"Alexander and Edith Tollmann, geologists at the University of Virginia, have argued that a series of large ocean impacts, coupled with smaller land collisions, in the middle of the eighth millennium BC is the cause of Noah's Flood... Greenland ice-core data and tree-rings show that something major did happen right at the time the Tollmanns propose. A very strong acid layer has been dated to 7630BC (+-170 years)"
They go on to propose: "...the Tollmanns argue that a comet with seven large fragments struck the world's oceans more or less simultaneously in the Tasman Sea southeast of Australia, in the South China Sea, in the west-central Indian Ocean, in the North Atlantic, in the central Atlantic south of the Azores, in the Pacific off Central America, and farther south in the Pacific just west of Tierra del Fuego. The impacts set up giant tsunamis...."
Looks like this could be a possible source of a giant tsunami in the correct time frame, huh.