REAL-TIME DOUBLE-DIFFERENCE EARTHQUAKE LOCATIONS FOR NORTHERN CALIFORNIA


Last updated on Tue Feb 18 16:08:44 UTC 2025    [DD-RT Version 2.0 | Contact: felixw@ldeo.columbia.edu]

IMPORTANT NOTE: A new comprehensive update of the Northern CA real-time double-difference catalog is available at https://nocaldd.ldeo.columbia.edu. The update includes a new base catalog (1984-2021) with hypocenter depths relative to the Geoid, consistent with USGS routine monitoring, and other improvements to the DD-RT system. We will retire this website soon.

How it works:
This website displays automatic near-real-time double-difference (DD-RT) hypocenter locations for earthquakes recorded in northern California and routinely processed at the Northern California Seismic Network (NCSN). The DD-RT process relocates new earthquakes relative to a high-resolution DD catalog of background seismicity, NCAeqDD, by using differential times between the new event and its neighboring (reference) events in the DD catalog. Routinely determined parametric data of new events, such as phase picks and hypocentral information, are automatically sent to LDEO by the NCSN and waveforms are accessed from the real-time DART server at the Northern California Earthquake Data Center (NCEDC) in Berkeley. Data associated with the reference events are accessed from a locally stored copy of the entire Northern CA seismic archive. See Waldhauser (BSSA, 2009) for more information. This web site is updated every 5 minutes.

Faults of special interest:
Hayward Fault | Calaveras Fault | Parkfield

Earthquakes of special interest:
2023-08-10 M4.3 Parkfield
2022-10-25 M5.0 Calaveras
2021-07-08 M6.0 SmithValley
2020-08-19 M4.0 Willits
2015-08-17 M4.0 Fremont
2014-08-24 M6.0 South Napa
2012-10-21 M5.3 King City
2012-08-06 M4.4 Parkfield
2011-10-20 M4.0 Berkeley

Archived DDRT solutions:
2012: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2013: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2014: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2015: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2016: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2017: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2018: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2019: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2020: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2021: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2022: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2023: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2024: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2025: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

Downloads:
Download the real-time double-difference catalog, Jan 2012 - present, here .
Download the double-difference base catalog, 1984-2011, here.
Search either catalog here.

Most recent events:
Events in queue: 0
Q: Quality of DDRT solution; DX: Shift between DD and network location (km); V: version (CISN.DD)
If Q='-': No DDRT solution computed.
tech: link to technical information; 3D: link to 3D viewer; gE: link to google Earth viewer
Faults/regions of special interest:
HAY = Hayward Fault; CAL = Calaveras Fault; PKF = Parkfield; LVC = Long Valley;
GGF = Geysers Geothermal Field; MTJ = Mendocino TJ

EVENT ID DATE TIME (UTC) LAT LON DEPTH ML Q DX V
75135647 2025/02/18 11:04:8.400 38.82891 -122.82130 1.889 0.40 1 0.45 2F.1 tech 3D gE usgs GGF
75135597 2025/02/18 09:04:50.010 37.33975 -122.23387 8.847 2.50 1 0.26 2F.1 tech 3D gE usgs
75135547 2025/02/18 07:55:1.870 38.83736 -122.81712 2.418 0.40 1 0.31 2F.1 tech 3D gE usgs GGF
75135537 2025/02/18 07:49:45.310 40.43100 -125.15670 10.000 3.10 - - 2F.0 tech 3D gE usgs MTJ
75135492 2025/02/18 05:55:50.970 38.80109 -122.77838 3.039 0.50 2 1.45 2F.1 tech 3D gE usgs GGF
75135432 2025/02/18 02:05:58.500 38.81860 -122.82359 3.040 0.20 1 0.70 2F.1 tech 3D gE usgs GGF
75135387 2025/02/17 23:31:48.030 38.80045 -122.77766 4.674 0.30 1 0.90 2F.1 tech 3D gE usgs GGF
75135367 2025/02/17 22:59:3.160 38.84058 -122.82403 2.477 0.40 2 0.20 2F.1 tech 3D gE usgs GGF
75135272 2025/02/17 19:20:32.470 38.81894 -122.82273 3.123 0.30 1 0.75 2F.1 tech 3D gE usgs GGF
75135182 2025/02/17 15:11:46.400 38.81757 -122.82419 3.316 -0.10 1 0.84 2F.1 tech 3D gE usgs GGF
75135142 2025/02/17 11:46:15.000 38.82836 -122.85952 3.174 0.30 1 0.58 2F.1 tech 3D gE usgs GGF
75135097 2025/02/17 09:25:50.860 38.79391 -122.75129 2.164 0.40 1 0.69 2F.1 tech 3D gE usgs GGF
75135007 2025/02/17 03:51:15.480 38.81926 -122.82312 3.053 0.20 2 0.30 2F.1 tech 3D gE usgs GGF
75134862 2025/02/16 22:04:43.710 38.53435 -122.44720 10.443 1.70 1 0.92 2F.1 tech 3D gE usgs
75134827 2025/02/16 21:06:6.110 38.81918 -122.76394 2.477 0.40 1 0.89 2F.1 tech 3D gE usgs GGF
75134807 2025/02/16 20:51:3.290 35.82805 -120.37735 6.755 0.70 2 1.33 2F.1 tech 3D gE usgs PKF
75134797 2025/02/16 20:33:42.780 38.81811 -122.82266 3.345 -0.20 1 0.84 2F.1 tech 3D gE usgs GGF
75134757 2025/02/16 19:31:32.260 38.55681 -122.67485 4.867 1.10 1 0.21 2F.1 tech 3D gE usgs
75134747 2025/02/16 19:17:26.780 36.07444 -120.20371 8.196 1.10 1 0.95 3F.1 tech 3D gE usgs
75134717 2025/02/16 17:58:49.520 36.08026 -120.18473 10.286 1.00 1 1.40 3F.1 tech 3D gE usgs

Events last re/processed:
75132742 2025/02/13 09:09:16.020 37.63315 -122.48294 7.959 1.60 2 0.25 2F.1 tech 3D gE usgs
75135647 2025/02/18 11:04:8.400 38.82891 -122.82130 1.889 0.40 1 0.45 2F.1 tech 3D gE usgs GGF
75134172 2025/02/15 20:15:22.400 36.03220 -120.60320 -0.610 0.90 - - 3F.0 tech 3D gE usgs
75135597 2025/02/18 09:04:50.010 37.33975 -122.23387 8.847 2.50 1 0.26 2F.1 tech 3D gE usgs
75133612 2025/02/14 23:32:49.520 38.82220 -122.84587 3.306 0.80 1 1.11 2F.1 tech 3D gE usgs GGF
75135547 2025/02/18 07:55:1.870 38.83736 -122.81712 2.418 0.40 1 0.31 2F.1 tech 3D gE usgs GGF
75135492 2025/02/18 05:55:50.970 38.80109 -122.77838 3.039 0.50 2 1.45 2F.1 tech 3D gE usgs GGF
75135432 2025/02/18 02:05:58.500 38.81860 -122.82359 3.040 0.20 1 0.70 2F.1 tech 3D gE usgs GGF
75135387 2025/02/17 23:31:48.030 38.80045 -122.77766 4.674 0.30 1 0.90 2F.1 tech 3D gE usgs GGF
75135367 2025/02/17 22:59:3.160 38.84058 -122.82403 2.477 0.40 2 0.20 2F.1 tech 3D gE usgs GGF


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Data sources: U.S. Geological Survey, Menlo Park; University of California, Berkeley; California Institute of Technology; University of Nevada, Reno; California Division of Water Resources; University of Utah; University of Southern California. Real-time data from the Northern California Seismic Network (NCSN) (parametric) and the Northern California Earthquake Data Center (NCEDC) (waveforms).
Project funded by USGS under its NEHRP program (06HQGR0054,08HQGR0043).
Website developed and maintained by Felix Waldhauser and Ben Engebreth at LDEO, Columbia University.