QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

55 km ENE of Cantwell, Alaska

Yes. A magnitude 1.5 earthquake was recorded 55 km ENE of Cantwell, Alaska, at 1:10 pm AKDT on 11 October 2020 (21:10 UTC), less than 1 km deep.

· 0.1 km deep · released about 5.4 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Denali Borough 108 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 1.5 (ml)
Depth
0.1 km below the surface
Felt
no reports yet
Nearest
Denali Borough, 108 km W
Nearest mapped fault
Denali fault, 1 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 2216 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 10 km (6 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 2002 Denali Fault, Alaska Earthquake · 21 km E of this epicentre
  2. 6.6 53 km ENE of Cantwell, Alaska · 2 km WNW of this epicentre
  3. 6.1 35 km E of Healy, Alaska · 47 km NNW of this epicentre
  4. 5.1 77 km E of Cantwell, Alaska · 22 km E of this epicentre
  5. 5.1 78 km ESE of McKinley Park, Alaska · 24 km E 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 63.5081, -147.8681. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Denali Borough, AK 108 km (67 mi) W earthquakes near Denali Borough

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

Aftershocks so far

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

  1. 1.6 63 km ESE of Denali Park, Alaska
  2. 1.6 71 km ESE of Denali Park, Alaska
  3. 3.0 66 km ESE of Cantwell, Alaska
  4. 2.0 67 km ESE of Cantwell, Alaska
  5. 1.5 67 km ESE of Cantwell, Alaska
  6. 1.9 35 km E of McKinley Park, Alaska
  7. 2.3 69 km E of Cantwell, Alaska
  8. 1.7 62 km ESE of McKinley Park, Alaska
  9. 2.0 81 km ESE of McKinley Park, Alaska
  10. 1.5 80 km ESE of Cantwell, Alaska
  11. 1.5 43 km ESE of Cantwell, Alaska
  12. 2.1 61 km ESE of McKinley Park, Alaska
  13. 2.0 66 km E of Cantwell, Alaska
  14. 2.3 32 km ENE of Cantwell, Alaska
  15. 1.6 61 km ESE of McKinley Park, 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.