Creepmeter
The data listed below are measures of surface fault slip (scaled in mm) as measured by creepmeters. Creepmeters consist of two piers separated by about 30 meters and connected by an invar wire. The main fault trace lies between the two piers. The invar wire oriented roughly a 30 degree angle from the local trace of the fault. A displacement transducer (LVDT) measures the change in length of the wire (or the change in distance between the piers).
For many of the creepmeters, the measurements are made once every 10 minutes and are sent via satellite telemetry to Menlo Park for analysis. In addition, periodic measurements are made manually for comparison with the electronically recorded data. For other creepmeters without telemetry, the measurements are made manually.
Below is a list of creepmeters, from North to South, located on the San Andreas, Hayward, and Calaveras Faults. For each site, the available data are listed. For sites with telemetry, the data are uploaded to this webpage daily. However, for the most recent observations, that is, within the past 2 weeks, they have not always been reviewed and, if needed, edited.
Note that at some sites, there exists both 10 minute and 1-day sampled data. The 10-minute and 1-day sampled data often do not cover the same interval of time. The 1-day data files will include older data.
The format of these data are year, day-of-year, and slip in mm. If there is a fourth column, then ignore that column.
More information can be found in the USGS Open File Report: Catalog of creepmeter measurements in California from 1966 through 1988
For information on 5 sites along the Hayward Fault (cpp, ctm, coz, chp, and cfw) see: Surface Creep on California faults
| Name | Code | Latitude | Longitude | Initial obs. | Notes | Manual data | 10-minute sampling | 1-day sampling |
|---|---|---|---|---|---|---|---|---|
Calaveras Fault | ||||||||
| Shore Rd #1 | XSH1 | 36.9430 | -121.4450 | 1971 | | | | |
| Shore Rd #2 | SHR2 | 36.9430 | -121.4450 | Apr-86 | | | | |
| Hollister Central | HLC1 | 36.8570 | -121.4050 | Apr-70 | | | | |
| Hollister D St | HLD1 | 36.8420 | -121.4030 | Apr-70 | | | | |
Hayward Fault | ||||||||
| Pt Pinole | CPP1 | 37.9900 | -122.3560 | Aug. 1995 | | | | |
| Temescal | CTM1 | 37.8440 | -122.2270 | Mar. 1997 | | | | |
| Oakland Zoo | COZ1 | 37.7530 | -122.1500 | Nov. 1996 | | | | |
| Hayward, Rose St #1 | HWR1 | 37.6800 | -122.0920 | Apr-68 | | | | |
| Hayward, Rose St #2 | HWR2 | 37.6800 | -122.0920 | Apr-68 | | | | |
| Hayward, D St #1 | HWE1 | 37.6700 | -122.0800 | Apr-68 | | | | |
| Hayward, D St #2 | HWW1 | 37.6700 | -122.0800 | Apr-68 | | | | |
| Hayward, Palisades St #1 | HWP1 | 37.6630 | -122.0740 | Apr-68 | | | | |
| Hayward, Palisades St #2 | CHP1 | 37.6630 | -122.0740 | Apr-94 | | | | |
| Fremont Winery | CFW1 | 37.5320 | -121.9520 | Dec. 1993 | | | | |
San Andreas Fault | ||||||||
| San Juan Bautista; Nyland | SJN1 | 36.8546 | 0.0000 | 2004 | | | | |
| San Juan Bautista #2 | XSJ2 | 36.8360 | -121.5210 | Jun-69 | | | | |
| San Juan Bautista #3 | XSJ3 | 36.8360 | -121.5210 | Jan. 2007 | | | | |
| Harris Ranch #1 | XHR1 | 36.7720 | -121.4220 | 1970 | | | | |
| Harris Ranch #2 | XHR2 | 36.7720 | -121.4220 | Apr-85 | | | | |
| Harris Ranch #3 | XHR3 | 36.7720 | -121.4220 | Aug. 2009 | | | | |
| Cienega Winery Central | CWC3 | 36.7500 | -121.3850 | Nov. 1968 | | | | |
| Cienega Winery North | CWN1 | 36.7500 | -121.3850 | Jun-72 | | | | |
| Frank Lewis Long | XFL1 | 36.6650 | -121.2720 | Apr-73 | | | | |
| Melendy Ranch | XMR1 | 36.5950 | -121.1870 | Jun-69 | | | | |
| Melendy Windmill | MRW1 | 36.5850 | -121.1770 | Sept. 1972 | | | | |
| Dry Lake Long | XDL2 | 36.4920 | -121.0780 | 1978 | | | | |
| Bitterwater | BIT1 | 36.3980 | -120.9820 | Jul-79 | | | | |
| Monarch Peak #1 | XMP1 | 36.2170 | -120.7980 | Jun-69 | | | | |
| Monarch Peak #1 | XMP2 | 36.2170 | -120.7980 | Jun-69 | | | | |
| Slacks Canyon | XSC1 | 36.0650 | -120.6280 | Jun-79 | | | | |
| Middle Mtn | XMM1 | 35.9580 | -120.5020 | Oct. 1979 | | | | |
| Middle Mtn; Big Creep | XMBC | 35.9580 | -120.5020 | Apr-04 | | | | |
| Middle Ridge | XMD1 | 35.9430 | -120.4850 | Jul-86 | | | | |
| Varian | XVA1 | 35.9220 | -120.4620 | Apr-87 | | | | |
| Roberson, SW trace | XRSW | 35.9070 | -120.4600 | May-87 | | | | |
| Parkfield, #1 | XPK1 | 35.9020 | -120.4420 | Oct. 1979 | | | | |
| Parkfield, #2 | XPK2 | 35.9020 | -120.4420 | Sept. 2004 | | | | |
| Taylor Ranch | XTA1 | 35.8900 | -120.4270 | Sept. 1985 | | | | |
| Taylor Ranch; Big Creep | TABC | 35.8900 | -120.4270 | Mar-04 | | | | |
| Hearst, SW trace | XHSW | 35.8620 | -120.4200 | Jun-87 | | | | |
| Work Ranch | WKR1 | 35.8580 | -120.3920 | 1976 | | | | |
| Carr Ranch | CRR1 | 35.8350 | -120.3630 | May-66 | | | | |
| Gold Hill | XGH1 | 35.8200 | -120.3480 | Jul-69 | | | | |
| Highway 46 | C461 | 35.7240 | -120.2820 | Sept. 2004 | | | | |
| Highway 46 | X461 | 35.7230 | -120.2780 | Aug. 1986 | | | | |
| Twisselman Ranch | TWR1 | 35.5970 | -120.1470 | Nov. 1976 | | | | |
| Panorama Hills | XPH1 | 35.1480 | -119.6920 | Aug. 1977 | | | | |
Dilatometer
The data listed below are measures of changes in volumetric strain (units of 0.001 part per million) as a function of time for instruments in California. Outliers due to telemetry problems, instrument visits, and etc have been removed. Offsets due to valve resets have been removed. Data are provided in two modes; 1) Cleaned strain data and 2) Clean strain data adjusted for the Earth Tide and atmospheric pressure changes. Pressure data (not scaled to units of pressure) are also provided.
The format of these data are year, day-of-year, and slip in mm. If there is a fourth column, then ignore that column.
Data are complete through the end of 2019. More data exist, but have not been archived.
The ReadMe file contains the lists of offsets and data removed for analysis. In addition, there is a table listing the estimates of the amplitude and phase of the O1 and M2 tides calculated as a function of time for the strainmeter.
| Name | Code | Latitude | Longitude | Initial obs. | Notes | Dilatation clean | Dilitation adjusted | Pressure data |
|---|---|---|---|---|---|---|---|---|
Long Valley | ||||||||
| Big Springs | BG | 37.7610 | -118.9440 | Jul. 2007 | | | | |
| Postpile | PO | 37.6350 | -119.0830 | Jul. 2007 | | | | |
| Motocross | MX | 37.6160 | -118.9520 | Jul. 2007 | | | | |
Parkfield | ||||||||
| Donna Lea | DL | 35.9400 | -120.4240 | Jan. 2008 | | | | |
| Vineyard Canyon | VC | 35.9220 | -120.5350 | Jan. 2008 | | | | |
| Frolich | FR | 35.9110 | -120.4870 | Jan. 2008 | | | | |
| Jack Canyon | JC | 35.7150 | -120.2060 | Dec. 2007 | | | | |
| Red Hills | RH | 35.6240 | -120.2570 | May-08 | | | | |
San Francisco Bay Area | ||||||||
| Russel Ranch | RR | 37.9200 | -122.1500 | Sept. 2006 | | | | |
| Garin | GA | 37.6500 | -122.0100 | Sept. 2006 | | | | |
| Sunol | SU | 37.6400 | -121.9400 | Aug. 2006 | | | | |
| Coyote | CY | 37.5630 | -122.0970 | Sept. 2006 | | | | |
| Mill Creek | MC | 37.5500 | -121.9000 | Jul-06 | | | | |
Southern Californa | ||||||||
| Chantry Flat | CN | 34.1960 | -118.0230 | Feb. 2007 | | | | |
| Big Dalton | BD | 34.1680 | -117.8140 | Feb. 2007 | | | | |
- DL ceased working Sept 2016
- VC ceased working Sept 2016
- FR ceased working Sept 2015
- JC ceased working Jan 2015
- RR ceased working Dec. 2014
- CN ceased working Jan 2019
- BD ceased working Aug 2014
Tensor Strainmeter
The data listed below are measures of changes in tensor strain (units of 0.001 part per million) as a function of time for instruments in California. We are providing data for two different instruments, one is a three component strainmeter made by Carnegie Dept. of Terrestial Magnetism (DTM) and the other is a three or 4 component strainmeter made by GTSM Technologies. Since these instruments have at least 3 extensometers, these data can be combined into tensor strain based upon analysis using the Earth Tides. We provide both the extensometer and the tensor strain changes. Data are provided in two modes; 1) Cleaned strain data and 2) Clean strain data adjusted for the Earth Tide and atmospheric pressure changes. Outliers due to telemetry problems, instrument visits, and etc have been removed. Offsets due to valve resets, for the Carnegie, DTM instruments, have been removed. Pressure data (not scaled to units of pressure) are also provided. Gauge data for the DTM instruments are not scaled to physical units.
For the GTSM instruments, the data are complete. These GTSM instruments are identified with a 3 letter code. None of these GTSM instruments currently work after more than 20 years of continuous operation.
For the DTM instruments, the data are complete through the end of 2019. More data exist, but have not been archived.
The ReadMe file contains the lists of offsets and data removed for analysis. In addition, there is a table listing the estimates of the amplitude and phase of the O1 and M2 tides calculated as a function of time for the strainmeter.
The format of these data are year, day-of-year, and slip in mm. If there is a fourth column, then ignore that column.
| Name | Code | Latitude | Longitude | Initial obs. | Instrument type | Notes | Pressure data | Gage data clean | Gage data adjusted | Tensor data clean | Tensor data adjusted |
|---|---|---|---|---|---|---|---|---|---|---|---|
Parkfield | |||||||||||
| Donna Lea | DLT | 35.9400 | -120.4250 | Jan. 1988 | | | | | | | |
| Frolich (2) | FLT | 35.9100 | -120.4900 | Mar. 1988 | | | | | | | |
| Eades (3) | EDT | 35.8900 | -120.4200 | Jan. 1988 | | | | | | | |
San Francisco Bay Area | |||||||||||
| Saint Vincents | SV | 38.0330 | -122.5260 | Jan. 2008 | | | | | | | |
| Ohlone | OH | 38.0070 | -122.2740 | Jan. 2008 | | | | | | | |
| Marin Headlands | MH | 37.8420 | -122.4940 | May-08 | | | | | | | |
| Chabot | CHT | 37.7430 | -122.0970 | Jun. 1993 | | | | | | | |
| Brisbane | BB | 37.6870 | -122.4100 | Apr. 2008 | | | | | | | |
| Garin (1) | GAT | 37.6500 | -122.0100 | Jan. 1993 | | | | | | | |
| Ox Mountain | OX | 37.4980 | -122.4250 | Jan. 2008 | | | | | | | |
| San Juan Bautista | SJT | 36.8370 | -121.5440 | Jan. 1984 | | | | | | | |
Southern California | |||||||||||
| Coldbrok | CBT | 34.2900 | -117.8400 | Jan-97 | | | | | | | |
| Pinon Flat (4) | PFT | 33.6200 | -116.4500 | Jan-83 | | | | | | | |
- Ceased working in Sep 1998
- Ceased working; second gage in Dec 2005
- Ceased working in Apr 2002
- Ceased working in Dec 2002