QuakeIndex

Earthquake · automatic estimate, may change

M 1.8ml

110 km S of McCarthy, Alaska

Yes. A magnitude 1.8 earthquake was recorded 110 km S of McCarthy, Alaska at 08:52 UTC on 2025-10-16, 13 km deep. The magnitude and location are an automatic first estimate and may change.

· 13 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N
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 1.8 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest mapped fault
Kosakuts fault (Chugach-St. Elias fold and thrust belt), 16 km from its surface trace — near is not the same as on
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 393 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 5 km (3 mi) from the epicentre. 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 4.3 on 2017-11-13 — about 5,600 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.2 90 km SSW of McCarthy, Alaska · 49 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 60.4470, -143.0129. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.7 109 km S of McCarthy, Alaska
  2. 1.8 128 km SSW of McCarthy, Alaska
  3. 1.7 105 km S of McCarthy, Alaska
  4. 1.9 120 km S of McCarthy, Alaska
  5. 1.8 118 km S of McCarthy, Alaska
  6. 1.6 105 km S of McCarthy, Alaska
  7. 1.5 106 km S of McCarthy, Alaska
  8. 1.5 140 km ESE of Cordova, Alaska
  9. 2.8 87 km S of McCarthy, Alaska
  10. 1.7 128 km S of McCarthy, Alaska
  11. 1.5 127 km S of McCarthy, Alaska
  12. 2.1 122 km S of McCarthy, Alaska
  13. 1.6 103 km S of McCarthy, Alaska
  14. 1.8 126 km SSW of McCarthy, Alaska
  15. 1.5 115 km SSW of McCarthy, 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.