Earthquake · reviewed by a seismologist
M 2.1ml
Earthquake near Willow, AK
No earthquake was likely felt in Willow in the 24 hours to 7:19 pm AKST (04:19 UTC). The last one was M 2.8, 20 km (12 mi) S, at 6:17 am AKST on 6 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Willow
This page: a magnitude 2.1 earthquake was recorded 15 km (9 mi) west-southwest of Willow, AK, at 1:25 pm AKST on 10 November 2021 (22:25 UTC), 4.5 km deep.
USGS: 15 km WSW of Willow, Alaska
55 km (34 mi) NNW of Anchorage, AK
- When
- 1:25 pm AKST on 10 November 2021 ()
- Where
- 15 km (9 mi) west-southwest of Willow, AK · earthquakes near Willow
- Magnitude
- M 2.1 (ml)
- Depth
- 4.5 km below the surface
- Felt
- no reports yet
- Nearest
- Matanuska-Susitna Borough, 77 km NNE
- Nearest mapped fault
- Castle Mountain fault, 14 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1796 days ago
Earthquake alerts for Willow, AK
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Alerts are on for .
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This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 17 km (11 mi) from the epicentre. In Willow, 15 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Willow 15 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
- Magna, Utah 2020 M 5.7 250,000× the energy of this one
- Around the size people start to feel M 3.0 22× the energy of this one
- This earthquake M 2.1 about 43 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
The largest earthquake within 50 km since 2016 was M 7.1 on 2018-11-30 — about 32,000,000 times the energy of this one.
Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 27 km SE of Skwentna, Alaska · 42 km WNW of this epicentre
- 5.9 23 km NE of Willow, Alaska · 38 km NE of this epicentre
- 5.6 11 km NW of Big Lake, Alaska · 14 km SE of this epicentre
- 5.6 5 km N of Susitna, Alaska · 15 km SW of this epicentre
- 5.5 9 km E of Susitna, Alaska · 16 km SSW of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 61.6779, -150.2821. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Matanuska-Susitna Borough, AK | 77 km (48 mi) | NNE | earthquakes near Matanuska-Susitna Borough |
| Anchorage Municipality, AK | 77 km (48 mi) | SE | earthquakes near Anchorage Municipality |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 2.3 33 km WNW of Willow, Alaska
- 2.4 8 km W of Point MacKenzie, Alaska
- 1.5 2 km SSE of Houston, Alaska
- 1.7 5 km S of Point MacKenzie, Alaska
- 3.1 Southern Alaska
- 2.1 3 km ESE of Big Lake, Alaska
- 1.9 Southern Alaska
- 1.5 3 km SE of Big Lake, Alaska
- 1.7 5 km SE of Point MacKenzie, Alaska
- 1.6 29 km S of Susitna, Alaska
- 1.8 12 km ENE of Willow, Alaska
- 2.7 3 km SSE of Houston, Alaska
- 2.1 27 km NW of Susitna, Alaska
- 1.5 12 km NNE of Susitna, Alaska
- 1.5 8 km NNW of Susitna, Alaska
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.