M 7.4 Earthquake and Tsunami (1.3 m) in United States from 22 Jul 2020 06:12 UTC to 06:12

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: 7.4M
Depth: 13 Km
Event Date: 22 Jul 2020 06:12 UTC
21 Jul 2020 19:12 Local
Exposed Population: Few people within 100km
Source: NTWC at00qdux98
Inserted at: 22 Jul 2020 06:21 UTC
INFORM Coping capacity of the alert score:
2.2 (United States)

GDACS Score

For more info on GDACS alert score click here.
  Earthquake Tsunami GDACS score
NTWC 0 1.1 1.1
at00qdux98 Scaled population (vector) 0.76 Max wave alert 1.26m  
  C1 earthquake 1 Max wave realtime 1.26m  
  C2 earthquake 0      
  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
1322921 1.1 22 Jul 2020 06:12 7.4M, 13km N/A Few people (in 100km) 1.3m (at 00:46) 00:08 NTWC
1322927 1.3 22 Jul 2020 06:12 7.8M, 10km N/A Few people (in 100km) 1.6m (at 00:56) 00:33 NEIC
1322939 0.9 22 Jul 2020 06:12 7.8M, 28km 7.15 N/A (in MMI>=VII) 0.9m (at 00:54) 01:17 NEIC
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  1.3m in Perryville, United States. This height is estimated for 22-Jul-2020 06:58:87.

Alert Date (UTC) Name Country Wave height (m)
22-Jul-2020 06:58:87 Perryville United States  1.3
22-Jul-2020 07:02:48 Mitrofania United States  0.9
22-Jul-2020 07:50:96 Chignik United States  0.3
22-Jul-2020 08:12:94 Unga United States  0.2
22-Jul-2020 09:04:62 Sand Point United States  0.2
22-Jul-2020 09:04:62 Sand_Point_AK USA  0.2
22-Jul-2020 09:34:55 King Cove United States  0.2
22-Jul-2020 07:20:56 Squaw Harbor United States  0.1
22-Jul-2020 09:22:26 Village United States  0.1
22-Jul-2020 09:02:82 Belkofski United States  0.1
22-Jul-2020 09:56:38 Pauloff Harbor United States  0.1

See full locations list (RSS)


Initial conditions

Title: ""84 km SSE of Perryville""

Fault parameters

  • Latitude: 55.22
  • Longitude: -158.594
  • Length: 79 km
  • Width: 22 km
  • Magnitude: 7.4 M

Okada parameters:

  • Slip: 2 m
  • Strike: 253 (geogr angle: north=0, south=180)
  • Dip: 15 degree
  • Rake: 90 degree
  • Depth: 13 km

Calculation parameters

  • Calculation space (lon/lat): -166.094, 47.72, -151.094, 62.72
  • Instead of Step -> use Cell size:1.25 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.