QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

40 km SSE of Old Harbor, Alaska

· 11 km deep · released about 170 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kodiak Island Borough 107 km
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
11 km below the surface
Felt
no reports yet
Nearest
Kodiak Island Borough, 107 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1903 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 56.8855, -152.9980. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kodiak Island Borough, AK 107 km (66 mi) SSE of here earthquakes near Kodiak Island Borough

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 1.9 36 km E of Old Harbor, Alaska
  2. 1.9 30 km SSE of Old Harbor, Alaska
  3. 2.2 88 km SSE of Old Harbor, Alaska
  4. 2.4 103 km SSE of Old Harbor, Alaska
  5. 2.0 54 km SSE of Old Harbor, Alaska
  6. 1.6 38 km SE of Old Harbor, Alaska
  7. 1.6 6 km WSW of Old Harbor, Alaska
  8. 1.5 55 km SE of Old Harbor, Alaska
  9. 1.7 22 km SSW of Old Harbor, Alaska
  10. 2.2 37 km S of Old Harbor, Alaska
  11. 1.9 51 km S of Old Harbor, Alaska
  12. 2.2 Kodiak Island region, Alaska
  13. 2.6 53 km SSE of Old Harbor, Alaska
  14. 3.0 41 km SE of Old Harbor, Alaska
  15. 1.7 34 km E 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.4 on 2017-05-11 — it released about 22,000 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.