Weak mag. 3.4 earthquake - Matanuska-Susitna Parish, 19 mi north of Alaska City, Anchorage, Alaska, USA, on Saturday, Sep 11, 2021 8:20 am (GMT -8) -

Weak mag. 3.4 earthquake - Matanuska-Susitna Parish, 19 mi north of Alaska City, Anchorage, Alaska, USA, on Saturday, Sep 11, 2021 8:20 am (GMT -8)

Weak magnitude 3.4 earthquake at 37 km depth

11 Sep 16:23 UTC: First to report: VolcanoDiscovery after 3 minutes.
11 Sep 16:24: Now using data updates from USGS
11 Sep 16:25: Hypocenter depth recalculated from 20.6 to 20.5 km (from 12.8 to 12.7 mi). Epicenter location corrected by 1.3 km (0.8 mi) towards SSE.
11 Sep 16:28: Magnitude recalculated from 3.5 to 3.4. Hypocenter depth recalculated from 20.5 to 37.1 km (from 12.7 to 23 mi). Epicenter location corrected by 4.9 km (3 mi) towards ENE.
Update Sat, 11 Sep 2021, 16:33
Magnitude 3.4 earthquake strikes near Alaska City, Anchorage, Alaska, USA
3.4 quake 11 Sep 8:20 am (GMT -8)
3.4 quake 11 Sep 8:20 am (GMT -8)
Just 12 minutes ago, a 3.4-magnitude earthquake struck near Alaska City, Anchorage, Alaska, USA. The tremor was recorded in the morning on Saturday, September 11th, 2021, at 8:20 am local time, at a moderately shallow depth of 23 miles below the surface.
The event was filed by the United States Geological Survey, the first seismological agency to report it.
A second report was later issued by the European-Mediterranean Seismological Centre (EMSC), which listed it as a magnitude 3.4 earthquake as well.
Towns or cities near the epicenter where the quake might have been felt as very weak shaking include Big Lake (pop. 3,400) located 2 miles from the epicenter, Knik-Fairview (pop. 14,900) 10 miles away, Meadow Lakes (pop. 7,600) 13 miles away, Wasilla (pop. 9,300) 16 miles away, Eagle River (pop. 24,800) 17 miles away, Eagle River (pop. 24,800) 17 miles away, and Tanaina (pop. 8,200) 18 miles away. In Alaska City (pop. 298,700, 19 miles away), and Lakes (pop. 8,400, 21 miles away), the quake was probably not felt.

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Earthquake data

Date & time: Sep 11, 2021 16:20:55 UTC -
Local time at epicenter: Saturday, Sep 11, 2021 8:20 am (GMT -8)
Magnitude: 3.4
Depth: 37.1 km
Epicenter latitude / longitude: 61.498°N / 149.9085°W (Matanuska-Susitna, Alaska, United States)
Antipode: 61.498°S / 30.092°E
Nearest volcano: Spurr (127 km / 79 mi)
Nearby towns and cities:
4 km (2 mi) SE of Big Lake (pop: 3,350) --> See nearby quakes!
15 km (10 mi) SSW of Houston (pop: 2,210) --> See nearby quakes!
16 km (10 mi) W of Knik-Fairview (pop: 14,900) --> See nearby quakes!
22 km (13 mi) SW of Meadow Lakes (pop: 7,570) --> See nearby quakes!
27 km (17 mi) NW of Eagle River (pop: 24,800) --> See nearby quakes!
27 km (17 mi) NW of Eagle River (Anchorage) (pop: 24,800) --> See nearby quakes!
29 km (18 mi) SSE of Willow (pop: 2,100) --> See nearby quakes!
31 km (19 mi) N of Alaska City (pop: 298,700) --> See nearby quakes!
34 km (21 mi) WSW of Lakes (pop: 8,360) --> See nearby quakes!
44 km (27 mi) WSW of Palmer (pop: 6,790) --> See nearby quakes!
Weather at epicenter at time of quake:
Scattered Clouds 6°C (43 F), humidity: 98%, wind: 2 m/s (3 kts) from N
Primary data source: USGS (United States Geological Survey)
Estimated released energy: 7.9 x 109 joules (2.21 megawatt hours, equivalent to 1.9 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
3.437 km3 Km SE of Big Lake, AlaskaUSGS
3.648 kmSOUTHERN ALASKAEMSC

User reports for this quake (5)

User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.
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Palmer (43.5 km ENE of epicenter) [Map] / Light shaking (MMI IV) / horizontal (sideways) swinging / 5-10 s : Like a vehicle ran into the house. | One user found this interesting. (reported through our app)  
Big Lake, Matanuska-Susitna, Alaska (7.8 km NE of epicenter) [Map] / Weak shaking (MMI III) / complex rolling (tilting in multiple directions) / 1-2 s : sitting on couch | One user found this interesting. (reported through our app)  
Wasilla, AK / Very weak shaking (MMI II) / simple rolling (tilting sideways along one direction) / 2-5 s : In Wasilla. Was on the phone and said, “earthquake,” but my dogs did not come running. Felt it come up behind me from the couch and roll through. My friend on the phone in Anchorage did not feel it. And again, my dogs didn’t even come running.  
Wasilla / Light shaking (MMI IV) / rattling, vibrating / 2-5 s (reported through our app)
Wasilla, ak / Very weak shaking (MMI II) / very short (reported through our app)
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