QuakeIndex

Earthquake · reviewed by a seismologist

M 4.1mw

19 km WSW of Skwentna, Alaska

· 100 km deep · released about 21 tons of TNT

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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 4.1 (mw)
Depth
100 km below the surface
Felt
10 reports · strongest reported intensity IV
Nearest
Matanuska-Susitna Borough, 123 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1151 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 10 people have reported feeling it to USGS.

How big was it?

This earthquake released about 21 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 7,900× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 350× the energy of this one
  3. Magna, Utah 2020 M 5.7 250× the energy of this one
  4. This earthquake M 4.1 about 21 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 45× 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 61.9195, -151.7478. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Matanuska-Susitna Borough, AK 123 km (76 mi) WSW of here earthquakes near Matanuska-Susitna Borough

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

Aftershocks so far

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

  1. 2.1 41 km WNW of Skwentna, Alaska
  2. 1.6 7 km WSW of Skwentna, Alaska
  3. 1.9 41 km N of Skwentna, Alaska
  4. 1.6 43 km WNW of Skwentna, Alaska
  5. 1.6 39 km WNW of Susitna, Alaska
  6. 1.7 42 km WNW of Skwentna, Alaska
  7. 1.8 23 km W of Skwentna, Alaska
  8. 1.5 34 km NW of Skwentna, Alaska
  9. 1.7 34 km SW of Skwentna, Alaska
  10. 1.5 34 km WSW of Skwentna, Alaska
  11. 1.7 42 km WNW of Skwentna, Alaska
  12. 1.7 46 km SW of Skwentna, Alaska
  13. 1.6 Southern Alaska
  14. 1.6 Central Alaska
  15. 1.6 36 km SW of Skwentna, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.