Soilscapes and geoenvironments at Stansbury Peninsula, Nelson Island, maritime Antarctica

Abstract

Considering that the extreme variation in Antarctica’s climate has important effects on soil properties and distribution, characterizing and mapping surface landforms in ice-free areas is strategic. We aimed to evaluate the pedogenetic processes, as well as classify and map the different types of soils at Stansbury Peninsula (ST), Nelson Island. In order to stratify the whole environment area of the Peninsula, we used the geosystems’ approach, identifying the landscape unit of geoenvironment. We mapped geoenvironments and soils, performing physical–chemical and mineralogical characterizations. Our results suggest that compared to other islands in the South Shetlands, the active layer at Stansbury is thin, so that it is more susceptible to climate change, representing a Key monitoring site for climate change studies. The northwestern area of Stansbury Peninsula is the preferential area for marine birds, mammals nesting and resting places. Hence, higher values of nutrients are recorded in their soils. The climate at ST is harsh due to strong northwest polar winds, which promote widespread wind ablation, erosion and contribute to physical weathering, with a high prevalence of periglacial processes under wet conditions, which is typical of this zone of South Shetlands areas, exposed to the Drake passage. Soils at ST are predominantly skeletal, gravelly, with little organic matter and little fauna activity, poor vegetation cover, and high levels of base saturation suggesting limited weathering of volcanic rocks. Soils display a strong characteristic of physical weathering due freezing and thawing process, resulting in typical patterned ground (cryoturbation forming Cryosols), under active periglacial processes. The unique proglacial and periglacial geoenvironments of Stansbury are influenced by melting water and widespread snow banks, under wet polar oceanic climate condition.