QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0ml

43 km NNW of Elfin Cove, Alaska

Yes. A magnitude 2.0 earthquake was recorded 43 km NNW of Elfin Cove, Alaska, at 7:50 am AKDT on 31 October 2017 (15:50 UTC), 7.6 km deep.

· 7.6 km deep · released about 30 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Hoonah-Angoon Census Area 49 kmHaines Borough 90 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 2.0 (ml)
Depth
7.6 km below the surface
Felt
no reports yet
Nearest
Hoonah-Angoon Census Area, 49 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1191 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 14 km (9 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 30 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 350,000× the energy of this one
  3. Around the size people start to feel M 3.0 32× the energy of this one
  4. This earthquake M 2.0 about 30 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 2017-01-16 — about 5,600 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.8 22 km W of Elfin Cove, Alaska · 34 km S of this epicentre
  2. 6.1 77 km SW of Covenant Life, Alaska · 43 km NNW of this epicentre
  3. 6.0 40 km WNW of Elfin Cove, Alaska · 28 km SW of this epicentre
  4. 5.6 34 km WNW of Elfin Cove, Alaska · 23 km SSW of this epicentre
  5. 5.2 63 km SW of Covenant Life, Alaska · 49 km N 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 58.5361, -136.6928. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Hoonah-Angoon Census Area, AK 49 km (31 mi) ESE earthquakes near Hoonah-Angoon Census Area
Haines Borough, AK 90 km (56 mi) NE earthquakes near Haines Borough
Skagway Municipality, AK 138 km (86 mi) NNE earthquakes near Skagway Municipality

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

Aftershocks so far

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

  1. 1.5 65 km NW of Elfin Cove, Alaska
  2. 2.2 59 km WNW of Elfin Cove, Alaska
  3. 2.2 60 km NW of Elfin Cove, Alaska
  4. 2.2 56 km NW of Elfin Cove, Alaska
  5. 2.2 53 km NW of Elfin Cove, Alaska
  6. 2.3 58 km WNW of Elfin Cove, Alaska
  7. 2.2 60 km NW of Elfin Cove, Alaska
  8. 2.1 54 km WNW of Elfin Cove, Alaska
  9. 2.3 50 km WNW of Elfin Cove, Alaska
  10. 2.3 55 km NW of Elfin Cove, Alaska
  11. 2.4 55 km WNW of Elfin Cove, Alaska
  12. 2.3 58 km WNW of Elfin Cove, Alaska
  13. 2.4 46 km NW of Elfin Cove, Alaska
  14. 2.4 58 km WNW of Elfin Cove, Alaska
  15. 2.3 55 km WNW of Elfin Cove, 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.