M 3.9 - 5 km WNW of Dublin, CA

  • 2025-03-18 02:46:33 (UTC)
  • 37.707°N 121.994°W
  • 11.0 km depth

ShakeAlert ®

 Contributed by EW last updated 2025-03-18 02:51:37 (UTC)
  • The data below are the most preferred data available
  • The data below have been reviewed by a scientist

Post ShakeAlert ® Message Summary

This report provides an overview of the performance of the ShakeAlert system during this event.

Reviewed: ShakeAlert Message issued at 2025-03-18 02:46:38.1 UTC.

Earthquake

Title
M 4.0 - 2.9 mi W of Dublin
Time
2025-03-18 02:46:33.300 (UTC)
ShakeAlert Event ID
ew1742265990

Summary Report

ShakeAlert Messages Issued (after origin time):
Initial: 4.8 s
Peak: 9.2 s
Final: 9.2 s
ShakeAlert System Magnitude Estimates:
Initial: M 3.8
Peak: M 4.2
Final: M 4.2
ANSS report: 196 s after origin, M4.0
ShakeAlert System Location Accuracy:
Initial: 1 km (1 mi) ENE
Peak: 1 km (0 mi) E
Final: 1 km (0 mi) E
Wireless Emergency Alert:
Magnitude below threshold for WEA system.
WEA alerts are distributed to the MMI 4+ area if ShakeAlert Peak M >= 5.0
Number of Stations Reporting:
3 within 10km of epicenter
101 within 100km of epicenter
60 used in final ShakeAlert update
Nearby Cities
CityDistanceTime*Shaking (MMI**)
Dublin 5 km (3 mi) ~0.0 s Light (IV)
Hayward 9 km (6 mi) — Weak (III)
Oakland 27 km (17 mi) — Weak (II)
San Francisco 39 km (24 mi) — Not felt (I)

Radius shaken before Message release: 12 km (8 mi)

  • Marker
    Initial MMI 3
    0.0 s
    10.0 s
    20.0 s
    30 km
    20 mi
    Figure 1. ShakeAlert initial earthquake location (black dot). Star is ANSS earthquake epicenter. Polygon approximates the outer range for felt ground motion. If shown, red circle is front of peak shaking when the Message was released***. Shaking takes 10 s to expand from circle to circle.
  • Marker
    MMI 3
    MMI 4
    30 km
    20 mi
    Figure 2. Polygons show the largest contours of estimated shaking intensity. Shaking of MMI 3 or less is often not felt. Star shows the ANSS earthquake epicenter.

Footnotes

  1. * Time — Time from message release to predicted S-wave arrival at the location. "—" for weak or imperceptable shaking.
  2. ** MMI — Modified Mercalli Intensity: a numeric shaking severity scale
  3. *** For earthquakes deeper than ~15 km, the ShakeAlert Message may be available before peak shaking reaches the surface.