EARTHSC 2GG3 Lecture Notes - Lecture 5: Cascadia Subduction Zone, Subduction, List Of Historical Tsunamis
30 Mar 2016
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Document Summary
Strongest when water is channeled into one area. Generated by earthquakes, also sudden displacement of water (massive rocks/soil makes waves) Oseanic plates being heavier than coninental plates. One plate (subducing plate) goes underneath other plate (overriding plate) Causes stress, displaces large volume of water. Stuck area ruptures, releasing energy in an earthquake. Displacement of sea loor, creates bulge of water in ocean and water is dispersed by tsunami. Greatest hazards where land is very close to boundaries. Islands in south are all close to boundaries. Subducion zone locaion >1000km ofshore southern bc (part of cascadia subducion zone) Tsunami-laid sediment (tls) there is material that has deposited on the coast of bc that we can see associated with tsunamis. Indicate historic tsunami impacts along the paciic northwest coastline. Arrival of tsunami less than 30 minutes ater tsunami trigger. Travel ime of tsunamis in the paciic ocean can be accurately calculated based on: seismograph data and topography of the ocean loor.
