Active layer temperature monitoring in two boreholes in Livingston Island, maritime Antarctic: first results for 2000–2006

摘要

This paper describes the active layer thermal regimes in two shallow boreholes, Sofía 275 m a.s.l. and Incinerador 35 m a.s.l., for which the ground temperature series has been recorded continuously from 2000 to 2006. The monitoring sites are located in Livingston Island, South Shetland Archipelago, Antarctica. This is one of the most sensitive regions of Earth to climate change, with a major warming trend over the last 50 years, of ca. +2.5oC in the Mean Annual Air Temperatures (MAAT). This region is located near the climatic limit of permafrost, since MAAT at sea level is close to -2oC. Lineal fits of the ground temperatures series for the study period at different depths in these boreholes show positive slopes. An outcome from the analysis of freezing and thawing indexes is that most of the ground warming seems to concentrate in the summer.