QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

48 km SSE of Nelchina, Alaska

Yes. A magnitude 1.7 earthquake was recorded 48 km SSE of Nelchina, Alaska, at 5:20 pm AKDT on 5 September 2024 (01:20 UTC), 20 km deep. 1 person has reported feeling it to USGS.

· 20 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N
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 1.7 (ml)
Depth
20 km below the surface
Felt
1 report · strongest reported intensity III
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 760 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 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 4.3 on 2018-10-16 — about 7,900 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 5.5 48 km WNW of Valdez, Alaska · 47 km SW of this epicentre
  2. 5.1 48 km NNW of Valdez, Alaska · 15 km WSW of this epicentre
  3. 5.1 9 km ESE of Eureka Roadhouse, Alaska · 47 km NW of this epicentre
  4. 5.1 48 km SSE of Nelchina, Alaska · 1 km SW 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 61.5968, -146.3963. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.6 41 km NNW of Valdez, Alaska
  2. 1.5 37 km NNW of Valdez, Alaska
  3. 1.6 46 km SSE of Nelchina, Alaska
  4. 1.9 37 km NNW of Valdez, Alaska
  5. 1.6 33 km NW of Valdez, Alaska
  6. 1.5 29 km NW of Valdez, Alaska
  7. 1.5 36 km S of Tolsona, Alaska
  8. 1.9 44 km NW of Valdez, Alaska
  9. 1.6 44 km N of Valdez, Alaska
  10. 1.6 19 km NNE of Valdez, Alaska
  11. 1.5 27 km NW of Valdez, Alaska
  12. 1.9 13 km NNE of Valdez, Alaska
  13. 1.9 48 km N of Valdez, Alaska
  14. 2.0 33 km NW of Valdez, Alaska
  15. 1.7 49 km SSE of Nelchina, 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.