QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

Earthquake near Tok, AK

No earthquake was likely felt in Tok in the 24 hours to 3:30 pm AKST (00:30 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 2.2 earthquake was recorded 33 km (21 mi) west-southwest of Tok, AK, at 7:37 am AKDT on 6 April 2021 (15:37 UTC), less than 1 km deep.

USGS: 25 km SSW of Tanacross, Alaska

7:37 am AKDT, Apr 6, 2021 · · 0.7 km deep · released about 60 lb of TNT

Every earthquake near Tok Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Southeast Fairbanks Census Area 79 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
7:37 am AKDT on 6 April 2021 ()
Where
33 km (21 mi) west-southwest of Tok, AK · earthquakes near Tok
Magnitude
M 2.2 (ml)
Depth
0.7 km below the surface
Felt
no reports yet
Nearest
Southeast Fairbanks Census Area, 79 km NNE
Nearest mapped fault
Cathedral Rapids faults (Northern Foothills fold and thrust belt), 16 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 2020 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 18 km (11 mi) from the epicentre. In Tok, 33 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 60 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 250,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 180,000× the energy of this one
  3. Around the size people start to feel M 3.0 16× the energy of this one
  4. This earthquake M 2.2 about 60 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 4.2 on 2020-10-26 — about 1,000 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 5.9 44 km WNW of Mentasta Lake, Alaska · 49 km W of this epicentre
  2. 5.1 3 km ENE of Mentasta Lake, Alaska · 28 km SSW of this epicentre
  3. 5.1 17 km ESE of Mentasta Lake, Alaska · 35 km S of this epicentre
  4. 5.0 16 km WNW of Mentasta Lake, Alaska · 33 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 63.1730, -143.5389. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Southeast Fairbanks Census Area, AK 79 km (49 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

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

  1. 1.1 19 km SE of Dot Lake Village, Alaska
  2. 1.6 7 km NE of Slana, Alaska
  3. 3.0 13 km ENE of Slana, Alaska
  4. 2.3 13 km SE of Mentasta Lake, Alaska
  5. 3.1 13 km N of Mentasta Lake, Alaska
  6. 1.5 14 km SE of Mentasta Lake, Alaska
  7. 2.0 29 km SW of Tetlin, Alaska
  8. 1.7 13 km E of Slana, Alaska
  9. 2.1 29 km SW of Tetlin, Alaska
  10. 1.8 24 km SE of Mentasta Lake, Alaska
  11. 1.7 26 km SSW of Tanacross, Alaska
  12. 2.2 22 km SW of Tanacross, Alaska
  13. 1.6 25 km SSW of Tanacross, Alaska
  14. 2.2 24 km SW of Tanacross, Alaska
  15. 1.8 7 km SE 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.