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.]
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.
Chart showing 13 volcanoes on a map of Washington, Oregon, and northern California, along with time lines for each volcano showing the ages of their eruptions.
Originally published in 1987, this general-interest booklet has been revised in anticipation of the Centennial of the Hawaiian Volcano Observatory (HVO) in January 2012.
Hawaiian Volcano Observatory's latest news with links to information on Kilauea, Mauna Loa, and other volcanoes, earthquakes, volcanic hazards, photo archive, and general information about the center.