QuakeIndex

Earthquake · reviewed by a seismologist

M 4.1mb

Southern Alaska

Yes. A magnitude 4.1 earthquake was recorded in Southern Alaska, at 8:02 pm AKDT on 30 October 2022 (04:02 UTC), 13 km deep. 15 people have reported feeling it to USGS.

· 13 km deep · released about 21 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 24 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 4.1 (mb)
Depth
13 km below the surface
Felt
15 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Nearest
Kenai Peninsula Borough, 24 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1401 days ago

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 104 km (65 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 21 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 7,900× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 350× the energy of this one
  3. Magna, Utah 2020 M 5.7 250× the energy of this one
  4. This earthquake M 4.1 about 21 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 45× 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 5.9 on 2021-12-21 — about 500 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 75 km WNW of Ninilchik, Alaska · 20 km SW of this epicentre
  2. 6.2 70 km E of Port Alsworth, Alaska · 36 km SSW of this epicentre
  3. 6.1 73 km WNW of Ninilchik, Alaska · 8 km SW of this epicentre
  4. 5.9 66 km ENE of Pedro Bay, Alaska · 48 km SSW of this epicentre
  5. 5.6 63 km WNW of Ninilchik, Alaska · 20 km S of this epicentre

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 60.4327, -152.7390. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 24 km (15 mi) ESE earthquakes near Kenai Peninsula Borough

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. 1.5 69 km WNW of Nikiski, Alaska
  2. 1.6 70 km WNW of Happy Valley, Alaska
  3. 1.7 71 km WNW of Ninilchik, Alaska
  4. 1.9 68 km WNW of Happy Valley, Alaska
  5. 2.2 69 km ENE of Pedro Bay, Alaska
  6. 1.9 48 km NW of Ninilchik, Alaska
  7. 1.8 66 km W of Happy Valley, Alaska
  8. 2.1 62 km ENE of Pedro Bay, Alaska
  9. 1.8 67 km W of Nikiski, Alaska
  10. 1.9 55 km WNW of Ninilchik, Alaska
  11. 2.1 69 km ENE of Port Alsworth, Alaska
  12. 2.0 44 km W of Happy Valley, Alaska
  13. 2.2 70 km WNW of Happy Valley, Alaska
  14. 2.0 56 km W of Nikiski, Alaska
  15. 2.1 Southern Alaska

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

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.