QuakeIndex

Earthquake · automatic estimate, may change

M 3.1ml

Earthquake near Nikiski, AK

No earthquake was likely felt in Nikiski in the 24 hours to 11:20 am AKST (20:20 UTC). The last one was M 4.3, 58 km (36 mi) SSE, at 2:30 am AKST on 1 November 2026, estimated intensity II (weak) in town; 115 felt reports to USGS. Every earthquake near Nikiski

This page: a magnitude 3.1 earthquake was recorded 38 km (24 mi) north of Nikiski, AK, at 4:29 am AKDT on 11 October 2025 (12:29 UTC), 57 km deep. The magnitude and location are an automatic first estimate and may change.

USGS: 13 km WSW of Tyonek, Alaska

82 km (51 mi) WSW of Anchorage, AK

4:29 am AKDT, Oct 11, 2025 · · 57 km deep · released about 1,300 lb of TNT

10 km30 km60 km120 km N Kenai Peninsula Borough 90 kmAnchorage Municipality 113 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
4:29 am AKDT on 11 October 2025 ()
Where
38 km (24 mi) north of Nikiski, AK · earthquakes near Nikiski
Magnitude
M 3.1 (ml)
Depth
57 km below the surface
Felt
no reports yet
Nearest
Kenai Peninsula Borough, 90 km SW
Nearest mapped fault
Granite Point anticline (Cook Inlet folds), 5 km from its surface trace — near is not the same as on
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 316 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Nikiski, 38 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.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 5.2 on 2017-05-30 — about 1,400 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 · 16 km ENE of this epicentre
  2. 6.8 4 km NE of Beluga, Alaska · 25 km NE of this epicentre
  3. 6.7 6 km WNW of Nikiski, Alaska · 35 km S of this epicentre
  4. 6.4 19 km SSE of Tyonek, Alaska · 23 km SE of this epicentre
  5. 6.0 Southern Alaska · 26 km NW 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 61.0335, -151.3746. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 90 km (56 mi) SW earthquakes near Kenai Peninsula Borough
Anchorage Municipality, AK 113 km (70 mi) E earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 1.7 39 km NNW of Beluga, Alaska
  2. 1.7 27 km WNW of Beluga, Alaska
  3. 2.6 36 km NNW of Beluga, Alaska
  4. 2.0 16 km WNW of Nikiski, Alaska
  5. 2.7 25 km WNW of Nikiski, Alaska
  6. 2.0 15 km NW of Beluga, Alaska
  7. 3.3 11 km WNW of Beluga, Alaska
  8. 2.1 38 km NW of Nikiski, Alaska
  9. 1.7 16 km WNW of Beluga, Alaska
  10. 1.6 14 km NNW of Sterling, Alaska
  11. 1.7 15 km WNW of Beluga, Alaska
  12. 4.8 11 km WNW of Beluga, Alaska
  13. 1.5 17 km W of Salamatof, Alaska
  14. 2.1 17 km NNE of Nikiski, Alaska
  15. 2.1 32 km WSW 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.

On USGS

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