Publications

Washington's Mount St. Helens volcano reawakens explosively on October 1, 2004, after 18 years of quiescence. Scientists at the U.S. Geological Survey's Cascades Volcano Observatory (CVO) study and observe Mount St. Helens and other volcanoes of the Cascade Range in Washington, Oregon, and northern California that hold potential for future eruptions. CVO is one of five USGS Volcano...

The inventory of structures in heavily urbanized communities within the greater San Francisco (SF) Bay area that will experience strong ground motions from the rupture of the Hayward Fault includes a variety of types of recent and older structures built with a variety of materials and to different code standards. Those who remember the effects of the 1989 Loma Prieta earthquake on...

The U.S. Geological Survey has recently released a 2008 version of the probabilistic National Seismic Hazard Maps. These maps plot the peak ground acceleration (PGA) and spectral acceleration (SA) ordinates at 0.2 and 1.0 sec with 2% and 10% probabilities of being exceeded in 50 years, corresponding to earthquake return periods of about 2,475 and 475 years, respectively. These...

The U.S. Geological Survey (USGS), Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data and is complete in that most data for events of M=1.5 are included. All latitude and longitude references in this report are stated in Old Hawaiian Datum. The HVO summaries have...

This Report introduces and summarizes the new Virtual Data Center (VDC) Tagged Format (VTF) Tool, which was developed by a diverse group of seismologists, earthquake engineers, and information technology professionals for internal use by the COSMOS VDC and other interested parties for the exchange, archiving, and analysis of earthquake strong-ground-motion data.

[1] Prominent low-albedo wind streaks issue from embayments at the north end of Victoria crater in Meridiani Planum, the site of surface investigations by the Mars Exploration Rover Opportunity. Opportunity was sent to examine the darkest of these wind streaks and compare it to the adjacent soil in the brighter corridor between the streaks. Two nearby sites inside and outside of the...

The U.S. Geological Survey’s Prompt Assessment of Global Earthquake’s Response (PAGER) Project and the Earthquake Engineering Research Institute’s World Housing Encyclopedia (WHE) are creating a global database of building stocks and their earthquake vulnerability. The WHE already represents a growing, community-developed public database of global housing and its detailed structural

One half-hour after the May 12th Mw 7.9 Wenchuan, China earthquake, the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) system distributed an automatically generated alert stating that 1.2 million people were exposed to severe-to-extreme shaking (Modified Mercalli Intensity VIII or greater). It was immediately clear that a large-scale disaster had...

Two‐dimensional inversion of audiomagnetotelluric (AMT) sounding data define buried resistivity distributions that reflect subsurface geology and structure within the upper kilometer beneath Pleasant Valley, a 1–2 km‐deep pull‐apart basin in Joshua Tree National Park, southern California. The Park lies within the Eastern California Shear Zone just east of the San Andreas Fault, and is...

Water analyses are reported for 157 samples collected from numerous hot springs, their overflow drainages, and Lemonade Creek in Yellowstone National Park (YNP) during 2003–2005. Water samples were collected and analyzed for major and trace constituents from ten areas of YNP including Terrace and Beryl Springs in the Gibbon Canyon area, Norris Geyser Basin, the West Nymph Creek thermal...

Maps showing the probability of surface manifestations of liquefaction in the northern Santa Clara Valley were prepared with liquefaction probability curves. The area includes the communities of San Jose, Campbell, Cupertino, Los Altos, Los Gatos Milpitas, Mountain View, Palo Alto, Santa Clara, Saratoga, and Sunnyvale. The probability curves were based on complementary cumulative...

Modelling of Very-Long-Period (VLP) seismic data recorded during explosive activity at Stromboli in 1997 provides an image of the uppermost 1 km of its volcanic plumbing system. Two distinct dyke-like conduit structures are identified, each representative of explosive eruptions from two different vents located near the northern and southern perimeters of the summit crater. Observed...