QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Earthquake near Lazy Mountain, AK

No earthquake was likely felt in Lazy Mountain in the 24 hours to 4:16 am AKST (13:16 UTC). The last one was M 4.4, 105 km (65 mi) ENE, at 11:11 am AKDT on 30 October 2026, estimated intensity II (weak) in town; 54 felt reports to USGS. Every earthquake near Lazy Mountain

This page: a magnitude 3.3 earthquake was recorded 4 km (3 mi) south of Lazy Mountain, AK, at 12:39 am AKDT on 12 May 2023 (08:39 UTC), 27 km deep. 120 people have reported feeling it to USGS.

USGS: 4 km S of Lazy Mountain, Alaska

65 km (41 mi) NE of Anchorage, AK

12:39 am AKDT, May 12, 2023 · · 27 km deep · released about 1.3 tons of TNT

Every earthquake near Lazy Mountain Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 49 kmMatanuska-Susitna Borough 81 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
12:39 am AKDT on 12 May 2023 ()
Where
4 km (3 mi) south of Lazy Mountain, AK · earthquakes near Lazy Mountain
Magnitude
M 3.3 (ml)
Depth
27 km below the surface
Felt
120 reports · strongest reported intensity III
Measured shaking
intensity III (ShakeMap)
Nearest
Anchorage Municipality, 49 km SSW
Nearest mapped fault
Castle Mountain fault, 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 1210 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, people at rest would likely notice it out to about 44 km (27 mi) from the epicentre. In Lazy Mountain, 4 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: Lazy Mountain 4 km, intensity II · Butte 7 km, intensity II · Palmer 9 km, intensity II · Sutton-Alpine 14 km, intensity II · Fishhook 23 km, intensity II · Tanaina 26 km, intensity II · Knik-Fairview 36 km, intensity II · Eagle River 44 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 14 km NNE of Fishhook, Alaska · 31 km NNW of this epicentre
  2. 5.5 2 km ENE of Eagle River, Alaska · 42 km SW of this epicentre
  3. 5.3 3 km NNE of Houston, Alaska · 45 km W of this epicentre
  4. 5.3 8 km NW of Knik-Fairview, Alaska · 41 km W of this epicentre
  5. 5.3 13 km ESE of Eagle River, Alaska · 39 km SSW 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 61.5889, -148.9483. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 49 km (31 mi) SSW earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 81 km (50 mi) NNW earthquakes near Matanuska-Susitna 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. 1.5 15 km N of Fishhook, Alaska
  2. 2.1 17 km N of Fishhook, Alaska
  3. 1.5 19 km NNW of Fishhook, Alaska
  4. 1.7 14 km NW of Fishhook, Alaska
  5. 2.4 13 km SSW of Chickaloon, Alaska
  6. 1.9 19 km NNW of Fishhook, Alaska
  7. 2.3 5 km SSW of Gateway, Alaska
  8. 2.0 0 km N of Chickaloon, Alaska
  9. 1.6 26 km NNW of Fishhook, Alaska
  10. 1.7 5 km SW of Fishhook, Alaska
  11. 1.6 6 km SSE of Chickaloon, Alaska
  12. 2.0 25 km NNW of Fishhook, Alaska
  13. 2.5 16 km N of Fishhook, Alaska
  14. 2.2 20 km NNW of Fishhook, Alaska
  15. 1.5 11 km W of Fishhook, 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.