Pocket beach sediment: A field investigation of the geodynamic processes of coarse-clastic beaches on the Maltese Islands (Central Mediterranean)

Abstract

Research on pocket beaches is generally lacking, and merits more intensive investigative efforts in view of the importance of coastal landscapes, especially along the Mediterranean coastline. This paper is a first as a geomorphological study of pocket coarse-clastic beaches in the Maltese Islands, shedding light on beach sediment dynamics and related spatio-temporal controls between and within beaches. Four beaches along the coastline of the Maltese Islands were selected as study areas, with distinct geological lithologies, coastal configurations and wave exposures. Systematic sampling was done with field data collected on beach morphology, sediment size and shape properties to account for both seasonal and post-storm trends. Sediment tracer experiments were also carried out to determine the major transport pathways and recoveries of gravel beach sediments. Wave exposure, geological background and coastal configuration were found to be important components in coarse-clastic pocket beach response to forcings. This study re-affirms that microtidal pocket beaches constitute individual environments, which require a rigorous and representative systematic sampling approach based on sediment behaviour in both the longshore and cross-shore dimensions. This study demonstrates the need to further investigate the different spatio-temporal processes in microtidal pocket beaches, including aspects related to intrinsic sediment dynamics.