M 5.54 in United States on 21 May 2023 18:44 UTC

Hazard models

Rapid Impact
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: 40.3775 , -125.5628333
Event Date: 21 May 2023 18:44 UTC
21 May 2023 10:44 Local
Exposed Population: Few people affected in MMI -
Source: NCAL SS nc73890906
Inserted at: 21 May 2023 19:37 UTC
INFORM Coping capacity of the alert score: 1.1 (United States)

GDACS Score

For more info on GDACS alert score click here.
  Earthquake
(Shakemap)		 GDACS score
NCAL SS 0 0
nc73890906 Scaled population (raster) 0  
  C1 shakemap 0  
  C2 shakemap 0  
  Country Vulnerability 0  
  INFORM_normalised 0  
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
1506894 0 21 May 2023 18:44 5.51M, 2.12km 3.64 Few people (in 100km) 00:04 NCAL SS
1506895 0 21 May 2023 18:44 5.63M, 2.12km 3.83 N/A (in MMI>=VII) 00:05 NCAL SS
1506905 0 21 May 2023 18:44 5.54M, 10km 3.86 N/A (in MMI>=VII) 00:53 NCAL SS
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 United States ,of California (population 30,971,320) . 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 1506895 -125.487/40.406 5.5 2.1 3.888 21 May 2023 18:52 00:08 (new episode)
2 0 1506895 -125.487/40.406 5.5 2.1 3.83 21 May 2023 19:18 00:34 (upd of #1)
3 0 1506905 -125.563/40.378 5.5 10 3.835 21 May 2023 19:42 00:58 (new episode)
4 0 1506905 -125.563/40.378 5.5 10 3.833 21 May 2023 19:54 01:10 (upd of #3)
5 0 1506905 -125.563/40.378 5.5 10 3.812 22 May 2023 00:49 06:05 (upd of #4)
6 0 1506905 -125.563/40.378 5.5 10 3.817 22 May 2023 07:41 12:57 (upd of #5)
7 0 1506905 -125.563/40.378 5.6 10 3.856 22 May 2023 19:41 1d 00:57 (upd of #6)

Affected Provinces

Intensity Region Province Country Population
California United States <1000 people
California United States 37000 people
California United States 33000 people
Oregon United States <1000 people

Affected populated places. Areas of interest

Intensity Name Region Province Country City class Population Distance
Capetown California United States Village - 103 km
Petrolia California United States Village - 109 km
Fortuna California United States Village 10000 people 123 km
Rohnerville California United States Village - 123 km
Honeydew California United States Village - 124 km
Scotia California United States Village - 125 km
Rio Dell California United States Village 3200 people 126 km
Shively California United States Village - 137 km
Weott California United States Village - 140 km
Whitethorn California United States Village - 143 km
Briceland California United States Village - 145 km
Miranda California United States Village - 149 km
Garberville California United States Village - 154 km
Piercy California United States Village - 157 km
Hoopa California United States Village - 177 km
Laytonville California United States Village 1300 people 193 km
Covelo California United States Village 1200 people 208 km
Willits California United States Village 5100 people 218 km
Philo California United States Village - 234 km
Redwood Valley California United States Village - 239 km
Calpella California United States Village - 239 km
Happy Camp California United States Village - 243 km
Ukiah California United States Village 15000 people 244 km

see full list


Critical infrastructure

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

Airports

Intensity Name IATA Code Elevation (m) Usage Runway type IFR Runway Length (ft) Distance
Rohnerville 119 Civ. Paved Yes 4000 123 km
Shelter Cove 21 0 133 km
Garberville 166 0 152 km
Hoopa 109 0 176 km
Andy Mc Beth 13 0 182 km
Hayfork 707 0 203 km
Round Valley 437 0 206 km
Happy Camp 369 0 241 km
Ukiah Municipal UKI 188 Civ. Paved Yes 4400 246 km

Ports

Intensity Name LOCODE Country Distance
Cape Mendocino Wake Island 99 km

More information

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