The Silent Fault That Will Destroy the Pacific Northwest

Off the coast of the Pacific Northwest lies a 600-mile fault that has been silent for over 300 years — and that silence is exactly what terrifies scientists. The Cascadia Subduction Zone stretches from northern California to Vancouver Island. Unlike the San Andreas, it barely produces small earthquakes. It is locked, storing the energy of centuries of tectonic pressure. When it finally breaks, scientists expect a magnitude 9.0+ megathrust earthquake affecting a region of more than 10 million people. In this video we walk through what happens, step by step: 🌲 The ghost forests and the Japanese "orphan tsunami" that revealed the great quake of January 26, 1700 🌍 How subduction turns the coastline into a compressed spring ⚡ P-waves, S-waves and why 3–5 minutes of shaking destroys cities 🏚️ Seattle and Portland: brick buildings, century-old bridges and liquefaction ⛽ Oregon's fuel hub and the collapse of the region's energy supply 🌊 The tsunami: 15–25 minutes to reach high ground on foot ⛰️ Landslides in the Coast Range that cut the coast off from the rest of the continent 🔥 Fires with no water pressure, hospitals running out of diesel 🗺️ A permanently changed coastline Geologists have found evidence of dozens of Cascadia megaquakes over the last 10,000 years. The question is not if, but when. 📌 Chapters 0:00 The silent fault XX:XX Ghost forests & the orphan tsunami of 1700 XX:XX How the plates are locked XX:XX The rupture: P-waves and S-waves XX:XX Seattle & Portland under the shaking XX:XX Liquefaction and the fuel hub XX:XX The tsunami XX:XX Cut off: landslides and isolation XX:XX Fire, darkness and collapse XX:XX A new map of the Pacific Northwest 🔔 Subscribe to Ground Truth for more stories about how our planet really works. 💬 Do you live in the Pacific Northwest? Do you have an emergency kit ready? Tell me in the comments. Cascadia earthquake, the Really Big One, magnitude 9.0, megathrust, Pacific Northwest, Seattle, Portland, tsunami, ghost forests, January 26 1700, orphan tsunami, liquefaction, subduction zone, overdue earthquake cascadia subduction zone, cascadia earthquake, magnitude 9 earthquake, megathrust earthquake, pacific northwest earthquake, the really big one, cascadia tsunami, 1700 cascadia earthquake, ghost forests, orphan tsunami, juan de fuca plate, seattle earthquake, portland earthquake, liquefaction, tsunami documentary, earthquake documentary, plate tectonics explained, natural disaster, geology documentary, ground truth