QuakeIndex

Earthquake · reviewed by a seismologist

M 4.6mb

Earthquake near Nikiski, AK

No earthquake was likely felt in Nikiski in the 24 hours to 7:06 am AKST (16:06 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 4.6 earthquake was recorded 41 km (25 mi) north of Nikiski, AK, at 7:53 pm AKDT on 12 May 2023 (03:53 UTC), 16 km deep. 300 people have reported feeling it to USGS.

USGS: Southern Alaska

69 km (43 mi) WSW of Anchorage, AK

7:53 pm AKDT, May 12, 2023 · · 16 km deep · released about 120 tons 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 101 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
7:53 pm AKDT on 12 May 2023 ()
Where
41 km (25 mi) north of Nikiski, AK · earthquakes near Nikiski
Magnitude
M 4.6 (mb)
Depth
16 km below the surface
Felt
300 reports · strongest reported intensity III
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
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 1210 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 148 km (92 mi) from the epicentre. In Nikiski, 41 km away, the estimate is intensity III (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 41 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 120 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 1,400× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 63× the energy of this one
  3. Magna, Utah 2020 M 5.7 45× the energy of this one
  4. This earthquake M 4.6 about 120 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 250× 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 2 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 · 18 km SSE of this epicentre
  5. 6.0 Southern Alaska · 34 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 61.0517, -151.1442. 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 101 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

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

  1. 1.8 Southern Alaska
  2. 1.6 17 km WNW of Tyonek, Alaska
  3. 1.6 35 km NNW of Beluga, Alaska
  4. 1.5 32 km NW of Beluga, Alaska
  5. 1.7 15 km NW of Beluga, Alaska
  6. 1.8 19 km ENE of Nikiski, Alaska
  7. 2.1 32 km NW of Beluga, Alaska
  8. 2.0 16 km NNW of Point Possession, Alaska
  9. 2.0 0 km NNW of Salamatof, Alaska
  10. 1.5 Southern Alaska
  11. 1.8 28 km NNW of Beluga, Alaska
  12. 2.0 13 km SSW of Tyonek, Alaska
  13. 1.5 20 km WNW of Beluga, Alaska
  14. 1.6 22 km WSW of Tyonek, Alaska
  15. 2.1 2 km ESE of Nikiski, 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.