CASCADIA: The Megaquake That Could Break America’s West Coast

On the night of January 26, 1700, a magnitude 9 earthquake ruptured seven hundred miles of the American Pacific coast — and no one in North America wrote it down. The story of how it was reconstructed three centuries later from dead cedar trees in a Washington salt marsh, a Japanese village ledger, sediment cores from the ocean floor, and the oral traditions of the Coast Salish — and why the next rupture of the Cascadia subduction zone is already overdue. CHAPTERS 00:00 The Fault Most Americans Never Hear About 01:13 Megathrust Earthquakes Around the World 02:20 How Cascadia Was Forgotten 04:23 Brian Atwater and the Ghost Forests 06:30 Tree Rings Date the Disaster 08:40 Japan's Orphan Tsunami Records 10:08 Kenji Satake Solves the Source 12:03 How Subduction Zones Store Energy 13:44 Chris Goldfinger and the Ocean Cores 16:06 The Pattern of Cascadia Ruptures 17:34 FEMA's Cascadia Scenario 19:49 Tsunami Impact and Evacuation Limits 23:03 The Fourth Witness: Oral Traditions 26:40 Why the Warning Was Not Heard 28:04 Preparedness, ShakeAlert, and What Comes Next ACADEMIC SOURCES Atwater, B.F. (1987). Evidence for great Holocene earthquakes along the outer coast of Washington State. Science, 236(4804), 942-944. https://doi.org/10.1126/science.236.4... Satake, K., Shimazaki, K., Tsuji, Y., Ueda, K. (1996). Time and size of a giant earthquake in Cascadia inferred from Japanese tsunami records of January 1700. Nature, 379, 246-249. https://doi.org/10.1038/379246a0 Yamaguchi, D.K., Atwater, B.F., Bunker, D.E., Benson, B.E., Reid, M.S. (1997). Tree-ring dating the 1700 Cascadia earthquake. Nature, 389, 922-923. https://doi.org/10.1038/40048 Goldfinger, C., Nelson, C.H., Morey, A.E., Johnson, J.E., Patton, J.R., Karabanov, E., Gutierrez-Pastor, J., Eriksson, A.T., Gracia, E., Dunhill, G., Enkin, R.J., Dallimore, A., Vallier, T. (2012). Turbidite Event History — Methods and Implications for Holocene Paleoseismicity of the Cascadia Subduction Zone. U.S. Geological Survey Professional Paper 1661-F. https://pubs.usgs.gov/pp/pp1661f/ Ludwin, R.S., Dennis, R., Carver, D., McMillan, A.D., Losey, R., Clague, J., Jonientz-Trisler, C., Bowechop, J., Wray, J., James, K. (2005). Dating the 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories. Seismological Research Letters, 76(2), 140-148. https://doi.org/10.1785/gssrl.76.2.140 Atwater, B.F., Musumi-Rokkaku, S., Satake, K., Tsuji, Y., Ueda, K., Yamaguchi, D.K. (2005). The Orphan Tsunami of 1700 — Japanese Clues to a Parent Earthquake in North America. U.S. Geological Survey Professional Paper 1707. https://pubs.usgs.gov/pp/pp1707/ Schulz, K. (2015). The Really Big One. The New Yorker, July 20, 2015. https://www.newyorker.com/magazine/20...