RAPID: Real-Time Investigations of the Tohoku and Darfield Earthquake Sequences

University Of Southern California, Los Angeles CA

Investigators

Abstract

The earthquake sequences excited by 2010 Darfield (New Zealand) and 2011 Tohoku (Japan) are natural experiments being conducted in two distinctive and well-instrumented tectonic laboratories. This NSF project supports U.S. scientists to participate in these experiments by collaborating with their Japanese and New Zealand colleagues. The international project team is gaining new knowledge about short-term earthquake predictability, which is a major unsolved problem of physical science. Intellectual Merit: The project goal is to improve the physical and statistical foundations for time-dependent earthquake forecasting. New forecasting models incorporating seismic, geodetic, and other data are being developed and evaluated using the existing infrastructure of the Collaboratory for the Study of Earthquake Predictability. The research is focused in two areas: (a) the retrospective calibration and prospective testing of physics-based forecasting models, including those based on rate/state-dependent friction, the Coulomb stress function, and observations of slow slip events, and (b) the evaluation of hypotheses critical to forecasting large earthquakes, including the characteristic earthquake hypothesis, the seismic gap hypothesis, and the maximum-magnitude hypothesis. Broader Impacts: The basic research sponsored by this project is elucidating critical scientific issues related to temporal changes in primary and secondary seismic hazards. The results will help the Working Group on California Earthquake Probabilities formulate an improved time-dependent Uniform California Earthquake Rupture Forecast, and they will also aid the U.S. Geological Survey and the National Oceanic and Atmospheric Administration improve their procedures for time-dependent forecasting of earthquake and tsunami hazards off the Cascadia coast.