Time-Dependent Earthquake Hazard: Committee on Solid Earth Geophysics Spring 2022 Meeting
Channel: National Academies - Earth and Life Studies
Date: 2022-05-03

Earthquake behavior is known to experience time dependent behavior. For example, earthquakes slip in response to a long preceding period of interseismic stress accumulation and repeated rupture of a given fault patch is not expected shortly after a major earthquake.  More generally, stress transfer between faults is widely recognized, such that a given earthquake might bring other faults or fault segments closer to (or farther from) failure. However, aside from the specific case of aftershock forecasts, quantifying time-dependent hazards has long been challenging.

Estimating earthquake hazards requires not only an understanding of stress transfer in the lithosphere, but also knowledge of regional tectonics and geology. This information, combined with measurements of ground shaking, allows scientists to make a probabilistic hazard maps of future shaking intensities. Although these maps represent, at best, a “snapshot in time,” they are often used without full critical evaluation in downstream engineering applications. Creating frameworks to capture the changing nature of time-dependent hazard, such as new earthquake occurrence or other tectonic or human processes (such as slow slip earthquakes, earthquake swarms, or fracking), is an area of cutting-edge research.