Earthquake near Big Lake, AK

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 117 km (73 mi) from the epicentre. In Big Lake, 6 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: Big Lake 6 km, intensity III · Knik-Fairview 20 km, intensity III · Eagle River 27 km, intensity III · Anchorage 28 km, intensity III · Willow 31 km, intensity III · Tanaina 34 km, intensity III · Palmer 48 km, intensity III · Fishhook 49 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 43 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 4,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 180× the energy of this one
3. Magna, Utah 2020 M 5.7 130× the energy of this one
4. This earthquake M 4.3 about 43 tons of TNT
5. Around the size people start to feel M 3.0 this one released 89× 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 16,000 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. 5.8 20 km ENE of Beluga, Alaska · 50 km WSW of this epicentre Dec 4, 2012
2. 5.6 11 km NW of Big Lake, Alaska · 15 km NNW of this epicentre Oct 7, 1966
3. 5.6 5 km N of Susitna, Alaska · 32 km WNW of this epicentre Dec 29, 1974
4. 5.5 2 km ENE of Eagle River, Alaska · 28 km ESE of this epicentre May 11, 1965
5. 5.5 9 km E of Susitna, Alaska · 21 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 61.4664, -149.9676. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

60 earthquakes have been recorded within 50 km since this one.

1. 2.0 1 km S of Big Lake, Alaska 08:28 UTC
2. 2.0 8 km S of Big Lake, Alaska 08:26 UTC
3. 2.3 4 km SSE of Big Lake, Alaska 08:25 UTC
4. 2.7 6 km NNW of Point MacKenzie, Alaska 08:24 UTC
5. 1.9 5 km WNW of Knik, Alaska 08:23 UTC
6. 3.4 8 km S of Big Lake, Alaska 08:21 UTC
7. 3.5 7 km SSW of Big Lake, Alaska 08:21 UTC
8. 2.8 3 km SE of Big Lake, Alaska 08:20 UTC
9. 3.0 5 km S of Big Lake, Alaska 08:19 UTC
10. 2.8 5 km S of Big Lake, Alaska 08:19 UTC
11. 1.6 2 km NW of Point MacKenzie, Alaska 08:17 UTC
12. 1.5 6 km SSW of Big Lake, Alaska 08:15 UTC
13. 1.9 11 km WNW of Anchorage, Alaska 08:12 UTC
14. 1.9 8 km SSW of Big Lake, Alaska 08:11 UTC
15. 3.0 8 km NNE of Point MacKenzie, Alaska 08:10 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:38 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.