QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

25 km SW of Susitna, Alaska

· 62 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 89 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 3.9 (ml)
Depth
62 km below the surface
Felt
62 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Nearest
Anchorage Municipality, 89 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1133 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 62 people have reported feeling it to USGS.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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 61.4012, -150.8890. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Anchorage Municipality, AK 89 km (56 mi) WNW of here earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 121 km (75 mi) SW of here earthquakes near Matanuska-Susitna Borough
Kenai Peninsula Borough, AK 139 km (86 mi) NNE of here earthquakes near Kenai Peninsula Borough

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

Aftershocks so far

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

  1. 1.5 38 km S of Skwentna, Alaska
  2. 2.0 23 km NE of Beluga, Alaska
  3. 1.6 28 km WSW of Susitna, Alaska
  4. 1.9 Southern Alaska
  5. 1.9 11 km SW of Susitna, Alaska
  6. 2.0 28 km SE of Skwentna, Alaska
  7. 2.4 20 km ENE of Beluga, Alaska
  8. 2.5 16 km W of Willow, Alaska
  9. 1.8 7 km NE of Beluga, Alaska
  10. 1.7 14 km ESE of Beluga, Alaska
  11. 1.5 38 km W of Susitna, Alaska
  12. 2.5 20 km SW of Susitna, Alaska
  13. 2.0 10 km SSE of Susitna, Alaska
  14. 1.7 Southern Alaska
  15. 2.4 22 km SSE of Susitna, 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 5.2 on 2019-09-17 — it released about 89 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.