M 5.5 in South Of Tonga Islands on 23 Jul 2021 23:13 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: 5.5M
Depth: 10 Km
Lat/Lon: -26.6454 , -175.6247
Event Date: 23 Jul 2021 23:13 UTC
23 Jul 2021 11:13 Local
Exposed Population: No people within 100km
Source: NEIC us6000eyj7
Inserted at: 23 Jul 2021 23:51 UTC
INFORM Coping capacity of the alert score: 1.1 ()

GDACS Score

For more info on GDACS alert score click here.
  Earthquake
(Shakemap)		 GDACS score
NEIC 0 0
us6000eyj7 Scaled population (vector) 0  
  C1 shakemap -0.59  
  C2 shakemap 0.53  
  Country Vulnerability 0  
  INFORM_normalised 1  
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
1387190 0 23 Jul 2021 23:13 5.5M, 10km N/A No people affected (in 100km) 00:23 NEIC
1387192 0 23 Jul 2021 23:13 5.5M, 10km N/A N/A (in MMI>=VII) 00:37 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.

Exposed population

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

Intensity Population
no people


Shakemaps Timeline

AlertShake id #ScoreepisodeidLat/LonMagnitudeDepthMax MMIDate shake (UTC)Delay (hh:mm) 
1 0 1387190 -26.624/-175.575 5.5 10.0 None 23 Jul 2021 23:37 00:23 (new episode)
2 0 1387192 -26.631/-175.607 5.5 10.0 None 24 Jul 2021 00:22 01:08 (new episode)
3 0 1387192 -26.631/-175.607 5.5 10.0 None 24 Jul 2021 01:17 02:03 (upd of #2)
4 0 1387192 -26.631/-175.607 5.5 10.0 None 24 Jul 2021 23:17 1d 00:03 (upd of #3)

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.