Earthquake near Diamond Ridge, 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 33 km (21 mi) from the epicentre. In Diamond Ridge, 4 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: Diamond Ridge 4 km, intensity II · Homer 5 km, intensity II · Anchor Point 16 km, intensity II · Fritz Creek 20 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 5.4 on 2023-03-19 — about 500 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 25 km NW of Nanwalek, Alaska · 41 km WSW of this epicentre Jun 24, 1963
2. 6.2 16 km WNW of Happy Valley, Alaska · 42 km NNW of this epicentre Dec 24, 1931
3. 6.0 6 km SSE of Fox River, Alaska · 42 km ENE of this epicentre Sep 5, 1961
4. 5.8 23 km WNW of Happy Valley, Alaska · 47 km NW of this epicentre May 10, 2014
5. 5.6 7 km SE of Fritz Creek, Alaska · 23 km E of this epicentre Dec 26, 1959

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 59.6676, -151.6329. 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. 1.5 10 km NE of Nikolaevsk, Alaska 12:51 UTC
2. 1.7 12 km SE of Ninilchik, Alaska 23:39 UTC
3. 2.0 15 km WNW of Anchor Point, Alaska 05:22 UTC
4. 1.6 16 km N of Fritz Creek, Alaska 10:16 UTC
5. 2.5 2 km NNW of Happy Valley, Alaska 19:29 UTC
6. 2.2 8 km ENE of Ninilchik, Alaska 00:02 UTC
7. 2.0 5 km E of Kachemak, Alaska 08:18 UTC
8. 1.8 6 km NW of Nanwalek, Alaska 05:16 UTC
9. 1.9 7 km ENE of Nikolaevsk, Alaska 06:22 UTC
10. 1.9 6 km W of Happy Valley, Alaska 14:44 UTC
11. 2.5 15 km WNW of Happy Valley, Alaska 20:20 UTC
12. 1.9 2 km SW of Homer, Alaska 07:20 UTC
13. 1.8 12 km WNW of Anchor Point, Alaska 13:13 UTC
14. 1.6 8 km W of Ninilchik, Alaska 18:59 UTC
15. 2.2 9 km WNW of Nanwalek, Alaska 19:47 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 10:21 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.