Earthquake near Anchorage, 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 48 km (30 mi) from the epicentre. In Anchorage, 29 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: Knik-Fairview 10 km, intensity II · Big Lake 11 km, intensity II · Houston 18 km, intensity II · Meadow Lakes 19 km, intensity II · Eagle River 20 km, intensity II · Tanaina 25 km, intensity II · Elmendorf Air Force Base 25 km, intensity II · Anchorage 29 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 45,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
3. Magna, Utah 2020 M 5.7 1,400× the energy of this one
4. This earthquake M 3.6 about 3.8 tons of TNT
5. Around the size people start to feel M 3.0 this one released 7.9× 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 180,000 times the energy of this one.

Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:

1. 5.9 23 km NE of Willow, Alaska · 48 km N of this epicentre Jan 1, 1975
2. 5.6 11 km NW of Big Lake, Alaska · 22 km WNW of this epicentre Oct 7, 1966
3. 5.6 5 km N of Susitna, Alaska · 42 km WNW of this epicentre Dec 29, 1974
4. 5.5 2 km ENE of Eagle River, Alaska · 21 km SE of this epicentre May 11, 1965
5. 5.5 9 km E of Susitna, Alaska · 31 km WNW 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 61.4740, -149.7690. Map © OpenStreetMap contributors.

Nearby places

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

No further earthquakes have been recorded within 50 km since this one.

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:09 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

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.