| Abstract: | In 2005, the San Andreas Fault Observatory at Depth (SAFOD) was drilled through the San Andreas Fault zone at a depth of about 3.1 km. The borehole has subsequently been instrumented with high-frequency geophones in order to better constrain locations and source processes of nearby microearthquakes that will be targeted in the upcoming phase of SAFOD. The microseismic monitoring software MIMO, developed by NORSAR, has been installed at SAFOD to provide near-real time locations and magnitude estimates using the high sampling rate (4000 Hz) waveform data. To improve the detection and location accuracy, we incorporate data from the nearby, shallow borehole (???250 m) seismometers of the High Resolution Seismic Network (HRSN). The event association algorithm of the MIMO software incorporates HRSN detections provided by the USGS real time earthworm software. The concept of the new event association is based on the generalized beam forming, primarily used in array seismology. The method requires the pre-computation of theoretical travel times in a 3D grid of potential microearthquake locations to the seismometers of the current station network. By minimizing the differences between theoretical and observed detection times an event is associated and the location accuracy is significantly improved. |
| Genre: | Conference Paper |
| ProdID: | 70030544 |
| Citation Author: | Oye, V.; Ellsworth, W. L. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 751 |
| Citation Issue: | |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Society of Petroleum Engineers - 69th European Association of Geoscientists and Engineers Conference and Exhibition 2007 - "Securing |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 5 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Monitoring microearthquakes with the San Andreas fault observatory at depth; 2007; Conference Paper; Society of Petroleum Engineers - 69th European Association of Geoscientists and Engineers Conference and Exhibition 2007 - "Securing; Oye, V.; Ellsworth, W. L. |
| Citation Start Page: | 747 |
| Citation Volume: | 2 |
| Citation Year: | 2007 |
| Type: | citation/reference |
| Text: | Monitoring microearthquakes with the San Andreas fault observatory at depth; 2007; Conference Paper; Society of Petroleum Engineers - 69th European Association of Geoscientists and Engineers Conference and Exhibition 2007 - "Securing; Oye, V.; Ellsworth, W. L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Mon, 1 Jan 2007 00:00 -0600 |
| Publisher: | |
