Features formed from those igneous rocks that have reached or nearly reached the Earth's surface before solidifying. [Adapted from Glossary of Geology, 4th ed.]
Homepage for USGS Volcano Hazards Program with feature stories, and links to worldwide volcano updates, volcanic hazards, reducing volcanic risk, USGS international programs, and resources such as educator's page, videos, and online reports.
Describes the monitoring effort and provides real-time data of the current restless activity of the caldera, including earthquakes, ground deformation, and release of volcanic gas and plus link to volcano monitoring techniques.
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.
Homepage for Alaska Volcano Observatory (AVO) with offices in Anchorage and Fairbanks monitors and studies Alaska's hazardous volcanoes. Links to featured news, updates, publications and products, and a volcano atlas for Alaska.
An explanation of toxic carbon dioxide emissions at Mammoth Mountain in Long Valley caldera, and a description of magmatic helium discharge at the Mammoth Mountain fumarole with photos, maps, and links to other studies.