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 ®
Catalog | Time |
---|---|
CI | 03:07:58 |
- 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
City | Distance | Time* | 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)
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. 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
- * Time — Time from message release to predicted S-wave arrival at the location. "—" for weak or imperceptable shaking.
- ** MMI — Modified Mercalli Intensity: a numeric shaking severity scale
- *** For earthquakes deeper than ~15 km, the ShakeAlert Message may be available before peak shaking reaches the surface.