QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

167 km S of Adak, Alaska

Yes. A magnitude 2.2 earthquake was recorded 167 km S of Adak, Alaska at 02:57 UTC on 2022-01-18, 25 km deep.

· 25 km deep · released about 60 lb 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 2.2 (ml)
Depth
25 km below the surface
Felt
no reports yet
Nearest mapped fault
Alaska-Aleutian subduction zone, 10 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 1738 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause 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 60 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 250,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 180,000× the energy of this one
  3. Around the size people start to feel M 3.0 16× the energy of this one
  4. This earthquake M 2.2 about 60 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 5.4 on 2019-09-09 — about 63,000 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 146 km S of Adak, Alaska · 23 km NNW of this epicentre
  2. 6.2 204 km S of Adak, Alaska · 37 km S of this epicentre
  3. 6.1 198 km S of Adak, Alaska · 33 km SSW of this epicentre
  4. 6.1 189 km S of Adak, Alaska · 29 km SW of this epicentre
  5. 6.0 136 km S of Adak, Alaska · 36 km NNW 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 50.3704, -176.7233. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.2 183 km SSW of Adak, Alaska
  2. 3.0 202 km S of Adak, Alaska
  3. 2.6 184 km S of Adak, Alaska
  4. 2.9 189 km S of Adak, Alaska
  5. 3.9 191 km S of Adak, Alaska
  6. 3.3 145 km SSW of Adak, Alaska
  7. 2.5 181 km S of Adak, Alaska
  8. 3.1 213 km S of Adak, Alaska
  9. 2.6 175 km S of Adak, Alaska
  10. 2.8 171 km S of Adak, Alaska
  11. 3.6 184 km S of Adak, Alaska
  12. 2.1 Andreanof Islands, Aleutian Islands, Alaska
  13. 2.6 139 km S of Adak, Alaska
  14. 2.6 175 km S of Adak, Alaska
  15. 4.0 173 km SSW 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.