Episodes during which gases, ash, and lava (molten rock) escape from vents in the earth's crust, accompanied by minor tremors.
Natural Hazards Gateway [ More info] News and related information about the importance of seven major types of natural hazards in the United States: earthquakes, floods, wildfires, hurricanes, landslides, volcanoes, and tsunamis.
Natural Hazards Support System [ More info] Shows where current natural hazard events are occurring within the US or worldwide, with information about the geographic extent of the hazard, the US agency engaged to work on it, and how long the hazard is expected be active.
Natural hazards [ More info] Research and monitoring to provide the Nation with a clear understanding of natural hazards and their potential threats to society, and assists with developing smart, cost-effective strategies for achieving preparedness and resilience.
Ozone in our air - friend or foe? - depends on where [ More info] Article on ozone layer and ozone as a pollutant from the weekly newsletter Volcano Watch (Hawaiian Volcano Observatory) for August 20, 2001.
Photo gallery of the Long Valley area, California [ More info] Selection of photographic images of the Long Valley area that illustrate the consequences of the past geologic history of the Sierra Nevada, Long Valley Caldera, the Mono-Inyo Craters volcanic chain, glaciation, and faulting.
Potential hazards from future volcanic eruptions in the Long Valley -- Mono Lake Area, California [ More info] An introduction to the volcano hazards in the Long Valley area based on the past geologic history of the Long Valley Caldera and the Mono-Inyo Craters volcanic chain.
Preparing for volcanic emergencies [ More info] Describes activities of USGS scientists to increase public awareness of volcano hazards with links to publication and videos for public information on understanding and preparing for volcanic hazards.
Scientific drilling in Long Valley, California: What will we learn? [ More info] Description of 1998 drilling project at Long Valley Exploratory Well located on Long Valley Caldera's resurgent dome to monitor changing conditions beneath the dome. (Document in PDF format.)
Selected volcano information [ More info] Selected books, maps, videos, and other materials produced by the USGS Volcano Hazards Program. Many products highlighted here are intended for general audiences.
Taming of a wild research well in Yellowstone National Park during November 1992 [ More info] A valve failed in a research well, causing an uncontrolled eruption of steam and hot water. Video program shows technical problems encountered in controlling and capping the well.
Alphabetical Index of Topics
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