Mitigating the devastating economic and humanitarian impact of natural and human-induced earthquakes requires advanced research on quantification of seismicity patterns, identification of induced seismicity, and improved forecasting ability. The risk posed by human-induced seismicity may be especially acute severe in California and other tectonic regions that operate geothermal, oil, and gas fields in highly populated areas with societal infrastructure. This project synthesizes novel earthquake cluster identification/classification techniques, physical modeling, and high-quality earthquake and geodetic data from different tectonic environments toward improved understanding of seismicity in relation to large events and human-induced earthquakes. A distinguishing property of the approach is uniform analysis and interpretation of thousands of earthquake clusters on different space-time-energy scales.
The investigations quantify the dynamics of seismicity on time scales of hours to tens of years, and zoom spatially from worldwide analysis to focused studies of selected regions with high-quality data. The research produces a comprehensive database of cluster styles such as dominant earthquake cluster types and values of their essential parameters, at global, regional, and local scales. The employed approach is intrinsically data-driven, but it is informed and motivated by models of seismicity with different types of rheologies and loadings that help interpreting the results. The combined observational and theoretical studies facilitate extracting fundamental information from the observed results on the basic underlying physics. The project develops improved methods for detecting human-induced seismicity, catalog declustering, establishes relations between earthquake clustering and principal loading mechanisms, and may provide additional signals for tracking the preparation process of large seismic events. The developed tools and results can have significant impact on understanding of seismicity and analysis of seismic hazard in active tectonic environments, oil, gas, and geothermal production areas, and regions containing both.
