The contribution of geoelectrical investigations in the analysis of periglacial and glacial landforms in ice free areas of the northern foothills (northern victoria land, antarctica)

Abstract

All periglacial and glacial landforms investigated in the Northern Foothills have a very thin active layer (0.1–0.3 m thickness) overlying a thin permafrost layer, characterised by electrical resistivities ranging between 13 and 50 kΩm and by different thicknesses. Below this surficial layer, different types of ground ice (with a resistivity range from 8000 to 0.1 kΩm) were detected. These different types of ground ice permitted ice‐cored rock glaciers to be distinguished from ice‐cemented rock glaciers, subsea permafrost to be identified in some raised beaches, and other interpretations to be suggested about a debris‐covered glacier. These results have been obtained by vertical electrical soundings (VES) carried out in ice‐free areas of the Northern Foothills, near Terra Nova Bay Station during the tenth national Italian expedition in Antarctica (1994–1995). In these areas on the basis of previous geomorphological research, some landforms such as rock glaciers, raised beaches with patterned ground and debris‐covered glaciers were chosen to carry out the VES. The electrical prospection can be considered a good means for understanding the origins of landforms in ice‐free areas of Antarctica and for making a contribution to the palaeoenvironmental reconstruction of this continent.

Detailed detection of active layer freeze–thaw dynamics using quasi-continuous electrical resistivity tomography (Deception Island, Antarctica)

“…Also, the drilling of boreholes to monitor temperature in deeper layers is very expensive in Antarctica, which further limits the application of boreholes for deep investigations and in areas with very heterogeneous ground conditions. As a cost-effective and ecologically non-hazardous alternative, 2-D geophysical monitoring, such as electrical resistivity tomography (ERT), allows for monitoring the spatiotemporal variability in the freezing and thawing characteristics of the active layer and the permafrost, as has been demonstrated in several applications in the European Alps (e.g., Hauck, 2002;Hilbich et al, 2008;Krautblatter et al, 2010;Ottowitz et al, 2011;Supper et al, 2014;Mewes et al, 2017;Mollaret et al, 2019). ERT is a non-invasive technique that is sensitive to the electrical conductivity (the reciprocal of electrical resistivity) of materials.…”

Frozen ground phenomena in the vicinity of terra nova bay, northern victoria land, antarctica: a preliminary report

“…More recently, a geomorphological and glaciological map of the larger area has been published at a scale of 1:250,000 (Baroni 1996). Initial attempts to characterize the permafrost conditions of the region were made using geophysical methods (Lozej et al 1992;Gragnani et al 1998;Guglielmin et al 1997).…”

T‐RFLP Fingerprinting Analysis of Bacterial Communities in Debris Cones, Northern Victoria Land, Antarctica

“…In the Boulder Clay area, an ablation till of late‐glacial age overlies a body of buried glacier ice (Guglielmin et al , ; Gragnani et al , ; Guglielmin and French, ), and surface features include perennially ice‐covered ponds with icing blisters and frost mounds, frost fissures, polygons and debris islands (French and Guglielmin, ). The age of the frost mound is younger than 1020 ± 70 14 C yr BP, while the till that generally covers the surface of the Boulder Clay area is of Late Pleistocene age and attributed to the Ross Sea I glaciations (Orombelli et al , ).…”

“…Amorphous Glacier and Boulder Clay have been studied for their isotopic composition, mechanisms of ice distribution and geological formation (Guglielmin et al , ; Gragnani et al , ; French and Guglielmin, ; Guglielmin and French, ). However, it is unknown whether microorganisms occur in these sites.…”