M 8.2 Earthquake and Tsunami (2.6 m) in United States on 29 Jul 2021 06:15 UTC

Event summary

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

Earthquake Magnitude: 8.2M
Depth: 32.2 Km
Event Date: 29 Jul 2021 06:15 UTC
28 Jul 2021 19:15 Local
Exposed Population: About 1000 people in MMI VII
No people within 100km
Source: ALASKA EC ak0219neiszm
Inserted at: 29 Jul 2021 07:56 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)
Tsunami GDACS score
ALASKA EC 0.2 1.8 1.8
ak0219neiszm Scaled population (raster) 1.91 Max wave alert 0m  
  C1 shakemap -0.59 Max wave realtime 2.63m  
  C2 shakemap 0.53      
  Country Vulnerability 0      
  INFORM_normalised 0.65      
Maximum expected impact using different data sources.
Click on image to zoom it.

Episode Timeline

IDAlertScoreDateMag, DepthMMI*Population**Tsunami risk***Delay (hh:mm)Source
1387963 0.2 29 Jul 2021 06:15 7.2M, 35km N/A No people affected (in 100km) 0.3m (at 00:54) 00:08 ALASKA EC
1387964 0.5 29 Jul 2021 06:15 7.3M, 3.4km 5.28 less than 100 (in MMI>=VII) 0.5m (at 01:06) 00:19 ALASKA EC
1387970 0.6 29 Jul 2021 06:15 7.3M, 5.5km N/A No people affected (in 100km) 0.6m (at 00:54) 00:24 ALASKA EC
1387980 1.7 29 Jul 2021 06:15 8.2M, 46.66km 6.42 less than 100 (in MMI>=VII) 2.4m (at 00:50) 00:35 NEIC
1388004 1.8 29 Jul 2021 06:15 8.2M, 32.2km 7.55 1 thousand (in MMI>=VII) 2.6m (at 00:50) 01:40 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.

Tsunami affected locations

The maximum Wave height is  2.6m in Mitrofania, United States. This height is estimated for 29-Jul-2021 07:05:83.

Alert Date (UTC) Name Country Wave height (m)
29-Jul-2021 07:05:83 Mitrofania United States  2.6
29-Jul-2021 08:34:41 Perryville United States  2.3
29-Jul-2021 07:43:97 Village United States  1.3
29-Jul-2021 10:44:53 Sand Point United States  1.2
29-Jul-2021 10:44:53 Sand_Point_AK USA  1.2
29-Jul-2021 10:47:81 Squaw Harbor United States  1.1
29-Jul-2021 10:50:75 Unga United States  0.5
29-Jul-2021 11:15:32 Belkofski United States  0.5
29-Jul-2021 11:41:37 Uyak United States  0.4
29-Jul-2021 11:17:84 Ayakulik United States  0.3
29-Jul-2021 09:31:85 Biorka United States  0.3
29-Jul-2021 10:27:02 Umnak United States  0.2
29-Jul-2021 11:45:97 Port Hobron United States  0.2
29-Jul-2021 10:39:21 Ikatan United States  0.2
29-Jul-2021 11:59:19 Sanak United States  0.2
29-Jul-2021 09:50:53 King Cove United States  0.2
29-Jul-2021 10:53:25 Chiniak United States  0.2
29-Jul-2021 11:45:92 Kachemak Silo United States  0.2
29-Jul-2021 10:05:48 Pauloff Harbor United States  0.1
29-Jul-2021 09:18:83 Kaguyak United States  0.1
29-Jul-2021 11:42:26 Ouzinkie United States  0.1
29-Jul-2021 11:32:43 Atka- AK USA  0.1
29-Jul-2021 10:51:73 Kodiak United States  0.1
29-Jul-2021 10:51:73 Aleksashkina United States  0.1
29-Jul-2021 11:49:34 Seward United States  0.1
29-Jul-2021 11:49:34 Bear Creek United States  0.1
29-Jul-2021 11:49:34 Seward_AK USA  0.1
29-Jul-2021 10:49:63 Port William United States  0.1
29-Jul-2021 11:25:85 Cape Yakataga United States  0.1
29-Jul-2021 06:53:15 230 NM Southeast of Shumagin Island- AK Station 46403  0.1
29-Jul-2021 11:59:19 Chernofski United States  0.1
29-Jul-2021 10:02:86 Portlock United States  0.1
29-Jul-2021 11:59:19 Anchor Point United States  0.1
29-Jul-2021 11:59:19 Kamishak United States  0.1
29-Jul-2021 09:25:99 Nikolski United States  0.1
29-Jul-2021 10:45:54 Makushin United States  0.1
29-Jul-2021 08:57:85 Situk United States  0.1
29-Jul-2021 10:41:48 Boswell Bay United States  0.1
29-Jul-2021 11:27:14 Whitshed United States  0.1
29-Jul-2021 10:51:66 Dutch Harbor United States  0.1
29-Jul-2021 10:51:66 Unalaska United States  0.1
29-Jul-2021 10:51:66 Unalaska USA  0.1
29-Jul-2021 11:15:15 Crystal United States  0.1

See full locations list (RSS)


Initial conditions

Title: ""M 8.2, 104 km SE of Perryville, Alaska""

Fault parameters

  • Length: 199 km
  • Width: 55 km
  • Magnitude: 8.2 M

Okada parameters:

  • Slip: 5.1 m
  • Strike: 247 (geogr angle: north=0, south=180)
  • Dip: 15 degree
  • Rake: 90 degree
  • Depth: 32 km

Calculation parameters

  • Calculation space (lon/lat): -177.341, 35.825, -138.341, 70
  • Instead of Step -> use Cell size:3.25 minutes

Sea Level

More information

  • Timeline:
    Tsunami calculations performed to this case, click here

  • Montecarlo:
    Tsunami Montecarlo simulation performed to this case, click here

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