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Erratum: Empirical evidence for acceleration-dependent amplification factors

Incorrect versions of Figures 5 and 6 containing normalization errors were accidentally published by Borcherdt (2002). They should be replaced with the figures shown here. The text and tabulated regression values published in Borcherdt (2002) are correct and refer to the figures shown here.
Authors
Roger D. Borcherdt

Direct measurement of methane hydrate composition along the hydrate equilibrium boundary

The composition of methane hydrate, namely nw for CH4·nwH2O, was directly measured along the hydrate equilibrium boundary under conditions of excess methane gas. Pressure and temperature conditions ranged from 1.9 to 9.7 MPa and 263 to 285 K. Within experimental error, there is no change in hydrate composition with increasing pressure along the equilibrium boundary, but nw may show a slight system
Authors
S. Circone, Stephen H. Kirby, Laura A. Stern

High-resolution seismic-reflection image of the Chesapeake Bay impact structure, NASA Langley Research Center, Hampton, Virginia

A 1-kilometer-long (0.62-mile-long) seismic reflection and refraction profile collected at the National Aeronautics and Space Administration (NASA) Langley Research Center, Hampton, Va., provides a detailed image of part of the annular trough of the buried, 35-million-year-old Chesapeake Bay impact structure. This profile passes within 5 meters (m; 16.4 feet (ft)) of a 635.1-m-deep (2,083.8-ft-dee
Authors
Rufus D. Catchings, David S. Powars, Gregory Gohn, Mark R. Goldman

Integrated surface and borehole strong-motion, soil-response arrays in San Francisco, California: Empirical measurements of low-strain site coefficients at site class E and D soil sites

An integrated set of four borehole arrays and ten surface installations is installed in the city of San Francisco, California to measure the response of soft-soil deposits to strong earthquake ground motions. The borehole arrays extend through thick layers of soft water-saturated soils of Holocene age and older more consolidated soils of Pleistocene age into bedrock at depths up to 90 m. The surfa
Authors
Roger D. Borcherdt, G. Glassmoyer, Christopher M. Dietel, R.E. Westerlund

libvaxdata: VAX data format conversion routines

libvaxdata provides a collection of routines for converting numeric data-integer and floating-point-to and from the formats used on a Digital Equipment Corporation1 (DEC) VAX 32-bit minicomputer (Brunner, 1991). Since the VAX numeric data formats are inherited from those used on a DEC PDP-11 16-bit minicomputer, these routines can be used to convert PDP-11 data as well. VAX numeric data formats
Authors
Lawrence M. Baker

InSAR studies of Alaska volcanoes

Interferometric synthetic aperture radar (InSAR) is a remote sensing technique capable of measuring ground surface deformation with sub-centimeter precision and spatial resolution in tens-of­meters over a large region. This paper describes basics of InSAR and highlights our studies of Alaskan volcanoes with InSAR images acquired from European ERS-l and ERS-2, Canadian Radarsat-l, and Japanese JERS
Authors
Zhong Lu, Chuck Wicks, Daniel Dzurisin, John A. Power

Wagon loads of sand blows in White County, Illinois

Several anecdotal accounts provide compelling evidence that liquefaction occurred at several sites in Illinois during the 1811-1812 New Madrid sequence, as much as 250 km north of the New Madrid seismic zone (NMSZ). At one Wabash Valley location, sand blows are still evident near Big Prairie, Illinois, a location described in a particularly detailed and precise historic account. This account inclu
Authors
Susan E. Hough, Roger Bilham, Karl Mueller, William Stephenson, Robert Williams, Jack Odum

Thermal regulation of methane hydrate dissociation: Implications for gas production models

Thermal self-regulation of methane hydrate dissociation at pressure, temperature conditions along phase boundaries, illustrated by experiment in this report, is a significant effect with potential relevance to gas production from gas hydrate. In surroundings maintained at temperatures above the ice melting point, the temperature in the vicinity of dissociating methane hydrate will decrease because
Authors
S. Circone, Stephen H. Kirby, Laura A. Stern

Remotely triggered earthquakes following moderate mainshocks (or, why California is not falling into the ocean)

On several occasions in recent memory California has experienced apparent clusters of earthquake activity that are too far apart to be considered related according to a classic taxonomy that includes foreshocks, mainshocks, and aftershocks. During a week-long period in July 1986, California experienced the M 6.0 North Palm Springs earthquake, the M 5.5 Oceanside earthquake, and a swarm of smaller
Authors
Susan E. Hough

Preliminary report on the 28 September 2004, M 6.0 Parkfield, California earthquake

The Mw 6.0 Parkfield earthquake struck central California at 17:15:14 UTC on 28 September 2004. The epicenter was located 11 km southeast of the rural town of Parkfield, adjacent to Gold Hill and on the San Andreas Fault (Figure 1). The California Integrated Seismic Network (CISN) reported that the hypocenter was located at 35.819°N, 120.364°W at a depth of 8.8 km. From the distribution of aftersh
Authors
John Langbein, Roger D. Borcherdt, Douglas Dreger, J. Fletcher, Jeanne L Hardebeck, Margaret Hellweg, C. Ji, Malcolm J. S. Johnston, Jessica R. Murray, Robert Nadeau, Michael J. Rymer, Jerome A. Treiman