Episodic Tremor and Slip of the Cascadia Subduction Zone

Schmalzle Gina M, Miami FL

Investigators

Abstract

Dr. Gina Schmalzle is awarded an NSF Earth Science Postdoctoral Fellowship to carry out a program of research and education at the University of Washington. She will work on Slow Slip Events (SSEs) and Episodic Tremor and Slip (ETS) observed on Cascadia subduction zone. These events, observed in subduction zones worldwide, slowly release significant stress throughout the earthquake cycle in a matter of days to weeks. In contrast, earthquakes release stress in a matter of seconds to minutes. How SSE and ETS events redistribute stresses and contribute to large earthquakes in subduction zones is largely unknown. Recent advances in GPS and seismic networks have led to many interesting observations regarding SSE and ETS events. For example, SSE and ETS events in Cascadia have variable recurrence times along the coastline that spans from the Mendocino Triple Junction to north of Vancouver Island. Another interesting characteristic of ETS events is its sensitivity to lunar tides. This study will investigate these two observations: variable recurrence time along the coast and effects of lunar tides. This research will use existing geodetic and seismic data sets combined with an aggressive modeling approach to explain these important and fundamental observations that are critical to understanding the earthquake cycle of subduction zones and are crucial in seismic hazard assessment. This project also includes teaching Research Methods of Seismology and GPS. This class covers theory and field methods of seismology and GPS, providing undergraduate and graduate students an opportunity to collect and analyze Cascadia field data.