QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

Earthquake near Valdez, AK

No earthquake was likely felt in Valdez in the 24 hours to 10:38 am AKST (19:38 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 2.3 earthquake was recorded 41 km (26 mi) south-southwest of Valdez, AK, at 1:59 pm AKDT on 12 July 2018 (21:59 UTC), 20 km deep.

USGS: 6 km SW of Tatitlek, Alaska

1:59 pm AKDT, Jul 12, 2018 · · 20 km deep · released about 85 lb of TNT

10 km30 km60 km120 km N Chugach Census Area 48 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
1:59 pm AKDT on 12 July 2018 ()
Where
41 km (26 mi) south-southwest of Valdez, AK · earthquakes near Valdez
Magnitude
M 2.3 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Chugach Census Area, 48 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1186 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, 41 km away, the estimate is intensity II (weak). 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 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 85 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 4.1 on 2017-06-22 — about 500 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 9.2 The 1964 Prince William Sound, Alaska Earthquake · 33 km WNW of this epicentre
  2. 6.7 Prince William Sound, Alaska · 22 km SW of this epicentre
  3. 6.6 37 km WNW of Tatitlek, Alaska · 37 km NW of this epicentre
  4. 6.4 Prince William Sound, Alaska · 49 km SSW of this epicentre
  5. 6.4 46 km WNW of Tatitlek, Alaska · 43 km WNW 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 60.8190, -146.7653. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chugach Census Area, AK 48 km (30 mi) SE earthquakes near Chugach Census Area

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

Aftershocks so far

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

  1. 1.8 33 km WNW of Tatitlek, Alaska
  2. 1.9 28 km WNW of Tatitlek, Alaska
  3. 1.6 Southern Alaska
  4. 1.8 9 km WSW of Tatitlek, Alaska
  5. 1.8 13 km SSE of Tatitlek, Alaska
  6. 1.6 39 km SW of Tatitlek, Alaska
  7. 1.7 14 km W of Tatitlek, Alaska
  8. 1.5 9 km WSW of Tatitlek, Alaska
  9. 3.1 10 km SW of Tatitlek, Alaska
  10. 1.6 44 km NW of Tatitlek, Alaska
  11. 1.6 23 km WSW of Tatitlek, Alaska
  12. 1.6 44 km WNW of Valdez, Alaska
  13. 1.5 33 km WNW of Valdez, Alaska
  14. 1.6 25 km WNW of Tatitlek, Alaska
  15. 3.1 24 km WNW of Tatitlek, 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.