GLG 301 Lecture 24: GLG301-2017-Summary 24
Document Summary
Tsunami: run-up heights (the height the water reaches) As wave of water enters shallower water, the wave slows and the height increases as water coming in from behind piles up. Bays and inlets (shape of the coast) can magnify wave height even more by focusing waves. Run-up heights reached 20 m on okushiri island, 1993, 20 m in indonesia 2004. Record run up height of 70 m reported at cape lopatka, Japan 2011 reached 40 m, waves focused near natori due: mitigation efforts to shape of coastline. Walls were constructed in japan to prevent tsunamis from inundating coastal cities. These barriers did not work well in 2011. All walls were overtopped, sometimes by nearly 10 m. But warnings (issued 9 min after quake 15 min warning) worked: 92% of people in affected area survived: far-field travel times. Velocity of wave = (g h) where g is gravity and h is water depth.
