QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

240 km S of Atka, Alaska

· 13 km deep · released about 43 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 2.1 (ml)
Depth
13 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1536 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 50.0652, -174.7418. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.9 210 km S of Atka, Alaska
  2. 2.6 236 km S of Atka, Alaska
  3. 3.4 242 km S of Atka, Alaska
  4. 2.8 213 km SSE of Adak, Alaska
  5. 2.6 228 km SSE of Adak, Alaska
  6. 2.5 239 km S of Atka, Alaska
  7. 2.8 194 km SSE of Adak, Alaska
  8. 3.2 232 km S of Atka, Alaska
  9. 2.3 201 km S of Atka, Alaska
  10. 2.8 198 km SSE of Adak, Alaska
  11. 2.8 205 km S of Atka, Alaska
  12. 2.8 208 km SE of Adak, Alaska
  13. 3.3 196 km S of Atka, Alaska
  14. 3.4 201 km SSW of Atka, Alaska
  15. 3.4 196 km S 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.

On USGS

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