45 km E of Knik River, Alaska

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 12 km (7 mi) from the epicentre. 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.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
3. Around the size people start to feel M 3.0 63× the energy of this one
4. This earthquake M 1.8 about 15 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 4.6 on 2018-01-27 — about 16,000 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

1. 6.8 31 km SSW of Glacier View, Alaska · 21 km NE of this epicentre May 4, 1934
2. 6.6 57 km ENE of Whittier, Alaska · 45 km SSE of this epicentre Feb 23, 1925
3. 6.4 23 km S of Glacier View, Alaska · 31 km NE of this epicentre Apr 3, 1964
4. 6.4 37 km SSE of Glacier View, Alaska · 37 km ENE of this epicentre Apr 20, 1964
5. 6.1 54 km WNW of Tatitlek, Alaska · 44 km SE of this epicentre Apr 3, 1963

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 61.4020, -148.0740. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.6 61 km NW of Tatitlek, Alaska 11:42 UTC
2. 1.1 34 km NE of Whittier, Alaska 07:38 UTC
3. 1.2 36 km SSE of Knik River, Alaska 06:06 UTC
4. 1.7 54 km SSW of Glacier View, Alaska 17:48 UTC
5. 1.8 45 km S of Glacier View, Alaska 00:12 UTC
6. 1.2 52 km ESE of Knik River, Alaska 10:12 UTC
7. 2.4 40 km SSE of Chickaloon, Alaska 15:32 UTC
8. 1.2 31 km SE of Knik River, Alaska 07:14 UTC
9. 1.3 62 km S of Glacier View, Alaska 00:31 UTC
10. 1.5 47 km ESE of Knik River, Alaska 00:45 UTC
11. 1.4 64 km S of Glacier View, Alaska 23:50 UTC
12. 1.1 20 km ESE of Chickaloon, Alaska 07:53 UTC
13. 1.3 62 km NW of Tatitlek, Alaska 06:05 UTC
14. 0.9 60 km WNW of Tatitlek, Alaska 03:42 UTC
15. 1.3 62 km NE of Whittier, Alaska 01:41 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:30 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.