EARTHSC 2GG3 Lecture Notes - Lecture 8: Coastal Erosion, Subsidence, Radiocarbon Dating
17 Feb 2017
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Document Summary
Tsunami is a series of waves caused by displacement of large volume of water. Triggered by: large earthquakes causing uplift/subsidence of sea floor, underwater landslides, volcano flank collapse, submarine volcanic explosion, asteroids. Earthquake rupture in seafloor : generally requires > 7. 5 m earthquake. Tsunamis move rapidly in deep ocean: can typically travel up to and over 500 km/h. Tsunamis near land, loses speed : depth of ocean decreases tsubami waves , translates laterally. Tsunami moves inland : can be m to tens of m high, trough may arrive first exposing sea floor, run up - furthest horizontal and vertical distance of largest wave. Dec 26, 2004 killing 230,000 people (about) Local people headed to high ground (knew because of experience unlike tourists) Caused quite a lot of coastal erosion - movement of sediment and debris. Have to have topography and accumulation of sediment that"s prone to failure. Second most deadly tsunami was triggered by the krokatoa: explosion heard 5000 km.
