QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Anchorage, AK

No earthquake was likely felt in Anchorage in the 24 hours to 7:54 am AKST (16:54 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 1.7 earthquake was recorded 36 km (22 mi) west-northwest of Anchorage, AK, at 6:43 am AKST on 25 December 2018 (15:43 UTC), 60 km deep. 2 people have reported feeling it to USGS.

USGS: 17 km S of Susitna, Alaska

36 km (22 mi) WNW of Anchorage, AK

6:43 am AKST, Dec 25, 2018 · · 60 km deep · released about 11 lb of TNT

Every earthquake near Anchorage Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 68 kmMatanuska-Susitna Borough 110 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
6:43 am AKST on 25 December 2018 ()
Where
36 km (22 mi) west-northwest of Anchorage, AK · earthquakes near Anchorage
Magnitude
M 1.7 (ml)
Depth
60 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Anchorage Municipality, 68 km ESE
Nearest mapped fault
Castle Mountain fault, 8 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 1184 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Anchorage, 36 km away, the estimate is intensity I (not felt). 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.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 lb of TNT

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 130,000,000 times the energy of this one.

Before 2016, the USGS record lists 27 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.8 Southern Alaska · 48 km SW of this epicentre
  2. 6.8 4 km NE of Beluga, Alaska · 38 km SW of this epicentre
  3. 5.8 27 km N of Beluga, Alaska · 30 km W of this epicentre
  4. 5.8 20 km ENE of Beluga, Alaska · 23 km SW of this epicentre
  5. 5.6 11 km NW of Big Lake, Alaska · 28 km NE 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 61.3916, -150.4678. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 68 km (42 mi) ESE earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 110 km (68 mi) NNE earthquakes near Matanuska-Susitna Borough
Kenai Peninsula Borough, AK 152 km (94 mi) SW earthquakes near Kenai Peninsula 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. 2.5 9 km SW of Point MacKenzie, Alaska
  2. 1.7 4 km WNW of Point MacKenzie, Alaska
  3. 1.6 5 km WNW of Point MacKenzie, Alaska
  4. 3.3 7 km SW of Point MacKenzie, Alaska
  5. 1.9 6 km NNW of Point MacKenzie, Alaska
  6. 1.7 11 km SW of Point MacKenzie, Alaska
  7. 1.6 9 km WSW of Big Lake, Alaska
  8. 1.6 10 km SW of Point MacKenzie, Alaska
  9. 1.8 11 km SW of Point MacKenzie, Alaska
  10. 2.6 9 km SW of Point MacKenzie, Alaska
  11. 1.8 10 km SW of Point MacKenzie, Alaska
  12. 1.9 9 km WSW of Point MacKenzie, Alaska
  13. 1.6 11 km SW of Point MacKenzie, Alaska
  14. 1.7 9 km SW of Point MacKenzie, Alaska
  15. 2.6 8 km WSW 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.