QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

31 km SE of Knik River, Alaska

· 27 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 46 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 2.1 (ml)
Depth
27 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Anchorage Municipality, 46 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1147 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 lb of TNT

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 61.2836, -148.4530. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Anchorage Municipality, AK 46 km (29 mi) ENE of here earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 122 km (76 mi) SSE 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

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

  1. 1.8 15 km S of Chickaloon, Alaska
  2. 2.0 19 km SE of Chickaloon, Alaska
  3. 1.5 40 km NNE of Whittier, Alaska
  4. 1.5 23 km ENE of Girdwood, Alaska
  5. 1.8 17 km SE of Chickaloon, Alaska
  6. 1.5 36 km NNE of Whittier, Alaska
  7. 2.5 Southern Alaska
  8. 1.5 45 km E of Knik River, Alaska
  9. 1.7 34 km NE of Whittier, Alaska
  10. 1.7 41 km SSW of Glacier View, Alaska
  11. 1.7 38 km NNE of Whittier, Alaska
  12. 1.6 19 km SE of Chickaloon, Alaska
  13. 1.6 45 km NNE of Whittier, Alaska
  14. 2.1 17 km SSE of Chickaloon, Alaska
  15. 1.8 38 km NNE of Whittier, 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.