Vents in the surface of the Earth through which magma and associated gases erupt; also, the forms or structures, usually conical, that are produced by the erupted material. [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.
This booklet presents a generalized summary of the nature, workings, publications, and hazards of the common types of volcanoes around the world, along with a brief introduction to the techniques of volcano monitoring and research.
Archive of feature stories on volcanic features on the Big Island, guided tours of Hawaii Volcanoes National Park, eruptions and eventful earthquakes, and other topics about the work of scientists at the Hawaiian Volcano Observatory.
Educational volcano site providing answers to frequently asked volcano questions with links to other general information on volcanoes and to information on specific volcanoes including the Cascade Range volcanoes.
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.
Portal to information provided by the Cascades Volcano Observatory in Vancouver, WA with links to reports and activity in the Cascade Range and other volcanoes and multiple links to general information on volcanology, reports, research, and maps.
Article in the May 28, 1998 issue of Volcano Watch describing of correlation of earth tides to volcanic eruptions and value in monitoring underground magma movement with deformation measurement instruments including tiltmeters and strainmeters.
Of 129 reported incidents, 94 are confirmed ash encounters, 79 of which entailed airframe or engine damage; 20 are low-severity events involving suspected ash or gas clouds; for 15 the data are insufficient to assess severity.
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.
Summarizes the eruptions of this spectacular volcano and the consequences for the surrounding landscape, explains how volcanoes like this form, and how we monitor their activity to mitigate hazards they pose.
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.
Overview of volcano hazards in California with links to monitoring data including earthquakes and deformations, long-term outlook, volcano hazards in the area, USGS response plan, image gallery, monitoring and topical studies, publications and references.
Visual monitoring of volcanoes by closed-circuit television and video monitoring for a permanent video record of events using slow-scan television which permits continuous surveillance at a distance for remote volcanoes or in times of danger.
Volcano Watch is a weekly newsletter issued by the U.S. Geological Survey's Hawaiian Volcano Observatory on volcanic features on the Big Island, volcanic hazards, and informational topics of Long Valley, Montserrat, or Alaska.
Homepage of the Yellowstone Volcano Observatory with links to information about the observatory at Yellowstone National Park, volcanic history, photo gallery, monitoring data, publications and products, and Frequently Asked Questions (FAQs).