QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

Earthquake near Sutton-Alpine, AK

No earthquake was likely felt in Sutton-Alpine in the 24 hours to 1:36 am AKST (10:36 UTC). The last one was M 4.4, 100 km (62 mi) E, at 11:11 am AKDT on 30 October 2026, estimated intensity II (weak) in town; 54 felt reports to USGS. Every earthquake near Sutton-Alpine

This page: a magnitude 2.4 earthquake was recorded 49 km (31 mi) northeast of Sutton-Alpine, AK, at 3:17 pm AKDT on 16 October 2020 (23:17 UTC), 20 km deep.

USGS: 30 km NNE of Chickaloon, Alaska

3:17 pm AKDT, Oct 16, 2020 · · 20 km deep · released about 120 lb of TNT

Every earthquake near Sutton-Alpine Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Matanuska-Susitna Borough 66 kmAnchorage Municipality 111 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
3:17 pm AKDT on 16 October 2020 ()
Where
49 km (31 mi) northeast of Sutton-Alpine, AK · earthquakes near Sutton-Alpine
Magnitude
M 2.4 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Matanuska-Susitna Borough, 66 km WNW
Nearest mapped fault
Castle Mountain fault, 21 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 2144 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 7 km (4 mi) from the epicentre. In Sutton-Alpine, 49 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 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 89,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.9× the energy of this one
  4. This earthquake M 2.4 about 120 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 4.6 on 2018-01-27 — about 2,000 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 5.9 15 km N of Glacier View, Alaska · 34 km ESE of this epicentre
  2. 5.8 14 km NNE of Fishhook, Alaska · 47 km WSW of this epicentre
  3. 5.3 55 km NNE of Chickaloon, Alaska · 26 km NNE of this epicentre
  4. 5.0 59 km NW of Eureka Roadhouse, Alaska · 37 km NNE of this epicentre
  5. 5.0 4 km N of Chickaloon, Alaska · 26 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 62.0563, -148.3058. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Matanuska-Susitna Borough, AK 66 km (41 mi) WNW earthquakes near Matanuska-Susitna Borough
Anchorage Municipality, AK 111 km (69 mi) SSW earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 2.9 50 km NNE of Chickaloon, Alaska
  2. 1.5 58 km N of Chickaloon, Alaska
  3. 1.8 13 km SSE of Chickaloon, Alaska
  4. 2.5 70 km N of Chickaloon, Alaska
  5. 2.0 43 km NNW of Chickaloon, Alaska
  6. 1.5 68 km NNE of Chickaloon, Alaska
  7. 1.7 50 km N of Chickaloon, Alaska
  8. 1.8 19 km SW of Glacier View, Alaska
  9. 1.5 35 km NNW of Glacier View, Alaska
  10. 1.8 16 km NNW of Glacier View, Alaska
  11. 2.0 59 km N of Chickaloon, Alaska
  12. 1.8 48 km NNE of Chickaloon, Alaska
  13. 1.5 33 km NNW of Glacier View, Alaska
  14. 1.9 51 km N of Sutton-Alpine, Alaska
  15. 1.7 Central 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.