QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Healy, AK

No earthquake was likely felt in Healy in the 24 hours to 8:17 am AKST (17:17 UTC). The last one was M 2.7, 23 km (14 mi) NNE, at 4:13 pm AKST on 3 November 2026, estimated intensity II (weak) in town. Every earthquake near Healy

This page: a magnitude 1.6 earthquake was recorded 44 km (28 mi) south of Healy, AK, at 10:26 am AKDT on 24 September 2020 (18:26 UTC), 8.5 km deep.

USGS: 9 km NE of Cantwell, Alaska

10:26 am AKDT, Sep 24, 2020 · · 8.5 km deep · released about 7.6 lb of TNT

Every earthquake near Healy Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Denali Borough 64 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
10:26 am AKDT on 24 September 2020 ()
Where
44 km (28 mi) south of Healy, AK · earthquakes near Healy
Magnitude
M 1.6 (ml)
Depth
8.5 km below the surface
Felt
no reports yet
Nearest
Denali Borough, 64 km WNW
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 2230 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 Healy, 44 km away, the estimate is intensity I (not felt). 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 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 4.1 on 2019-09-25 — about 5,600 times the energy of this one.

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

  1. 6.6 53 km ENE of Cantwell, Alaska · 47 km E of this epicentre
  2. 5.4 38 km SSE of Cantwell, Alaska · 44 km SSE of this epicentre
  3. 5.1 36 km ENE of Cantwell, Alaska · 30 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 63.4608, -148.8436. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Denali Borough, AK 64 km (39 mi) WNW earthquakes near Denali Borough

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

Aftershocks so far

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

  1. 2.3 26 km SSW of Cantwell, Alaska
  2. 1.8 22 km W of McKinley Park, Alaska
  3. 1.7 22 km WSW of McKinley Park, Alaska
  4. 1.5 21 km WNW of Cantwell, Alaska
  5. 3.3 7 km NNE of Cantwell, Alaska
  6. 2.0 37 km S of Cantwell, Alaska
  7. 1.5 23 km W of McKinley Park, Alaska
  8. 2.5 23 km WSW of McKinley Park, Alaska
  9. 1.6 8 km E of Healy, Alaska
  10. 1.6 13 km E of Cantwell, Alaska
  11. 1.5 10 km NNE of Cantwell, Alaska
  12. 1.5 31 km SSW of Cantwell, Alaska
  13. 2.0 17 km W of Healy, Alaska
  14. 1.6 15 km W of Healy, Alaska
  15. 1.7 5 km SSE of Healy, 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.