Description of the hydrogeologic framework of Antelope Valley and Bedell Flat in west-central Nevada north of Reno-Sparks area. Gravimetric and seismic-refraction methods were used in the study. Report available in PDF format or HTML format.
Coordinated studies of the effect of historical mining for mercury, origin and composition of metals in groundwaters and surface waters, history of volcanic and intrusive activity, and the complex geological history of this area.
Explanation of the Earth's gravitational field, emphasizing how USGS scientists measure gravity and portray these measurements on maps. Explains terminology of gravity anomaly maps and their relationship to the rock types and other geologic features.
Description of earthquake that was felt in Joshua Tree region (1999) and links to earthquake summary, shaded relief map, aerial photos of the rupture zone, shaking intensity maps, damage reports, and seismograph network map.
Study of the probability of a major earthquake in San Francisco Bay region with colored map and links to relevant publications. Text also available in PDF format and graphic available in Illustrator or Photoshop format.