Event Number 2864

M3.8 km SE of San Ramon, CA - 2025/12/20 03:56:09 37.748 -121.942 M3.8 9.9 5 km SE of San Ramon, CA at 2025/12/20 03:56:09 UTC / 2025/12/19 19:56:09 PDT

Error Map and Stations Used to Locate Event

Errors from USGS Location and Magnitude:

EQPROC = 7.3km (4.5 mi)
HYPO2K = 9.5km (5.9 mi) Magnitude = 0.1

USGS Report:

Date       Time       Lat    Lon      Mag    Depth                Location   
-----------------------------------------------------------------------------------
2025/12/20 03:56:09  37.748 -121.942  M3.8   9.9 5 km SE of San Ramon, CA

EQPROC Summary:

2864 2025Dec20  356 10.97  37.7293 -122.0215  7.63 0.12 21.4 55.9 139  9
LCGPZ SHZ PN 01 2025Dec20  356 17.34 P ?3  32.3   0.21
GLFBZ SHZ PN 01 2025Dec20  356 17.36 P D0  33.6  -0.00
RE9A7 EHZ AM 00 2025Dec20  356 19.76 P D3  53.4  -0.93
ADUB1 SHZ PN 01 2025Dec20  356 20.74 P D0  53.7  -0.00
ATZ   SHZ PN 01 2025Dec20  356 25.59 P ?0  84.2  -0.00
B058  EHZ PB -- 2025Dec20  356 28.25 PnD2 110.4  -1.07
B054  EHZ PB -- 2025Dec20  356 15.32 P U0  21.4  -0.00
B057  EHZ PB -- 2025Dec20  356 21.06 P U0  58.3  -0.47
B073  EHZ PB -- 2025Dec20  356 46.70 PnU3 240.7   0.78

HYPO2K Report:

 YEAR MO DA  --ORIGIN--  --LAT N-  --LON W--  DEPTH-M RMS   ERH   ERZ  XMAG1 FMAG1 PMAG GEOID-DEP
 2025-12-20  0356 11.33  37 43.849 122W 2.852 10.79  0.02  1.55  2.30        3.69  3.69E   10.78
                                                                                          SOURCE
 NSTA NPHS  DMIN MODEL GAP ITR NFM NWR NWS NVR REMRKS-AVH  N.XMG-XMMAD-T   N.FMG-FMMAD-T  L F X
    9    9  19.6  Emb  212  11   7   5   0   9                                 7  2.36 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
                                                     3.69      7  2.36 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 19.6 318 115  PU    15.32  3.99  3.99 0.00 -0.00  1.19  W  0.993 0.00  101   3.57 E                        
 LCGPZPN SHZ 01 A 31.1 214 106  P  3  17.34  6.01  5.73 0.00  0.28  0.04  W  0.002 0.00  121   3.81 E                        
 GLFBZPN SHZ 01 A 33.0 197 105  PD    17.36  6.03  6.04 0.00 -0.01  1.19  W  0.977 0.00 97.0   3.61 E                        
 ADUB1PN SHZ 01 A 54.0 173  99  PD    20.74  9.41  9.37 0.00  0.04  1.19  W  0.425 0.00  217 1 4.45 E                        
 RE9A7AM EHZ 00 A 55.6  91  99  PD 3  19.76  8.43  9.63 0.00 -1.20* 0.00  W  0.000 0.00 59.0 4 3.19XE                        
 B057 PB EHZ -- A 56.2 306  99  PU    21.06  9.73  9.72 0.00  0.01  1.19  W  0.991 0.00 79.0 1 3.48 E                        
 ATZ  PN SHZ 01 A 84.6 170  96  P     25.59 14.26 14.29 0.00 -0.03  1.19  W  0.610 0.00  300   4.79 E                        
 B058 PB EHZ -- A111.3 158  94  PD 2  28.25 16.92 18.63 0.00 -1.71* 0.00  W  0.000 0.00 75.0   3.49 E                        
 B073 PB EHZ -- A242.8 144  48  PU 3  46.70 35.37 36.55 0.00 -1.18* 0.00  W  0.000 0.00 1.00 4                               

Event Files: December 2025