QuakeIndex

Earthquake · reviewed by a seismologist

M 4.5mwr

6 km NW of Willow, Alaska

· 41 km deep · released about 85 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 61 kmAnchorage Municipality 82 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 4.5 (mwr)
Depth
41 km below the surface
Felt
1659 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Matanuska-Susitna Borough, 61 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 304 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 1659 people have reported feeling it to USGS.

How big was it?

This earthquake released about 85 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 2,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 89× the energy of this one
  3. Magna, Utah 2020 M 5.7 63× the energy of this one
  4. This earthquake M 4.5 about 85 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 180× 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 61.7972, -150.1102. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Matanuska-Susitna Borough, AK 61 km (38 mi) SSW of here earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 82 km (51 mi) NNW of here earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 3.0 12 km SSE of Susitna North, Alaska
  2. 2.7 11 km E of Susitna, Alaska
  3. 1.5 12 km NNE of Susitna, Alaska
  4. 1.6 16 km S of Susitna, Alaska
  5. 2.2 3 km S of Susitna, Alaska
  6. 2.1 3 km SSE of Willow, Alaska
  7. 1.7 9 km SSW of Big Lake, Alaska
  8. 2.8 9 km NW of Susitna, Alaska
  9. 1.5 6 km SE of Willow, Alaska
  10. 2.9 4 km NW of Point MacKenzie, Alaska
  11. 1.5 9 km NE of Susitna, Alaska
  12. 2.4 12 km NW of Willow, Alaska
  13. 1.5 13 km N of Willow, Alaska
  14. 2.5 12 km WNW of Willow, Alaska
  15. 1.6 7 km N of Willow, 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 5.2 on 2018-11-30 — it released about 11 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.