OFFSHORE AEOLIAN TRANSPORT ACROSS A BEACH - CARRICK-FINN STRAND, IRELAND

This study examined cross-shore differences in wind speed and aeolian sediment transport rate in relation to beach surface conditions in the lee of a 6 m high dune during 2 days of offshore winds at Carrick Fin n Strand, Ireland. Near-surface wind speed, surface moisture, carbonat e content and mean grain size increased in the offshore direction; sed iment sorting became slightly poorer. The rate of sediment transport w as small from the dune toe out to a distance of about 20 m and then in creased rapidly to about 40 m seaward of the dune. The rate decreased seaward of this location early each day due to a great increase in sur face moisture content. Greater rates of transport occurred seaward of this location later in the day and are attributed to drying of the bea ch surface and increased wind speeds. Rates of offshore aeolian transp ort on the beach in the lee of the dune are affected by shore-parallel zones differing in wind speed, surface moisture and sediment characte ristics that change in location through time. These zones include a Le e-of-Dune Zone, where no aeolian entrainment occurs because of low win d speeds; an Erosion Zone, located sufficiently far from the dune that wind is effective in entraining and removing sediments; a Transport Z one where erosional losses are replaced by inputs from upwind; and an Accretion Zone on the moist portion of the foreshore.