Publications

The Parkfield earthquake prediction is generally stated as a 95% probability that the next moderate earthquake there should occur before January 1993. That time limit is based on a two-sided 95% confidence interval. Because at the time of the prediction (1985) it was already clear that the earthquake had not occurred prior to 1985, a one-sided 95% confidence interval would have been more

Landslides are triggered by factors such as heavy rainfall, seismic activity, and construction on hillslopes. The leading cause of landslides in Puerto Rico is intense and/or prolonged rainfall. A rainfall threshold for rainfall-triggered landsliding is delimited by 256 storms that occurred between 1959 and 1991 in the central mountains of Puerto Rico, where mean annual rainfall is close...

Paleointensity determinations have been obtained from 22 basaltic lava flows on the island of Hawaii using the Thelliers' method. Radiocarbon dating indicates that these flows erupted at intervals ranging from about 200 to 1000 years, and results of the experiments provide an estimate of broad trends in geomagnetic paleointensity during Holocene time in the vicinity of Hawaii. Most of...

Severe earthquakes of the last decade in Mexico, Armenia, and the United States have reemphasized the importance of local geologic site conditions in estimating damage and consequent losses. Recent advances in geographic information system (GIS) technology have created new opportunities for maintaining and integrating extensive spatial databases for applications in seismic hazard...

The Thwaites Glacier/iceberg tongue complex has been a significant feature of the Antarctic coastline for at least 50 years. In 1986, major changes began to occur in this area. Fast ice melted and several icebergs calved from the base of the iceberg tongue and the terminus of Thwaites Glacier. The iceberg tongue rotated to an east-west orientation and drifted westward. Between 1986 and...

The preparation of this report had two purposes. One was to present a catalog of seismic background noise spectra obtained from a worldwide network of seismograph stations. The other purpose was to refine and document models of seismic background noise that have been in use for several years. The second objective was, in fact, the principal reason that this study was initiated and...

No abstract available.

No abstract available.

This report describes the instrumentation and evolution of the U.S. Geological Survey’s regional seismograph network in southern Alaska, provides phase and hypocenter data for seismic events from October 1971 through May 1989, reviews the location methods used, and discusses the completeness of the catalog and the accuracy of the computed hypocenters. Included are arrival time data for...

More than 40 historically active volcanic centers, each consisting of one or more volcanoes, are located on the Alaska Peninsula and Aleutian Islands (see map on next page). On average, at least one of these volcanoes erupts each year.

No abstract available.

Active volcanoes on the island of Hawai'i provide scientists with exceptional opportunities to observe volcanic phenomena at close range. Such an opportunity occurred on November 24, 1992, when geologists from the Hawaiian Volcano Observatory (HVO) witnessed spectacular explosive interactions between lava and seawater on the southeast coast of the island. As seawater invaded submarine...