QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

5 km SSE of Big Lake, Alaska

· 36 km deep · released about 43 lb of TNT

10 km30 km60 km120 km N Anchorage Municipality 48 kmMatanuska-Susitna Borough 91 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
36 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Anchorage Municipality, 48 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1382 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 61.4754, -149.9294. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Anchorage Municipality, AK 48 km (30 mi) NW of here earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 91 km (56 mi) SSW 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. 1.7 5 km ENE of Susitna, Alaska
  2. 2.2 13 km N of Meadow Lakes, Alaska
  3. 1.6 1 km ESE of Big Lake, Alaska
  4. 1.6 4 km E of Big Lake, Alaska
  5. 2.9 3 km N of Eagle River, Alaska
  6. 1.5 8 km NNE of Point MacKenzie, Alaska
  7. 3.2 10 km W of Point MacKenzie, Alaska
  8. 2.1 1 km W of Meadow Lakes, Alaska
  9. 1.5 11 km NNE of Houston, Alaska
  10. 1.5 6 km NNW of Willow, Alaska
  11. 1.9 Southern Alaska
  12. 1.7 Southern Alaska
  13. 1.6 4 km ESE of Point MacKenzie, Alaska
  14. 1.8 5 km NW of Eagle River, Alaska
  15. 1.5 8 km SE of Houston, 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 32,000,000 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.