Tsunami Crash Course

Images from UNESCO IOC Brochure:Tsunami: The Great Waves

Shallow Water Wave!

• C = √(gd)

Similar to surge, much depends on bathymetry

Near shore

Deep water

Before and After

• Warnings:– If close to event center, only defense is to head

for high ground (U. West Coast, esp. Wash/Ore.)

– Sometimes there is time to warn, or at least cancel warnings (DART)

Crescent City, CATsunami Magnet

• Offshore Bathymetry (underwater Topography): Mendocino Fracture Zone

• Shape of near-shore shelf • Shape of coastline itself– 8 Feet in Sendai Tsunami– 22+ feet in 1964 (from

Alaskan Earthquake)