Contact | RSS | EN | DE | EL | ES | FR | IT | RU

Moderate mag. 5.2 earthquake - North Pacific Ocean, 101 mi southwest of Unalaska, Aleutians West, Alaska, USA, on Wednesday, Nov 3, 2021 at 9:57 pm (GMT -11) -

Moderate mag. 5.2 earthquake - North Pacific Ocean, 101 mi southwest of Unalaska, Aleutians West, Alaska, USA, on Wednesday, Nov 3, 2021 at 9:57 pm (GMT -11) Moderate mag. 5.2 earthquake - North Pacific Ocean, 101 mi southwest of Unalaska, Aleutians West, Alaska, USA, on Wednesday, Nov 3, 2021 at 9:57 pm (GMT -11)

Moderate magnitude 5.2 earthquake at 36 km depth

4 Nov 09:03 UTC: First to report: USGS after 6 minutes.
4 Nov 09:21: Magnitude recalculated from 5.3 to 5.2. Hypocenter depth recalculated from 33.0 to 30.9 km (from 21 to 19.2 mi). Epicenter location corrected by 41 km (26 mi) towards NW.
4 Nov 12:56: Hypocenter depth recalculated from 30.9 to 35.8 km (from 19.2 to 22 mi). Epicenter location corrected by 1.2 km (0.7 mi) towards SSE.
Update Thu, 4 Nov 2021, 09:09

Significant earthquake of magnitude 5.3 just reported 64 miles southeast of Nikolski, Alaska, United States

5.3 quake 3 Nov 9:57 pm (GMT -11)
5.3 quake 3 Nov 9:57 pm (GMT -11)
A magnitude 5.3 earthquake near Nikolski, Aleutians West, Alaska, USA, was reported only 12 minutes ago by the United States Geological Survey, considered the key international and national agency that monitors seismic activity in the US. The earthquake occurred at a moderately shallow depth of 21 miles beneath the epicenter in the evening on Wednesday, November 3rd, 2021, at 9:57 pm local time. The exact magnitude, epicenter, and depth of the quake might be revised within the next few hours or minutes as seismologists review data and refine their calculations, or as other agencies issue their report.
A second report was later issued by France's Réseau National de Surveillance Sismique (RéNaSS), which listed it as a magnitude 5.6 earthquake. Other agencies reporting the same quake include the European-Mediterranean Seismological Centre (EMSC) at magnitude 5.5, and the German Research Centre for Geosciences (GFZ) at magnitude 5.6.
Generally quakes of this magnitude are recorded by more than one agency and the results can vary, with subsequent reports that come in after the first one often showing more accuracy.
Based on the preliminary seismic data, the quake should not have caused any significant damage, but was probably felt by many people as light vibration in the area of the epicenter.
Weak shaking might have been felt in Nikolski (pop. 18) located 64 miles from the epicenter.
VolcanoDiscovery will automatically update magnitude and depth if these change and follow up if other significant news about the quake become available. If you're in the area, please send us your experience through our reporting mechanism, either online or via our mobile app. This will help us provide more first-hand updates to anyone around the globe who wants to know more about this quake.

Download the Volcanoes & Earthquakes app and get one of the fastest seismic alerts online: Android | iOS

Earthquake details

Date & timeNov 4, 2021 08:57:06 UTC -
Local time at epicenterWednesday, Nov 3, 2021 at 9:57 pm (GMT -11)
Depth35.8 km
Epicenter latitude / longitude52.7003°N / 167.9814°W (North Pacific Ocean, Alaska, United States)
Antipode52.7°S / 12.019°E
Shaking intensityLight shaking near epicenter
Felt0 reports
Primary data sourceUSGS (United States Geological Survey)
Nearest volcanoRecheschnoi (103 km / 64 mi)
Nearby towns and cities65 km (40 mi) ESE of Nikolski (pop: 18) | Show on map | Quakes nearby
162 km (101 mi) SW of Unalaska (pop: 4,490) | Show on map | Quakes nearby
163 km (101 mi) SW of Dutch Harbor (pop: 4,380) | Show on map | Quakes nearby
216 km (134 mi) SW of Akutan (pop: 1,040) | Show on map | Quakes nearby
384 km (239 mi) SW of False Pass (pop: 40) | Show on map | Quakes nearby
441 km (274 mi) SW of Cold Bay (pop: 123) | Show on map | Quakes nearby
455 km (282 mi) WSW of King Cove (pop: 1,010) | Show on map | Quakes nearby
Weather at epicenter at time of quakeLight Rain 2.7°C (37 F), humidity: 55%, wind: 12 m/s (23 kts) from NW
Estimated seismic energy released4 x 1012 joules (1.11 gigawatt hours, equivalent to 951 tons of TNT) | about seismic energy
Show interactive Map
[smaller] [bigger]

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.
5.236 km65 Km ESE of Nikolski, AlaskaUSGS
5.234 kmFox Islands, Aleutian IslandsGFZ
5.710 kmNear AnchorageRENASS
5.244 kmFox Islands, Aleutian IslandsGeoAu
5.344 kmFox Islands, Aleutian IslandsBMKG


Seismic station: Adak, Aleutian Islands, Alaska (ADK/IU network) | Distance from quake: 598 km / 372 mi | Show on map | Station Info
Seismic station Adak, Aleutian Islands, Alaska: vertical movement plot around time of quake (source: IRIS/BUD)
Seismogram (vertical component) around time of quake. Thin dotted red line indicates time of quake. Seismic waves arrive some time later, depending on distance. Source: IRIS Buffer of Uniform Data (BUD) webtool
Show more

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.


[More info]

Recorded aftershocks, latest first (2 quakes)

Date and timeMag
Dec 21, 2021 17:02
49 weeks ago

46 km
Bering Sea, 104 mi SW of Unalaska, Aleutians West, Alaska, USAMore
Dec 21, 2021 16:59
49 weeks ago

35 km
North Pacific Ocean, 109 mi SW of Unalaska, Aleutians West, Alaska, USAMore

Earlier earthquakes in the same area

Try our free app!
Volcanoes & Earthquakes - new app for Android
Android | iOS version

Support us - Help us upgrade our services!

We truly love working to bring you the latest volcano and earthquake data from around the world. Maintaining our website and our free apps does require, however, considerable time and resources.
We need financing to increase hard- and software capacity as well as support our editor team. We're aiming to achieve uninterrupted service wherever an earthquake or volcano eruption unfolds, and your donations can make it happen! Every donation will be highly appreciated. If you find the information useful and would like to support our team in integrating further features, write great content, and in upgrading our soft- and hardware, please make a donation (PayPal or Online credit card payment).

Planned features:
  • Improved multilanguage support
  • Tsunami alerts
  • Faster responsiveness
Thanks to your past donations, these features have been added recently:
  • Design upgrade
  • Detailed quake stats
  • Additional seismic data sources
Download and Upgrade the Volcanoes & Earthquakes app to get one of the fastest seismic and volcano alerts online:
Android | IOS
Thank you!
Sources: VolcanoDiscovery / VolcanoAdventures and other sources as noted.
Use of material: Most text and images on our websites are owned by us. Re-use is generally not permitted without authorization. Contact us for licensing rights.
Volcanoes & Earthquakes
VolcanoDiscovery Home
Volcanoes | Earthquakes | Photos | Volcano News | App
Adventure & Study Travel
Tours to Volcanoes and Volcanic Areas: walking tours, photo tours, study tours
Tours & Dates | FAQ | About us
Get our newsletter!
Company info
Contact | Legal info | Terms & conditions
Follow us
Follow us on facebook Follow us on Instagram Follow us on Twitter Visit our Youtube channel
EN | DE | EL | ES | FR | IT | RU
VolcanoDiscovery GmbH, Germany, Reg. nr.: HRB 103744, EU Tax Id: DE 310 395 322 owned and created by
Dr. Tom Pfeiffer, volcanologist, volcano photographer, tour organizer member of
Volcanological Society
Ecotourism Greece
Insured by R+V
VolcanoDiscovery © 2004- All Rights Reserved | Privacy - cookie settings