QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0ml

Earthquake near Anchorage, AK

No earthquake was likely felt in Anchorage in the 24 hours to 1:42 pm AKST (22:42 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 4.0 earthquake was recorded 18 km (11 mi) north of Anchorage, AK, at 4:58 pm AKDT on 27 April 2019 (00:58 UTC), 45 km deep. 250 people have reported feeling it to USGS.

USGS: 4 km NE of Point MacKenzie, Alaska

18 km (11 mi) N of Anchorage, AK

4:58 pm AKDT, Apr 27, 2019 · · 45 km deep · released about 15 tons of TNT

Every earthquake near Anchorage Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 41 kmMatanuska-Susitna Borough 100 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
4:58 pm AKDT on 27 April 2019 ()
Where
18 km (11 mi) north of Anchorage, AK · earthquakes near Anchorage
Magnitude
M 4.0 (ml)
Depth
45 km below the surface
Felt
250 reports · strongest reported intensity V
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Anchorage Municipality, 41 km SE
Nearest mapped fault
Castle Mountain fault, 23 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 2566 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 86 km (53 mi) from the epicentre. In Anchorage, 18 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: Big Lake 16 km, intensity III · Anchorage 18 km, intensity III · Eagle River 19 km, intensity III · Knik-Fairview 22 km, intensity II · Tanaina 37 km, intensity II · Willow 41 km, intensity II · Palmer 49 km, intensity II · Butte 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 15 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 11,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 500× the energy of this one
  3. Magna, Utah 2020 M 5.7 350× the energy of this one
  4. This earthquake M 4.0 about 15 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 32× 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 45,000 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 20 km ENE of Beluga, Alaska · 49 km WSW of this epicentre
  2. 5.6 11 km NW of Big Lake, Alaska · 25 km NNW of this epicentre
  3. 5.6 5 km N of Susitna, Alaska · 40 km NW of this epicentre
  4. 5.5 2 km ENE of Eagle River, Alaska · 21 km ESE of this epicentre
  5. 5.5 9 km E of Susitna, Alaska · 29 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 61.3824, -149.9079. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 41 km (25 mi) SE earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 100 km (62 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. 1.6 7 km NNW of Point MacKenzie, Alaska
  2. 1.5 5 km W of Point MacKenzie, Alaska
  3. 1.8 10 km NNW of Point MacKenzie, Alaska
  4. 1.9 7 km NW of Point MacKenzie, Alaska
  5. 1.6 Southern Alaska
  6. 1.6 5 km WNW of Point MacKenzie, Alaska
  7. 2.3 5 km NNW of Point MacKenzie, Alaska
  8. 3.2 2 km NNW of Point MacKenzie, Alaska
  9. 2.0 1 km NNE of Big Lake, Alaska
  10. 1.6 5 km SE of Point MacKenzie, Alaska
  11. 2.3 7 km NNW of Anchorage, Alaska
  12. 1.5 4 km NNW of Point MacKenzie, Alaska
  13. 1.9 17 km NNE of Houston, Alaska
  14. 1.9 17 km NNW of Hope, Alaska
  15. 1.6 22 km W 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.