QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

21 km W of Willow, Alaska

· 59 km deep · released about 1.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 76 kmAnchorage Municipality 89 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 3.3 (ml)
Depth
59 km below the surface
Felt
3 reports · strongest reported intensity II
Measured shaking
intensity III (ShakeMap)
Nearest
Matanuska-Susitna Borough, 76 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 983 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 3 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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 61.7502, -150.4497. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Matanuska-Susitna Borough, AK 76 km (47 mi) SW of here earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 89 km (55 mi) NW of here earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 2.5 2 km SSE of Big Lake, Alaska
  2. 1.9 14 km E of Susitna, Alaska
  3. 1.6 27 km ENE of Skwentna, Alaska
  4. 2.1 10 km ESE of Susitna, Alaska
  5. 1.8 6 km SSE of Big Lake, Alaska
  6. 1.6 27 km NNW of Susitna, Alaska
  7. 1.5 6 km S of Willow, Alaska
  8. 1.5 20 km NW of Susitna, Alaska
  9. 1.5 11 km ENE of Susitna, Alaska
  10. 1.8 29 km SW of Susitna North, Alaska
  11. 1.9 3 km N of Big Lake, Alaska
  12. 1.5 8 km SSW of Big Lake, Alaska
  13. 1.9 37 km E of Skwentna, Alaska
  14. 1.7 32 km NW of Susitna, Alaska
  15. 1.5 14 km NNE 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 710 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.