QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Tok, AK

No earthquake was likely felt in Tok in the 24 hours to 10:33 am AKST (19:33 UTC). The last one was M 7.0, 382 km (237 mi) SSE, at 11:41 am AKST on 6 December 2025, estimated intensity III (weak) in town; 1,058 felt reports to USGS. Every earthquake near Tok

This page: a magnitude 2.5 earthquake was recorded 27 km (17 mi) west-southwest of Tok, AK, at 2:49 am AKST on 27 January 2018 (11:49 UTC), 8.2 km deep.

USGS: 15 km SSW of Tanacross, Alaska

2:49 am AKST, Jan 27, 2018 · · 8.2 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Southeast Fairbanks Census Area 68 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
2:49 am AKST on 27 January 2018 ()
Where
27 km (17 mi) west-southwest of Tok, AK · earthquakes near Tok
Magnitude
M 2.5 (ml)
Depth
8.2 km below the surface
Felt
no reports yet
Nearest
Southeast Fairbanks Census Area, 68 km NNE
Nearest mapped fault
Cathedral Rapids faults (Northern Foothills fold and thrust belt), 7 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 1190 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 21 km (13 mi) from the epicentre. In Tok, 27 km away, the estimate is intensity II (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.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.1 3 km ENE of Mentasta Lake, Alaska · 38 km SSW of this epicentre
  2. 5.1 17 km ESE of Mentasta Lake, Alaska · 45 km S of this epicentre
  3. 5.0 16 km WNW of Mentasta Lake, Alaska · 42 km SW 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 63.2623, -143.4942. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Southeast Fairbanks Census Area, AK 68 km (42 mi) NNE earthquakes near Southeast Fairbanks Census Area

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

Aftershocks so far

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

  1. 1.6 19 km S of Tok, Alaska
  2. 1.9 9 km SE of Mentasta Lake, Alaska
  3. 2.1 6 km ESE of Mentasta Lake, Alaska
  4. 1.6 17 km SE of Mentasta Lake, Alaska
  5. 1.6 15 km NNW of Mentasta Lake, Alaska
  6. 1.7 8 km SE of Mentasta Lake, Alaska
  7. 1.7 9 km SSE of Mentasta Lake, Alaska
  8. 1.9 6 km E of Mentasta Lake, Alaska
  9. 1.6 6 km SE of Mentasta Lake, Alaska
  10. 4.1 6 km ESE of Mentasta Lake, Alaska
  11. 4.1 9 km ESE of Mentasta Lake, Alaska
  12. 1.8 29 km N of Mentasta Lake, Alaska
  13. 2.2 15 km S of Tanacross, Alaska
  14. 2.2 25 km SSW of Tanacross, Alaska
  15. 2.1 13 km NNW of Mentasta Lake, 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.