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A plate flexure approximation to postseismic and interseismic deformation

The rather large postseismic deformation that is associated with two‐dimensional dip‐slip faulting in the lithosphere is related to the bending of a free plate generated by dip‐slip faulting. In the absence of gravity, asthenosphere relaxation eventually permits the faulted lithosphere to assume the dihedral configuration of a faulted free plate. For thrust faulting, the faulted area is depressed
Authors
James C. Savage, Guohua Gu

Rate and depth of pedogenic-carbonate accumulation in soils: Formation and testing of a compartment model.

The rate and depth of pedogenic carbonate accumulation in soils formed in Quaternary alluvium may be viewed as a theoretical problem that involves the mutual interaction of several independent and dependent soil-forming variables. We propose a model for carbonate accumulation in which the soil column is defined by a vertical sequence of 1-cm2-area compartments, each with a specified texture, bulk
Authors
Leslie D. McFadden, John Tinsley

Inversion of seismic refraction data in planar dipping structure

A new method is presented for the direct inversion of seismic refraction data in dipping planar structure. Three recording geometries, each consisting of two common-shot profiles, are considered: reversed, split, and roll-along profiles. Inversion is achieved via slant stacking the common-shot wavefield to obtain a delay time—slowness (tau—p) wavefield. The tau—p curves from two shotpoints describ
Authors
B. Milkereit, Walter D. Mooney, W. M. Kohler

The relocation of microearthquakes in the northern Mississippi Embayment

Three-component seismograms, recorded by a small array of digital instruments in the northern Mississippi embayment, consistently show a high-amplitude phase on the vertical component that arrives approximately 0.8 s before the shear wave. On the basis of its timing and apparent velocity, this phase is identified as an S-P conversion from the boundary between the unconsolidated Cenozoic sediments
Authors
M.C. Andrews, Walter D. Mooney, R.P. Meyer

Remote sensing of lunar pyroclastic mantling deposits

Mantling deposits on the Moon are considered to be pyroclastic units emplaced on the lunar surface as a result of explosive fire fountaining. These pyroclastic units are characterized as having low albedos, having smooth fine-textured surfaces, and consisting in part of homogeneous, Febearing volcanic glass and partially crystallized spheres. Mantling units exhibit low returns on depolarized 3.8-c
Authors
Lisa R. Gaddis, Carle M. Pieters, B. Ray Hawke

Plasticity at crack tips in Gd3Ga5O12 garnet single crystals deformed at temperatures below 950°C

Single crystals of Gd3Ga5O12 have been strained under confining pressure (1 5 GPa) at temperatures below 950°C. No evidence for macroscopic plasticity was found, but transmission electron microscopy revealed dislocation generation at crack tips. Deformation mechanisms are different from those operating in the high-temperature regime: extending stacking faults in {110} planes and the 〈010〉{100} gli
Authors
H. Garem, J. Rabier, Stephen H. Kirby

Geomorphologic evidence for ground ice on Mars

For ground ice to exist on Mars, two conditions have to be met. One is the presence of permafrost; the second is the availability of water. Because the mean temperature of Mars’surface is − 80 C., permafrost 1–3 km thick occurs over the entire planet. Remote-sensing measurements suggest that water presently exists in the atmosphere and in the polar caps; frost has been observed at the Viking landi
Authors
Baerbel K. Lucchitta

Landslides and related features, West Virginia, Ohio, Kentucky; Huntington

No abstract available.
Authors
William E. Davies, Vernon Mast, Gregory C. Ohlmacher

Report on recommended list of structures for seismic instrumentation in San Bernardino County, California

No abstract available.
Authors
G. Brady, Mehmet Çelebi, C. Rojahn, Wilfred Iwan, G. Hart, G. Pardoen, L. Schoelkopf, R. Haskell, K. Topping, Erdal Safak, R.P. Maley