QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

20 km ENE of Willow, Alaska

· 38 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 48 kmAnchorage Municipality 78 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 1.8 (ml)
Depth
38 km below the surface
Felt
no reports yet
Nearest
Matanuska-Susitna Borough, 48 km NNE
Status
Reviewed by a seismologist

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

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 61.8453, -149.7016. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Matanuska-Susitna Borough, AK 48 km (30 mi) SSW of here earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 78 km (48 mi) NNW of here earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 1.5 17 km ESE of Susitna North, Alaska
  2. 1.5 16 km NNE of Willow, Alaska
  3. 2.1 5 km S of Meadow Lakes, Alaska
  4. 1.5 20 km ESE of Susitna North, Alaska
  5. 1.5 10 km WSW of Big Lake, Alaska
  6. 2.6 14 km SE of Susitna North, Alaska
  7. 1.8 12 km NNE of Meadow Lakes, Alaska
  8. 1.6 14 km NNE of Susitna North, Alaska
  9. 1.7 12 km ENE of Willow, Alaska
  10. 1.6 19 km WNW of Fishhook, Alaska
  11. 2.4 27 km E of Susitna North, Alaska
  12. 1.9 23 km ENE of Willow, Alaska
  13. 2.1 7 km N of Susitna North, Alaska
  14. 2.8 21 km N of Meadow Lakes, Alaska
  15. 2.0 23 km WNW of Fishhook, 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 4.1 on 2016-08-02 — it released about 2,800 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.