Event Number 2865

M2.9 km SE of San Ramon, CA - 2025/12/20 04:10:00 37.749 -121.949 M2.9 8.1 4 km SE of San Ramon, CA at 2025/12/20 04:10:00 UTC / 2025/12/19 20:10:00 PDT

Error Map and Stations Used to Locate Event

Errors from USGS Location and Magnitude:

EQPROC = 2.7km (1.7 mi)
HYPO2K = 3.9km (2.4 mi) Magnitude = 0.1

USGS Report:

Date       Time       Lat    Lon      Mag    Depth                Location   
-----------------------------------------------------------------------------------
2025/12/20 04:10:00  37.749 -121.949  M2.9   8.1 4 km SE of San Ramon, CA

EQPROC Summary:

2865 2025Dec20  410  0.99  37.7733 -121.9509  4.21 0.03 24.0 57.5 160  6
RE9A7 EHZ AM 00 2025Dec20  410  9.70 P ?0  47.6   0.00
GLFBZ SHZ PN 01 2025Dec20  410  8.30 P ?3  40.6  -0.21
ADUB1 SHZ PN 01 2025Dec20  410 11.55 P ?0  58.5   0.00
B057  EHZ PB -- 2025Dec20  410 11.47 P ?3  61.1  -0.53
B058  EHZ PB -- 2025Dec20  410 20.12 Pg?3 113.0   0.00
B054  EHZ PB -- 2025Dec20  410  5.70 P U0  24.0   0.00

HYPO2K Report:

 YEAR MO DA  --ORIGIN--  --LAT N-  --LON W--  DEPTH-M RMS   ERH   ERZ  XMAG1 FMAG1 PMAG GEOID-DEP
 2025-12-20  0410  1.42  37 46.902 121W57.273  4.20  0.02  0.55  8.38        2.79  2.79E    4.19
                                                                                          SOURCE
 NSTA NPHS  DMIN MODEL GAP ITR NFM NWR NWS NVR REMRKS-AVH  N.XMG-XMMAD-T   N.FMG-FMMAD-T  L F X
    6    6  23.3  Emb  160   6   1   4   0   6      -                          4  2.79 E  W W  

 XMAG2-N.XMG2-XMMAD-T-S  FMAG2-N.FMG2-FMMAD-T-S  PREF.MAG-N.PMAG-PRMAD-T DEPDAT NS ZT TYP
                                                     2.79      4  2.79 E     11  5  M CRH
 REGION=                          

 STA NET COM L CR DIST AZM  AN P/S WT   SEC (TOBS -TCAL -DLY  =RES)  WT   SR  INFO  CAL  DUR-W-FMAG-T -AMP-U-PER-W-XMAG-T DE
 B054 PB EHZ -- A 23.3 293  95  PU     5.70  4.28  4.27 0.00  0.01  1.27  W  1.000 0.00 41.0   2.71 E                        
 GLFBZPN SHZ 01 A 41.2 205  93  P  3   8.30  6.88  7.18 0.00 -0.30  0.00  W  0.000 0.00 43.0   2.86 E                        
 RE9A7AM EHZ 00 A 48.0  98  92  P      9.70  8.28  8.28 0.00  0.00  1.27  W  1.000 0.00 3.00 4 0.30XE                        
 ADUB1PN SHZ 01 A 59.3 183  92  P     11.55 10.13 10.13 0.00  0.00  1.27  W  1.000 0.00  109 1 3.78 E                        
 B057 PB EHZ -- A 60.3 298  92  P  3  11.47 10.05 10.28 0.00 -0.23  0.19  W  0.999 0.00 31.0   2.57 E                        
 B058 PB EHZ -- A113.9 162  91  P  3  20.12 18.70 19.02 0.00 -0.32  0.00  W  0.000 0.00 1.00 4                               

Event Files: December 2025