behavior (deceleration levels and jerk) to compare the effectiveness of an audio-visual warning only, an added haptic brake pulse warning, and an added Head-Up Display in reducing the frequency of collisions with pedestrians. Further, this study provides a detailed data set suited for the design of assessment methods for car-to-pedestrian FCW systems. Brake response characteristics were measured for heavily distracted drivers who were subjected to a single FCW event in a high-fidelity driving simulator. The drivers maintained a self-regulated speed of 30km/h in an urban area, with gaze direction diverted from the forward roadway by a secondary task. Collision rates and brake reaction times differed significantly across FCW settings. Brake pulse warnings resulted in the lowest number of collisions and the shortest brake reaction times (mean 0.8s, SD 0.29s). Brake jerk and deceleration were independent of warning type. Ninety percent of drivers exceeded a maximum deceleration of 3.6m/s 2 and a jerk of 5.3m/s 3 . Brake pulse warning was the most effective FCW interface for preventing collisions. In addition, this study presents the data required for driver modeling for car-to-pedestrian FCW similar to Euro NCAP's 2015 car-to-car FCW assessment. Practical applications: Vehicle manufacturers should consider the introduction of brake pulse warnings to their FCW systems. Euro NCAP could introduce an assessment that quantifies the safety benefits of pedestrian FCW systems and thereby aid the proliferation of effective systems. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

El Cobreloa: A geyser with two distinct eruption styles

NASA Astrophysics Data System (ADS)

Namiki, A.; Munoz, C.; Manga, M.; Hurwitz, S.; King, E.; Negri, A.; Ortega, P.; Patel, A.; Rudolph, M.

2013-12-01

El Cobreloa geyser has two distinct eruption styles: vigorous major eruptions, and less energetic minor eruptions. Minor eruptions splash hot water intermittently over an approximately 4 minute time period. Major eruptions begin with an eruption style similar to minor eruptions, but then transition to a voluminous and water-dominated eruption, and finally end with energetic steam discharge. The steam discharge continues for approximately 1 hour. We calculated the eruption intervals by visual observations, acoustic measurements, and ground temperature measurements. All of measurements consistently show that each eruption style has a regular interval: 4 hours and 40 minutes for major eruptions, and ~13 minutes for minor eruptions. From these observations, we infer that there are two boiling loci that source each type of eruption, one at the bottom and the other at the top of the conduit. If the bottom of the conduit is hot enough, boiling begins at the bottom of the conduit to make a steam slug. As this slug ascends in the conduit, it heats the surrounding water. If the slug rises fast enough it splashes water when it reaches the surface, creating minor eruptions. Each successive steam slug continues to heat water in the conduit until it eventually reaches the boiling temperature everywhere. Once the top of the conduit begins boiling, the energetic steam discharge begins and the boiling propagates downward. Such a process causes major eruption. Geysers are often studied as an analogue to magmatic volcanoes because it is easier to document how mass and energy transfer lead to eruptions. El Cobreloa provides insight into how the system becomes primed for large eruptions.

Progress and challenges with Warn-on-Forecast

NASA Astrophysics Data System (ADS)

Stensrud, David J.; Wicker, Louis J.; Xue, Ming; Dawson, Daniel T.; Yussouf, Nusrat; Wheatley, Dustan M.; Thompson, Therese E.; Snook, Nathan A.; Smith, Travis M.; Schenkman, Alexander D.; Potvin, Corey K.; Mansell, Edward R.; Lei, Ting; Kuhlman, Kristin M.; Jung, Youngsun; Jones, Thomas A.; Gao, Jidong; Coniglio, Michael C.; Brooks, Harold E.; Brewster, Keith A.

2013-04-01

The current status and challenges associated with two aspects of Warn-on-Forecast-a National Oceanic and Atmospheric Administration research project exploring the use of a convective-scale ensemble analysis and forecast system to support hazardous weather warning operations-are outlined. These two project aspects are the production of a rapidly-updating assimilation system to incorporate data from multiple radars into a single analysis, and the ability of short-range ensemble forecasts of hazardous convective weather events to provide guidance that could be used to extend warning lead times for tornadoes, hailstorms, damaging windstorms and flash floods. Results indicate that a three-dimensional variational assimilation system, that blends observations from multiple radars into a single analysis, shows utility when evaluated by forecasters in the Hazardous Weather Testbed and may help increase confidence in a warning decision. The ability of short-range convective-scale ensemble forecasts to provide guidance that could be used in warning operations is explored for five events: two tornadic supercell thunderstorms, a macroburst, a damaging windstorm and a flash flood. Results show that the ensemble forecasts of the three individual severe thunderstorm events are very good, while the forecasts from the damaging windstorm and flash flood events, associated with mesoscale convective systems, are mixed. Important interactions between mesoscale and convective-scale features occur for the mesoscale convective system events that strongly influence the quality of the convective-scale forecasts. The development of a successful Warn-on-Forecast system will take many years and require the collaborative efforts of researchers and operational forecasters to succeed.

The Financial Benefit of Early Flood Warnings in Europe

NASA Astrophysics Data System (ADS)

Pappenberger, Florian; Cloke, Hannah L.; Wetterhall, Fredrik; Parker, Dennis J.; Richardson, David; Thielen, Jutta

2015-04-01

Effective disaster risk management relies on science based solutions to close the gap between prevention and preparedness measures. The outcome of consultations on the UNIDSR post-2015 framework for disaster risk reduction highlight the need for cross-border early warning systems to strengthen the preparedness phases of disaster risk management in order to save people's lives and property and reduce the overall impact of severe events. In particular, continental and global scale flood forecasting systems provide vital information to various decision makers with which early warnings of floods can be made. Here the potential monetary benefits of early flood warnings using the example of the European Flood Awareness System (EFAS) are calculated based on pan-European Flood damage data and calculations of potential flood damage reductions. The benefits are of the order of 400 Euro for every 1 Euro invested. Because of the uncertainties which accompany the calculation, a large sensitivity analysis is performed in order to develop an envelope of possible financial benefits. Current EFAS system skill is compared against perfect forecasts to demonstrate the importance of further improving the skill of the forecasts. Improving the response to warnings is also essential in reaping the benefits of flood early warnings.

Personal Cabin Pressure Monitor and Warning System

NASA Technical Reports Server (NTRS)

Zysko, Jan A. (Inventor)

2002-01-01

A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded. and a second more serious alarm condition when either a second. higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.

Personal Cabin Pressure Monitor and Warning System

NASA Astrophysics Data System (ADS)

Zysko, Jan A.

2002-09-01

A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded. and a second more serious alarm condition when either a second. higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.

Designing Fatigue Warning Systems: The perspective of professional drivers.

PubMed

Meng, Fanxing; Li, Shuling; Cao, Lingzhi; Peng, Qijia; Li, Musen; Wang, Chunhui; Zhang, Wei

2016-03-01

Professional drivers have been characterized as experiencing heavy fatigue resulting from long driving time in their daily work. This study aimed to explore the potential demand of Fatigue Warning Systems (FWSs) among professional drivers as a means of reducing the danger of fatigue driving and to examine their opinions regarding the design of FWSs. Six focus groups with 35 participants and a questionnaire survey with 600 respondents were conducted among Chinese truck and taxi drivers to collect qualitative and quantitative data concerning the current situation of fatigue driving and opinions regarding the design of FWSs. The results revealed that both truck and taxi drivers had a positive attitude toward FWSs, and they hoped this system could not only monitor and warn them regarding their fatigue but also somewhat relieve their fatigue before they could stop and rest. As for warning signals, participants preferred auditory warnings, as opposed to visual, vibrotactile or electric stimuli. Interestingly, it was proposed that verbal warnings involving the information regarding consequences of fatigue driving or the wishes of drivers' family members would be more effective. Additionally, different warning patterns, including graded, single and continuous warnings, were discussed in the focus group. Finally, the participants proposed many other suggestions, as well as their concerns regarding FWSs, which will provide valuable information for companies who wish to develop FWSs for professional drivers. Copyright © 2015. Published by Elsevier Ltd.

Potential for Expanding the Near Real Time ForWarn Regional Forest Monitoring System to Include Alaska

NASA Technical Reports Server (NTRS)

Spruce, Joseph P.; Gasser, Gerald; Hargrove, William; Smoot, James; Kuper, Philip D.

2014-01-01

The on-line near real time (NRT) ForWarn system is currently deployed to monitor regional forest disturbances within the conterminous United States (CONUS), using daily MODIS Aqua and Terra NDVI data to derive monitoring products. The Healthy Forest Restoration Act of 2003 mandated such a system. Work on ForWarn began in 2006 with development and validation of retrospective MODIS NDVI-based forest monitoring products. Subsequently, NRT forest disturbance monitoring products were demonstrated, leading to the actual system deployment in 2010. ForWarn provides new CONUS forest disturbance monitoring products every 8 days, using USGS eMODIS data for current NDVI. ForWarn currently does not cover Alaska, which includes extensive forest lands at risk to multiple biotic and abiotic threats. This poster discusses a case study using Alaska eMODIS Terra data to derive ForWarn like forest change products during the 2010 growing season. The eMODIS system provides current MODIS Terra NDVI products for Alaska. Resulting forest change products were assessed with ground, aerial, and Landsat reference data. When cloud and snow free, these preliminary products appeared to capture regional forest disturbances from insect defoliation and fires; however, more work is needed to mitigate cloud and snow contamination, including integration of eMODIS Aqua data.

Floods in 2002 and 2013: comparing flood warnings and emergency measures from the perspective of affected parties

NASA Astrophysics Data System (ADS)

Kreibich, Heidi; Pech, Ina; Schröter, Kai; Müller, Meike; Thieken, Annegret

2016-04-01

Early warning is essential for protecting people and mitigating damage in case of flood events. However, early warning is only helpful if the flood-endangered parties are reached by the warning and if they know how to react effectively. Finding suitable methods for communicating helpful warnings to the "last mile" remains a challenge, but not much information is available. Surveys were undertaken after the August 2002 and the June 2013 floods in Germany, asking affected private households and companies about warnings they received and emergency measures they undertook. Results show, that in 2002 early warning did not work well: in too many areas warnings came too late or were too imprecise and many people (27%) and companies (45%) did not receive a flood warning. Afterwards, the warning systems were significantly improved, so that in 2013 only a small share of the affected people (7%) and companies (7 %) was not reached by any warning. Additionally, private households and companies were hardly aware of the flood risk in the Elbe catchment before 2002, mainly due to a lack of flood experience. For instance, in 2002 only 14% of private households clearly knew how to protect themselves and their assets when the warning reached them, in 2013 this fraction was 46 %. Although the share of companies which had an emergency plan in place had increased from 10 % in 2002 to 26 % in 2013, and the share of those conducting regular emergency exercises had increased from 4 % to 13 %, there is still plenty of room for improvement. Therefore, integrated early warning systems from monitoring through to the reaction of the affected parties as well as effective risk and emergency communication need continuous further improvement to protect people and mitigate residual risks in case of floods.

Ultrafast syn-eruptive degassing and ascent trigger high-energy basic eruptions.

PubMed

Giuffrida, Marisa; Viccaro, Marco; Ottolini, Luisa

2018-01-09

Lithium gradients in plagioclase are capable of recording extremely short-lived processes associated with gas loss from magmas prior to extrusion at the surface. We present SIMS profiles of the 7 Li/ 30 Si ion ratio in plagioclase crystals from products of the paroxysmal sequence that occurred in the period 2011-2013 at Mt. Etna (Italy) in an attempt to constrain the final ascent and degassing processes leading to these powerful eruptions involving basic magma. The observed Li concentrations reflect cycles of Li addition to the melt through gas flushing, and a syn-eruptive stage of magma degassing driven by decompression that finally produce significant Li depletion from the melt. Modeling the decreases in Li concentration in plagioclase by diffusion allowed determination of magma ascent timescales that are on the order of minutes or less. Knowledge of the storage depth beneath the volcano has led to the quantification of a mean magma ascent velocity of ~43 m/s for paroxysmal eruptions at Etna. The importance of these results relies on the application of methods, recently used exclusively for closed-system volcanoes producing violent eruptions, to open-conduit systems that have generally quiet eruptive periods of activity sometimes interrupted by sudden re-awakening and the production of anomalously energetic eruptions.

Performance of advance warning systems in a coordinated system : final report.

DOT National Transportation Integrated Search

2016-09-01

The Advance Warning System (AWS), developed by the Nebraska Department of Roads (NDOR) has proven to be effective at improving traffic safety at isolated signalized intersections. However, the effectiveness of the system has not been analyzed at sign...

The role of integrating natural and social science concepts for risk governance and the design of people-centred early warning systems. Case study from the German-Indonesian Tsunami Early Warning System Project (GITEWS)

NASA Astrophysics Data System (ADS)

Gebert, Niklas; Post, Joachim

2010-05-01

The development of early warning systems are one of the key domains of adaptation to global environmental change and contribute very much to the development of societal reaction and adaptive capacities to deal with extreme events. Especially, Indonesia is highly exposed to tsunami. In average every three years small and medium size tsunamis occur in the region causing damage and death. In the aftermath of the Indian Ocean Tsunami 2004, the German and Indonesian government agreed on a joint cooperation to develop a People Centered End-to-End Early Warning System (GITEWS). The analysis of risk and vulnerability, as an important step in risk (and early warning) governance, is a precondition for the design of effective early warning structures by delivering the knowledge base for developing institutionalized quick response mechanisms of organizations involved in the issuing of a tsunami warning, and of populations exposed to react to warnings and to manage evacuation before the first tsunami wave hits. Thus, a special challenge for developing countries is the governance of complex cross-sectoral and cross-scale institutional, social and spatial processes and requirements for the conceptualization, implementation and optimization of a people centered tsunami early warning system. In support of this, the risk and vulnerability assessment of the case study aims at identifying those factors that constitute the causal structure of the (dis)functionality between the technological warning and the social response system causing loss of life during an emergency situation: Which social groups are likely to be less able to receive and respond to an early warning alert? And, are people able to evacuate in due time? Here, only an interdisciplinary research approach is capable to analyze the socio-spatial and environmental conditions of vulnerability and risk and to produce valuable results for decision makers and civil society to manage tsunami risk in the early warning context. This requires the integration of natural / spatial and social science concepts, methods and data: E.g. a scenario based approach for tsunami inundation modeling was developed to provide decision makers with options to decide up to what level they aim to protect their people and territory, on the contrary household surveys were conducted for the spatial analysis of the evacuation preparedness of the population as a function of place specific hazard, risk, warning and evacuation perception; remote sensing was applied for the spatial analysis (land-use) of the socio-physical conditions of a city and region for evacuation; and existing social / population statistics were combined with land-use data for the precise spatial mapping of the population exposed to tsunami risks. Only by utilizing such a comprehensive assessment approach valuable information for risk governance can be generated. The results are mapped using GIS and designed according to the specific needs of different end-users, such as public authorities involved in the design of warning dissemination strategies, land-use planners (shelter planning, road network configuration) and NGOs mandated to provide education for the general public on tsunami risk and evacuation behavior. The case study of the city of Padang (one of the pilot areas of GITEWS), Indonesia clearly show, that only by intersecting social (vulnerability) and natural hazards research a comprehensive picture on tsunami risk can be provided with which risk governance in the early warning context can be conducted in a comprehensive, systemic and sustainable manner.

Ash3d: A finite-volume, conservative numerical model for ash transport and tephra deposition

USGS Publications Warehouse

Schwaiger, Hans F.; Denlinger, Roger P.; Mastin, Larry G.

2012-01-01

We develop a transient, 3-D Eulerian model (Ash3d) to predict airborne volcanic ash concentration and tephra deposition during volcanic eruptions. This model simulates downwind advection, turbulent diffusion, and settling of ash injected into the atmosphere by a volcanic eruption column. Ash advection is calculated using time-varying pre-existing wind data and a robust, high-order, finite-volume method. Our routine is mass-conservative and uses the coordinate system of the wind data, either a Cartesian system local to the volcano or a global spherical system for the Earth. Volcanic ash is specified with an arbitrary number of grain sizes, which affects the fall velocity, distribution and duration of transport. Above the source volcano, the vertical mass distribution with elevation is calculated using a Suzuki distribution for a given plume height, eruptive volume, and eruption duration. Multiple eruptions separated in time may be included in a single simulation. We test the model using analytical solutions for transport. Comparisons of the predicted and observed ash distributions for the 18 August 1992 eruption of Mt. Spurr in Alaska demonstrate to the efficacy and efficiency of the routine.

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

PubMed Central

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

2016-01-01

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

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

PubMed

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

2016-10-07

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

REWSET: A prototype seismic and tsunami early warning system in Rhodes island, Greece

NASA Astrophysics Data System (ADS)

Papadopoulos, Gerasimos; Argyris, Ilias; Aggelou, Savvas; Karastathis, Vasilis

2014-05-01

Tsunami warning in near-field conditions is a critical issue in the Mediterranean Sea since the most important tsunami sources are situated within tsunami wave travel times starting from about five minutes. The project NEARTOWARN (2012-2013) supported by the EU-DG ECHO contributed substantially to the development of new tools for the near-field tsunami early warning in the Mediterranean. One of the main achievements is the development of a local warning system in the test-site of Rhodes island (Rhodes Early Warning System for Earthquakes and Tsunamis - REWSET). The system is composed by three main subsystems: (1) a network of eight seismic early warning devices installed in four different localities of the island, one in the civil protection, another in the Fire Brigade and another two in municipality buildings; (2) two radar-type (ultrasonic) tide-gauges installed in the eastern coastal zine of the island which was selected since research on the historical earthquake and tsunami activity has indicated that the most important, near-field tsunami sources are situated offshore to the east of Rhodes; (3) a crisis Geographic Management System (GMS), which is a web-based and GIS-based application incorporating a variety of thematic maps and other information types. The seismic early warning devices activate by strong (magnitude around 6 or more) earthquakes occurring at distances up to about 100 km from Rhodes, thus providing immediate mobilization of the civil protection. The tide-gauges transmit sea level data, while during the crisis the GMS supports decisions to be made by civil protection. In the near future it is planned the REWSET system to be integrated with national and international systems. REWSET is a prototype which certainly could be developed in other coastal areas of the Mediterranean and beyond.

History of the magmatic feeding system of the Campi Flegrei caldera (Italy)

NASA Astrophysics Data System (ADS)

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

2007-05-01

The definition of the magmatic feeding system of active volcanoes in terms of architecture, composition, crystallization time-scale, relationships between composition of the erupted magmas and structural position of the vents, and magma processes, is of paramount importance for volcanic hazards evaluation. Investigations aimed at defining the Campi Flegeri magmatic system, include detailed mineralogical, geochemical and isotopic analyses (Sr, Nd, Pb, Th,U). The magmatic feeding system of the Campi Flegrei caldera is characterized by deep and shallow magma reservoirs. In the deep reservoirs (20-10 km depth) mantle- derived magmas differentiated and were contaminated by continental crust. In the shallow reservoirs isotopically distinct magmas, further differentiated, contaminated, and mixed and mingled before eruptions. These processes generated isotopically distinct components, variably interacting with the different structural elements of the Campi Flegrei caldera through time. The relationships between the structural position of the eruption vents, during the last 15 ka of activity, and the isotopic composition of the magmas erupted at the Campi Flegrei caldera allow us to reconstruct the architecture of the magmatic feeding system and to infer the chemical and isotopic composition of the magma feeding a future eruption, according to vent position.

Research and Application of an Air Quality Early Warning System Based on a Modified Least Squares Support Vector Machine and a Cloud Model.

PubMed

Wang, Jianzhou; Niu, Tong; Wang, Rui

2017-03-02

The worsening atmospheric pollution increases the necessity of air quality early warning systems (EWSs). Despite the fact that a massive amount of investigation about EWS in theory and practicality has been conducted by numerous researchers, studies concerning the quantification of uncertain information and comprehensive evaluation are still lacking, which impedes further development in the area. In this paper, firstly a comprehensive warning system is proposed, which consists of two vital indispensable modules, namely effective forecasting and scientific evaluation, respectively. For the forecasting module, a novel hybrid model combining the theory of data preprocessing and numerical optimization is first developed to implement effective forecasting for air pollutant concentration. Especially, in order to further enhance the accuracy and robustness of the warning system, interval forecasting is implemented to quantify the uncertainties generated by forecasts, which can provide significant risk signals by using point forecasting for decision-makers. For the evaluation module, a cloud model, based on probability and fuzzy set theory, is developed to perform comprehensive evaluations of air quality, which can realize the transformation between qualitative concept and quantitative data. To verify the effectiveness and efficiency of the warning system, extensive simulations based on air pollutants data from Dalian in China were effectively implemented, which illustrate that the warning system is not only remarkably high-performance, but also widely applicable.

Research and Application of an Air Quality Early Warning System Based on a Modified Least Squares Support Vector Machine and a Cloud Model

PubMed Central

Wang, Jianzhou; Niu, Tong; Wang, Rui

2017-01-01

The worsening atmospheric pollution increases the necessity of air quality early warning systems (EWSs). Despite the fact that a massive amount of investigation about EWS in theory and practicality has been conducted by numerous researchers, studies concerning the quantification of uncertain information and comprehensive evaluation are still lacking, which impedes further development in the area. In this paper, firstly a comprehensive warning system is proposed, which consists of two vital indispensable modules, namely effective forecasting and scientific evaluation, respectively. For the forecasting module, a novel hybrid model combining the theory of data preprocessing and numerical optimization is first developed to implement effective forecasting for air pollutant concentration. Especially, in order to further enhance the accuracy and robustness of the warning system, interval forecasting is implemented to quantify the uncertainties generated by forecasts, which can provide significant risk signals by using point forecasting for decision-makers. For the evaluation module, a cloud model, based on probability and fuzzy set theory, is developed to perform comprehensive evaluations of air quality, which can realize the transformation between qualitative concept and quantitative data. To verify the effectiveness and efficiency of the warning system, extensive simulations based on air pollutants data from Dalian in China were effectively implemented, which illustrate that the warning system is not only remarkably high-performance, but also widely applicable. PMID:28257122

Main components and characteristics of landslide early warning systems operational worldwide

NASA Astrophysics Data System (ADS)

Piciullo, Luca; Cepeda, José

2017-04-01

During the last decades the number of victims and economic losses due to natural hazards are dramatically increased worldwide. The reason can be mainly ascribed to climate changes and urbanization in areas exposed at high level of risk. Among the many mitigation measures available for reducing the risk to life related to natural hazards, early warning systems certainly constitute a significant cost-effective option available to the authorities in charge of risk management and governance. The aim is to help and protect populations exposed to natural hazards, reducing fatalities when major events occur. Landslide is one of the natural hazards addressed by early warning systems. Landslide early warning systems (LEWSs) are mainly composed by the following four components: set-up, correlation laws, decisional algorithm and warning management. Within this framework, the set-up includes all the preliminary actions and choices necessary for designing a LEWS, such as: the area covered by the system, the types of landslides and the monitoring instruments. The monitoring phase provides a series of important information on different variables, considered as triggering factors for landslides, in order to define correlation laws and thresholds. Then, a decisional algorithm is necessary for defining the: number of warning levels to be employed in the system, decision making procedures, and everything else system managers may need for issuing warnings in different warning zones. Finally the warning management is composed by: monitoring and warning strategy; communication strategy; emergency plan and, everything connected to the social sphere. Among LEWSs operational worldwide, two categories can be defined as a function of the scale of analysis: "local" and "territorial" systems. The scale of analysis influences several actions and aspects connected to the design and employment of the system, such as: the actors involved, the monitoring systems, type of landslide phenomena addressed and variables to be considered for correlations. The characteristics of LEWSs at local scale are strongly affected by numerous constraints and factors, from time to time different, related to the characteristics of the problem they address. Monitoring measures, variables and correlation laws considered for the design and employment of local LEWSs, strongly depends on the type of landslide to be addressed. On the other hand, territorial LEWSs mainly deals with rainfall-induced landslides characterized by fast slope movement. These systems have become a risk management approach, employed worldwide over areas of relevant extension. Before 2005 only few experiences of LEWSs at a regional scale were carried out, such as in: Hong Kong, China; Zhejiang Province, China; San Francisco Bay, California, USA; Appalachians, USA; Oregon, USA; Rio de Janeiro, Brazil. Since the beginning of the XXI century, increased knowledge on rainfall-landslide correlations and upgraded technologies in weather forecast have promoted the development and improvement of territorial LEWSs around the world.

Divergent El Niño responses to volcanic eruptions at different latitudes over the past millennium

NASA Astrophysics Data System (ADS)

Liu, Fei; Li, Jinbao; Wang, Bin; Liu, Jian; Li, Tim; Huang, Gang; Wang, Zhiyuan

2017-08-01

Detection and attribution of El Niño-Southern Oscillation (ENSO) responses to radiative forcing perturbation are critical for predicting the future change of ENSO under global warming. One of such forcing perturbation is the volcanic eruption. Our understanding of the responses of ENSO system to explosive tropical volcanic eruptions remains controversial, and we know little about the responses to high-latitude eruptions. Here, we synthesize proxy-based ENSO reconstructions, to show that there exist an El Niño-like response to the Northern Hemisphere (NH) and tropical eruptions and a La Niña-like response to the Southern Hemisphere (SH) eruptions over the past millennium. Our climate model simulation results show good agreement with the proxy records. The simulation reveals that due to different meridional thermal contrasts, the westerly wind anomalies can be excited over the tropical Pacific to the south of, at, or to the north of the equator in the first boreal winter after the NH, tropical, or SH eruptions, respectively. Thus, the eastern-Pacific El Niño can develop and peak in the second winter after the NH and tropical eruptions via the Bjerknes feedback. The model simulation only shows a central-Pacific El Niño-like response to the SH eruptions. The reason is that the anticyclonic wind anomaly associated with the SH eruption-induced southeast Pacific cooling will excite westward current anomalies and prevent the development of eastern-Pacific El Niño-like anomaly. These divergent responses to eruptions at different latitudes and in different hemispheres underline the sensitivity of the ENSO system to the spatial structure of radiative disturbances in the atmosphere.

The chemically zoned 1949 eruption on La Palma (Canary Islands): Petrologic evolution and magma supply dynamics of a rift zone eruption

NASA Astrophysics Data System (ADS)

Klügel, Andreas; Hoernle, Kaj A.; Schmincke, Hans-Ulrich; White, James D. L.

2000-03-01

The 1949 rift zone eruption along the Cumbre Vieja ridge on La Palma involved three eruptive centers, 3 km spaced apart, and was chemically and mineralogically zoned. Duraznero crater erupted tephrite for 14 days and shut down upon the opening of Llano del Banco, a fissure that issued first tephrite and, after 3 days, basanite. Hoyo Negro crater opened 4 days later and erupted basanite, tephrite, and phonotephrite, while Llano del Banco continued to issue basanite. The eruption ended with Duraznero erupting basanite with abundant crustal and mantle xenoliths. The tephrites and basanites from Duraznero and Llano del Banco show narrow compositional ranges and define a bimodal suite. Each batch ascended and evolved separately without significant intermixing, as did the Hoyo Negro basanite, which formed at lower degrees of melting. The magmas fractionated clinopyroxene +olivine±kaersutite±Ti-magnetite at 600-800 MPa and possibly 800-1100 MPa. Abundant reversely zoned phenocrysts reflect mixing with evolved melts at mantle depths. Probably as early as 1936, Hoyo Negro basanite entered the deep rift system at 200-350 MPa. Some shallower pockets of this basanite evolved to phonotephrite through differentiation and assimilation of wall rock. A few months prior to eruption, a mixing event in the mantle may have triggered the final ascent of the magmas. Most of the erupted tephrite and basanite ascended from mantle depths within hours to days without prolonged storage in crustal reservoirs. The Cumbre Vieja rift zone differs from the rift zones of Kilauea volcano (Hawaii) in lacking a summit caldera or a summit reservoir feeding the rift system and in being smaller and less active with most of the rift magma solidifying between eruptions.

The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR

USGS Publications Warehouse

Chadwick, W.W.; Jonsson, Sigurjon; Geist, Dennis J.; Poland, M.; Johnson, Daniel J.; Batt, S.; Harpp, Karen S.; Ruiz, A.

2011-01-01

The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45–60°) toward the caldera at the surface and more gently dipping (~12–14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another.

Imaging Seismic Source Variations Using Back-Projection Methods at El Tatio Geyser Field, Northern Chile

NASA Astrophysics Data System (ADS)

Kelly, C. L.; Lawrence, J. F.

2014-12-01

During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and determine variations in source depth and distribution in the conduit and larger geyser field over many eruption cycles.

Global time-size distribution of volcanic eruptions on Earth.

PubMed

Papale, Paolo

2018-05-01

Volcanic eruptions differ enormously in their size and impacts, ranging from quiet lava flow effusions along the volcano flanks to colossal events with the potential to affect our entire civilization. Knowledge of the time and size distribution of volcanic eruptions is of obvious relevance for understanding the dynamics and behavior of the Earth system, as well as for defining global volcanic risk. From the analysis of recent global databases of volcanic eruptions extending back to more than 2 million years, I show here that the return times of eruptions with similar magnitude follow an exponential distribution. The associated relative frequency of eruptions with different magnitude displays a power law, scale-invariant distribution over at least six orders of magnitude. These results suggest that similar mechanisms subtend to explosive eruptions from small to colossal, raising concerns on the theoretical possibility to predict the magnitude and impact of impending volcanic eruptions.

PBO H2O: Plate Boundary Observatory Studies of the Water Cycle

NASA Astrophysics Data System (ADS)

Larson, K. M.; Small, E. E.; Chew, C. C.; Nievinski, F. G.; Pratt, J.; McCreight, J. L.; Braun, J.; Boniface, K.; Evans, S. G.

2013-12-01

The EarthScope Plate Boundary Observatory was built to measure the deformation of the North American continent. PBO stations can also be used to measure ground displacements at much higher frequencies (5-Hz) for studies of fault slip during large earthquakes and for warnings of volcanic eruptions. There is also a long history of using atmospheric delays on the GPS signals to estimate precipitable water vapor (for weather and climate studies) and total electron content (space weather studies). Recently the PBO H2O research group has demonstrated that GPS signals that reflect from the nearby environment can be used for water cycle research. These GPS reflections measure how much water is in the top layer of the soil, how much snow is on its surface, and water content of nearby vegetation. Observing and monitoring spatial and temporal changes in the water cycle is critical for both understanding and predicting Earth's climate. Since GPS reflections encompass an area of ~1000 m^2, they provide a spatial footprint that complements satellite systems which sense much larger areas and in situ systems that sense regions < 1 m^2. Water cycle products are produced from PBO data each day and updated on the PBO H2O website.

In-Vehicle Safety Advisory And Warning System (Ivsaws), Volume I: Executive Summary

DOT National Transportation Integrated Search

1996-03-01

THE INVEHICLE SAFETY ADVISORY AND WARNING SYSTEM (IVSAWS) IS A FEDERAL HIGHWAY ADMINISTRATION EFFORT TO DEVELOP A NATIONWIDE VEHICULAR INFORMATION SYSTEM THAT PROVIDES DRIVERS WITH ADVANCE, SUPPLEMENTAL NOTIFICATION OF DANGEROUS ROAD CONDITIONS USING...

Highway fog warning system

DOT National Transportation Integrated Search

1999-04-01

The need for a highway fog warning system has long been internationally recognized. With such a system, motorists can avoid tragic pile-up accidents caused by dense or patchy fog. The development of a cost-effective highway visibility sensor that mea...

Landslide early warning system prototype with GIS analysis indicates by soil movement and rainfall

NASA Astrophysics Data System (ADS)

Artha, Y.; Julian, E. S.

2018-01-01

The aim of this paper is developing and testing of landslide early warning system. The early warning system uses accelerometersas ground movement and tilt-sensing device and a water flow sensor. A microcentroller is used to process the input signal and activate the alarm. An LCD is used to display the acceleration in x,y and z axis. When the soil moved or shifted and rainfall reached 100 mm/day, the alarm rang and signal were sentto the monitoring center via a telemetry system.Data logging information and GIS spatial data can be monitored remotely as tables and graphics as well as in the form of geographical map with the help of web-GIS interface. The system were tested at Kampung Gerendong, Desa Putat Nutug, Kecamatan Ciseeng, Kabupaten Bogor. This area has 3.15 cumulative score, which mean vulnerable to landslide. The results show that the early warning system worked as planned.