QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

Earthquake near Anchorage, AK

No earthquake was likely felt in Anchorage in the 24 hours to 4:36 am AKST (13:36 UTC). The last one was M 3.5, 39 km (24 mi) SSW, at 4:48 pm AKDT on 27 October 2026, estimated intensity II (weak) in town; 98 felt reports to USGS. Every earthquake near Anchorage

This page: a magnitude 3.9 earthquake was recorded 10 km (6 mi) north-northwest of Anchorage, AK, at 11:02 pm AKST on 30 November 2018 (08:02 UTC), 45 km deep. 3 people have reported feeling it to USGS.

USGS: 6 km SSE of Point MacKenzie, Alaska

10 km (6 mi) NNW of Anchorage, AK

11:02 pm AKST, Nov 30, 2018 · · 45 km deep · released about 11 tons of TNT

Every earthquake near Anchorage Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 38 kmMatanuska-Susitna Borough 109 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
11:02 pm AKST on 30 November 2018 ()
Where
10 km (6 mi) north-northwest of Anchorage, AK · earthquakes near Anchorage
Magnitude
M 3.9 (ml)
Depth
45 km below the surface
Felt
3 reports · strongest reported intensity II
Measured shaking
intensity III (ShakeMap)
Nearest
Anchorage Municipality, 38 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1184 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 77 km (48 mi) from the epicentre. In Anchorage, 10 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: Anchorage 10 km, intensity II · Eagle River 20 km, intensity II · Big Lake 24 km, intensity II · Knik-Fairview 29 km, intensity II · Tanaina 45 km, intensity II · Willow 50 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× 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 7.1 on 2018-11-30 — about 63,000 times the energy of this one.

Before 2016, the USGS record lists 22 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 20 km ENE of Beluga, Alaska · 45 km W of this epicentre
  2. 5.6 11 km NW of Big Lake, Alaska · 32 km NNW of this epicentre
  3. 5.6 5 km N of Susitna, Alaska · 45 km NW of this epicentre
  4. 5.5 2 km ENE of Eagle River, Alaska · 22 km E of this epicentre
  5. 5.5 9 km E of Susitna, Alaska · 34 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 61.3029, -149.9375. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 38 km (23 mi) ESE earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 109 km (68 mi) NNE earthquakes near Matanuska-Susitna Borough

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

Aftershocks so far

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

  1. 2.8 6 km NW of Point MacKenzie, Alaska
  2. 2.0 3 km WNW of Point MacKenzie, Alaska
  3. 1.9 6 km NW of Point MacKenzie, Alaska
  4. 2.0 5 km NW of Point MacKenzie, Alaska
  5. 1.7 2 km NW of Point MacKenzie, Alaska
  6. 2.8 1 km SE of Big Lake, Alaska
  7. 2.8 4 km S of Big Lake, Alaska
  8. 1.6 8 km NNW of Point MacKenzie, Alaska
  9. 2.5 8 km S of Big Lake, Alaska
  10. 2.4 4 km N of Point MacKenzie, Alaska
  11. 3.7 3 km NNW of Point MacKenzie, Alaska
  12. 1.9 4 km NNW of Point MacKenzie, Alaska
  13. 1.8 4 km NW of Point MacKenzie, Alaska
  14. 2.0 5 km SSE of Big Lake, Alaska
  15. 2.0 10 km SW of Big Lake, 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.