Fault · Alaska
Cathedral Rapids faults (Northern Foothills fold and thrust belt)
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 4.2 in 2020 (18 km SSW of Tanacross, Alaska) — about 63 times the energy of an M3.0, the size people start to feel. It released about 30 tons of TNT.
USGS maps it as 2 sections: Cathedral Rapids fault A, Cathedral Rapids fault B.
This week vs. its last ten years
Too quiet to rank: fewer than half a year's worth of weeks with any M1.5+ quake within 5 km, in ten years. A single quake here would read as "unusual", so we do not score it.
Computed from the USGS catalogue · a description of the past, not a forecast · method
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
- M 4.2 18 km SSW of Tanacross, Alaska
October 26, 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
- M 4.2 18 km SSW of Tanacross, Alaska
2020-10-26 · 8 km from the trace - M 2.5 15 km SSW of Tanacross, Alaska
2018-01-27 · 7 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.