Weak mag. 3.9 earthquake - Aleutians West Parish, 21 mi southwest of Unalaska, Aleutians West, Alaska, USA, on Thursday, 20 May 2021 5:05 pm (GMT -8) -

Weak mag. 3.9 earthquake - Aleutians West Parish, 21 mi southwest of Unalaska, Aleutians West, Alaska, USA, on Thursday, 20 May 2021 5:05 pm (GMT -8)

Weak magnitude 3.9 earthquake at 77 km depth

21 May 01:37 UTC: First to report: EMSC after 31 minutes.
21 May 01:37: Now using data updates from USGS
21 May 01:59: Magnitude recalculated from 3.3 to 3.9. Hypocenter depth recalculated from 73.4 to 76.8 km (from 46 to 48 mi). Epicenter location corrected by 6 km (3.8 mi) towards NW.
Update Fri, 21 May 2021, 01:42
Small tremor of magnitude 3.3 reported 22 miles southwest of Unalaska, Alaska, United States
3.3 quake 20 May 5:05 pm (GMT -8)
3.3 quake 20 May 5:05 pm (GMT -8)
Just 36 minutes ago, a 3.3-magnitude earthquake struck near Unalaska, Aleutians West, Alaska, USA. The tremor was recorded in the afternoon on Thursday 20 May 2021 at 5:05 pm local time, at an intermediate depth of 46 miles below the surface.
The event was filed by the United States Geological Survey, the first seismological agency to report it.
Our monitoring service identified a second report from the European-Mediterranean Seismological Centre (EMSC) which listed the quake at magnitude 3.3 as well.
According to preliminary calculations, we do not expect that the quake was felt by many people and did not cause any damage. In Unalaska (pop. 4,500, 22 miles away), the quake was probably not felt.
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Earthquake data:

Date & time: 21 May 2021 01:05:51 UTC -
Local time at epicenter: Thursday, 20 May 2021 5:05 pm (GMT -8)
Magnitude: 3.9
Depth: 76.8 km
Epicenter latitude / longitude: 53.6062°N / 166.7547°W (Aleutians West, Alaska, United States)
Nearest volcano: Makushin (39 km / 24 mi)
Nearby towns and cities:
33 km (21 mi) SSW of Unalaska (pop: 4,490) --> See nearby quakes!
87 km (54 mi) SW of Akutan (pop: 1,040) --> See nearby quakes!
159 km (99 mi) ENE of Nikolski (pop: 18) --> See nearby quakes!
258 km (160 mi) WSW of False Pass (pop: 40) --> See nearby quakes!
315 km (196 mi) WSW of Cold Bay (pop: 123) --> See nearby quakes!
330 km (205 mi) WSW of King Cove (pop: 1,010) --> See nearby quakes!
444 km (276 mi) SW of Nelson Lagoon (pop: 52) --> See nearby quakes!
450 km (280 mi) SSE of Saint Paul (pop: 479) --> See nearby quakes!
Weather at epicenter at time of quake:
Light Rain 3.9°C (39 F), humidity: 93%, wind: 4 m/s (8 kts) from NNW
Primary data source: USGS (United States Geological Survey)
Estimated released energy: 4.5 x 1010 joules (12.4 megawatt hours, equivalent to 10.7 tons of TNT) More info
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Data for the same earthquake reported by different agencies

Info: The more agencies report about the same quake and post similar data, the more confidence you can have in the data. It takes normally up to a few hours until earthquake parameters are calculated with near-optimum precision.
Mag.DepthLocationSource
3.977 km33 Km SSW of Unalaska, AlaskaUSGS
3.977 kmFOX ISLANDS, ALEUTIAN ISLANDSEMSC

User reports for this quake

User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.
There are no user reports for this quake yet. If you felt it be the first to report it!
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Earlier earthquakes in the same area

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