Publications

The second-largest volcanic eruption of this century, and by far the largest eruption to affect a densely populated area, occurred at Mount Pinatubo in the Philippines on June 15, 1991. The eruption produced high-speed avalanches of hot ash and gas, giant mudflows, and a cloud of volcanic ash hundreds of miles across. The impacts of the eruption continue to this day.

The climactic June 1991 eruption of Mount Pinatubo, Philippines, was the largest volcanic eruption in this century to affect a heavily populated area. Because it was forecast by scientists from the Philippine Institute of Volcanology and Seismology and the U.S. Geological Survey, civil and military leaders were able to order massive evacuations and take measures to protect property before the erup

During the past 35 years, scientists have developed a vast network of seismometers that record earthquakes, volcanic eruptions, and nuclear explosions throughout the world. Seismographic data support disaster response, scientific research, and global security. With this network, the United States maintains world leadership in monitoring the greatest natural and technological events that threaten o

The Cascade Range of the Pacific Northwest has more than a dozen potentially active volcanoes. Cascade volcanoes tend to erupt explosively, and on average two eruptions occur per century—the most recent were at Mount St. Helens, Washington (1980–86 and 2004–8), and Lassen Peak, California (1914–17). To help protect the Pacific Northwest’s rapidly expanding population, USGS scientists at the Cascad

These reports are presented in response to a charge of the Earthquake Hazards Reduction Program (EHRP) Program Council of the U.S. Geological Survey to 'define the future of the USGS National Strong-Motion Program (NSMP)' (Appendix A). The council requested that a 'Vision Paper' and an 'Options Document' be prepared. Each of these reports is a separate document. The 'Executive Summary' of both rep

This report constitutes the requested 'Options Document'. This report considers three options. Option I assumes a constant level of financial support for Operating Expenses (OE) with not additional personnel support. Option II assumes a slight increase in OE support of $150K for FY 99 and beyond. Option III considers the role that a NSMP must play if the nation's urgent need to record the main ear

This document provides the requested vision for the future of the National Strong-Motion Program operated by the US Geological Survey. Options for operation of the program are presented in a companion document. Each of the three major charges of the EHRP, program council pertaining to the vision document is addressed here. The 'Vision Summary' through a series of answers to specific questions

This dataset consists of polygons enclosing areas of landslide incidence and susceptibility for the conterminous United States.

No abstract available.

Iron, manganese, and iron-manganese deposits occur in nearly all geomorphologic and tectonic environments in the ocean basins and form by one or more of four processes: (1) hydrogenetic precipitation from cold ambient seawater, (2) precipitation from hydrothermal fluids, (3) precipitation from sediment pore waters that have been modified from bottom water compositions by diagenetic reactions in th

Knowledge of the crustal structure of the Washington Cascades and adjacent Puget Lowland is important to both earthquake hazards studies and geologic studies of the evolution of this tectonically active region. We present a model for crustal velocity structure derived from analysis of seismic refraction/wide-angle reflection data collected in 1991 in western Washington. The 280-km-long north-south

The nature of the Great Valley basement, whether oceanic or continental, has long been a source of controversy. A velocity model (derived from a 200-km-long east-west reflection-refraction profile collected south of the Mendocino triple junction, northern California, in 1993), further constrained by density and magnetic models, reveals an ophiolite underlying the Great Valley (Great Valley ophioli