Publications
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Density structure of the lithosphere in the southwestern United States and its tectonic significance
We calculate a density model of the lithosphere of the southwestern United States through an integrated analysis of gravity, seismic refraction, drill hole, and geological data. Deviations from the average upper mantle density are as much as ?? 3%. A comparison with tomographic images of seismic velocities indicates that a substantial part (>50%) of these density variations is due to changes in co
Authors
M.K. Kaban, Walter D. Mooney
Density model of the Cascadia subduction zone
The main goal of this work is to construct self-consistent density models along two profiles crossing the northern and central Cascadia subduction zone that have been comprehensively studied on the basis of geological, geophysical, etc. data.
Authors
T.V. Romanyuk, Walter D. Mooney, R. J. Blakely
Urban seismic experiments investigate Seattle fault and basin
In the past decade, Earth scientists have recognized the seismic hazards that crustal faults and sedimentary basins pose to Seattle, Washington (Figure 1). In 1998, the US. Geological Survey and its collaborators initiated a series of urban seismic studies of the upper crust to better map seismogenic structures and sedimentary basins in the Puget Lowland. These studies are called the Seismic Hazar
Authors
Thomas M. Brocher, Thomas L. Pratt, Ken C. Creager, Robert S. Crosson, William P. Steele, Craig S. Weaver, Arthur Frankel, Anne Trøhu, Catherine M. Snelson, Kate C. Miller, Steven H. Harder, Uri S. ten Brink
Program to convert SUDS2ASC files to a single binary SEGY file
This program, SUDS2SEGY, converts and combines ASCII files created using SUDS2ASC Version 2.60, to a single SEGY file.
SUDS2ASC has been used previously to create an ASCII file of three-component seismic data for an individual recording station. However, many seismic processing packages have difficulty reading in ASCII data. In addition, it may be cumbersome to process a separate file for each re
Authors
Mark Goldman
Seismic instrumentation of buildings
The purpose of this report is to provide information on how and why we deploy seismic instruments in and around building structures.
The recorded response data from buildings and other instrumented structures can be and are being primarily used to facilitate necessary studies to improve building codes and therefore reduce losses of life and property during damaging earthquakes. Other uses of such
Authors
Mehmet Çelebi
The age of scarplike landforms from diffusion-equation analysis
The purpose of this paper is to review developments in the quantitative modeling of fault-scarp geomorphology, principally those since 1980. These developments utilize diffusionequation mathematics, in several different forms, as the basic model of fault-scarp evolution. Because solutions to the general diffusion equation evolve with time, as we expect faultscarp morphology to evolve with time, th
Authors
Thomas C. Hanks
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
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