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2 Research and Hazard Assessment
Pages 29-50

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From page 29... ... RESEARCH It is difficult to separate the contributions to basic volcanological knowledge made by VHP scientists from those made by their colleagues in other parts of the USGS, other government agencies, universities, other countries, and the private sector. Nonetheless, throughout much of the second half of the twentieth century, members of the present day USGS VoIcano Hazards Program were national if not global leaders in the formulation of ideas about how volcanoes work. Read the entire page →
From page 30... ... How will eruptive style change over time? How can the potential for short- and long-term volcano hazards potential best be communicated? Read the entire page →
From page 31... ... This section considers hazard assessment, which forms a foundation for the other two operational components. The committee first describes what volcano hazard assessment is and why it falls within the purview of the USGS. Read the entire page →
From page 32... ... VoIcano hazard assessment aims to determine where and when future volcano hazards will occur and their potential severity. This kind of appraisal provides a long-term view of the locations and probabilities of large-scale eruptions and related phenomena such as volcanic debris avalanches and tsunamis. Read the entire page →
From page 33... ... Ash deposits can also seriously alter drainage patterns and sediment loads, leading to widespread flooding. Voicanoes themselves tend to be unstable structures, occasionally collapsing to form landslides and, rarely, massive volcanic debris avalanches. Read the entire page →
From page 34... ... What Is the Status of Assessment Within the VHP? Traditionally, volcano hazard assessment within the VHP focused on field-based and geochronological studies of individual volcanoes. Read the entire page →
From page 35... ... .- .~-.1 . Pvroclastic Flow F'~m~roln,; Figure 2.1 Simplified sketch of a volcano typical of those found in the western United States showing a variety of hazards associated with volcanoes (USGS, 1998~. Read the entire page →
From page 36... ... Review of the USGS's Volcano Hazards Program B Damage due to lahars Within four hours of the beginning of the eruption of Nevada del Ruiz, lahars had traveled 100 km and left behind a wake of destruction killing more than 23,000 people. Read the entire page →
From page 37... ... Although not widely appreciated prior to this event, the potential for such hazards is now acknowledged in assessments for Mount Baker, Mount Rainier, and similar volcanoes. The committee commends VHP efforts to integrate findings of geologic studies into volcanic hazard assessments. Read the entire page →
From page 38... ... The committee encourages the VHP to include more theoretical modeling of volcanic phenomena in its hazard assessments. Probabilistic Hazard Assessments Because it is impossible to predict eruptive behavior with certainty, particularly for dormant volcanoes, most hazard assessments are inherently probabilistic in nature. Read the entire page →
From page 39... ... assessment program that takes advantage of the full range of techniques available to voicanologists today. The State of Volcano Hazard Assessment at USGS Observatories Assessment priorities vary from observatory to observatory, reflecting local differences in the nature of the volcanic hazard and the expertise of resident scientists and technicians. Read the entire page →
From page 40... ... , may benefit from volcano hazard assessments. Volcanic ash interaction with jet aircraft poses the greatest danger from Alaskan volcanoes, because ingestion of ash can result in engine damage or failure. Read the entire page →
From page 41... ... Because the Aleutians are so active, they are important testing grounds for methods that will ultimately be applied in more populous areas. Hawaiian Voicano Observatory Although most visitors to Hawaii get the impression that its volcanoes erupt spectacularly but safely, HVO scientists have documented major volcanic hazards to both local and distant populations. Read the entire page →
From page 42... ... Cascades Voicano Observatory The Cascades Voicano Observatory is responsible for assessing and monitoring the hazards of the volcanoes of the Cascades Range, which stretches from British Columbia to northern California (Figure I.1~. Two features of Cascades volcanoes most affect the assessment work of CVO: (~) Read the entire page →
From page 43... ... . Lava flows erupted since 1823, gray; principal subdivisions, dark Way; boundary between Kilauea and Mauna Loa flows, heavy black line (USGS, 1992~. Read the entire page →
From page 44... ... Several of the Cascades volcanoes have permanent glaciers, increasing the likelihood of dangerous debris flows. Even slight increases in hydrothermal activity near a volcano's summit may enhance glacial melting and debris flow formation. Read the entire page →
From page 45... ... Seismic unrest and rapid uplift of the caldera floor in the 1980s caused widespread concern that a major magmatic explosion might be imminent. This uplift coincided with similar events at Yellowstone National Park; outside the city of Naples, Italy; and at Rabaul Volcano in Papua New Guinea. Read the entire page →
From page 46... ... Because volcanology is inherently multidisciplinary, volcano hazard assessment could provide the VHP and USGS with a flagship example of collaborative science. Read the entire page →
From page 47... ... Fifteen volcanoes around the world were selected for comprehensive study on the basis of the size of the population at risk and the style of volcanic activity. Although the efficacy of the program was hampered by a lack of finding, in the most successful cases international teams of government and academic researchers carried out a coordinated regime of mapping, monitoring, and public education. Read the entire page →
From page 48... ... If these problems are not solved, the program will likely be forced to reduce levels of in-house basic research and/or to increase collaboration with non-USGS scientists. Hazard assessments, although traditionally strong in geologic mapping, radiometric age dating, and related activities, must be strengthened in modeling and probabilistic approaches, if the program is to continue to meet appropriate scientific goals. Read the entire page →
From page 49... ... Research and Hazard Assessment 49 appropriate, may not be effectively integrated with other studies or with the VHP as a whole. Read the entire page →

From page 29...

... RESEARCH It is difficult to separate the contributions to basic volcanological knowledge made by VHP scientists from those made by their colleagues in other parts of the USGS, other government agencies, universities, other countries, and the private sector. Nonetheless, throughout much of the second half of the twentieth century, members of the present day USGS VoIcano Hazards Program were national if not global leaders in the formulation of ideas about how volcanoes work.

2 Research and Hazard Assessment Pages 29-50

2 Research and Hazard Assessment
Pages 29-50