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Advisor(s)
Abstract(s)
Topography exerts a key role in controlling permafrost distribution in areas where mean annual temperatures
are slightly negative. One such case is the low-altitude environments of Maritime Antarctica, where permafrost
is sporadic to discontinuous below 20–40 m asl and continuous at higher areas and active layer dynamics are
thus strongly conditioned by geomorphological setting. In January 2014 we installed three sites for monitoring
active layer temperatures across Byers Peninsula (Livingston Island, South Shetland Islands) at elevations between 45 and 100 m. The sites are situated in lake catchments (lakes Escondido, Cerro Negro, and Domo) that
have different geomorphological and topographical conditions. Our objective was to examine the role of topography and microclimatic conditions in determining the active layer thermal regime in order to identify the factors
that control geomorphic processes in these lake catchments. At each site a set of loggers was installed to monitor
air temperature (AT), snow thickness (SwT) and soil temperature (ST) down to 80 cm depth. Mean annual air
temperatures (MAAT) showed similar values in the three sites (−2.7 to −2.6 °C) whereas soil temperatures
showed varying active layer thicknesses at the three catchments. The ground thermal regime was strongly controlled by soil properties and snow cover thickness and duration, which is influenced by local topography. Geomorphological processes operating at the lake catchment scale control lacustrine sedimentation processes, and
both are dependent on the combination of topographical and climatic conditions. Therefore, the interpretation
of lake sediment records from these three lakes requires that soil thermal regime and snow conditions at each
site be taken into account in order to properly isolate the geomorphological, environmental and climatic signals
preserved in these lake records.
Description
Keywords
Active layer Topography Snow cover Byers Peninsula Antarctica
Pedagogical Context
Citation
Oliva, M., Hrbacek, F., Ruiz-Fernandez, J., Angel de Pablo, M., Vieira, G., Ramos, M., & Antoniades, D. (2017). Active layer dynamics in three topographically distinct in Byers Peninsula (Livingston Island, Antarctica). Catena, 149(Part 2), 548–559. https://doi.org/10.1016/j.catena.2016.07.011
Publisher
Elsevier