Strong‐motion seismology

Abstract

Strong‐motion seismology is concerned with earthquake ground motion in the amplitude range that poses the threat of human injury or property damage. Because the occurrence of strong motion cannot be predicted in advance and because the time between significant events at any one place may range from tens to thousands of years, strong‐motion data is recorded on triggered instruments that typically must be maintained in readiness for years between periods of significant recording. As a consequence the strong‐motion data set is sparse. Because of the engineering need for estimates of future ground motion, the scope of the field of strong‐motion seismology encompasses seismic source theory and any other aspect of seismology that can provide insights helpful in making the best possible estimates given the limited data. This relationship with the rest of seismology is a reciprocal one in that strong‐motion data gives perhaps the best information available on earthquake source processes.