QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0ml

Earthquake near Sterling, AK

No earthquake was likely felt in Sterling in the 24 hours to 5:40 pm AKST (02:40 UTC). The last one was M 2.5, 22 km (13 mi) NNE, at 9:11 pm AKST on 11 November 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Sterling

This page: a magnitude 4.0 earthquake was recorded 47 km (29 mi) north of Sterling, AK, at 3:12 pm AKDT on 31 October 2023 (23:12 UTC), 45 km deep. 249 people have reported feeling it to USGS.

USGS: 3 km NNE of Point Possession, Alaska

50 km (31 mi) SW of Anchorage, AK

3:12 pm AKDT, Oct 31, 2023 · · 45 km deep · released about 15 tons of TNT

Every earthquake near Sterling Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 78 kmKenai Peninsula Borough 111 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
3:12 pm AKDT on 31 October 2023 ()
Where
47 km (29 mi) north of Sterling, AK · earthquakes near Sterling
Magnitude
M 4.0 (ml)
Depth
45 km below the surface
Felt
249 reports · strongest reported intensity IV
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, 78 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1039 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 86 km (53 mi) from the epicentre. In Sterling, 47 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Nikiski 45 km, intensity II · Sterling 47 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 11,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
  3. Magna, Utah 2020 M 5.7 350× the energy of this one
  4. This earthquake M 4.0 about 15 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 32× 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.8 on 2022-07-12 — about 16 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 Southern Alaska · 29 km WNW of this epicentre
  2. 6.8 4 km NE of Beluga, Alaska · 31 km NW of this epicentre
  3. 6.8 24 km ENE of Sterling, Alaska · 37 km SSE of this epicentre
  4. 6.7 6 km WNW of Nikiski, Alaska · 48 km WSW of this epicentre
  5. 6.4 19 km SSE of Tyonek, Alaska · 22 km WSW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 60.9525, -150.6619. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 78 km (49 mi) ENE earthquakes near Anchorage Municipality
Kenai Peninsula Borough, AK 111 km (69 mi) SW earthquakes near Kenai Peninsula Borough

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. 2.3 21 km WSW of Anchorage, Alaska
  2. 1.5 23 km WSW of Point MacKenzie, Alaska
  3. 1.6 7 km SE of Nikiski, Alaska
  4. 2.0 16 km NE of Nikiski, Alaska
  5. 1.5 15 km NNE of Beluga, Alaska
  6. 1.8 18 km SSE of Tyonek, Alaska
  7. 2.1 1 km N of Point Possession, Alaska
  8. 1.5 6 km E of Nikiski, Alaska
  9. 2.5 6 km NNE of Sterling, Alaska
  10. 1.6 12 km S of Tyonek, Alaska
  11. 1.6 10 km S of Tyonek, Alaska
  12. 2.2 22 km ENE of Sterling, Alaska
  13. 1.6 10 km W of Point Possession, Alaska
  14. 1.5 12 km ESE of Nikiski, Alaska
  15. 1.8 1 km NW 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.

On USGS

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