Circular-shaped depressions at the summit of a volcanic core or on the surface of the land caused by the impact of a meteorite; man-made depressions caused by an explosion. [USGS GNIS Feature Class Definitions <http://geonames.usgs.gov/domestic/feature_class.htm>]
Links to information on the formation and structure of Chesapeake Bay including online reports, recent field work, field work archives, cooperating agencies, bibliography, and links to articles about other terrestrial impact craters.
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.
Hydrologic monitoring data for Long Valley caldera, California, on springs, streams, wells, fumaroles, and precipitation to study the natural hydrologic variations and the response of the hydrologic system to volcanic and tectonic processes.
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.
Explanation of uplift in the land surface of the northern part of the Yellowstone caldera (12cm, about ~5 inches) that occurred between 1997 and 2003, including the scientific methods by which it was detected and analyzed.