Publications
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Reflections from midcrustal rocks within the Mesozoic subduction complex near the eastern Aleutian Trench Reflections from midcrustal rocks within the Mesozoic subduction complex near the eastern Aleutian Trench
Seismic reflection data collected in 1973 by Western Geophysical Company show that highly reflective rocks make up the midcrust of the convergent margin adjacent to the eastern Aleutian Trench. These rocks form an arch that strikes obliquely across the strongly expressed northeast-southwest structural grain of exposed Mesozoic rocks. In an earlier report we proposed that the deep events...
Authors
M. A. Fisher, Roland E. von Huene, G.L. Smith
The crustal structure of the axis of the Great Valley, California, from seismic refraction measurements The crustal structure of the axis of the Great Valley, California, from seismic refraction measurements
In 1982 the U.S. Geological Survey collected six seismic refraction profiles in the Great Valley of California: three axial profiles with a maximum shot-to-receiver offset of 160 km, and three shorter profiles perpendicular to the valley axis. This paper presents the results of two-dimensional raytracing and synthetic seismogram modeling of the central axial profile. The crust of the...
Authors
W.S. Holbrook, Walter D. Mooney
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, May 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, May 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, August 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, August 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, December 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, December 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, March 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, March 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Sedimentary deposits in the northern lowland plains, Mars Sedimentary deposits in the northern lowland plains, Mars
The lowland plains on Mars have surfaces marked by large polygonal fracture patterns. It was recently proposed that the fracture patterns were developed on sedimentary deposits from outflow channels. We support this hypothesis because of the following observations. (1) Polygonal fracture patterns tend to occur in low areas on Mars that apparently received influx of sediments; the area of...
Authors
Baerbel K. Lucchitta, H.M. Ferguson, C.H. Summers
Crustal structure of Yunnan Province, People's Republic of China, from seismic refraction profiles Crustal structure of Yunnan Province, People's Republic of China, from seismic refraction profiles
Seismic refraction, profiles in Yunnan Province, southwestern China, define the crustal structure in an area of active tectonics on the southern end of the Himalaya-Burma arc. The crustal thickness ranges from 38 to 46 kilometers, and the relatively low mean crustal velocity indicates a crustal composition compatible with normal continental crust and consisting mainly of meta-sedimentary...
Authors
Rong-Ju Kan, Hong-Xiang Hu, Rong-Sheng Zeng, Walter D. Mooney, T. McEvilly
Influence of welded boundaries in anelastic media on energy flow, and characteristics of P, S-I, and S-II waves: Observational evidence for inhomogeneous body waves in low-loss solids Influence of welded boundaries in anelastic media on energy flow, and characteristics of P, S-I, and S-II waves: Observational evidence for inhomogeneous body waves in low-loss solids
A general computer code, developed to calculate anelastic reflection-refraction coefficients, energy flow, and the physical characteristics for general P, S-I, and S-II waves, quantitatively describes physical characteristics for wave fields in anelastic media that do not exist in elastic media. Consideration of wave fields incident on boundaries between anelastic media shows that...
Authors
Roger D. Borcherdt, Gary Glassmoyer, Leif Wennerberg
Short-period strain (0.1–105 s): Near-source strain field for an earthquake (ML 3.2) near San Juan Bautista, California Short-period strain (0.1–105 s): Near-source strain field for an earthquake (ML 3.2) near San Juan Bautista, California
Measurements of dilational earth strain in the frequency band 25–10−5 Hz have been made on a deep borehole strainmeter installed near the San Andreas fault. These data are used to determine seismic radiation fields during nuclear explosions, teleseisms, local earthquakes, and ground noise during seismically quiet times. Strains of less than 10−10 on these instruments can be clearly...
Authors
M.J.S. Johnston, Roger D. Borcherdt, A. T. Linde
Implications of recent advances in instrumentation for strong-motion studies Implications of recent advances in instrumentation for strong-motion studies
No abstract available.
Authors
Roger D. Borcherdt
Crustal structure of Oaxaca, Mexico, from seismic refraction measurements Crustal structure of Oaxaca, Mexico, from seismic refraction measurements
Seismic refraction and gravity data have been analyzed to obtain a model of the compressional-wave velocity structure of the ocean-to-continent transition in the State of Oaxaca in southwestern Mexico. Crustal thickness on the continent at the latitude 18°N is 45 ± 4 km, based on reflected phases from the Moho discontinuity. The crust has been modeled with three layers, with velocities...
Authors
C.M. Valdes, Walter D. Mooney, S.K. Singh, C. Lomnitz, James H. Luetgert, C.E. Helsley, B.T.R. Lewis, M. Mena