| Institution: | (1) Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan;(2) Disaster Control Research Center, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan;(3) Disaster Affairs, Earthquake Research Department, Lodumlu, Ankara, Turkey;(4) Dating and Material Research Center, Nagoya University, Nagoya 464-0814, Japan;(5) Institute of Geodynamics, National Observatory of Athens, P.O. Box 20048, 11810 Athens, Greece;(6) Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan;(7) Department of Civil and Environmental Engineering, Faculty of Engineering and Resource Science, Akita University, Akita 010- 8502, Japan;(8) Coastal and Harbor Engineering Research Center, Civil Engineering Department, Middle East Technical University, 06531 Ankara, Turkey |
| Abstract: | A tsunamigenic sediment layer has been discovered in fluvio-alluvial sequences on the northern coast of the Marmara Sea, northwestern
Turkey. The layer consists of unsorted silty coarse sand including terrestrial molluscs and charcoal fragments. The AMS radiometric
ages of the shells have been estimated at around BC 400, AD 300, AD 400, and AD 1000. We propose that a tsunami occurred in
the Marmara Sea in the middle of 11th century and invaded the fluvial plains. The older fossils were derived from the underlying
horizons, and it is probable that buoyant materials such as terrestrial molluscs and charcoals were isolated from liquefied
sediments during submarine sliding. Slope failure of coastal blocks triggered by fault movement generated tsunamis, which
might have transported floating materials to the backshore. |
