238-8 Seasonal Grain-Size Dynamics Along Cliff-Dominated Beaches in the Eastern Mediterranean: The Role of Cliff Erosion, Waves and Wind

Session: Recent Advances and New Voices in Marine and Coastal Geoscience

Presenting Author:

Authors:

Abstract:

Grain-size of beach sediments and their interactions with wave climate are crucial for modeling cross-shore and longshore sediment-transport processes and the evolution of beach morphology. Although recent studies have emphasized the temporal and spatial variability of beach sediments, these dynamics have been mostly studied in flat coasts, where coastal cliffs are absent. Thus, the spatial and temporal dynamics of beach sediments along cliff-dominated coastlines remain as one of the less constrained aspects of coastal sediment dynamics. Here we quantify the temporal dynamics of sand along cliff-dominated beaches in the Eastern Mediterranean coast of Israel based on repeat, seasonal-scale sampling of surficial sediments over three years. We found a general periodicity in the beach grain size: Winter/spring cliff erosion associated with intense wave storms contributes to the beach eolianite clasts (very coarse sand 1-2 mm) and quartz (fine sand 180-220 µm). During strong wave storms, beach sediments are transported alongshore northwards and deposited all over the beach as the storm ceases. After being deposited, the surficial sediments become finner with time due to gradual burial of the beach by  wind-transported fine sand. Eolian abrasion might also contribute to the observed seasonal finning pattern of the beach sediments by disintegrating eolianite clasts. We stress that cliff erosion, waves and wind control seasonal changes in particle size distribution of sand along cliff-dominated beaches.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-8318

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.