M 4.6 - 23km NNE of Barstow, CA

  • 2020-01-25 03:03:34 (UTC)
  • 35.098°N 116.970°W
  • 3.1 km depth

ShakeAlert ®

Contributed by EW last updated 2020-01-25 03:07:58 (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: Confirming earthquake alert at 2020-01-25 03:03:35.0 UTC.

Earthquake

Title
M 4.5 - 14.2 mi N of Barstow
Time
2020-01-25 03:03:35.000 (UTC)
ShakeAlert Event ID
ew7118

Summary Report

ShakeAlert Messages Issued (after origin time):
Initial: 6.7 s
Final: 20.1 s
ShakeAlert System Magnitude Estimates:
Initial: M 5.1
Final: M 4.9
ANSS report: 127 s after origin, M4.5
ShakeAlert System Location Accuracy:
Initial: 1 km (1 mi) W
Final: 0 km (0 mi) E
Wireless Emergency Alert:
WEA alerts are distributed to the MMI 4+ area if ShakeAlert Peak M >= 5.0
Number of Stations Reporting:
0 within 10km of epicenter
31 within 100km of epicenter
43 used in final ShakeAlert update
Nearby Cities
CityDistanceTime*Shaking (MMI**)
Barstow 23 km (14 mi) ~0.0 s Light (IV)
Ridgecrest 86 km (54 mi) Weak (III)
San Bernardino 114 km (71 mi) Weak (II)
Los Angeles 165 km (102 mi) Weak (II)

Radius shaken before Message release: 24 km (15 mi)

  • Marker
    50 km
    50 mi
    Figure 1. ShakeAlert initial earthquake location (black dot). Star is regional network epicenter. MMI 4 polygon is the estimated initial alert area. Red circle is front of peak shaking when the alert was released. Shaking takes 10 s to expand from circle to circle.
  • Marker
    50 km
    50 mi
    Figure 2. Polygons show shaking intensity contours for the final ShakeAlert. Shaking of intensity 3 or less is often not felt. Star shows the regional network 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.