Development of comprehensive techniques for coastal site characterisation, 3; Conceptualisation of long-term geosphere evolution

Niizato, Tadafumi  ; Amano, Kenji  ; Ota, Kunio ; Kunimaru, Takanori; Lanyon, B.*; Alexander, W. R.*

A critical issue for building confidence in the long-term safety of geological disposal is to demonstrate the stability of the geosphere, taking into account its likely future evolution. This study aims to establish comprehensive techniques for characterising the overall evolution of coastal sites through studying the palaeohydrogeological evolution in the coastal system around the Horonobe area, Hokkaido, northern Japan. Information on natural events and processes related to the palaeohydrogelogical evolution of the area have been integrated into the conceptual models that indicates the temporal and spatial sequences of the events and processes, such as climatic and sea-level changes, palaeogeography, and geomorphological and geological evolution in the area. The methodology will be applied to other analogous coastal areas on Japan to produce comprehensive techniques to support understanding the geosphere evolution of potential coastal sites for the repositories.