GeoPRISMS Synthesis Workshop: The Geological Fingerprints of Slow Earthquakes

University Of Washington, Seattle WA

Investigators

Abstract

Slow earthquakes are a family of events similar to regular earthquakes, but which occur more slowly. They typically do not cause the ground shaking that we associate with regular earthquakes, and are otherwise innocuous. However, these events do have important implications for earthquake hazards. The discovery of slow earthquakes nearly two decades ago has revolutionized our understanding of how plate motions are accommodated at major tectonic boundaries because they can be as large as regular earthquakes. Yet a physical understanding of slow earthquakes remains out of reach. The understanding of slow earthquakes is critical to better constraining regional seismic hazards, can inform us of the physical conditions and fault loading rates at depth, and is therefore central to our understanding of plate boundary fault and shear zone mechanics. This grant will support a synthesis workshop for a multi-disciplinary group of geoscientists to discuss and debate how geological observations may be used to test competing hypotheses for slow earthquake occurrence and characteristics. This workshop will allow scientific progress to advance in new directions, and allow for a better understanding of these enigmatic fault processes. The participation of early career researchers and those from underrepresented groups within the geosciences will be emphasized. The objectives of this workshop are to: (1) Provide a field-based and academic forum for cross-disciplinary discussions of the geological expressions of slow slip and tremor, and their mechanisms. (2) Use field-based examples to develop a common understanding amongst different disciplines of what we currently know about the structures of subduction plate boundaries at slow earthquake conditions. (3) Determine the structural data needed to test different models for slow slip using an exhumed subduction plate boundary to guide discussions. (4) Discuss multiple potential underlying geological processes and formulate future research strategies by identifying what new observations and constraints are needed. (5) Promote better communication between disciplines and forge new multidisciplinary collaborations. The multi-day conference will include a field trip to examine and debate different hypotheses using processes recorded in the rock record. 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.