SAFOD (San Andreas Fault Observatory at Depth)
Data access | Collaborations
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The San Andreas Fault Observatory at Depth (SAFOD) is a deep borehole observatory that will directly measure the physical conditions under which plate boundary earthquakes occur. SAFOD is one component of the EarthScope Major Research Initiative funded by the National Science Foundations (NSF). The SAFOD site is located in the Parkfield region of northern California. The SAFOD main hole is a 3.2 km inclined borehole across the San Andreas Fault Zone. The SAFOD pilot hole is a separate, 2.2-km-deep scientific drilling experiment at the same surface location as SAFOD. This site is ~ 1.8 km SW of the San Andreas fault near Parkfield, CA, on a segment of the fault that moves through a combination of aseismic creep and repeating microearthquakes. It lies just north of the rupture zone of the 2004, magnitude 6 Parkfield earthquake, the most recent in a series of events that have ruptured the fault six times since 1857. The Parkfield region is the most comprehensively instrumented section of a fault anywhere in the world, and has been the focus of intensive study for the past two decades as part of the Parkfield Earthquake Experiment. The SAFOD hole are a collaborative effort between the International Continental Drilling Program (ICDP), NSF and the U.S. Geological Survey (USGS). The SAFOD pilot hole was initially instrumented with a seismic string containing 32 levels of 3-component 15-Hz geophones. The sensors were recorded by a GERI 24-bit mutichannel recorder. The event waveform data from 2002/09/13 through 2004/05/30 contain all 96 channels of data. In the process of drilling the main SAFOD hole in 2004, the pilot hole sensor string was inadvertently damaged, resulting in a loss of the lower 25 sensor packages. The waveforms from 2004/09/26 through 2004/10/30 therefore contain waveforms only from the remaining 7 sensors (21 channels). This sensor string was later remove, and a single 3-component seismometer has been deployed in summer 2005 and most of 2006. Data from SAFOD has been assigned a network code of SF. |
- Main Hole Equipment
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2 levels of 3-component GS-20DM 15 Hz geophone sensors
24-bit GERI multi-channel data acquisition system.
GPS clock
On-site recording. - Typical Recorded Channels
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Continuous recordings from 2006/01/17 through 2006/11/19 consists of 6 data channels
at 2 distinct depths in the main hole, and 3 data channels at one depth in the pilot hole.
Start Date End Date Sensor SEED Channels Rate (samples/sec) Sampling Mode FIR Filter 2006/01/17 (2006.017) 2006/11/16 (2006.320) Geophone GP1, GP2, GP3 4000 Hz Continuous Unknown - Pilot Hole Equipment
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32 levels of 3-component GS-20DM 15 Hz geophone sensors
24-bit GERI multi-channel data acquisition system.
GPS clock
On-site recording. - Typical Recorded Channels
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Event recordings from 2002/09/13 through 2004/05/30 consists of 96 data channels
at 32 distinct depths.
In the process of drilling the main SAFOD hole in 2004, the pilot hole
sensor string was inadvertently damaged, resulting in a loss of the lower 25 sensor
packages. The waveforms from 2004/09/26 through 2004/10/30 therefore contain waveforms
only from the remaining 7 sensors (21 channels).
This sensor string was later remove, and a single 3-component seismometer has been
deployed in summer 2005 and most of 2006.
Start Date End Date Sensor SEED Channels Rate (samples/sec) Sampling Mode FIR Filter 2002/09/13 (2002.256) 2002/09/17 (2002.260) Geophone DP1, DP2, DP3 250 Hz Triggered Unknown 2002/09/24 (2002.267) 2002/12/08 (2002.342) Geophone GP1, GP2, GP3 1000 Hz Triggered Unknown 2002/12/20 (2002.354) 2003/11/12 (2003.316) Geophone GP1, GP2, GP3 2000 Hz Triggered Unknown 2003/11/21 (2003.325) 2003/11/24 (2003.328) Geophone DP1, DP2, DP3 250 Hz Triggered Unknown 2003/11/26 (2003.330) 2004/05/30 (2004.151) Geophone GP1, GP2, GP3 2000 Hz Triggered Unknown 2006/01/17 (2006.017) 2006/11/16 (2006.320) Geophone GP1, GP2, GP3 4000 Hz Continuous Unknown - Station Information
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- SF Information Directory, including
- List of station locations
- List of available channels
- Instrument Response
- SF Information Directory, including
- Data access
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All SAFOD pilot hole and main hole seismic waveform data are available in SEED format.
The triggered pilot data may be accessed
using SEED-format tools as well as through the
EVT_FAST waveform request form,
which allows you to request waveform by trigger id.
The SAFOD pilot hole trigger list provides a list of NCEDC triggerids and trigger times that can be used with EVT_FAST or STP waveform request system. Several tools provide access to SEED format data at the NCEDC, both in terms of querying the archives and allowing data requests.
- Querying the archives
- Requesting data by channel and time
- Requesting data by event
Help on using these tools is available.
SAFOD tilt data are available as an "assembled data set" here.
The NCEDC also has event and continuous waveform data covering the same time periods from the Parkfield borehole High Resolution Seismic Network and the Northern California Seismic Network as well as the authoritative earthquake catalog for the region.
- Collaborations
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The waveform data from the SAFOD pilot hole from 2002/09/13 through 2004/12/31
was recorded by and provided to the NCEDC by the research group of
Dr. Peter Malin at Duke University.
SAFOD is one component of the EarthScope Major Research Initiative funded by the National Science Foundations (NSF).
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Northern California Earthquake Data Center
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Copyright 1995-2005, The Regents of the University of California.
Last modified: Wed Apr 25 18:44:22 PDT 2012