QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

2 km SW of Knik, Alaska

· 41 km deep · released about 1,300 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 39 kmMatanuska-Susitna Borough 93 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 3.1 (ml)
Depth
41 km below the surface
Felt
no reports yet
Measured shaking
intensity III (ShakeMap)
Nearest
Anchorage Municipality, 39 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1137 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 61.4421, -149.7594. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Anchorage Municipality, AK 39 km (24 mi) NW of here earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 93 km (58 mi) S 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

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

  1. 2.6 4 km SSE of Big Lake, Alaska
  2. 2.6 3 km SSE of Big Lake, Alaska
  3. 2.6 2 km SSW of Big Lake, Alaska
  4. 2.2 4 km SE of Big Lake, Alaska
  5. 3.5 10 km NNW of Point MacKenzie, Alaska
  6. 2.6 8 km SSW of Big Lake, Alaska
  7. 3.8 6 km WSW of Knik, Alaska
  8. 2.8 6 km WNW of Point MacKenzie, Alaska
  9. 3.0 7 km E of Big Lake, Alaska
  10. 2.8 2 km WSW of Point MacKenzie, Alaska
  11. 2.4 6 km SSW of Big Lake, Alaska
  12. 2.7 9 km NNW of Point MacKenzie, Alaska
  13. 3.1 6 km S of Big Lake, Alaska
  14. 2.6 9 km SSW of Big Lake, Alaska
  15. 3.0 6 km SSW of Big Lake, 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 7.1 on 2018-11-30 — it released about 1,000,000 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.