[HCG22-P01] Numerical estimation of Holocene paleowave changes in an estuarine environment: case of Tokyo Bay, central Japan
Keywords:wind wave, Tokyo Bay, Holocene, numerical simulation, sea level change
During the Holocene, many estuaries and embayments has changed their shape due to shoreline transgressions caused by the sea-level rise and regressions due mainly to the sedimentation, which may have changed the condition of the wind-wave propagation and development within the area. In this study, a paleowave simulation of Tokyo Bay has been carried out by using SWAN model to estimate changes in the wave field and to evaluate the role of wind waves on the formation of the estuarine morphology taken place during the Holocene. Tokyo Bay was chosen as a study area due to the following three reasons: 1. paleoshorelines are well identified by a large number of geological and archeological proxies, 2. the head of the elongated bay has extended northward during the mid-Holocene transgression stage and the maximum length of the bay was estimated to be twice as large as that at present and the fetch within the area during the winter monsoon season and during typhoon events in summer are expected to have changed greatly, and 3. many erosive features are estimated to have formed by wave actions, such as erosive cliffs and underwater wave-cut platforms, indicating a strong relevance of waves on the formation of the present-day morphology.