QuakeIndex

Fault · Alaska

Chaix Hills fault (Chugach-St. Elias fold and thrust belt)

85 kmlong (53 mi), as mapped
1–5 mm/yrhow fast it slips
< 130,000 yearssince it last broke the surface
59quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 1 to 5 mm a year — 10 to 50 cm (4 to 20 inches) every century.

Its most recent surface rupture is younger than 130,000 years.

The largest earthquake recorded near it was M 5.0 in 2022 (111 km NW of Yakutat, Alaska) — about 1,000 times the energy of an M3.0, the size people start to feel. It released about 480 tons of TNT.

This week vs. its last ten years

0/100

quiet

0 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 0% of weeks since 2016. A normal week: 0–2.

Computed from the USGS catalogue · a description of the past, not a forecast · method

Denali faultFairweather fault systemPamplona faultYakutat fault (also known as Foothills fault)Kosakuts fault (Chugach-St. Elias fold and thrust belt)Hope Creek fault (Chugach-St. Elias fold and thrust belt)Coal Glacier fault (Chugach-St. Elias fold and thrust belt)Malaspina fault (Chugach-St. Elias fold and thrust belt)White River syncline (Chugach-St. Elias fold and thrust belt)Yakataga anticline (Chugach-St. Elias fold and thrust belt)Miller Creek fault (Chugach-St. Elias fold and thrust belt)Sullivan fault (Chugach-St. Elias fold and thrust belt)Bancas Point faultYaga syncline (Chugach-St. Elias fold and thrust belt)Otmeloi fault
The Chaix Hills fault (Chugach-St. Elias fold and thrust belt) as mapped at the surface (glowing), with the other mapped faults nearby, 59 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), . Traces: USGS Quaternary Fault and Fold Database. Historic epicentres are estimates.

Every year since 2016

Earthquakes of M2.5+ with an epicentre within 10 km of the mapped trace. Near is not the same as on: some will have slipped on neighbouring faults.

The big ones recorded near it

  1. M 5.0 111 km NW of Yakutat, Alaska
    September 29, 2022 · epicentre 6 km from the trace
  2. M 4.8 98 km NW of Yakutat, Alaska
    January 11, 2023 · epicentre on the trace
  3. M 4.1 105 km NW of Yakutat, Alaska
    December 26, 2016 · epicentre on the trace

Before 1973 from the USGS ComCat historical catalogue (within 25 km; epicentres of old earthquakes are estimates). Since 2016, M4+ within 10 km.

Most recent near it

  1. M 3.5 100 km NW of Yakutat, Alaska
    2026-07-16 · 2 km from the trace
  2. M 2.9 90 km NW of Yakutat, Alaska
    2026-05-27 · 5 km from the trace
  3. M 2.7 89 km NW of Yakutat, Alaska
    2026-05-20 · 3 km from the trace
  4. M 2.6 102 km NW of Yakutat, Alaska
    2026-02-24 · 8 km from the trace
  5. M 3.1 93 km NW of Yakutat, Alaska
    2026-02-23 · 2 km from the trace
  6. M 2.9 112 km NW of Yakutat, Alaska
    2026-01-24 · 1 km from the trace

Neighbouring faults

Fault trace, slip rate and age: USGS Quaternary Fault and Fold Database (public domain), simplified for the web. Earthquakes: USGS ComCat. QuakeIndex does not forecast earthquakes; a fault's history describes the past. For early warning use ShakeAlert.