A Late Holocene Tsunami at Basta Voe,Yell, Shetland Isles

A distinctive sand layer enclosed within Holocene peat is described from Basta Voe, Isle of Yell, Shetland Isles. The sand layer, that can be traced considerable distances inland and up to a maximum altitude of c. + 9 m OD, is here interpreted as having been deposited by a former tsunami. AMS dating appears to indicate that the tsunami occurred between 1300 – 1570 cal years BP. At present, the tsunami has no known source mechanism although the most likely mechanism is thought to have been an offshore slump or slide. The available information would presently seem to indicate that this tsunami was restricted to the eastern coastline of Shetland. The relatively young age of this inferred tsunami is of considerable importance to planners and engineers concerned with estimating coastal flood frequency and magnitude.