Pre-earthquake Response: Closing critical data gaps and preparing for large earthquakes

Yehuda Ben-Zion, Mark Benthien, Jason Ballmann, & Christine A. Goulet

Published August 15, 2019, SCEC Contribution #9742, 2019 SCEC Annual Meeting Poster #068

The limited understanding of earthquakes stems partially from their highly complex dynamics, along with significant observational gaps in the available in-situ data. The existing natural observations in earthquake physics are generally associated with an “impossible” inverse problem of deriving information from far-field data where the fine-scale information is lost. Consequently, there are currently near-zero direct constraints on the dynamic processes and fields associated with large earthquake ruptures. In the aftermath of large earthquakes, rapid deployments try to capture as much information as possible about the evolving post-mainshock processes. These and regional deployments provide valuable data, but they miss precious opportunities to record near-field data on local processes (e.g., evolving width and strain-rate of the zone sustaining inelastic deformation, dynamic strain field around rupture fronts, near-field PGV and PGA) during the critical time intervals leading to and during large earthquake ruptures. The only way to remedy these critical observational gaps is to install before the next set of large earthquakes arrays of sensors (accelerometers, broadband stations and high-rate GPS stations) across fault sections with high likelihood of rupturing in the next decade or so. Fault zone arrays with co-located accelerometers, broadband stations and GPS stations can record ground motion over wide ranges of amplitudes and frequencies that will allow monitoring fault sections in the period leading to large events and recovering the physical processes that occur within the earthquake rupture zones. These “core arrays” may be augmented by additional monitoring devices such as cameras (for optical images of the fault zone), distributed acoustic sensors (for dense spatial sampling) and other geophysical instruments. Data from any such array that captures large earthquake ruptures can revolutionize the field of earthquake physics. The data recorded by these arrays will also provide the earliest early-warning signals (including directivity) from the monitored fault sections. Building codes and community preparation are fundamental components of pre-earthquake response that already save lives and reduce economic losses. Collecting near-field data before and during moderate to large events would impact our understanding of earthquake processes and contribute to better science-informed building codes, preparedness, and overall improved societal resilience.

Key Words
field observations, earthquake physics, building codes, community preparedness

Citation
Ben-Zion, Y., Benthien, M., Ballmann, J., & Goulet, C. A. (2019, 08). Pre-earthquake Response: Closing critical data gaps and preparing for large earthquakes. Poster Presentation at 2019 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology