QuakeIndex

Earthquake · reviewed by a seismologist

M 4.6mb

70 km ENE of Port Alsworth, Alaska

· 148 km deep · released about 120 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 41 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 4.6 (mb)
Depth
148 km below the surface
Felt
7 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Kenai Peninsula Borough, 41 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 878 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 7 people have reported feeling it to USGS.

How big was it?

This earthquake released about 120 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 1,400× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 63× the energy of this one
  3. Magna, Utah 2020 M 5.7 45× the energy of this one
  4. This earthquake M 4.6 about 120 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 250× 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 60.3641, -153.0756. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kenai Peninsula Borough, AK 41 km (26 mi) W 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

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

  1. 1.6 65 km WNW of Happy Valley, Alaska
  2. 1.7 53 km ENE of Pedro Bay, Alaska
  3. 1.7 59 km ENE of Pedro Bay, Alaska
  4. 1.9 65 km NE of Pedro Bay, Alaska
  5. 1.7 49 km WNW of Ninilchik, Alaska
  6. 2.3 81 km ENE of Port Alsworth, Alaska
  7. 1.8 68 km WNW of Ninilchik, Alaska
  8. 1.9 68 km ENE of Pedro Bay, Alaska
  9. 2.0 48 km E of Port Alsworth, Alaska
  10. 1.9 73 km E of Port Alsworth, Alaska
  11. 1.6 63 km WNW of Ninilchik, Alaska
  12. 1.8 73 km WNW of Ninilchik, Alaska
  13. 2.2 46 km NE of Pedro Bay, Alaska
  14. 1.5 64 km WNW of Anchor Point, Alaska
  15. 1.8 55 km E of Port Alsworth, 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 5.9 on 2021-12-21 — it released about 89 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.