Both Ends Of America's Deadliest Fault Just Shook — Here's What We Know

Описание: Would your household be ready if Cascadia moved? Read the state scenario maps for your own home plan: https://thefieldreportstore.com

KEY PENINSULA, WASHINGTON, September 29, 2026 — A magnitude 4.2 earthquake struck 17 miles beneath the Key Peninsula on Tuesday afternoon, shaking Seattle, Tacoma and Olympia from below the Tacoma fault zone. Nine and a half hours earlier, a magnitude 4.8 broke inside the Gorda plate about 60 miles off Petrolia, California, at the opposite end of the Cascadia system.

Nobody was hurt and no tsunami formed. Two days earlier, three quakes up to magnitude 5.4 had struck off northern Vancouver Island, and the Washington quake landed within two kilometers of a magnitude 4.8 from 1978.

Scientists say neither quake was the start of the big one. The fault zone above the Washington quake has done far worse before, and the numbers that would change that answer are still being watched.

CHAPTERS
0:00 Introduction
0:33 Two quakes nine hours apart
3:11 Seventeen miles under the Key Peninsula
5:52 The same spot shook in 1978
7:32 Sixty miles off Petrolia
9:19 The corner that never stops talking
10:45 Why neither quake was the big one
13:29 The fault zone under Tacoma
15:25 Forests that died in one winter
17:22 The slow slip nobody felt
19:13 The southern clock since 1700
20:56 What would change the picture

SOURCES
M4.8 97 km W of Petrolia, CA, USGS — https://earthquake.usgs.gov/earthquak...
M5.4 231 km WSW of Port McNeill, Canada, USGS — https://earthquake.usgs.gov/earthquak...
4.2 magnitude quake jolts Seattle, Seattle Times via Spokesman-Review — https://www.spokesman.com/stories/202...
Western Washington shaken by 4.2 magnitude earthquake, KUOW — https://www.kuow.org/news-stories/202...
4.2-magnitude earthquake on the Kitsap Peninsula, KIRO 7 — https://www.kiro7.com/news/local/did-...
4.2 magnitude earthquake rattles Gig Harbor area, Gig Harbor Now — https://www.gigharbornow.org/news/com...
4.7M earthquake strikes off coast, SFist — https://sfist.com/2026/09/29/4-7-eart...
No damage after multiple earthquakes strike off B.C. coast, CP24 — https://www.cp24.com/news/canada/2026...
A Magnitude 7.1 Earthquake in the Tacoma Fault Zone, USGS Fact Sheet 2010-3023 — https://pubs.usgs.gov/fs/2010/3023
Slow slip and tremor observations, Pacific Northwest Seismic Network — https://pnsn.org/tremor

This video is for educational and informational purposes. It draws on public data and reporting from the U.S. Geological Survey, the Pacific Northwest Seismic Network, the National Tsunami Warning Center, Pierce County Emergency Management and regional news outlets, and details reflect the best available information at the time of publishing; magnitudes, locations and aftershock counts can still be revised. Any speculation is clearly labeled as such.

#CascadiaEarthquake #TacomaFault