Geologic characterization of seismic sources: Moving into the 1990s

The objective of this paper is to discuss leading-edge directions in paleoseismology and seismic geology, particularly as they relate to characterizing seismic sources. The paper builds on earlier articles that discuss some of these trends (Schwartz and Coppersmith, 1986; Schwartz, 1987). There are several areas that appear to be especially important. These are: fault segmentation, which provides a physical framework for evaluating both the size and potential location of future earthquakes on a fault zone; earthquake recurrence models, which provide information on the frequency of different size earthquakes on a fault; and long-term earthquake potential, an area in which significant advances have been made through development of earthquake hazard models that use probabilistic methodology to incorporate the uncertainties in seismic source characterization and the evolving understanding of the earthquake process.