LONGSHORE SEDIMENT MOVEMENT ALONG THE ENSHUNADA COAST INFERRED FROM FELDSPAR THERMOLUMINESCENCE

Investigation on the sediment movement characteristics was conducted in a broad research area with a 150-kilometer stretch along the Enshunada Coast and the Suruga Bay, Japan based on feldspar thermoluminescence (TL) properties. River sand grains (primary source) present a higher TL signal than beach sand. Along the nearshore area, local TL intensity peaks are observed at the river mouth and sample TL intensity gradually deceases with increasing distance from the river mouth, which indicates sediment longshore transport features. Far away from the river mouth, the decreasing trend on TL intensities terminates. Taking the spatial distribution of TL intensities into account, a quantitative estimation on the longshore sediment flux was carried out based on the total river sand discharge. A sunbath test was implemented to help to distinguish the beach sand constituents. Identification of coastal sand sources was achieved in terms of the profile and magnitude of the measured TL glow curves.