QuakeIndex

Earthquake · reviewed by a seismologist

M 4.5ml

28 km S of Susitna, Alaska

· 72 km deep · released about 85 tons of TNT

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10 km30 km60 km120 km N Anchorage Municipality 67 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 4.5 (ml)
Depth
72 km below the surface
Felt
427 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Anchorage Municipality, 67 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1138 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 427 people have reported feeling it to USGS.

How big was it?

This earthquake released about 85 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 2,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 89× the energy of this one
  3. Magna, Utah 2020 M 5.7 63× the energy of this one
  4. This earthquake M 4.5 about 85 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 180× 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 61.2868, -150.5223. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Anchorage Municipality, AK 67 km (42 mi) W of here earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 121 km (75 mi) SSW of here earthquakes near Matanuska-Susitna Borough
Kenai Peninsula Borough, AK 141 km (88 mi) NE 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

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

  1. 1.6 22 km WNW of Susitna, Alaska
  2. 1.7 2 km NNE of Beluga, Alaska
  3. 1.9 27 km S of Susitna, Alaska
  4. 1.5 8 km WNW of Point Possession, Alaska
  5. 1.6 16 km SE of Susitna, Alaska
  6. 1.9 22 km WSW of Susitna, Alaska
  7. 1.6 7 km NE of Susitna, Alaska
  8. 2.3 11 km SE of Tyonek, Alaska
  9. 2.8 18 km S of Susitna, Alaska
  10. 1.7 24 km E of Point Possession, Alaska
  11. 2.1 11 km NNW of Big Lake, Alaska
  12. 1.6 7 km S of Big Lake, Alaska
  13. 2.0 26 km WSW of Anchorage, Alaska
  14. 1.5 27 km E of Point Possession, Alaska
  15. 1.6 26 km NE of Point Possession, 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 4.2 on 2018-07-06.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.