On August 26, a magnitude 6 earthquake struck the Napa area. Because this was both late summer and a drought, most streams were dry. However, after the earthquake many started to flow. This provided an excellent opportunity to test various hypotheses about why streamflow changes after earthquakes. We concluded that the earthquake changed permeability, allowing groundwater in the mountains to flow to the streams. Our results are now published. More background about this general topic is provided here. We are grateful for all the local residents who let us know what happened and provided access to their land, and for a NSF RAPID grant to allow us to collect samples and make geochemical measurements.
The Napa earthquake did cause some damage.
Stream in Napa Valley that was dry before the earthquake and started to flow.
Stream in Sonoma Valley that was dry before the earthquake and started to flow
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