Wind and Water Erosion of a Peat and Sand Area on Subantarctic Macquarie Island

Abstract

This study presents rates of geomorphic processes on subantarctic Macquarie Island (54°30′S, 155°55′E) over a 3.3-yr period associated with erosion of a mixed sand and peat substrate at a site 180 m above sea level. Erosion pins were used to measure lowering of up to 43 mm yr⁻¹ in the northern section of the site and accretion of 28 mm yr⁻¹ in the southern section of the site. The present area of exposed sand and peat was compared with that in 1976 from aerial photography, which revealed the influence of the prevailing wind direction and the slope of the site. A thermoluminescence date of 22,100 ± 2800 yr BP (W2193) from sand and a radiocarbon date from peat of 1530 ± 30 yr BP (β-94180) allowed partial reconstruction of environmental conditions at the site during the last 22,000 yr.