QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Valdez, AK

No earthquake was likely felt in Valdez in the 24 hours to 1:39 pm AKST (22:39 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 1.7 earthquake was recorded 49 km (31 mi) east of Valdez, AK, at 10:25 pm AKST on 28 December 2020 (07:25 UTC), 14 km deep.

USGS: 49 km E of Valdez, Alaska

10:25 pm AKST, Dec 28, 2020 · · 14 km deep · released about 11 lb of TNT

Every earthquake near Valdez Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Chugach Census Area 82 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
10:25 pm AKST on 28 December 2020 ()
Where
49 km (31 mi) east of Valdez, AK · earthquakes near Valdez
Magnitude
M 1.7 (ml)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Chugach Census Area, 82 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2132 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. In Valdez, 49 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 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.0 Near Valdez, Alaska · 46 km WSW of this epicentre
  2. 5.5 36 km NE of Cordova, Alaska · 41 km SSE of this epicentre
  3. 5.2 63 km S of Chitina, Alaska · 49 km ESE 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 61.1206, -145.4302. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chugach Census Area, AK 82 km (51 mi) SSW earthquakes near Chugach Census Area
Copper River Census Area, AK 129 km (80 mi) NE earthquakes near Copper River Census Area

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. 1.9 30 km NNE of Cordova, Alaska
  2. 2.2 37 km SSW of Tonsina, Alaska
  3. 2.3 40 km ENE of Valdez, Alaska
  4. 1.9 32 km NNE of Cordova, Alaska
  5. 1.7 48 km NE of Cordova, Alaska
  6. 2.2 40 km NE of Valdez, Alaska
  7. 2.0 33 km SE of Valdez, Alaska
  8. 1.5 61 km SW of Chitina, Alaska
  9. 2.5 58 km SW of Chitina, Alaska
  10. 1.7 35 km NE of Valdez, Alaska
  11. 1.7 34 km NNW of Cordova, Alaska
  12. 1.6 38 km ESE of Valdez, Alaska
  13. 1.7 48 km SW of Chitina, Alaska
  14. 2.1 42 km ENE of Valdez, Alaska
  15. 1.7 31 km NNW of Cordova, 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.