Skip to main content
U.S. flag

An official website of the United States government

What do data used to develop ground-motion prediction equations tell us about motions near faults?

January 6, 2014

A large database of ground motions from shallow earthquakes occurring in active tectonic regions around the world, recently developed in the Pacific Earthquake Engineering Center’s NGA-West2 project, has been used to investigate what such a database can say about the properties and processes of crustal fault zones. There are a relatively small number of near-rupture records, implying that few recordings in the database are within crustal fault zones, but the records that do exist emphasize the complexity of ground-motion amplitudes and polarization close to individual faults. On average over the whole data set, however, the scaling of ground motions with magnitude at a fixed distance, and the distance dependence of the ground motions, seem to be largely consistent with simple seismological models of source scaling, path propagation effects, and local site amplification. The data show that ground motions close to large faults, as measured by elastic response spectra, tend to saturate and become essentially constant for short periods. This saturation seems to be primarily a geometrical effect, due to the increasing size of the rupture surface with magnitude, and not due to a breakdown in self similarity.

Publication Year 2014
Title What do data used to develop ground-motion prediction equations tell us about motions near faults?
DOI 10.1007/s00024-013-0748-9
Authors David M. Boore
Publication Type Article
Publication Subtype Journal Article
Series Title Pure and Applied Geophysics
Index ID 70059915
Record Source USGS Publications Warehouse
USGS Organization Earthquake Science Center