QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

163 km SSE of Old Harbor, Alaska

· 12 km deep · released about 170 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 2.5 (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 589 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 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 55.8508, -152.2611. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 2.6 121 km SSE of Old Harbor, Alaska
  2. 2.5 167 km SSE of Old Harbor, Alaska
  3. 2.4 153 km SSE of Old Harbor, Alaska
  4. 3.0 188 km SSE of Old Harbor, Alaska
  5. 3.2 115 km SSE of Old Harbor, Alaska
  6. 2.5 194 km SSE of Old Harbor, Alaska
  7. 2.5 168 km SSE of Old Harbor, Alaska
  8. 3.1 150 km SE of Old Harbor, Alaska
  9. 3.2 142 km SE of Old Harbor, Alaska
  10. 3.3 130 km SSE of Old Harbor, Alaska
  11. 3.1 134 km SSE of Old Harbor, Alaska
  12. 2.5 127 km SSE of Old Harbor, Alaska
  13. 2.3 133 km SE of Old Harbor, Alaska
  14. 3.0 126 km SSE of Old Harbor, Alaska
  15. 2.7 116 km SSE of Old Harbor, 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.