We show how vertical downhole distributed acoustic sensing arrays can be used for P- and S- velocity analysis along the array. Using such velocity models, the array can be used in an effective moveout-based earthquake detection approach. We demonstrate both applications on 20 days of passive records at the San Andreas Fault Observatory at Depth, which comprises of a ~800 m deep vertical array. Estimated P velocities are comparable to an active geophone survey and S velocities are extracted for the first time in the area. Over 75% of the events in the USGS catalog in the area are detected, as well as a new earthquake.
Presentation Date: Tuesday, September 17, 2019
Session Start Time: 1:50 PM
Presentation Time: 3:55 PM
Presentation Type: Oral