An earthquake detection and recording system known as EARSS has been developed for permanent seismograph stations and temporary field installations. It records three components of ground motion with a dynamic range of 120 dB. A frequency-domain algorithm detects earthquakes and initiates the recording of data on magnetic tape. Alternatively, EARSS can record data continuously, for preselected p...

A new technique utilizing theoretical wave forms has been developed to determine precise shear wave travel times. This technique was applied to long-period World-Wide Standard Seismograph Network and Canadian network seismograms of five large nuclear explosions to obtain a surface focus shear wave data set containing about 100 travel times for distances greater than 30 ø. Very little scatter is...

The paper outlines a probabilistic basis for the automatic estimation from observed surface wave dispersion of structural model parameters with uncertainties. Given an earth model, a wave type and pertinent parameter values, the group velocity of seismic waves can be computed from theory as a function of frequency. Such a function may also be based on the dynamic spectrum representation of an e...