¹⁴C Ages of Large Coral Boulders Washed Ashore on the Southeast Coast of Miyako Island, Okinawa Prefecture

Abstract

Two coral samples were collected from large tsunami boulders washed ashore on the Maibahbama and Yoshino beach, southeast and east of Miyako Island, and they were radiocarbon dated.
A Porites sample of Maibahbama yielded an age of 675±22 BP （1,664±33 cal AD）, while another sample collected from Yoshino beach yielded an age of 559±22 BP （1,791±33 cal AD）.
These ages are conformable with ages of past tsunamis originated in the Okinawa trough on 1,667 and in the submarine bottom far off of Ishigaki Island on 1,771, respectively.