QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Southern Alaska

Yes. A magnitude 1.9 earthquake was recorded in Southern Alaska, at 11:06 pm AKST on 19 November 2023 (08:06 UTC), 20 km deep.

· 20 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Chugach Census Area 88 kmAnchorage Municipality 107 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
Magnitude
M 1.9 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Chugach Census Area, 88 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1073 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. This earthquake M 1.9 about 21 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 4.4 on 2022-07-09 — about 5,600 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 9.2 The 1964 Prince William Sound, Alaska Earthquake · 17 km S of this epicentre
  2. 6.7 Prince William Sound, Alaska · 45 km SSE of this epicentre
  3. 6.6 57 km ENE of Whittier, Alaska · 25 km W of this epicentre
  4. 6.6 37 km WNW of Tatitlek, Alaska · 4 km SSE of this epicentre
  5. 6.4 37 km SSE of Glacier View, Alaska · 48 km N 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 61.0638, -147.3082. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Chugach Census Area, AK 88 km (54 mi) SE earthquakes near Chugach Census Area
Anchorage Municipality, AK 107 km (66 mi) W earthquakes near Anchorage Municipality

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

Aftershocks so far

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

  1. 2.3 52 km NW of Valdez, Alaska
  2. 1.6 40 km SSE of Glacier View, Alaska
  3. 1.6 36 km NW of Valdez, Alaska
  4. 2.7 37 km WNW of Valdez, Alaska
  5. 1.6 22 km NW of Tatitlek, Alaska
  6. 1.8 19 km WNW of Tatitlek, Alaska
  7. 1.9 44 km WSW of Tatitlek, Alaska
  8. 1.8 45 km WSW of Tatitlek, Alaska
  9. 1.7 55 km S of Glacier View, Alaska
  10. 1.6 30 km WNW of Valdez, Alaska
  11. 3.6 32 km WNW of Valdez, Alaska
  12. 1.5 41 km WNW of Valdez, Alaska
  13. 1.7 53 km WNW of Tatitlek, Alaska
  14. 2.5 48 km NW of Valdez, Alaska
  15. 1.6 28 km WNW 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.