Strong‐motion seismology

Abstract

Although this is the first review on this topic to appear in a quadrennial report, the roots of strong‐motion seismology extend back to at least 1932, when far‐sighted engineers in the Seismological Field Survey of the U. S. Coast and Geodetic Survey installed rugged, fieldworthy instruments designed to make on‐scale recordings of large earthquakes (Carder, 1964); these instruments are called accelerographs, for their output closely mimics ground acceleration (Hudson, 1979). The original instruments and their offspring have provided a wealth of information about ground motions of direct use to engineers. Due in large part to the continued devotion of the Seismological Field Survey (now part of the Branch of Engineering Seismology and Geology at the U. S. Geological Survey), the number of recordings has increased substantially, particularly in the last two decades, and multiple recordings of a few California earthquakes have provided the data necessary to begin to unravel the complexities of the ground motions and to predict these motions on an empirical basis. Although seismologists used accelerograph records in studies of earthquake energy and ground motion attenuation as long ago as 1942 (Gutenberg and Richter, 1942, 1956), widespread seismological use of the records began with Aki's (1968) analysis of the 1966 Parkfield earthquake.

Strong Ground Motion Seismology

“…A number of studies have found that very simple relations between the corner frequencies and moment lead to predictions that are in excellent agreement with many measures of strong ground motion (McGuire and Boore, 1983;Atkinson, 1984;Hanks and Boore, 1984;McGuire et aI, 1984;Boore, 1986aBoore, , 1986bBoore and Atkinson, 1986). In these studies, …”

“…The time-domain method, discussed in detail in Boore (1983), is very simple: Gaussian white noise is generated witb a random-number generator. This noise is windowed with either a shaping function or a box car whose duration is related to the source corner frequency (at distances of several kilometers from moderate to large earthquakes the duration is given by the inverse of f , and farther away an.…”

“…A detailed discussion of the applicable theory, largely taken from Cartwright and Longuet-Higgins (1956), is contained in Boore (1983) and Boore and Joyner (1984b). A detailed discussion of the applicable theory, largely taken from Cartwright and Longuet-Higgins (1956), is contained in Boore (1983) and Boore and Joyner (1984b).…”

“…Boore (1983) discusses such a comparison for pseudo-relative velocity spectra, and Figures 16 and 17 show comparisons for the output of a Wood-Anderson seismograph (used in determining MI) and a World-Wide Standardized Seismograph Network shortperiod instrument, respectively. Boore (1983) discusses such a comparison for pseudo-relative velocity spectra, and Figures 16 and 17 show comparisons for the output of a Wood-Anderson seismograph (used in determining MI) and a World-Wide Standardized Seismograph Network shortperiod instrument, respectively.…”

“…Moment-magnitude data for central California earthquakes (crosses, box for 1906 earthquake) and model calculations afterBoore (1983) (solid circles; dashed line forLuco, 1982, correction for difference in near-source and far-source estimates of ~); seeHanks and Boore (1984) for details. Observed (symbols) and predicted (lines) amplitudes on WWSSN short-period instruments as a function of moment magnitude.…”