QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Houston, AK

No earthquake was likely felt in Houston in the 24 hours to 9:02 am AKST (18:02 UTC). The last one was M 2.8, 13 km (8 mi) WSW, at 6:17 am AKST on 6 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Houston

This page: a magnitude 1.9 earthquake was recorded 6 km (4 mi) south of Houston, AK, at 9:51 pm AKDT on 16 August 2023 (05:51 UTC), 57 km deep.

USGS: 6 km S of Houston, Alaska

40 km (25 mi) N of Anchorage, AK

9:51 pm AKDT, Aug 16, 2023 · · 57 km deep · released about 21 lb of TNT

Every earthquake near Houston Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Anchorage Municipality 53 kmMatanuska-Susitna Borough 79 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
9:51 pm AKDT on 16 August 2023 ()
Where
6 km (4 mi) south of Houston, AK · earthquakes near Houston
Magnitude
M 1.9 (ml)
Depth
57 km below the surface
Felt
no reports yet
Nearest
Anchorage Municipality, 53 km SSE
Nearest mapped fault
Castle Mountain fault, 5 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1174 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 Houston, 6 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.

Earthquakes near other towns within 30 km: Big Lake, Meadow Lakes, Knik-Fairview, Wasilla, Tanaina, Willow.

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 7.1 on 2018-11-30 — about 63,000,000 times the energy of this one.

Before 2016, the USGS record lists 22 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 23 km NE of Willow, Alaska · 38 km N of this epicentre
  2. 5.8 14 km NNE of Fishhook, Alaska · 49 km NE of this epicentre
  3. 5.6 11 km NW of Big Lake, Alaska · 16 km W of this epicentre
  4. 5.6 5 km N of Susitna, Alaska · 37 km W of this epicentre
  5. 5.5 2 km ENE of Eagle River, Alaska · 31 km SSE 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 61.5729, -149.8148. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Anchorage Municipality, AK 53 km (33 mi) SSE earthquakes near Anchorage Municipality
Matanuska-Susitna Borough, AK 79 km (49 mi) NNE earthquakes near Matanuska-Susitna Borough

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. 2.0 8 km NW of Point MacKenzie, Alaska
  2. 1.5 16 km SW of Willow, Alaska
  3. 1.9 7 km WSW of Knik, Alaska
  4. 1.6 5 km WNW of Point MacKenzie, Alaska
  5. 1.5 8 km N of Point MacKenzie, Alaska
  6. 1.6 8 km WNW of Point MacKenzie, Alaska
  7. 1.6 14 km ENE of Susitna, Alaska
  8. 1.8 3 km E of Big Lake, Alaska
  9. 1.9 16 km SE of Eagle River, Alaska
  10. 1.8 1 km SE of Big Lake, Alaska
  11. 1.9 4 km SE of Big Lake, Alaska
  12. 1.9 3 km S of Houston, Alaska
  13. 2.1 16 km E of Willow, Alaska
  14. 1.8 11 km W of Point MacKenzie, Alaska
  15. 1.9 9 km WNW of Fishhook, 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.