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Test and calibration of the Seismic Research Observatory

The Seismic Research Observatory (SRO) network is generating an important new data base for seismological research. The SRO systems have extended both the range and resolution of seismic measurements beyond the limits of conventional seismographs and the data are recorded in digital format making it convenient to automate processing and analysis. The SRO network now comprises 12 stations and one a

Authors
Jon Peterson, Charles R. Hutt, L. Gary Holcomb

Preliminary observations of noise spectra at the SRO and ASRO stations

The seismic noise spectra presented in this report were derived from SRO and ASRO station data for the purpose of evaluating the performance of the seismic instruments. They are also useful for constructing a spectral estimate of earth noise at a quiet site based on noise samples obtained from a network of globally distributed sites. It is hoped that the spectra will be usefull for other purposes
Authors
Jon Peterson

Speculations on processes responsible for mesoscale current lineations on the continental shelf, southern California

A side-scan sonar survey of San Pedro shelf, California, reveals areas of mesoscale current lineations oriented approximately north-northeast in water depths of 20-25 m. Widths of sand ribbons range from 40 to 120 m and intervening erosional furrows, from 15 to 50 m. A conceptual model shows that the scale and orientation of current lineations agree with the dimensions and axial directions of Lang
Authors
Herman A. Karl

Nuclear event time histories and computed site transfer functions for locations in the Los Angeles region

This report presents a collection of Nevada Test Site (NTS) nuclear explosion recordings obtained at sites in the greater Los Angeles, Calif., region. The report includes ground velocity time histories, as well as, derived site transfer functions. These data have been collected as part of a study to evaluate the validity of using low-level ground motions to predict the frequency-dependent response
Authors
A. M. Rogers, P. A. Covington, R.B. Park, R. D. Borcherdt, D. M. Perkins

In-situ measurements of seismic velocity at 27 locations in the Los Angeles, California region

Studies conducted in the San Francisco Bay Region (Gibbs, Fumal and Borcherdt, 1980) have shown that average shear-wave velocity can be readily tied to quantitative estimates of ground motion such as ground amplification and earthquake intensity. Furthermore, when certain physical properties of the geologic materials such as texture, hardness and fracture spacing are observed during geologic mappi
Authors
James F. Gibbs, Thomas E. Fumal, Edward F. Roth

Exploratory trench across the Pleasant Valley Fault, Nevada

An exploratory trench was excavated across the 1915 trace of the Pleasant Valley fault 60 km south of Winnemucca, Nevada, to get information on the history of recent displacements on a fault that had produced a major earthquake in historic time, and on the appearance of such a fault in a trench cut in gravels, sands and silts of an alluvial fan. The trench exposed 16 mappable sedimentary units and
Authors
Manuel G. Bonilla, H. A. Villalobos, R. E. Wallace

Holocene geomagnetic secular variation in the western United States: implications for the global geomagnetic field

A record of Holocene geomagnetic secular variation in the western 14 United States has been measured from volcanic rocks dated by 14C. Analysis of errors associated with the paleomagnetic techniques used suggests that all laboratory measurement errors are smaller than those introduced by deformation of the volcanic units and the errors of orientation of cores in the field. The dispersion in the ca
Authors
Duane E. Champion

Surface faulting near Livermore, California, associated with the January 1980 earthquakes

The earthquakes of 24 January (Ms 5.8) 1980 north of Livermore, California, and 26 January (Ms 5.2), were accompanied by surface faulting in the Greenville fault zone and apparently in the Las Positas fault zone also. The surface faulting was discontinuous and of small displacement. The main rupture within the Greenville fault zone trended about N.38°W. It was at least 4.2 km long and may have ext
Authors
Manuel G. Bonilla, James J. Lienkaemper, J. C. Tinsley

Influence of San Gabriel submarine canyon on narrow-shelf sediment dynamics, southern California

Variations in the concentration of total suspended particulate matter (TSM) collected 1 m above bottom, changes in vertical profiles of light transmission, and substrate textural patterns reveal a corridor for preferential sediment transport on San Pedro continental shelf, California. During the winter, this corridor, designated the preferential transport corridor (PTC), is defined by higher conce
Authors
Herman A. Karl

Debris-flow deposits of Early Miocene age, Deadman Stream, Marlborough, New Zealand.

Detailed analysis is presented of a conformable succession of conglomerates and sandstones lying between massive marine mudstones. The coarse sediments reflect deposition by a spectrum of subaqueous debris-flow mechanisms during an early pulse of tectonism that ultimately resulted in Plio-Pleistocene eversion of the Kaikoura Mountains. Sparse pebbly mudstones and rare sandy conglomerates show diso
Authors
D.W. Lewis, M.G. Laird, R. D. Powell