QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

257 km SSW of Adak, Alaska

· 10 km deep · released about 340 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 2.7 (ml)
Depth
10 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 866 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 49.7829, -178.2021. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.1 257 km SSW of Adak, Alaska
  2. 2.5 232 km SSW of Adak, Alaska
  3. 3.2 236 km SSW of Adak, Alaska
  4. 2.8 244 km SSW of Adak, Alaska
  5. 2.6 271 km SSW of Adak, Alaska
  6. 3.9 265 km SSW of Adak, Alaska
  7. 2.4 249 km SSW of Adak, Alaska
  8. 2.9 246 km SSW of Adak, Alaska
  9. 2.8 244 km SSW of Adak, Alaska
  10. 2.6 220 km SSW of Adak, Alaska
  11. 2.3 220 km SSW of Adak, Alaska
  12. 4.0 250 km SSW of Adak, Alaska
  13. 2.8 240 km SSW of Adak, Alaska
  14. 2.3 243 km SSW of Adak, Alaska
  15. 2.8 220 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.8 on 2018-08-10 — it released about 1,400 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.