Earthquake near Knik-Fairview, 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 30 km (19 mi) from the epicentre. In Knik-Fairview, 5 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 5 km, intensity II · Tanaina 11 km, intensity II · Big Lake 20 km, intensity II · Palmer 25 km, intensity II · Eagle River 27 km, intensity II · Fishhook 28 km, intensity II · Butte 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 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 250,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
4. This earthquake M 3.1 about 1,300 lb of TNT
5. Around the size people start to feel M 3.0 this one released 1.4× 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 1,000,000 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 · 40 km NNW of this epicentre Jan 1, 1975
2. 5.8 14 km NNE of Fishhook, Alaska · 42 km NE of this epicentre Aug 14, 1984
3. 5.6 11 km NW of Big Lake, Alaska · 29 km W of this epicentre Oct 7, 1966
4. 5.6 5 km N of Susitna, Alaska · 49 km W of this epicentre Dec 29, 1974
5. 5.5 2 km ENE of Eagle River, Alaska · 26 km S of this epicentre May 11, 1965

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 61.5596, -149.5871. 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. 3.1 4 km SSE of Big Lake, Alaska 18:29 UTC
2. 2.8 3 km SSW of Big Lake, Alaska 18:28 UTC
3. 2.8 3 km S of Big Lake, Alaska 18:27 UTC
4. 3.0 4 km SSE of Big Lake, Alaska 18:27 UTC
5. 3.0 2 km NE of Big Lake, Alaska 18:27 UTC
6. 2.8 3 km WNW of Point MacKenzie, Alaska 18:26 UTC
7. 2.2 2 km E of Big Lake, Alaska 18:25 UTC
8. 2.5 8 km NNW of Anchorage, Alaska 18:24 UTC
9. 2.3 7 km SSE of Big Lake, Alaska 18:24 UTC
10. 2.3 10 km NW of Point MacKenzie, Alaska 18:24 UTC
11. 2.4 6 km WSW of Knik, Alaska 18:23 UTC
12. 2.5 8 km N of Point MacKenzie, Alaska 18:22 UTC
13. 3.6 6 km NW of Point MacKenzie, Alaska 18:21 UTC
14. 3.6 7 km WSW of Knik, Alaska 18:21 UTC
15. 3.0 7 km NW of Point MacKenzie, Alaska 18:20 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 04:23 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.