QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

14 km SSW of Halibut Cove, Alaska

· 45 km deep · released about 11 tons of TNT

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10 km30 km60 km120 km N Kenai Peninsula Borough 114 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 3.9 (ml)
Depth
45 km below the surface
Felt
7 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Kenai Peninsula Borough, 114 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1144 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 7 people have reported feeling it to USGS.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× more

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 59.4701, -151.3224. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kenai Peninsula Borough, AK 114 km (71 mi) SSE of here earthquakes near Kenai Peninsula Borough

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

Aftershocks so far

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

  1. 1.5 26 km S of Halibut Cove, Alaska
  2. 4.3 29 km SE of Seldovia Village, Alaska
  3. 2.1 11 km WSW of Halibut Cove, Alaska
  4. 1.7 12 km W of Fox River, Alaska
  5. 1.5 14 km S of Anchor Point, Alaska
  6. 1.9 16 km SSE of Fox River, Alaska
  7. 1.9 13 km SSW of Halibut Cove, Alaska
  8. 1.6 19 km ENE of Halibut Cove, Alaska
  9. 1.5 13 km SSE of Port Graham, Alaska
  10. 1.7 13 km W of Fox River, Alaska
  11. 1.6 35 km SSE of Port Graham, Alaska
  12. 2.1 6 km NW of Nikolaevsk, Alaska
  13. 1.6 12 km SSW of Fox River, Alaska
  14. 2.2 31 km SSE of Port Graham, Alaska
  15. 1.5 9 km ENE of Nikolaevsk, 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 4.0 on 2016-10-14 — it released about 1.4 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.