REAL-TIME DOUBLE-DIFFERENCE EARTHQUAKE LOCATIONS FOR NORTHERN CALIFORNIA


Last updated on Fri Jul 11 06:52:17 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
75208142 2025/07/11 04:52:53.710 37.66980 -121.42530 9.110 1.30 - - 3F.0 tech 3D gE usgs
75208047 2025/07/10 20:57:36.850 37.06335 -121.50234 7.052 0.90 1 1.93 3F.1 tech 3D gE usgs
75208002 2025/07/10 17:18:4.510 37.68559 -118.93515 1.516 0.40 2 2.88 3F.1 tech 3D gE usgs LVC
75207902 2025/07/10 10:16:49.660 37.19776 -119.76738 17.746 1.80 2 0.40 3F.1 tech 3D gE usgs
75207882 2025/07/10 08:47:50.600 37.52068 -119.41285 11.979 1.10 2 0.51 3F.1 tech 3D gE usgs
75207787 2025/07/10 04:18:58.460 37.52543 -118.98114 3.720 0.50 2 0.46 3F.1 tech 3D gE usgs LVC
75207767 2025/07/10 03:12:40.590 38.10592 -118.84764 6.950 1.30 2 0.64 3F.1 tech 3D gE usgs LVC
75207757 2025/07/10 02:47:50.760 37.08950 -119.71520 30.210 2.20 - - 4F.0 tech 3D gE usgs
75207747 2025/07/10 01:50:10.910 36.48180 -121.02750 7.600 1.10 - - 2F.0 tech 3D gE usgs
75207707 2025/07/09 23:57:54.770 37.32716 -122.13113 5.542 1.00 2 0.79 2F.1 tech 3D gE usgs
75207657 2025/07/09 21:41:42.760 35.97120 -120.52950 5.840 0.60 - - 2F.0 tech 3D gE usgs
75207597 2025/07/09 19:06:36.630 40.32020 -124.79900 15.440 2.10 - - 3F.0 tech 3D gE usgs MTJ
75207542 2025/07/09 15:38:38.450 40.28320 -124.50850 19.670 2.90 - - 4F.0 tech 3D gE usgs MTJ
75207522 2025/07/09 14:39:27.470 37.27616 -121.65405 5.761 1.00 1 0.70 6F.1 tech 3D gE usgs CAL
75207502 2025/07/09 13:26:45.280 41.37530 -122.11680 5.810 1.30 - - 3F.0 tech 3D gE usgs
75207497 2025/07/09 13:20:25.120 36.67637 -121.31380 4.889 0.90 1 3.29 2F.1 tech 3D gE usgs
75207457 2025/07/09 11:59:10.550 36.61513 -121.07538 11.486 1.10 2 2.14 4F.1 tech 3D gE usgs
75207442 2025/07/09 10:21:27.650 37.04998 -121.50351 9.106 0.70 1 3.07 3F.1 tech 3D gE usgs
75207382 2025/07/09 06:02:53.780 36.83810 -121.56281 6.006 0.60 1 0.56 3F.1 tech 3D gE usgs
75207357 2025/07/09 05:14:51.020 37.38096 -118.74220 4.325 0.90 2 0.41 5F.1 tech 3D gE usgs LVC

Events last re/processed:
75208142 2025/07/11 04:52:53.710 37.66980 -121.42530 9.110 1.30 - - 3F.0 tech 3D gE usgs
75207597 2025/07/09 19:06:36.630 40.32020 -124.79900 15.440 2.10 - - 3F.0 tech 3D gE usgs MTJ
75207502 2025/07/09 13:26:45.280 41.37530 -122.11680 5.810 1.30 - - 3F.0 tech 3D gE usgs
75207442 2025/07/09 10:21:27.650 37.04998 -121.50351 9.106 0.70 1 3.07 3F.1 tech 3D gE usgs
75207247 2025/07/08 21:41:45.020 37.32878 -122.12887 5.515 0.90 1 0.77 2F.1 tech 3D gE usgs
75207232 2025/07/08 21:18:3.850 37.32683 -122.13332 5.473 1.30 1 0.97 2F.1 tech 3D gE usgs
75207202 2025/07/08 20:54:17.620 37.10419 -121.55828 6.326 0.70 2 2.24 3F.1 tech 3D gE usgs CAL
75207152 2025/07/08 18:19:9.530 38.99020 -123.31270 5.880 1.10 - - 2F.0 tech 3D gE usgs
75208047 2025/07/10 20:57:36.850 37.06335 -121.50234 7.052 0.90 1 1.93 3F.1 tech 3D gE usgs
75208002 2025/07/10 17:18:4.510 37.68559 -118.93515 1.516 0.40 2 2.88 3F.1 tech 3D gE usgs LVC


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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.