Collaborative Research: Investigating Seimogenesis and Faults in Eastern North America Using a Deep Magnitude Earthquake Catalog

Earthquakes are known to occur at plate boundaries, yet these natural hazards can also occur within stable continental regions beyond the plate boundary, such as in eastern North America. The hazard and risk posed by earthquakes in eastern North America is great because the region includes half of the top ten most populous metropolitan areas in the United States and generates 25% of its GDP. Though earthquakes are rare in the region, the recent April 2024 Mw4.8 earthquake in New Jersey highlights the importance of studying earthquake seismicity within stable continental regions. However, the earthquake rate in eastern North America is low, and sparse seismic networks have hampered progress in understanding the nature of faults and the earthquakes they produce. In this project, scientists will develop new machine-learning and cross-correlation methods to detect previously undetected earthquake events at a significantly lower magnitude detection threshold and higher location precision compared to existing catalogs, providing fundamental new data to study seismogenesis and seismotectonics in eastern North America at a broad range of spatial scales. This project aims to significantly improve on and expand currently available catalogs of earthquake parameters (including location, magnitude, focal mechanism) for eastern North America by applying advanced machine-learning and cross-correlation based earthquake detection and characterization methods to decades of continuous waveforms recorded in the region. The instrumentally recorded seismicity in eastern North America is sparse and typically only complete down to ~M2.5 and often higher in regions of sparse instrumentation. The new high-resolution, deep-magnitude earthquake catalog will include many previously undetected events that are expected to illuminate active faults at depths, providing new data and new insight into seismotectonics, fault mechanics, earthquake generation, and the stress conditions under which faults fail. The project harnesses the availability of long seismic archives, recent game-changing developments in event detection and characterization, and a recent Mw4.8 event in New Jersey that serves for ground-truthing both methods and new knowledge gained from the data. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.