Event Number 2820

M2.3 km ESE of Alum Rock, CA - 2025/10/18 09:23:17 37.344 -121.704 M2.3 7.7 11 km ESE of Alum Rock, CA at 2025/10/18 09:23:17 UTC / 2025/10/18 02:23:17 PDT

Error Map and Stations Used to Locate Event

Errors from USGS Location and Magnitude:

EQPROC = 5.3km (3.3 mi)
HYPO2K = 6.4km (4.0 mi) Magnitude = -0.4

USGS Report:

Date       Time       Lat    Lon      Mag    Depth                Location   
-----------------------------------------------------------------------------------
2025/10/18 09:23:17  37.344 -121.704  M2.3   7.7 11 km ESE of Alum Rock, CA

EQPROC Summary:

2820 2025Oct18  923 18.30  37.3465 -121.7634 10.79 0.07 35.9 59.9 199  6
GLFBZ SHZ PN 01 2025Oct18  923 25.08 P ?1  35.9  -0.09
LCGPZ SHZ PN 01 2025Oct18  923 26.73 P U0  45.3  -0.00
ATZ   SHZ PN 01 2025Oct18  923 26.28 P ?0  42.6  -0.00
B054  EHZ PB -- 2025Oct18  923 30.41 P D2  68.8  -0.00
B058  EHZ PB -- 2025Oct18  923 28.68 P D2  62.9  -0.86
B057  EHZ PB -- 2025Oct18  923 35.43 P U1 103.6  -0.00

HYPO2K Report:

 YEAR MO DA  --ORIGIN--  --LAT N-  --LON W--  DEPTH-M RMS   ERH   ERZ  XMAG1 FMAG1 PMAG GEOID-DEP
 2025-10-18  0923 17.53  37 23.133 121W39.960 11.64  0.08  2.03  9.58        2.65  2.65E   11.63
                                                                                          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  43.4  Emb  220   8   4   5   0   6      -                          3  1.32 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
                                                     2.65      3  1.32 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
 GLFBZPN SHZ 01 A 43.4 279 103  P  1  25.08  7.55  7.71 0.00 -0.16  0.94  W  0.765 0.00 15.0   1.87 E                        
 ATZ  PN SHZ 01 A 49.7 205 101  P     26.28  8.75  8.71 0.00  0.04  1.25  W  0.933 0.00 74.0   3.42 E                        
 LCGPZPN SHZ 01 A 52.4 284 100  PU    26.73  9.20  9.13 0.00  0.07  1.25  W  0.529 0.00 17.0   2.00 E                        
 B058 PB EHZ -- A 65.5 173  98  PD 2  28.68 11.15 11.23 0.00 -0.08  0.62  W  0.874 0.00 5.00 4 0.84XE                        
 B054 PB EHZ -- A 70.7 319  97  PD 2  30.41 12.88 12.07 0.00  0.81* 0.00  W  0.000 0.00 7.00 4 1.17XE                        
 B057 PB EHZ -- A106.6 313  95  PU 1  35.43 17.90 17.88 0.00  0.02  0.94  W  0.897 0.00 5.00 4 0.88XE                        

Event Files: October 2025