Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 2823

A seismic refraction study of the Oregon Cascades A seismic refraction study of the Oregon Cascades

A 275‐km‐long reversed refraction profile in the Oregon Cascades, two shallow earthquakes of magnitude 5 in southern Washington, a shallow earthquake of magnitude 4.6 in northern California, and a previously published analysis of the Bouguer gravity field are used to develop a crustal P wave velocity model for the Oregon Cascades. Travel time analysis of the refraction profile indicates...
Authors
Donald S. Leaver, Walter D. Mooney, W.M. Kohler

A seismic refraction survey of the Imperial Valley Region, California A seismic refraction survey of the Imperial Valley Region, California

The U.S. Geological Survey conducted an extensive seismic refraction survey in the Imperial Valley region of California in 1979. The Imperial Valley is located in the Salton Trough, an active rift between the Pacific and North American plates. Forty shots fired at seven shot points were recorded by 100 portable seismic instruments at typical spacing of 0.5–1 km. More than 1300 recording...
Authors
Gary S. Fuis, Walter D. Mooney, J. H. Healy, G. A. McMechan, W. J. Lutter

Introduction and digest to the Special Issue on Chemical Effects of Water on the Deformation and Strengths of Rocks Introduction and digest to the Special Issue on Chemical Effects of Water on the Deformation and Strengths of Rocks

The important role of pore pressure in promoting such brittle processes as cataclasis, hydraulic fracturing, large‐scale faulting, and earthquakes within the crust is widely accepted in geology and geophysics [, 1957; , 1959; , 1958; ., 1963; , 1968; ., 1968; ., 1976; , 1973, 1980; , 1981]. Provided that fluid pressure is fully communicated with rock pore space, the effective normal...
Authors
Stephen H. Kirby

Experimental deformation of topaz crystals: Possible embrittlement by intracrystalline water Experimental deformation of topaz crystals: Possible embrittlement by intracrystalline water

Crystallographically oriented single‐crystal prisms of gem quality topaz (composition AlSiO (OH− F) where x = 0.04 ± 0.01) were deformed at a confining pressure of 1.50 GPa, a temperature of 800°C, and a strain rate of 2×10 s. Under nearly identical conditions, all crystals of anhydrous rock‐forming minerals that have been tested to date, such as olivine, quartz, feldspars, pyroxenes...
Authors
R. W. Lee, Stephen H. Kirby

Effects of compression direction on the plasticity and rheology of hydrolytically weakened synthetic quartz crystals at atmospheric pressure Effects of compression direction on the plasticity and rheology of hydrolytically weakened synthetic quartz crystals at atmospheric pressure

A hydrothermally grown synthetic quartz crystal with 370±60 ppm hydroxyl impurity was cut into right rectangular prisms in eight crystallographic orientations. We compressed the prisms under constant axial force corresponding to a uniaxial stress of 140.0±0.5 MPa, and temperatures of 510° and 750°C. All but one of the samples sustained permanent axial strains of 2–3%. We established the...
Authors
Mark F. Linker, Stephen H. Kirby, A. Ord, J.M. Christie

Noise analysis of the seismic system employed in the northern and southern California seismic nets Noise analysis of the seismic system employed in the northern and southern California seismic nets

The seismic networks have been designed and operated to support recording on Develocorders (less than 40db dynamic range) and analog magnetic tape (about 50 db dynamic range). The principal analysis of the records has been based on Develocorder films; and background earth noise levels have been adjusted to be about 1 to 2 mm p-p on the film readers. Since the traces are separated by only...
Authors
J. P. Eaton

Data from the GEOS digital recorder Data from the GEOS digital recorder

No abstract available.
Authors
J. B. Fletcher, Roger D. Borcherdt, C. Mueller, E. Cranswick
Was this page helpful?