THE IMPACT OF TSUNAMI ON THE COASTLINE OF JERVIS-BAY, SOUTHEASTERN AUSTRALIA

The Jervis Bay area offers a diversity of landforms that do not fit wi thin contemporary views of coastal evolution. Field evidence indicates that catastrophic tsunami have had a significant impact on the coast and its hinterland both within and outside the embayment. Runup has ov ertopped cliffs 80 m above sea level and deposited chevron-shaped ridg es to elevations of 130 m on the southern headland. Boulders, up to 6 m in diameter, have been deposited in an imbricated fashion against cl iffs, on clifftops, and along shoreline ramps. Bed-form features and t he size of transported material indicate flow depths up to 10 m and ve locities around 8 m s(-1). While significant Pleistocene material has been swept onto the coastline, mainly in the form of barriers, radioca rbon dating indicates that tsunami have occurred repetitively througho ut the Holocene. The most recent event occurred just before European s ettlement over 200 years ago.