Event Number 2870

M3.5 km SW of Ridgemark, CA - 2025/12/21 20:40:49 36.786 -121.410 M3.5 7.2 5 km SW of Ridgemark, CA at 2025/12/21 20:40:49 UTC / 2025/12/21 12:40:49 PDT

Error Map and Stations Used to Locate Event

Errors from USGS Location and Magnitude:

EQPROC = 10.7km (6.6 mi)
HYPO2K = 8.2km (5.1 mi) Magnitude = 0.1

USGS Report:

Date       Time       Lat    Lon      Mag    Depth                Location   
-----------------------------------------------------------------------------------
2025/12/21 20:40:49  36.786 -121.410  M3.5   7.2 5 km SW of Ridgemark, CA

EQPROC Summary:

2870 2025Dec21 2040 49.71  36.7198 -121.4964  3.00 0.00 11.6 63.6 175  4
ATZ   SHZ PN 01 2025Dec21 2040 58.19 P ?0  45.7   0.00
ADUB1 SHZ PN 01 2025Dec21 2041  2.83 P ?3  72.5   0.09
B058  EHZ PB -- 2025Dec21 2040 52.41 P U0  11.6   0.00
B073  EHZ PB -- 2025Dec21 2041 10.46 P ?2 124.7   0.00

HYPO2K Report:

 YEAR MO DA  --ORIGIN--  --LAT N-  --LON W--  DEPTH-M RMS   ERH   ERZ  XMAG1 FMAG1 PMAG GEOID-DEP
 2025-12-21  2040 49.84  36 43.331 121W27.913  2.40  0.11  7.25 11.19        3.44  3.44E    2.39
                                                                                          SOURCE
 NSTA NPHS  DMIN MODEL GAP ITR NFM NWR NWS NVR REMRKS-AVH  N.XMG-XMMAD-T   N.FMG-FMMAD-T  L F X
    4    4  13.4  Emb  174   5   1   4   0   4      -                          3  1.71 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
                                                     3.44      3  1.71 E      8  3  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
 B058 PB EHZ -- A 13.4 310  91  PU    52.41  2.57  2.66 0.00 -0.09  1.45  W  1.000 0.00 71.0   3.18 E                        
 ATZ  PN SHZ 01 A 48.0 307  90  P     58.19  8.35  8.27 0.00  0.08  1.45  W  1.000 0.00 37.0 4 2.72XE                        
 ADUB1PN SHZ 01 A 74.2 322  90  P  3  62.83 12.99 12.52 0.00  0.47  0.36  W  0.999 0.00 98.0   3.69 E                        
 B073 PB EHZ -- A123.9 133  90  P  2  70.46 20.62 20.62 0.00  0.00  0.73  W  1.000 0.00 59.0   3.26 E                        

Event Files: December 2025