EAR-PF An Automated Search for Deep Tremor and its Relationship to the Seismic Cycle in Southern California

Brown Justin R, Stanford CA

Investigators

Abstract

Dr. Justin Brown has been granted an NSF Earth Sciences postdoctoral fellowship to carry out a research and education plan at California Institute of Technology. This project aims to improve our understanding of the earthquake cycle by applying newly developed, high resolution methods. Recent analyses of continuous seismic waveform data allowed seismologists to discover a new class of seismic signals on faults that host large subduction earthquakes named non-volcanic tremors. This newly identified signal has been shown to comprise repeating low-frequency earthquakes that occur in both temporal and spatial patterns throughout the seismic cycle. In addition, recent studies have shown that non-volcanic tremor can be triggered by surface waves of large earthquakes at remote distances. Previous investigations have identified tremor in limited regions in southern California, but a comprehensive effort to detect and catalog non-volcanic tremor in southern California has not yet been done. This project will utilize waveform cross-correlation techniques to characterize non-volcanic tremor in southern California in context of the seismic cycle. Dr. Brown will search systematically for tremor and determine the recurrence intervals of low frequency earthquakes. Investigations and central cataloging of tremor in southern California will provide new insights into the nature of seismogenic faults and earthquake source physics. This project also includes a middle school Earth sciences outreach program. The program has three goals: 1) To introduce young students from underrepresented minorities to the Earth sciences; 2) To help prepare young people for natural disasters in their communities; and 3) To expose students to cutting-edge research regardless of their background. This program will take place over the course of two years and will include monthly field trips, outdoor activities and community-based service projects led by students themselves.