QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Nikiski, AK

No earthquake was likely felt in Nikiski in the 24 hours to 2:08 pm AKST (23:08 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 1.8 earthquake was recorded 42 km (26 mi) north-northeast of Nikiski, AK, at 7:59 pm AKST on 7 November 2023 (04:59 UTC), 8.6 km deep. 1 person has reported feeling it to USGS.

USGS: Southern Alaska

60 km (37 mi) WSW of Anchorage, AK

7:59 pm AKST, Nov 7, 2023 · · 8.6 km deep · released about 15 lb of TNT

Every earthquake near Nikiski Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 90 kmKenai Peninsula Borough 105 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
7:59 pm AKST on 7 November 2023 ()
Where
42 km (26 mi) north-northeast of Nikiski, AK · earthquakes near Nikiski
Magnitude
M 1.8 (ml)
Depth
8.6 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Anchorage Municipality, 90 km ENE
Nearest mapped fault
Granite Point anticline (Cook Inlet folds), 18 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 1087 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Nikiski, 42 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 4.8 on 2022-07-12 — about 32,000 times the energy of this one.

Before 2016, the USGS record lists 19 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 Southern Alaska · 12 km NW of this epicentre
  2. 6.8 4 km NE of Beluga, Alaska · 17 km NNW of this epicentre
  3. 6.7 6 km WNW of Nikiski, Alaska · 42 km SW of this epicentre
  4. 6.4 19 km SSE of Tyonek, Alaska · 16 km SSW of this epicentre
  5. 6.0 Southern Alaska · 45 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 61.0246, -150.9348. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 90 km (56 mi) ENE earthquakes near Anchorage Municipality
Kenai Peninsula Borough, AK 105 km (65 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

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

  1. 1.5 19 km E of Beluga, Alaska
  2. 1.6 19 km NNE of Sterling, Alaska
  3. 1.5 18 km SSE of Point Possession, Alaska
  4. 1.7 11 km SE of Tyonek, Alaska
  5. 1.5 17 km SSW of Point Possession, Alaska
  6. 1.6 2 km SE of Point Possession, Alaska
  7. 1.7 18 km SSE of Tyonek, Alaska
  8. 1.7 24 km SSW of Susitna, Alaska
  9. 1.6 26 km ENE of Beluga, Alaska
  10. 3.0 15 km W of Tyonek, Alaska
  11. 2.4 14 km NNE of Sterling, Alaska
  12. 1.6 23 km SSE of Point Possession, Alaska
  13. 1.8 27 km NNW of Beluga, Alaska
  14. 1.8 4 km SE of Point Possession, Alaska
  15. 1.6 3 km NNW 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.