Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 1848

Height changes in the epicentral region preceding the January 17, 1994 Northridge earthquake

Analysis of the results of repeated levelings through the epicentral region of the Mw 6.7, 1994 Northridge earthquake has disclosed the occurrence of differential uplift in this area that preceded the earthquake. Although the distribution of the relevant vertical-control data is somewhat sparse, in both space and time, those data that we have recovered indicate that this uplift exceeded 0.10 m and
Authors
Robert O. Castle, Robert F. Packard, Laura B. Dinitz

Methane Hydrate Dissociation Rates at 0.1 MPa and Temperatures above 272 K

 We performed rapid depressurization experiments on methane hydrate under isothermal conditions above 272 K to determine the amount and rate of methane evolution. Sample temperatures rapidly drop below 273 K and stabilize near 272.5 K during dissociation. This thermal anomaly and the persistence of methane hydrate are consistent with the reported recovery of partially dissociated methane hydrate f
Authors
S. Circone, Laura A. Stern, Stephen H. Kirby, J.C. Pinkston, William B. Durham

Methane hydrate dissociation rates at 0.1 MPa and temperatures above 272 K

We performed rapid depressurization experiments on methane hydrate under isothermal conditions above 272 K to determine the amount and rate of methane evolution. Sample temperatures rapidly drop below 273 K and stabilize near 272.5 K during dissociation. This thermal anomaly and the persistence of methane hydrate are consistent with the reported recovery of partially dissociated methane hydrate fr
Authors
S. Circone, Laura A. Stern, Stephen H. Kirby, John C. Pinkston, William B Durham

Duration of sedimentation of Creede Formation from 40Ar/39Ar ages

The Oligocene Creede Formation was deposited in the moat of the Creede caldera, which formed as a result of eruption of ythe Snowshoe Mountains Tuff. The Creede Formation in the two moat drill holes contains ash layers that are considered fallout tuffs derived from Fisher Dacite volcanoes that were erupting during accumulation of the Creede Formation. The duration of sedimentation of the Creede Fo
Authors
Marvin A. Lanphere

Archive report for most USGS seismic refraction investigations conducted between 1978 and 1991

In 1978, the U.S. Geological Survey (USGS) began acquiring seismic refraction data throughout the U.S. and Saudi Arabia. Numerous professional papers have been published in the literature and the technical details and goals for most of these surveys have been described in USGS Open-file reports (Table 1). This report describes the archiving of the data.
Authors
Janice M. Murphy

A filter circuit board for the Earthworm Seismic Data Acquisition System

The Earthworm system is a seismic network data acquisition and processing system used by the Northern California Seismic Network as well as many other seismic networks. The input to the system is comprised of many realtime electronic waveforms fed to a multi-channel digitizer on a PC platform. The digitizer consists of one or more National Instruments Corp. AMUX–64T multiplexer boards attached to
Authors
Edward Gray Jensen

Report for explosion and earthquake data acquired in the 1999 Seismic Hazards Investigation of Puget Sound (SHIPS), Washington

This report describes the acquisition, processing, and quality of seismic reflection and refraction data obtained in the Seattle basin, central Puget Lowland, western Washington, in September 1999 during the Seismic Hazards Investigation of Puget Sound (SHIPS). As a sequel to the 1998 SHIPS air gun experiment (also known as 'Wet SHIPS'), the 1999 experiment, nicknamed 'Dry SHIPS,' acquired a 112-k
Authors
Thomas M. Brocher, Thomas L. Pratt, Kate C. Miller, Anne M. Tréhu, Catherine M. Snelson, Craig S. Weaver, Ken C. Creager, Robert S. Crosson, Uri S. ten Brink, Marcos G. Alvarez, Steven H. Harder, Isa Asudeh

SMSIM--Fortran programs for simulating ground motions from earthquakes: Version 2.0.--a revision of OFR 96-80-A

A simple and powerful method for simulating ground motions is based on the assumption that the amplitude of ground motion at a site can be specified in a deterministic way, with a random phase spectrum modified such that the motion is distributed over a duration related to the earthquake magnitude and to distance from the source. This method of simulating ground motions often goes by the name "the
Authors
David M. Boore

Hydrogen defects in α-Al2O3 and water weakening of sapphire and alumina ceramics between 600°C and 1000°C: II. Mechanical properties

Hydrogen impurities in alumina have been introduced by hydrothermal annealing (see part I). In this paper, we report on reductions in the flow strength of α-Al2O3 single crystals and polycrystals associated with hydrogen incorporation. Prior to deformation, α-Al2O3 single crystal and ceramic specimens were annealed in the presence of supercritical water at 850° or 900°C, under 1500 MPa pressure. S
Authors
J. Castaing, A. K. Kronenberg, S. H. Kirby, T. E. Mitchell

Towards policy relevant environmental modeling: contextual validity and pragmatic models

"What makes for a good model?" In various forms, this question is a question that, undoubtedly, many people, businesses, and institutions ponder with regards to their particular domain of modeling. One particular domain that is wrestling with this question is the multidisciplinary field of environmental modeling. Examples of environmental models range from models of contaminated ground water flow
Authors
Scott B. Miles

Three-month performance evaluation of the Nanometrics, Inc., Libra Satellite Seismograph System in the northern California Seismic Network

In 1999 the Northern California Seismic Network (NCSN) purchased a Libra satellite seismograph system from Nanometrics, Inc to assess whether this technology was a cost-effective and robust replacement for their analog microwave system. The system was purchased subject to it meeting the requirements, criteria and tests described in Appendix A. In early 2000, Nanometrics began delivery of various c
Authors
David H. Oppenheimer