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Light mag. 3.9 earthquake - Bering Sea, 51 mi southwest of Atka, Aleutians West, Alaska, USA, on 18 Jul 11:30 am (GMT -9) -

Light mag. 3.9 earthquake - Bering Sea, 51 mi southwest of Atka, Aleutians West, Alaska, USA, on 18 Jul 11:30 am (GMT -9) Light mag. 3.9 earthquake - Bering Sea, 51 mi southwest of Atka, Aleutians West, Alaska, USA, on 18 Jul 11:30 am (GMT -9)

Light magnitude 3.9 earthquake at 49 km depth

18 Jul 20:58 UTC: First to report: EMSC after 28 minutes.
18 Jul 20:58: Now using data updates from USGS
18 Jul 21:02: Magnitude recalculated from 3.5 to 3.9. Hypocenter depth recalculated from 25.9 to 48.9 km (from 16.1 to 30 mi). Epicenter location corrected by 22 km (14 mi) towards NNW.
Update Sun, 18 Jul 2021, 21:06
Small magnitude 3.9 earthquake 51 miles southwest of Atka, Alaska, United States
3.9 quake 18 Jul 11:30 am (GMT -9)
3.9 quake 18 Jul 11:30 am (GMT -9)
Just 36 minutes ago, a 3.9-magnitude earthquake struck near Atka, Aleutians West, Alaska, USA. The tremor was recorded in the morning on Sunday 18 July 2021 at 11:30 am local time, at a moderately shallow depth of 30 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 3.9 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 Atka (pop. 64, 51 miles away), the quake was probably not felt.

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Earthquake data

Earthquake details

Date & timeJul 18, 2021 20:30:13 UTC -
Local time at epicenter18 Jul 11:30 am (GMT -9)
StatusConfirmed
Magnitude3.9
Depth48.9 km
Epicenter latitude / longitude51.7744°N / 175.1854°W (Bering Sea, Alaska, United States)
Antipode51.774°S / 4.815°E
Shaking intensityWeak shaking near epicenter
Felt0 reports
Primary data sourceUSGS (United States Geological Survey)
Nearest volcanoKasatochi (49 km / 30 mi)
Nearby towns and cities82 km (51 mi) SW of Atka (pop: 64) | Show on map | Quakes nearby
100 km (62 mi) E of Adak (pop: 332) | Show on map | Quakes nearby
Weather at epicenter at time of quakeOvercast Clouds 8.5°C (47 F), humidity: 96%, wind: 9 m/s (17 kts) from SSW
Estimated seismic energy released4.5 x 1010 joules (12.4 megawatt hours, equivalent to 10.7 tons of TNT) | about seismic energy
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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
3.949 km82 Km SW of Atka, AlaskaUSGS
3.949 km90 Km SW of Atka, AlaskaEMSC

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.
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