QuakeIndex

Earthquake · reviewed by a seismologist

M 4.3mb

142 km E of Atka, Alaska

Yes. A magnitude 4.3 earthquake was recorded 142 km E of Atka, Alaska at 10:34 UTC on 2024-12-07, 50 km deep.

· 50 km deep · released about 43 tons of TNT

10 km30 km60 km120 km N
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 4.3 (mb)
Depth
50 km below the surface
Felt
no reports yet
Measured shaking
intensity III (ShakeMap)
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 636 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 110 km (68 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 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 5.0 on 2023-11-03 — about 11 times the energy of this one.

Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.3 Fox Islands, Aleutian Islands, Alaska · 24 km SE of this epicentre
  2. 6.9 170 km E of Atka, Alaska · 28 km E of this epicentre
  3. 6.5 143 km ESE of Atka, Alaska · 50 km S of this epicentre
  4. 6.3 143 km E of Atka, Alaska · 20 km S of this epicentre
  5. 6.1 157 km ESE of Atka, Alaska · 37 km SSE 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 52.1909, -172.1111. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.9 179 km E of Atka, Alaska
  2. 2.9 179 km E of Atka, Alaska
  3. 3.5 176 km E of Atka, Alaska
  4. 2.8 176 km E of Atka, Alaska
  5. 3.9 170 km E of Atka, Alaska
  6. 4.4 171 km E of Atka, Alaska
  7. 3.0 173 km E of Atka, Alaska
  8. 4.4 167 km E of Atka, Alaska
  9. 3.5 178 km E of Atka, Alaska
  10. 5.6 172 km ENE of Atka, Alaska
  11. 3.2 174 km ENE of Atka, Alaska
  12. 4.9 168 km E of Atka, Alaska
  13. 3.2 116 km E of Atka, Alaska
  14. 3.4 182 km E of Atka, Alaska
  15. 3.2 130 km ESE of Atka, 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.