Event Number 2819

M2.8 km ESE of Alum Rock, CA - 2025/10/18 09:16:41 37.346 -121.708 M2.8 7.5 11 km ESE of Alum Rock, CA at 2025/10/18 09:16:41 UTC / 2025/10/18 02:16:41 PDT

Error Map and Stations Used to Locate Event


   

   





Errors from USGS Location and Magnitude:

EQPROC =  4.5km (2.8 mi)

HYPO2K =  5.4km (3.3 mi)
Magnitude = -0.2


USGS Report:


Date       Time       Lat    Lon      Mag    Depth                Location   
-----------------------------------------------------------------------------------
2025/10/18 09:16:41  37.346 -121.708  M2.8   7.5 11 km ESE of Alum Rock, CA



EQPROC Summary:


2819 2025Oct18  916 41.96  37.3536 -121.7583  8.02 0.15 36.1 75.5 107  8
LCGPZ SHZ PN 01 2025Oct18  916 50.39 P ?0  45.5   0.04
GLFBZ SHZ PN 01 2025Oct18  916 48.76 P U0  36.1  -0.02
ATZ   SHZ PN 01 2025Oct18  916 50.02 P U0  43.5  -0.00
RE9A7 EHZ AM 00 2025Oct18  916 51.47 P D3  50.3   0.31
B057  EHZ PB -- 2025Oct18  916 59.22 P D2 103.3  -0.13
B054  EHZ PB -- 2025Oct18  916 54.27 P U0  68.4   0.04
B073  EHZ PB -- 2025Oct18  917 11.25 PnU3 193.2   0.43
B058  EHZ PB -- 2025Oct18  916 52.69 P D0  63.5  -0.71



HYPO2K Report:


 YEAR MO DA  --ORIGIN--  --LAT N-  --LON W--  DEPTH-M RMS   ERH   ERZ  XMAG1 FMAG1 PMAG GEOID-DEP
 2025-10-18  0916 41.99  37 20.073 121W46.070 19.44  0.19  2.72  1.71        3.03  3.03E   19.44
                                                                                          SOURCE
 NSTA NPHS  DMIN MODEL GAP ITR NFM NWR NWS NVR REMRKS-AVH  N.XMG-XMMAD-T   N.FMG-FMMAD-T  L F X
    8    8  36.1  Emb  106   5   7   8   0   8                                 7  1.84 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
                                                     3.03      7  1.84 E      4  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
 GLFBZPN SHZ 01 A 36.1 290 116  PU    48.76  6.77  7.01 0.00 -0.24  1.35  W  0.417 0.00 33.0   2.71 E                        
 ATZ  PN SHZ 01 A 41.2 197 113  PU    50.02  8.03  7.77 0.00  0.26  1.35  W  0.595 0.00  123   4.01 E                        
 LCGPZPN SHZ 01 A 45.6 294 111  P     50.39  8.40  8.42 0.00 -0.02  1.35  W  0.385 0.00 33.0   2.74 E                        
 RE9A7AM EHZ 00 A 52.5  36 108  PD 3  51.47  9.48  9.47 0.00  0.01  0.34  W  0.959 0.00 59.0   3.31 E                        
 B058 PB EHZ -- A 61.7 164  66  PD    52.69 10.70 10.89 0.00 -0.19  1.35  W  0.751 0.00 33.0   2.76 E                        
 B054 PB EHZ -- A 69.7 327  66  PU    54.27 12.28 12.09 0.00  0.19  1.35  W  0.657 0.00 37.0   2.88 E                        
 B057 PB EHZ -- A104.2 318  66  PD 2  59.22 17.23 17.24 0.00 -0.01  0.67  W  0.190 0.00 33.0 1 2.81 E                        
 B073 PB EHZ -- A192.8 142  48  PU 3  71.25 29.26 29.51 0.00 -0.25  0.25  W  0.042 0.00 1.00 4                               



Event Files: October 2025