Earthquake near Willow, AK

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 55 km (34 mi) from the epicentre. In Willow, 15 km away, the estimate is intensity III (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 III · Big Lake 25 km, intensity II · Knik-Fairview 41 km, intensity II · Tanaina 46 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 89,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
4. This earthquake M 3.4 about 1.9 tons of TNT
5. Around the size people start to feel M 3.0 this one released 4× more

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 350,000 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

1. 6.9 27 km SE of Skwentna, Alaska · 42 km WNW of this epicentre Nov 3, 1943
2. 5.9 23 km NE of Willow, Alaska · 39 km NE of this epicentre Jan 1, 1975
3. 5.6 11 km NW of Big Lake, Alaska · 14 km SE of this epicentre Oct 7, 1966
4. 5.6 5 km N of Susitna, Alaska · 15 km SW of this epicentre Dec 29, 1974
5. 5.5 9 km E of Susitna, Alaska · 15 km S of this epicentre Dec 30, 1985

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 61.6768, -150.2880. Map © OpenStreetMap contributors.

Nearby places

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.

1. 1.6 29 km S of Susitna, Alaska 02:02 UTC
2. 1.8 12 km ENE of Willow, Alaska 13:46 UTC
3. 2.7 3 km SSE of Houston, Alaska 12:12 UTC
4. 2.1 27 km NW of Susitna, Alaska 22:18 UTC
5. 1.5 12 km NNE of Susitna, Alaska 21:07 UTC
6. 1.5 8 km NNW of Susitna, Alaska 16:09 UTC
7. 1.8 22 km NNW of Susitna, Alaska 10:10 UTC
8. 1.5 1 km WNW of Big Lake, Alaska 10:45 UTC
9. 1.5 36 km ESE of Skwentna, Alaska 05:54 UTC
10. 1.5 21 km NW of Susitna, Alaska 05:43 UTC
11. 2.9 25 km WNW of Willow, Alaska 01:00 UTC
12. 1.6 5 km E of Susitna, Alaska 02:02 UTC
13. 1.5 5 km W of Point MacKenzie, Alaska 22:45 UTC
14. 1.7 13 km NNE of Willow, Alaska 01:39 UTC
15. 2.0 27 km NW of Willow, Alaska 20:00 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 11:55 UTC. 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.