QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

225 km SE of Unalaska, Alaska

· 12 km deep · released about 60 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 2.2 (ml)
Depth
12 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1236 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

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.

Where

Epicentre 52.2395, -164.5355. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.9 194 km SSE of Akutan, Alaska
  2. 2.7 182 km SSE of Unalaska, Alaska
  3. 3.5 175 km SE of Unalaska, Alaska
  4. 3.0 184 km SSE of Akutan, Alaska
  5. 2.4 193 km SSE of Akutan, Alaska
  6. 2.9 207 km SSE of Unalaska, Alaska
  7. 2.2 230 km SSE of Unalaska, Alaska
  8. 3.0 255 km SSE of Unalaska, Alaska
  9. 2.6 206 km SSE of Akutan, Alaska
  10. 3.2 230 km SSE of Akutan, Alaska
  11. 2.7 179 km SSE of Akutan, Alaska
  12. 3.0 201 km SSE of Akutan, Alaska
  13. 2.3 192 km SSE of Unalaska, Alaska
  14. 2.7 207 km SSE of Unalaska, Alaska
  15. 3.2 210 km SSE of Unalaska, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.1 on 2018-12-23 — it released about 710 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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