Spatial modelling of the temperature at the top of Permafrost in Cierva Point (Antarctic Peninsula)

• Main Author: Ramos Marín, Sara
• Other Authors: Vieira, Gonçalo, Goyanes, Gabriel
• Format: Master Thesis
• Language: English
• Published: 2019
• Subjects: Permafrost; Active layer; Temperature regime; Western Antarctic Peninsula; TTOP; Geografia; Antarctic; Antarctic Peninsula; Cierva; Cierva Point; Danco; Danco Coast; Active layer monitoring; Active layer temperature; Antarc*; permafrost
• Online Access: http://hdl.handle.net/10451/36229

The Western Antarctic Peninsula (WAP) has shown complex reactions to climate change in the last decades. To evaluate the changes occurring in these environments, permafrost and active layer monitoring and modelling are essential. In this dissertation, the characteristics of the ground temperature regime are analysed and the spatial distribution of the “Temperature at the Top of Permafrost” (TTOP) in Cierva Point (Danco Coast, WAP) is estimated using topo-climatic information over an area of 0.65 km2. With the results, the climate sensitivity of permafrost in this area and the potential impact of small climate change in its extent are evaluated. A first evaluation of the temperature regimes allowed to determine the temperature and depth of the permafrost table and the ground thermal offset using observed borehole and climate data from nine different monitoring sites, in selected periods from 2012 to 2018. The top of permafrost was observed at depths of 0.4, 1 and 5m and the temperature at these depths was observed to be -1.4 ºC, -2.6 ºC and 1.2 ºC in these locations. For the monitoring boreholes where the top of permafrost was not reached, the depth of the top of permafrost was estimated to range between 0.4 and 5 m with temperatures ranging between -0.2 ºC and -2.6 ºC. The results were used together with topographic data to implement the spatial TTOP model using a Geographical Information System (GIS)-based methodology to implement a high-resolution model (1 x 1 m grid cell) that allows a further insight into the spatial characteristics of permafrost. Permafrost was estimated to be present in nearly 88% of the area and the lower TTOP values were found at high altitudes and unconsolidated soil or peat areas covered by moss. The highest TTOP results were found at low altitudes, bare surfaces and concave areas. Bare surfaces increase exposure to solar radiation during the summer and the concavity of the terrain promotes higher snowpack accumulation during the winter, which acts as a good thermal insulator hindering ...