M 5.6 in United States on 16 Sep 2021 17:51 UTC

Hazard models

EQ parameters
Shakemap
Tsunami

Event summary

This earthquake is expected to have a low humanitarian impact based on the magnitude and the affected population and their vulnerability.

Earthquake Magnitude: 5.6M
Depth: 36.5 Km
Lat/Lon: 55.0291 , -156.4898
Event Date: 16 Sep 2021 17:51 UTC
16 Sep 2021 07:51 Local
Exposed Population: No people affected in 100km
Source: ALASKA EC ak021bwmmasc
Inserted at: 16 Sep 2021 18:12 UTC
INFORM Coping capacity of the alert score: 2.2 (United States)

GDACS Score

For more info on GDACS alert score click here.
  Earthquake
(Shakemap)		 GDACS score
ALASKA EC 0 0
ak021bwmmasc Scaled population (raster) 0  
  C1 shakemap -0.59  
  C2 shakemap 0.53  
  Country Vulnerability 0  
  INFORM_normalised 0.65  
Maximum expected impact using different data sources.

ShakeMap is a product of the USGS Earthquake Hazards Program in conjunction with the regional seismic networks. ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes.


Episode Timeline

IDAlertScoreDateMag, DepthMMI*Population**Tsunami risk***Delay (hh:mm)Source
1397044 0 16 Sep 2021 17:51 5.6M, 1.2km N/A No people affected (in 100km) 00:12 ALASKA EC
1397045 0 16 Sep 2021 17:51 5.6M, 5km 3.32 N/A (in MMI>=VII) 00:14 ALASKA EC
1397047 0 16 Sep 2021 17:51 5.6M, 36.5km 3.24 N/A (in MMI>=VII) 00:20 ALASKA EC
The episode that generated the alert; the next major evaluations beyond 12 hours will not trigger additional alerts.
The episode that has the last updated information.
* The max MMI detected for sources having shakemaps;
** The population detected in MMI>=7 for episode with shakemap or in a 100km radius;
*** The tsunami max height.

Exposed population

The earthquake happened in unknowed a zone. The alertlevel for this event is GREEN

Intensity Population


Shakemaps Timeline

AlertShake id #ScoreepisodeidLat/LonMagnitudeDepthMax MMIDate shake (UTC)Delay (hh:mm) 
1 0 1397047 55.234/-156.637 5.6 1.2 3.324 16 Sep 2021 18:07 00:15 (new episode)
2 0 1397047 55.029/-156.49 5.6 36.5 3.244 16 Sep 2021 18:46 00:54 (upd of #1)
3 0 1397047 55.029/-156.49 5.6 36.5 3.244 16 Sep 2021 19:21 01:30 (upd of #2)
4 0 1397047 55.029/-156.49 5.6 36.5 3.244 16 Sep 2021 19:56 02:04 (upd of #3)
5 0 1397047 55.029/-156.49 5.6 36.5 3.244 16 Sep 2021 23:07 05:16 (upd of #4)
6 0 1397047 55.029/-156.49 5.6 36.5 3.244 17 Sep 2021 17:58 1d 00:06 (upd of #5)

Affected Provinces



Critical infrastructure

Airports, ports, nuclear plants and hydrodams at risk, if affected, are listed below.

More information

For a full list of available products related to this event, please refer to the GDACS Resources page.