Real-Time Double-Difference Earthquake Catalog for Northern California

Last updated on Mon Sep 14 21:26:05 UTC 2026 ( Mon Sep 14 17:26:05 EDT 2026 )

IMPORTANT CHANGE NOTE:
This is a comprehensive update of the previous DD-RT system for Northern California. Main changes are: (1) New DD base catalog with events from 1984-2021. (2) All earthquake depths now with respect to geoid (consistent with USGS locations).

About:
This website displays double-difference hypocenter locations computed in real-time (DD-RT) for earthquakes recorded at the Northern California Seismic Network (NCSN). New earthquakes are automatically cross-correlated and relocated relative to a high-resolution base catalog (1984-2021). For more details see here. This site is updated every 5 minutes.

Faults of interest:
Hayward | Calaveras | SAF Parkfield

Earthquakes of interest:
2023-08-10 M4.3 Parkfield
2025-01-10 M3.6 San Francisco

Archived DDRT solutions:
2022: 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12
2023: 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12
2024: 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12
2025: 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12
2026: 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12

Downloads:
DD real-time catalog, Jan 2022 - present
DD base catalog, 1984-2021
Search either catalog here.

Most recent events (events in queue = 0):

Q: Solution quality DX: Shift between DD and network location (km); V: version (CISN.DD)
If Q='-': No DDRT solution computed.
tech: technical information; 3D: 3D viewer; waves: wave plots; USGS: USGS event page
Faults/regions of interest:
HAY = Hayward F; CAL = Calaveras F; PKF = Parkfield; LVC = Long Valley
GGF = Geysers Geothermal Field; MTJ = Mendocino Triple Junction

ID DATE TIME (UTC) LAT LON DEPTH ML Q DX V
75435767 2026/09/14 20:46:18.610 38.81952 -122.81186 3.473 0.60 1 0.30 0A.3 tech 3D waves usgs GGF
75435737 2026/09/14 20:12:20.110 38.84257 -122.83798 1.440 0.80 1 0.37 0A.3 tech 3D waves usgs GGF
75435722 2026/09/14 19:48:2.090 38.83109 -122.86842 3.007 0.90 2 0.09 0A.3 tech 3D waves usgs GGF
75435702 2026/09/14 19:17:24.760 38.80381 -122.77780 3.451 0.70 2 0.44 0A.3 tech 3D waves usgs GGF
75435687 2026/09/14 18:23:30.440 36.91255 -121.25389 8.556 1.10 2 1.62 0A.3 tech 3D waves usgs
75435637 2026/09/14 15:58:53.490 38.82321 -122.81182 3.902 0.80 2 0.15 0A.3 tech 3D waves usgs GGF
75435632 2026/09/14 15:55:4.450 38.82349 -122.79500 3.046 0.80 1 0.34 0A.3 tech 3D waves usgs GGF
75435627 2026/09/14 15:44:30.330 36.00880 -120.57470 4.380 0.50 - - 0A.0 tech 3D waves usgs PKF
75435622 2026/09/14 15:34:43.660 38.78247 -122.76890 3.595 0.80 2 0.30 0A.3 tech 3D waves usgs GGF
75435617 2026/09/14 15:17:42.090 38.08092 -122.19985 6.231 1.50 1 1.48 0A.3 tech 3D waves usgs
75435612 2026/09/14 15:15:10.810 38.79535 -122.76328 1.030 0.30 1 0.14 0A.3 tech 3D waves usgs GGF
75435602 2026/09/14 15:10:0.410 38.78746 -122.93542 2.764 1.10 1 0.33 0A.3 tech 3D waves usgs
75435582 2026/09/14 14:47:22.850 38.83901 -122.79307 2.402 1.00 1 0.08 0A.3 tech 3D waves usgs GGF
75435577 2026/09/14 14:33:42.730 38.83700 -122.79352 2.192 0.70 2 0.12 0A.3 tech 3D waves usgs GGF
75435572 2026/09/14 14:20:52.780 38.83052 -122.81694 1.623 0.60 2 0.04 0A.3 tech 3D waves usgs GGF
75435562 2026/09/14 13:50:13.290 38.85089 -122.84616 1.725 0.90 2 0.40 0A.3 tech 3D waves usgs GGF
75435552 2026/09/14 13:47:9.420 37.86568 -121.81443 13.199 1.50 1 0.31 0A.3 tech 3D waves usgs
75435557 2026/09/14 13:47:28.560 37.86546 -121.80788 13.906 3.00 1 3.19 2A.3 tech 3D waves usgs
75435542 2026/09/14 12:34:49.680 38.81383 -122.81458 3.070 1.00 1 0.42 0A.3 tech 3D waves usgs GGF
75435532 2026/09/14 12:14:33.680 38.80067 -122.82048 3.202 1.10 2 0.34 0A.3 tech 3D waves usgs GGF

Events last processed:
75430102 2026/09/05 09:16:1.500 38.78451 -122.72986 1.797 0.50 1 0.15 2F.3 tech 3D waves usgs GGF
75430097 2026/09/05 08:58:3.510 36.69521 -121.34854 8.992 1.30 1 3.19 2F.3 tech 3D waves usgs
75435767 2026/09/14 20:46:18.610 38.81952 -122.81186 3.473 0.60 1 0.30 0A.3 tech 3D waves usgs GGF
75430077 2026/09/05 08:23:25.890 38.41675 -122.68909 6.681 1.40 1 1.20 2F.3 tech 3D waves usgs
75430032 2026/09/05 04:35:31.520 37.89820 -121.74553 15.982 1.70 2 3.67 2F.3 tech 3D waves usgs
75435737 2026/09/14 20:12:20.110 38.84257 -122.83798 1.440 0.80 1 0.37 0A.3 tech 3D waves usgs GGF
75429992 2026/09/05 03:04:21.510 40.28719 -120.42266 2.518 2.40 2 0.51 2F.3 tech 3D waves usgs
75429867 2026/09/04 22:07:37.460 37.11102 -121.49201 10.682 0.60 2 1.06 3F.3 tech 3D waves usgs
75429822 2026/09/04 20:58:36.550 37.11316 -121.51836 6.500 0.50 2 1.21 3F.3 tech 3D waves usgs CAL
75429567 2026/09/04 08:51:19.780 35.47616 -120.75676 3.706 1.10 1 2.46 2F.3 tech 3D waves usgs



____________________________________________________________________________________________________
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-NEHRP grants 06HQGR0054, 08HQGR0043, G09AP00018, G10AC00040, G20AP00025.
Website developed and maintained by Felix Waldhauser and Ben Engebreth at LDEO, Columbia University.
[DD-RT Version 3.0.ncsn | Contact:  felixw@ldeo.columbia.edu]