Tsunamis are the most famous and destructive results of coastal earthquakes, in part because they can cause damage thousands of miles from the earthquake epicenter. Typically, two small local tsunamis occur each year throughout the world. Instead, major tsunamis are infrequent events that may hit the same portion of the coastline with a recurrence time of centuries. Even on a tectonically active coastline, the most recent large tsunami may predate the written record (e.g. 1700 Cascadia).
Researchers have spent decades comparing the results of models of ancient tsunamis to the deposits of modern tsunamis. In the last three decades, geologists have been to most areas hit by tsunamis soon after the event (starting with 1992 Nicaragua), and in each case, sedimentologists have collected data to help benchmark models of tsunami deposition. We still don’t know exactly what processes affect the tsunami sediments nor how much of the original deposit is returned to the ocean.
We focus on tsunami and storm sedimentation, in an effort not only to understand how to identify ancient catastrophes from their deposits but to determine how large those catastrophes were and the processes acting on their sediments after deposition.