QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Valdez, AK

No earthquake was likely felt in Valdez in the 24 hours to 8:34 am AKST (17:34 UTC). The last one was M 4.4, 85 km (53 mi) NNW, at 11:11 am AKDT on 30 October 2026, estimated intensity II (weak) in town; 54 felt reports to USGS. Every earthquake near Valdez

This page: a magnitude 1.5 earthquake was recorded 28 km (17 mi) northwest of Valdez, AK, at 2:41 pm AKDT on 31 August 2021 (22:41 UTC), 9.4 km deep.

USGS: 27 km NW of Valdez, Alaska

2:41 pm AKDT, Aug 31, 2021 · · 9.4 km deep · released about 5.4 lb of TNT

Every earthquake near Valdez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Chugach Census Area 96 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
2:41 pm AKDT on 31 August 2021 ()
Where
28 km (17 mi) northwest of Valdez, AK · earthquakes near Valdez
Magnitude
M 1.5 (ml)
Depth
9.4 km below the surface
Felt
no reports yet
Nearest
Chugach Census Area, 96 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1884 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 4 km (2 mi) from the epicentre. In Valdez, 28 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 16,000 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 37 km WNW of Tatitlek, Alaska · 45 km SW of this epicentre
  2. 6.4 37 km SSE of Glacier View, Alaska · 43 km WNW of this epicentre
  3. 6.0 Near Valdez, Alaska · 42 km SE of this epicentre
  4. 5.9 42 km S of Glacier View, Alaska · 50 km WNW of this epicentre
  5. 5.8 45 km WNW of Tatitlek, Alaska · 49 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 61.3177, -146.6897. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chugach Census Area, AK 96 km (60 mi) SSE earthquakes near Chugach Census Area

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 46 km N of Valdez, Alaska
  2. 1.6 Southern Alaska
  3. 2.2 44 km SSE of Nelchina, Alaska
  4. 2.2 49 km SSE of Nelchina, Alaska
  5. 1.5 46 km SSE of Nelchina, Alaska
  6. 1.8 44 km NNW of Valdez, Alaska
  7. 1.6 44 km NW of Tatitlek, Alaska
  8. 1.9 19 km N of Valdez, Alaska
  9. 1.6 37 km NW of Valdez, Alaska
  10. 2.1 42 km N of Valdez, Alaska
  11. 1.7 40 km NNW of Valdez, Alaska
  12. 2.7 39 km NNW of Valdez, Alaska
  13. 1.5 45 km NNW of Valdez, Alaska
  14. 1.6 47 km N of Valdez, Alaska
  15. 1.5 29 km NNW of Valdez, 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.