TOCS Event-Silicon Valley Campus - Carnegie Mellon University

TOCS Event


Benjamin Brooks


Research Scientist

Earthquake Science Center

US Geological Survey, Menlo Park


September 24, 1:30 pm



CMUSV, Rm 118 [directions]

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Title: Crowd-sourced Earthquake Geodesy

Space-based platforms such as the Global Positioning System (GPS) or Synthetic Aperture Radar (SAR) satellites have, over the past two decades, provided Earth Scientists with unprecedented capability to study how Earth's surface deforms in response to varying stages of the earthquake cycle. These geodetic tools permit detection of displacements ranging from meters to millimeters and, for the case of many continuous GPS networks (cGPS), with negligible temporal latency. Accordingly, they are invaluable tools for assessing and mitigating earthquake hazard. Both ground-based cGPS networks and radar satellite missions, however, are expensive to operate: for example, many countries with significant earthquake hazards do not have cGPS networks and the United States does not currently have an operational radar satellite mission.

In this talk I present two new and much less expensive ways of doing earthquake geodesy that employ crowd-sourcing philosophy. The first employs the GPS pseudorange data recorded by smartphones. Although individual instrument's positional precision can be as much as three orders of magnitude worse than carrier-phase processed data, we show that large numbers of reporting instruments could provide derived earthquake parameters with the necessary levels of accuracy to be useful in earthquake early warning scenarios. The second uses LiDAR (Light Detection and Ranging) data collected from a moving platform in the same manner that robotic vehicles perform collision avoidance. We tested the method on a creeping section of the Hayward fault in Fremont, CA and find good agreement with independently measured displacements. In addition to presenting case studies, I will discuss some of the challenges that need to be met - data transmission, processing strategy, privacy - before these methods can become operational.

Speaker Bio:

Dr. Brooks graduated UC Santa Cruz with a BS in Earth Sciences in 1992. He received a PhD in Earth Sciences from Cornell University in 1999. In 2003, after three years as research faculty, Brooks assumed the directorship of the Pacific GPS Facility in the University of Hawaii's School of Ocean and Earth Science and Technology. He was awarded tenure in 2008. In 2012 he took a research position with the Earthquake Science Center at the US Geological Survey.

Dr. Brooks' research focuses on studying Earth's active tectonic processes by making geodetic field measurements. Brooks was awarded the University of Hawaii Regents' medal for excellence in research, is a Fullbright fellow, and serves, or has served, on multiple advisory committees including the National Research Council's Committee on Sea Level Rise in California, Oregon, and Washington.