QuakeIndex

Fault · Alaska

Totschunda fault

212 kmlong (132 mi), as mapped
> 5 mm/yrhow fast it slips
last 150 yearssince it last broke the surface
25quakes of M2.5+ within 10 km since 2016

Updated , with the latest earthquake of M2.5 or more within 10 km of the trace: M 2.8, 88 km ENE of McCarthy, Alaska.

In plain English

The two sides grind past each other faster than 5 mm a year — more than half a metre (20 inches) every century.

It has broken the ground surface within the last 150 years.

The largest earthquake recorded near it was M 5.3 in 2017 (20 km NE of Nabesna, Alaska) — about 2,800 times the energy of an M3.0, the size people start to feel. It released about 1.3 kilotons of TNT.

This week vs. its last ten years

0/100

quiet

No quakes of M1.5+ within 5 km of the trace in the last 7 days. A normal week: 0–1.

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

Denali faultCathedral Rapids faults (Northern Foothills fold and thrust belt)
The Totschunda fault as mapped at the surface (glowing), with the other mapped faults nearby and 25 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 5.3 20 km NE of Nabesna, Alaska
    February 13, 2017 · epicentre 3 km from the trace
  2. M 4.1 86 km E of McCarthy, Alaska
    August 20, 2021 · epicentre 3 km from the trace
  3. M 4.1 9 km ESE of Mentasta Lake, Alaska
    July 26, 2021 · epicentre 2 km from the trace
  4. M 4.1 6 km ESE of Mentasta Lake, Alaska
    July 26, 2021 · epicentre on the trace
  5. M 4.0 4 km E of Mentasta Lake, Alaska
    October 10, 2019 · epicentre 2 km from 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 2.8 88 km ENE of McCarthy, Alaska
    2026-10-26 · 9 km from the trace
  2. M 3.1 13 km N of Mentasta Lake, Alaska
    2026-08-28 · 9 km from the trace
  3. M 2.9 32 km ESE of Nabesna, Alaska
    2026-01-25 · 5 km from the trace
  4. M 3.1 91 km E of McCarthy, Alaska
    2025-12-31 · 7 km from the trace
  5. M 2.6 82 km E of McCarthy, Alaska
    2025-09-01 · 1 km from the trace
  6. M 3.5 91 km E of McCarthy, Alaska
    2025-08-06 · 5 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.