QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

157 km E of McCarthy, Alaska

Yes. A magnitude 1.7 earthquake was recorded 157 km E of McCarthy, Alaska at 03:17 UTC on 2023-09-14, 6.3 km deep.

· 6.3 km deep · released about 11 lb of TNT

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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
6.3 km below the surface
Felt
no reports yet
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1143 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 11 km (7 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 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 4.8 on 2023-08-06 — about 45,000 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.7 152 km E of McCarthy, Alaska · 6 km WSW of this epicentre
  2. 5.4 140 km SSE of Alcan Border, Alaska · 20 km NW of this epicentre
  3. 5.4 136 km SSE of Alcan Border, Alaska · 21 km NNW of this epicentre
  4. 5.3 136 km E of McCarthy, Alaska · 23 km WNW of this epicentre
  5. 5.2 130 km SSE of Alcan Border, Alaska · 28 km NNW 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 61.3632, -139.9769. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 1.7 147 km E of McCarthy, Alaska
  2. 1.7 140 km ESE of McCarthy, Alaska
  3. 1.7 135 km ESE of McCarthy, Alaska
  4. 3.2 152 km SSE of Alcan Border, Alaska
  5. 3.6 154 km E of McCarthy, Alaska
  6. 1.7 159 km ESE of McCarthy, Alaska
  7. 1.6 139 km E of McCarthy, Alaska
  8. 1.9 140 km E of McCarthy, Alaska
  9. 1.5 157 km ESE of McCarthy, Alaska
  10. 2.5 149 km SSE of Alcan Border, Alaska
  11. 1.6 155 km ESE of McCarthy, Alaska
  12. 2.5 130 km E of McCarthy, Alaska
  13. 1.6 142 km E of McCarthy, Alaska
  14. 1.8 173 km N of Yakutat, Alaska
  15. 1.5 129 km E of McCarthy, 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.