QuakeIndex

Earthquake · reviewed by a seismologist

M 4.3ml

31 km SW of Skwentna, Alaska

· 111 km deep · released about 43 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N
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 4.3 (ml)
Depth
111 km below the surface
Felt
57 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1607 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 57 people have reported feeling it to USGS.

How big was it?

This earthquake released about 43 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 4,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 180× the energy of this one
  3. Magna, Utah 2020 M 5.7 130× the energy of this one
  4. This earthquake M 4.3 about 43 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 89× 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 61.7854, -151.8071. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.8 39 km WSW of Skwentna, Alaska
  2. 1.6 38 km SW of Skwentna, Alaska
  3. 1.5 2 km SSE of Skwentna, Alaska
  4. 1.7 32 km WSW of Skwentna, Alaska
  5. 1.6 18 km N of Skwentna, Alaska
  6. 2.0 39 km SSW of Skwentna, Alaska
  7. 1.6 58 km SSW of Skwentna, Alaska
  8. 1.6 63 km WNW of Beluga, Alaska
  9. 1.5 11 km SSW of Skwentna, Alaska
  10. 1.7 36 km WSW of Skwentna, Alaska
  11. 2.2 38 km SSW of Skwentna, Alaska
  12. 1.9 14 km N of Skwentna, Alaska
  13. 2.8 19 km N of Skwentna, Alaska
  14. 1.6 29 km WSW of Skwentna, Alaska
  15. 2.5 40 km WNW of Skwentna, 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 4.5 on 2021-03-03 — it released about 2 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.