Current Research

My current research focuses on tsunami earthquakes.  Unlike large earthquakes (~M9) that we expect to produce tsunamis, “tsunami earthquakes” are smaller events that produce larger or unexpected tsunamis compared to their magnitude.  Because the size of these earthquakes is not an indicator that a tsunami will occur, it is difficult to warn people early enough for them to evacuate before the waves reach shore.  The purpose of my research is to look into the site, source, and path characteristics that characterize tsunami earthquakes to be able to identify them in near-real time for use in early hazard warning.     

IRIS Internship

In the summer of 2018, I worked as an IRIS intern under Kate Allstadt at the USGS in Golden, CO.  My work there was focused on searching current scientific literature for possible ways to predict duration parameters of earthquakes, such as Arias intensity and cumulative absolute velocity (CAV).  This was done with the intention of determining the best ground motion prediction equation (GMPE) and incorporating it into Shakemap, a system for producing near-real time maps of intensity following significant events.  We specifically looked at the Travasarou (2003) and the Foulser-Pigott (2012) GMPEs for Arias intensity as well as the Liu (2016) correlation equation between PGA and Arias intensity.  

AGU Poster

Undergraduate Research

Ron Harris

Indonesia is one of the most tectonically-active regions in the world.  It is a volcanic arc, formed by the subduction of the Indian plate beneath the Eurasian plate, and it faces frequent major earthquakes, sometimes resulting in tsunamis.  Despite this region experiencing great tectonic activity, many of the residents are unaware of the seismic hazard risks in the region.  Professor Ron Harris (Brigham Young University) created an outreach organization called In Harm’s Way to educate and inform the people of Indonesia about the seismic hazards they face and how to prepare for them. 

As part of the In Harm’s Way group, my focus was mainly on Sumatra, Indonesia.  I used GPS data and recent seismic activity to calculate the amount of loading that has accumulated along the Sumatra subduction zone.  This can be equated to how much the fault segment is expected to slip if an earthquake were to rupture there now.  The loading along a fault can be calculated by multiplying the convergence rate by the years since the fault was “reset.”  A fault is reset when all of the stress is released from a major (M8.5+) earthquake.  The moment magnitude of an earthquake is a function of the size of the fault and its slip (loading), so using the loading calculations, I was able to calculate the largest magnitude earthquake that could occur along each fault segment.   

Results indicate the greatest risk for a major earthquake to be near Padang in the West Sumatra province as well as in some locations along the trench in the southernmost part of Sumatra.  This is where the largest seismic gaps are, so more loading has accumulated in these areas.  A figure of Sumatra with the loading and expected magnitude of each fault segment is shown to the right. 

The Sumatra subduction zone is shown divided into 6 fault segments. The amount of loading along each segment and the estimated magnitude earthquake the fault segment would produce if it ruptured are indicated. The yellow-highlighted regions indicate areas of greatest concern for a large earthquake because of the large amount of loading accumulated.

John McBride

For this project, I assisted in conducting P- and S-wave seismic surveys at Pah Tempe Hot Springs in Hurricane, UT.  After these surveys were collected, I used the Kingdom seismic interpretation software to identify 1st, 2nd, and 3rd order faults in the surveys.  These faults were correlated with geothermal springs in the area.

P-wave seismic reflection data with 1st, 2nd, and 3rd order faults identified.

S-wave seismic reflection data with 1st, 2nd, and 3rd order faults identified.