GS1 – Geography
Context:
Recent research highlights the threat of a mega-tsunami if a major earthquake occurs along the Cascadia Subduction Zone (CSZ) off the Pacific Coast of the US. Such an event could lower sea levels by approximately 6.5 feet and produce waves up to 1,000 feet high, far surpassing typical tsunami heights.
Cascadia Subduction Zone (CSZ):
- Location & Extent: A 600-mile-long fault extending from Northern California to Vancouver Island.
- Tectonic Setting: Convergent plate boundary where the Juan de Fuca Plate subducts beneath the North American Plate.
- Seismic Behaviour: Accumulates tectonic stress over centuries; sudden release triggers major earthquakes and tsunamis.
- Probability: Current estimates suggest a 15% chance of an earthquake of magnitude 8.0 or higher within the next 50 years.