Publications
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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
Stratigraphic potential of Bolboforma significantly increased by new finds in the North Atlantic and South Pacific Stratigraphic potential of Bolboforma significantly increased by new finds in the North Atlantic and South Pacific
Until now, the genus Bolboforma, a problematic group of calcareous microfossils, has been recorded only in Oligocene to Pliocene marine sedimentary rocks, chiefly in the eastern North Atlantic region. We add to this eastern North Atlantic record six new sites and eleven undescribed species from the continental slopes of Ireland and Morocco. More significantly, we record, for the first...
Authors
C. Wylie Poag, A. L. Karowe
Volcano monitoring at the U.S. Geological Survey's Hawaiian Volcano Observatory Volcano monitoring at the U.S. Geological Survey's Hawaiian Volcano Observatory
The island of Hawaii has one of the youngest landscapes on Earth, formed by frequent addition of new lava to its surface. Because Hawaiian are generally nonexplosive and easily accessible, the island has long attracted geologists interested in studying the extraordinary power of volcanic eruptions. The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO), now nearing its 75th...
Authors
Christina C. Heliker, J. D. Griggs, T. Jane Takahashi, Thomas L. Wright
Multispectral digital image mapping of Antarctic ice features Multispectral digital image mapping of Antarctic ice features
Landsat multispectral images of the Antarctic ice sheet have been digitally enhanced by the US Geological Survey to show ice surface features not seen in earlier photographic products of the same scenes. Now for the first time it is worthwhile to prepare image maps at scales of up to 1:250 000 of ice sheet areas even where no nunataks are visible. Derivatives of the data can be stretched...
Authors
Charles Swithinbank, Baerbel K. Lucchitta
Book review of Slope Instability, D. Brunsden and D.B. Prior, eds., Wiley, New York, 620 p. Book review of Slope Instability, D. Brunsden and D.B. Prior, eds., Wiley, New York, 620 p.
No abstract available.
Authors
Richard M. Iverson
Site of Charleston earthquakes pinned down? Site of Charleston earthquakes pinned down?
No abstract available.
Authors
R. A. Kerr