QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Southern Alaska

Yes. A magnitude 2.1 earthquake was recorded in Southern Alaska at 06:49 UTC on 2021-10-03, 17 km deep.

· 17 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Yakutat City and Borough 52 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 2.1 (ml)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Yakutat City and Borough, 52 km SE
Nearest mapped fault
Coal Glacier fault (Chugach-St. Elias fold and thrust belt), 12 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 1803 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 4.5 on 2019-09-08 — about 4,000 times the energy of this one.

Before 2016, the USGS record lists 25 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.1 113 km SE of McCarthy, Alaska · 44 km NNW of this epicentre
  2. 6.0 90 km NNW of Yakutat, Alaska · 45 km E of this epicentre
  3. 5.9 115 km NW of Yakutat, Alaska · 12 km SW of this epicentre
  4. 5.7 126 km NW of Yakutat, Alaska · 20 km NNE of this epicentre
  5. 5.7 100 km NW of Yakutat, Alaska · 23 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 60.3088, -141.1621. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Yakutat City and Borough, AK 52 km (33 mi) SE earthquakes near Yakutat City and 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 71 km NW of Yakutat, Alaska
  2. 1.6 71 km NW of Yakutat, Alaska
  3. 1.5 113 km NW of Yakutat, Alaska
  4. 1.8 118 km WNW of Yakutat, Alaska
  5. 3.0 115 km WNW of Yakutat, Alaska
  6. 1.8 100 km NW of Yakutat, Alaska
  7. 1.5 126 km WNW of Yakutat, Alaska
  8. 1.6 128 km WNW of Yakutat, Alaska
  9. 1.5 109 km NW of Yakutat, Alaska
  10. 1.6 112 km NW of Yakutat, Alaska
  11. 1.6 113 km WNW of Yakutat, Alaska
  12. 2.3 112 km WNW of Yakutat, Alaska
  13. 1.7 103 km NW of Yakutat, Alaska
  14. 2.1 74 km NW of Yakutat, Alaska
  15. 1.6 Southern Yukon Territory, Canada

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.