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DEFORESTATION AND LANDSLIDES IN YUNNAN, CHINA. DEFORESTATION AND LANDSLIDES IN YUNNAN, CHINA.

Landslides historically have caused severe erosion problems in the Xiao River drainage region of northeastern Yunnan Province, China, that hence resulted in serious economic and social consequences. Owing to monsoonal storms of high rainfall intensity, the erosion potential is high in this mountainous, seismically active region. Landslides transported large quantities of materials into...
Authors
Gerald F. Wieczorek, Jishan Wu, Tianchi Li

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

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
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