QuakeIndex

Earthquake · reviewed by a seismologist

M 4.1ml

Earthquake near Anchorage, AK

No earthquake was likely felt in Anchorage in the 24 hours to 6:20 pm AKST (03:20 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 4.1 earthquake was recorded 15 km (9 mi) northwest of Anchorage, AK, at 11:48 pm AKDT on 27 August 2019 (07:48 UTC), 41 km deep. 827 people have reported feeling it to USGS.

USGS: 6 km SW of Point MacKenzie, Alaska

15 km (9 mi) NW of Anchorage, AK

11:48 pm AKDT, Aug 27, 2019 · · 41 km deep · released about 21 tons of TNT

Every earthquake near Anchorage Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 45 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
11:48 pm AKDT on 27 August 2019 ()
Where
15 km (9 mi) northwest of Anchorage, AK · earthquakes near Anchorage
Magnitude
M 4.1 (ml)
Depth
41 km below the surface
Felt
827 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Anchorage Municipality, 45 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2554 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 96 km (60 mi) from the epicentre. In Anchorage, 15 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: Anchorage 15 km, intensity III · Big Lake 23 km, intensity III · Eagle River 27 km, intensity III · Knik-Fairview 33 km, intensity III · Willow 47 km, intensity II · Tanaina 48 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 21 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 7,900× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 350× the energy of this one
  3. Magna, Utah 2020 M 5.7 250× the energy of this one
  4. This earthquake M 4.1 about 21 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 45× 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 32,000 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 20 km ENE of Beluga, Alaska · 38 km WSW of this epicentre
  2. 5.6 11 km NW of Big Lake, Alaska · 29 km N of this epicentre
  3. 5.6 5 km N of Susitna, Alaska · 38 km NW of this epicentre
  4. 5.5 2 km ENE of Eagle River, Alaska · 30 km E of this epicentre
  5. 5.5 9 km E of Susitna, Alaska · 28 km NNW 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 61.3216, -150.0750. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 45 km (28 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

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

  1. 1.5 5 km WNW of Point MacKenzie, Alaska
  2. 1.5 9 km SSW of Knik, Alaska
  3. 1.5 4 km S of Big Lake, Alaska
  4. 2.5 4 km NNW of Anchorage, Alaska
  5. 2.1 1 km SSW of Point MacKenzie, Alaska
  6. 2.1 9 km ENE of Big Lake, Alaska
  7. 1.8 4 km E of Big Lake, Alaska
  8. 1.5 7 km NNE of Point MacKenzie, Alaska
  9. 1.7 29 km ENE of Beluga, Alaska
  10. 1.5 14 km WNW of Anchorage, Alaska
  11. 1.5 5 km ESE of Big Lake, Alaska
  12. 3.0 7 km SSW of Big Lake, Alaska
  13. 1.6 7 km W of Point MacKenzie, Alaska
  14. 1.6 6 km NW of Point MacKenzie, Alaska
  15. 1.5 3 km SE of Point MacKenzie, 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.