QuakeIndex

Fault · Oregon, Washington

Cascadia fold and fault belt

484 kmlong (301 mi), as mapped
1–5 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
24quakes 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 15,000 years.

The largest earthquake recorded near it was M 9.0 in 1700 (The 1700 Cascadia Earthquake) — about 1,000,000,000 times the energy of an M3.0, the size people start to feel. It released about 480 megatons 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: 0–0.

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

Alaska-Aleutian subduction zoneSan Andreas faultCascadia megathrustBartlett Springs fault systemMaacama faultBlanco transform faultNehalem Bank faultLittle Salmon faultOlympia structureCalawah faultMad River faultDaisy Bank faultNorth Ninitat faultAlvin Canyon faultStonewall anticlineSeattle faultSouthern Whidbey Island faultSouth Ninitat faultBald Mountain-Big Lagoon faultFault HThompson Ridge faultWillapa Canyon faultCoos Basin faultLangley Hill faultNoyo Basin faultLake Creek-Boundary Creek faultUtsalady Point faultCoquille anticlineSaddle Hill faultBirch Bay faultTacoma faultGrays Harbor faultKonocti Bay faultMount Angel faultHeceta Bank structureSouth Slough synclineBig Valley faultSouth Slough thrust and reverse faultsMattole Canyon faultSaddle Mountain faultsSandy Point fault M 9.0 · 1700 · The 1700 Cascadia Earthquake M 6.0 · 1926 · 119 km SSW of Ucluelet, Canada
The Cascadia fold and fault belt as mapped at the surface (glowing), with the other mapped faults nearby, 24 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), and the epicentres of the large historic earthquakes recorded near it (rings). 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 9.0 The 1700 Cascadia Earthquake
    January 27, 1700 · epicentre 1 km from the trace
  2. M 6.0 119 km SSW of Ucluelet, Canada
    September 17, 1926 · epicentre 4 km from the trace
  3. M 4.5 46 km WNW of Neah Bay, Washington
    January 24, 2020 · epicentre 8 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 2.9 62 km W of Yachats, Oregon
    2026-09-05 · 0 km from the trace
  2. M 2.5 81 km W of Neskowin, Oregon
    2026-09-04 · 1 km from the trace
  3. M 2.5 42 km W of Port Orford, Oregon
    2026-06-09 · 1 km from the trace
  4. M 2.6 10 km NW of Langlois, Oregon
    2026-05-19 · 8 km from the trace
  5. M 2.5 71 km W of Yachats, Oregon
    2025-09-02 · 6 km from the trace
  6. M 2.8 57 km W of Waldport, Oregon
    2025-03-22 · 8 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.