QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4ml

201 km SSW of Atka, Alaska

Yes. A magnitude 3.4 earthquake was recorded 201 km SSW of Atka, Alaska at 13:11 UTC on 2024-12-15, 10 km deep.

· 10 km deep · released about 1.9 tons of TNT

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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 3.4 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest mapped fault
Alaska-Aleutian subduction zone, 24 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 634 days ago

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 57 km (35 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 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 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 4.6 on 2023-04-22 — about 63 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 216 km SSE of Adak, Alaska · 49 km SW of this epicentre
  2. 6.6 208 km S of Atka, Alaska · 34 km ESE of this epicentre
  3. 6.1 193 km SE of Adak, Alaska · 14 km NW of this epicentre
  4. 5.6 178 km SE of Adak, Alaska · 29 km NNW of this epicentre
  5. 5.6 185 km S of Atka, Alaska · 20 km NE 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 50.4238, -174.7758. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.9 186 km S of Atka, Alaska
  2. 2.7 192 km SSE of Adak, Alaska
  3. 2.9 164 km SSW of Atka, Alaska
  4. 2.5 162 km SSW of Atka, Alaska
  5. 2.6 209 km SE of Adak, Alaska
  6. 3.1 176 km SE of Adak, Alaska
  7. 2.6 213 km S of Atka, Alaska
  8. 2.6 155 km SSW of Atka, Alaska
  9. 2.7 207 km SSE of Adak, Alaska
  10. 2.6 223 km SSE of Adak, Alaska
  11. 2.4 159 km S of Atka, Alaska
  12. 2.5 158 km SE of Adak, Alaska
  13. 3.0 204 km SSE of Adak, Alaska
  14. 2.7 174 km SSE of Adak, Alaska
  15. 3.2 191 km SSE of Adak, 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.