QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

187 km SE of Atka, Alaska

· 10 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
10 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1527 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 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.

Where

Epicentre 50.8804, -172.5056. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.3 213 km SE of Atka, Alaska
  2. 3.7 195 km SE of Atka, Alaska
  3. 3.8 176 km SSE of Atka, Alaska
  4. 3.7 176 km SSE of Atka, Alaska
  5. 2.9 189 km SSE of Atka, Alaska
  6. 2.7 145 km SE of Atka, Alaska
  7. 2.9 199 km SSE of Atka, Alaska
  8. 3.6 212 km SE of Atka, Alaska
  9. 2.9 184 km SSE of Atka, Alaska
  10. 2.3 193 km SE of Atka, Alaska
  11. 2.8 163 km SSE of Atka, Alaska
  12. 3.4 214 km SSE of Atka, Alaska
  13. 2.9 181 km SSE of Atka, Alaska
  14. 3.9 198 km SSE of Atka, Alaska
  15. 3.8 184 km SSE of Atka, 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 4.2 on 2019-03-17 — it released about 130 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.