SCEC Award Number 15137 View PDF
Proposal Category Individual Proposal (Special Fault Study Area)
Proposal Title Characterization of Induced micro-seismicity associating with one hydraulic fracturing experiment near the San Andreas fault, Central California
Investigator(s)
Name Organization
Chen Ji University of California, Santa Barbara
Other Participants Trevor Smith
SCEC Priorities 2f, 2a SCEC Groups Seismology, CS, CCSP
Report Due Date 03/15/2016 Date Report Submitted 03/19/2016
Project Abstract
 We apply match filter (e.g., Shelly et al., 2007) and match&locate (M&L, Zhang and Wen, 2015) to study the micro-seismicity induced by a hydraulic fracture experiment in a central California site only 8 km away from the San Andreas fault. Two modifications have been made to improve the detection capability of M&L algorithm and reduce its computational cost. Using a 16-geophones array that located less than 400 m away from the treatment well, the new M&L algorithm detects 12,944 earthquakes with-in a 7.5 hour injection period, 12 times more than what were registered in the industry catalog. The events span a magnitude range from -4.17 to -0.77 with a magnitude completeness Mc of -3.0, in contrast with Mc -2.2 of the industry catalog. The new catalog reveals a magnitude-frequency distribution during the injection period that clearly deviates from the Gutenberg-Richter relation.
Intellectual Merit The work further improves a newly developed earthquake detection and relocation algorithm. The result reveals that during the injection period, the magnitude-frequency distribution of induced seismicity deviates from Gutenberg-Richter statistics.
Broader Impacts The software package can be used to study the earthquakes in other region. The research improves our understanding to the seismicity induced by hydraulic fracture experiments, an area with extensive public attention. The fund is used to support the research of graduate student Trevor Smith.
Exemplary Figure Figure 2. Magnitude-frequency distribution of earthquakes occurring during a 7.5 hour period of hydraulic fracture injection. GR denotes Gutenberg and Richter relation. Caputo and Utsu denote two non-GR models that match this distribution well.