QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

45 km NNW of Petersville, Alaska

Yes. A magnitude 1.9 earthquake was recorded 45 km NNW of Petersville, Alaska, at 2:50 am AKDT on 18 October 2026 (10:50 UTC), 100 km deep.

· 100 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Denali Borough 103 kmMatanuska-Susitna Borough 105 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
Magnitude
M 1.9 (ml)
Depth
100 km below the surface
Felt
no reports yet
Nearest
Denali Borough, 103 km NNE
Nearest mapped fault
Denali fault, 25 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 2 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. 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. This earthquake M 1.9 about 21 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 5.3 on 2016-05-15 — about 130,000 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 Central Alaska · 49 km SSW of this epicentre
  2. 5.7 66 km ESE of Denali National Park, Alaska · 43 km NNE of this epicentre
  3. 5.5 59 km SE of Denali National Park, Alaska · 28 km N of this epicentre
  4. 5.4 48 km N of Petersville, Alaska · 21 km ENE of this epicentre
  5. 5.4 32 km W of Petersville, Alaska · 47 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 62.8810, -151.0530. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Denali Borough, AK 103 km (64 mi) NNE earthquakes near Denali Borough
Matanuska-Susitna Borough, AK 105 km (65 mi) SE earthquakes near Matanuska-Susitna Borough

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

Aftershocks so far

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

  1. 2.8 64 km N of Petersville, Alaska
  2. 3.1 43 km N of Petersville, Alaska
  3. 2.1 29 km NNW of Petersville, Alaska
  4. 2.0 60 km NNW of Petersville, Alaska
  5. 1.7 29 km NNW of Petersville, 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.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

What changedFromToWhen
review statusautomaticreviewed
location46 km NNW of Petersville, Alaska45 km NNW of Petersville, Alaska
longitude-151.1-151.05
latitude62.8862.88
depth99.2100.2
magnitude1.71.9

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.