Mag. 3.3 earthquake - Gulf of Alaska, 40 mi east of Simeonof Island, Aleutians East County, Alaska, USA, on Friday, 31 July 2020 at 21:32 (GMT) -
This quake was likely an aftershock of the 7.8 quake Gulf of Alaska, 31 mi east of Simeonof Island, Aleutians East County, Alaska, USA, 22 July 2020 06:12 GMT, which had occurred 10 days earlier.
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Minor magnitude 3.3 earthquake at 22 km depth
31 Jul 21:47 UTC: First to report: USGS after 15 minutes.
Hypocenter depth recalculated from 29.8 to 34.3 km.
Aug 1 00:00: Magnitude recalculated from 3.5 to 3.3.
Hypocenter depth recalculated from 34.3 to 22.1 km.
Hypocenter depth recalculated from 29.8 to 34.3 km.
Aug 1 00:00: Magnitude recalculated from 3.5 to 3.3.
Hypocenter depth recalculated from 34.3 to 22.1 km.
Magnitude: 3.3
Depth: 22.1 km
Epicenter latitude / longitude: 55.0675°N / 158.2999°W
(Gulf of Alaska, Alaska, United States)Nearest volcano: Kupreanof (136 km / 85 mi)
Nearby towns and cities:
108 km (67 mi) SSE of Perryville (pop: 113) --> See nearby quakes!
135 km (84 mi) SSE of Chignik Lake (pop: 73) --> See nearby quakes!
137 km (85 mi) S of Chignik (pop: 87) --> See nearby quakes!
143 km (89 mi) E of Sand Point (pop: 1,060) --> See nearby quakes!
210 km (130 mi) S of Port Heiden (pop: 98) --> See nearby quakes!
210 km (131 mi) ESE of Nelson Lagoon (pop: 52) --> See nearby quakes!
256 km (159 mi) E of King Cove (pop: 1,010) --> See nearby quakes!
281 km (175 mi) E of Cold Bay (pop: 123) --> See nearby quakes!
6048 km (3758 mi) NW of Washington DC (District of Columbia) (pop: 601,700) --> See nearby quakes!
6048 km (3758 mi) NW of Washington DC (District of Columbia) (pop: 601,700) --> See nearby quakes!
65 km (40 mi) ENE of Simeonof Island --> See nearby quakes!
86 km (53 mi) ENE of Chernabura Island --> See nearby quakes!
Primary data source: USGS (United States Geological Survey)
Estimated released energy: 5.6 x 109 joules (1.56 megawatt hours, equivalent to 1.34 tons of TNT) More info
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.
| Magnitude | Depth | Location | Source |
| M 3.3 | 22 km | 108 km SSE of Perryville, Alaska (USA) | USGS |
| M 3.5 | 28 km | Alaska Peninsula (USA) | EMSC |
User reports for this quake
User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.
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Earlier earthquakes in the same area
Mag. 3.3 earthquake - Gulf of Alaska, 40 mi east of Simeonof Island, Aleutians East County, Alaska, USA, on Friday, 31 July 2020 at 21:32 (GMT)
Click here to search our database for earlier earthquakes in the same area since 1900!
