Earthquake · reviewed by a seismologist
M 2.7ml
Earthquake near Willow, AK
No earthquake was likely felt in Willow in the 24 hours to 6:13 am AKST (15:13 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 2.7 earthquake was recorded 9 km (6 mi) south-southwest of Willow, AK, at 4:15 am AKST on 24 November 2021 (13:15 UTC), 24 km deep.
USGS: 9 km SSW of Willow, Alaska
51 km (32 mi) N of Anchorage, AK
- When
- 4:15 am AKST on 24 November 2021 ()
- Where
- 9 km (6 mi) south-southwest of Willow, AK · earthquakes near Willow
- Magnitude
- M 2.7 (ml)
- Depth
- 24 km below the surface
- Felt
- no reports yet
- Nearest
- Anchorage Municipality, 69 km SE
- Nearest mapped fault
- Castle Mountain fault, 8 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 1749 days ago
Earthquake alerts for Willow, AK
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 7 km (4 mi) from the epicentre. In Willow, 9 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.
Earthquakes near other towns within 30 km: Houston, Big Lake, Meadow Lakes.
How big was it?
This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
- Magna, Utah 2020 M 5.7 32,000× the energy of this one
- Around the size people start to feel M 3.0 2.8× the energy of this one
- This earthquake M 2.7 about 340 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 4,000,000 times the energy of this one.
Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:
- 5.9 23 km NE of Willow, Alaska · 33 km NNE of this epicentre
- 5.6 11 km NW of Big Lake, Alaska · 10 km SSW of this epicentre
- 5.6 5 km N of Susitna, Alaska · 24 km WSW of this epicentre
- 5.5 2 km ENE of Eagle River, Alaska · 48 km SE of this epicentre
- 5.5 9 km E of Susitna, Alaska · 19 km SW 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 61.6656, -150.0838. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Anchorage Municipality, AK | 69 km (43 mi) | SE | earthquakes near Anchorage Municipality |
| Matanuska-Susitna Borough, AK | 73 km (46 mi) | NNE | earthquakes near Matanuska-Susitna Borough |
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.
- 2.9 0 km E of Big Lake, Alaska
- 1.6 2 km SE of Big Lake, Alaska
- 3.0 11 km E of Willow, Alaska
- 1.5 4 km SW of Big Lake, Alaska
- 2.9 1 km N of Point MacKenzie, Alaska
- 2.1 2 km S of Houston, Alaska
- 1.5 15 km S of Susitna North, Alaska
- 1.5 1 km SW of Susitna, Alaska
- 1.7 6 km NW of Big Lake, Alaska
- 1.6 2 km E of Big Lake, Alaska
- 1.5 5 km ESE of Big Lake, Alaska
- 1.8 4 km SSE of Big Lake, Alaska
- 1.5 22 km WNW of Willow, Alaska
- 3.2 2 km WNW of Point MacKenzie, Alaska
- 1.6 5 km NNE of Point MacKenzie, 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.