Aeolian processes and landforms on sub-Antarctic Marion Island

Abstract

Sub-Antarctic Marion Island has a hyperoceanic climate characterised by cold and wet conditions with consistently strong wind velocities throughout the year. Recent observations have recognised the increasing role of aeolian processes as a geomorphic agent on this sub-Antarctic island. The first data on intra-annual variations in aeolian sediment flux at the study site near Mesrug (46° 56’ 41”S; 37° 49’ 59”E. are presented. An intensive and high resolution environmental monitoring campaign was conducted between May 2015 and April 2016 at the study site. Aeolian transported sediments were collected using Big Spring Number Eight (BSNE. sediment traps at four different heights above the ground (i.e. 0.05, 0.25, 0.45, 0.65 m. on a monthly basis. Local meteorological condition, namely air temperature, soil moisture, wind speed, wind direction and rainfall were also monitored at five-minute intervals using Pace Scientific sensors and recorded on Pace Scientific XR5 data loggers. An annual sediment flux of 1.37 kg cm-2 y-1 has been calculated. This value is lower than the initial annual sediment flux of 3.85 kg cm-2 y-1 for the same site, based on preliminary data, presented by Hedding et al. (2015.. Modelled aeolian sediment movement appears to cease from 0.93 m above the ground. A notable limitation of the research is the incomplete dataset of monitored environmental parameters. As such, no single environmental parameter can be correlated with aeolian sediment flux. This study advocates further long-term monitoring of aeolian processes on Marion Island and that the link between aeolian processes and synoptic climate should be investigated. - Abstract as displayed in the - Abstract booklet. The presentation on the day may differ from the - Abstract.