The Seismic Signature of California's Droughts, Floods, and Earthquakes
Timothy Clements
USGS
- Date & Time
- Location
- Online-only seminar via Microsoft Teams
- Summary
Extreme natural events, including magnitude 7+ earthquakes, heavy rainfall and flooding from atmospheric rivers, and multi-year droughts, can alter the elastic properties of the near-surface on time scales ranging from seconds to decades. Tracking the influence these events on the near-surface at a variety of temporal and spatial scales, however, is difficult to achieve with a single dataset. Here, I show that the change in seismic velocity (dv/v) derived from the auto-correlation of the ambient seismic field can be used to track the state of California's aquifers and the post-seismic relaxation following the Hector Mine, Baja, and Ridgecrest earthquakes over the past two decades. I leverage the computing language Julia and cloud computing resources to make daily measurements of dv/v for every available broadband seismometer in California since 1999. I will show the dominant components of dv/v time series for locations across California and their comparisons to measured groundwater levels, modeled groundwater levels from precipitation data, gravitational data from the GRACE satellite, and ground displacement from GPS stations.
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