QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Fox Islands, Aleutian Islands, Alaska

Yes. A magnitude 2.8 earthquake was recorded in the Fox Islands, Aleutian Islands, Alaska at 15:34 UTC on 2022-07-07, 35 km deep.

· 35 km deep · released about 480 lb of TNT

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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 2.8 (ml)
Depth
35 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1523 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 it was probably too small to be felt, even directly above it. 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 5.9 on 2018-08-25 — about 45,000 times the energy of this one.

Before 2016, the USGS record lists 54 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.1 Fox Islands, Aleutian Islands, Alaska · 33 km S of this epicentre
  2. 6.2 179 km SW of Nikolski, Alaska · 16 km ENE of this epicentre
  3. 6.2 Fox Islands, Aleutian Islands, Alaska · 19 km SE of this epicentre
  4. 6.1 185 km ESE of Atka, Alaska · 45 km WNW of this epicentre
  5. 6.1 207 km ESE of Atka, Alaska · 28 km WSW 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 51.7452, -170.9276. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.9 151 km SW of Nikolski, Alaska
  2. 2.6 184 km SW of Nikolski, Alaska
  3. 3.2 197 km ESE of Atka, Alaska
  4. 3.1 215 km ESE of Atka, Alaska
  5. 3.0 217 km SW of Nikolski, Alaska
  6. 3.8 190 km E of Atka, Alaska
  7. 3.0 200 km SW of Nikolski, Alaska
  8. 3.3 194 km SW of Nikolski, Alaska
  9. 3.5 187 km SW of Nikolski, Alaska
  10. 4.8 186 km SW of Nikolski, Alaska
  11. 3.2 187 km SW of Nikolski, Alaska
  12. 4.0 176 km SW of Nikolski, Alaska
  13. 4.5 186 km SW of Nikolski, Alaska
  14. 3.6 170 km SW of Nikolski, Alaska
  15. 2.9 169 km SW of Nikolski, 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.