QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Nikiski, AK

No earthquake was likely felt in Nikiski in the 24 hours to 2:05 am AKST (11:05 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 1.6 earthquake was recorded 41 km (26 mi) north of Nikiski, AK, at 12:26 am AKST on 24 February 2021 (09:26 UTC), 66 km deep.

USGS: 1 km SW of Tyonek, Alaska

70 km (43 mi) WSW of Anchorage, AK

12:26 am AKST, Feb 24, 2021 · · 66 km deep · released about 7.6 lb of TNT

Every earthquake near Nikiski Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kenai Peninsula Borough 100 kmAnchorage Municipality 102 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
12:26 am AKST on 24 February 2021 ()
Where
41 km (26 mi) north of Nikiski, AK · earthquakes near Nikiski
Magnitude
M 1.6 (ml)
Depth
66 km below the surface
Felt
no reports yet
Nearest
Kenai Peninsula Borough, 100 km SW
Nearest mapped fault
Granite Point anticline (Cook Inlet folds), 6 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2072 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Nikiski, 41 km away, the estimate is intensity I (not felt). 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 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 lb of TNT

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 4.2 on 2018-07-06 — about 7,900 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 Southern Alaska · 5 km NNE of this epicentre
  2. 6.8 4 km NE of Beluga, Alaska · 15 km NNE of this epicentre
  3. 6.7 6 km WNW of Nikiski, Alaska · 40 km SSW of this epicentre
  4. 6.4 19 km SSE of Tyonek, Alaska · 19 km SSE of this epicentre
  5. 6.0 Southern Alaska · 33 km WNW 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 61.0580, -151.1596. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kenai Peninsula Borough, AK 100 km (62 mi) SW earthquakes near Kenai Peninsula Borough
Anchorage Municipality, AK 102 km (63 mi) E earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 2.1 33 km NW of Beluga, Alaska
  2. 1.7 26 km NNW of Nikiski, Alaska
  3. 1.6 16 km SSE of Tyonek, Alaska
  4. 1.5 14 km N of Sterling, Alaska
  5. 2.0 10 km WNW of Point Possession, Alaska
  6. 2.1 12 km ESE of Beluga, Alaska
  7. 1.6 25 km WNW of Beluga, Alaska
  8. 1.6 1 km E of Nikiski, Alaska
  9. 1.9 Kenai Peninsula, Alaska
  10. 1.5 25 km WSW of Susitna, Alaska
  11. 1.5 45 km NW of Beluga, Alaska
  12. 2.4 24 km SSW of Susitna, Alaska
  13. 1.6 14 km SW of Susitna, Alaska
  14. 1.9 14 km WNW of Point Possession, Alaska
  15. 1.9 23 km WNW of Tyonek, 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.