A new CALM-S site at Irizar, Deception Island (Antarctic Peninsula region). First results.

VIEIRA, G., M. NEVES, A. CASELLI, M. RAMOS, V. BATISTA, I. BERNARDO.

Oslo

Conferencia; International Polar Year Oslo Open Science Conference; 2010

SCAR

Following ongoing research on permafrost and active layer in Deception Island (Maritime Antarctic), a new site for long-term monitoring of the active layer was installed in January 2009 in the framework of a Portuguese-Argentinean-Spanish collaboration. The site is integrated in the Circumpolar Active Layer Monitoring network – Southern Hemisphere (CALM-S) and intends to monitor changes in active layer thickness and geomorphological dynamics induced by climate. Since Deception Island is an active volcano, the site should also contribute to better understand the influence of anomalous geothermal heat flow on permafrost and active layer. The Irizar CALM-S site is located ca. 1 km SW of the Argentinean Station Decepción at a gently sloping site ca. 130m asl, on volcano-sedimentary substratum, mainly composed of ashes and pyroclastic deposits. A 100x100m grid for mechanical probing of the active layer has been installed, with measurements being made at 121 nodes regularly spaced at 10m intervals. Air temperatures and snow thickness data are collected using mini-loggers. Two shallow boreholes of 0.8m have been installed with hourly measurements at different depths. Solifluction is being measured once per year using wooden stakes and a laser total station. In order to obtain stable reference marks for positioning the total station, and since no bedrock outcrops occur, stainless rods with circular carvings in the lower end were buried into the permafrost that is present at ca. 80cm depth. This rods are anchored in the permafrost allowing for stable positioning. In this poster we present the general setup of the Irizar CALM-S site and the first data from 2009 and Summer 2010. This CALM-S site is especially interesting for comparing with data from the Crater Lake CALM-S site located at ca. 90m asl, about 2.5km east. In the later, despite the lower altitude, maximum active layer thicknesses are of ca. 30-40 cm, while at Irizar they are ca. 0.7m. This should be related to the more insulating surface cover at Crater Lake mainly composed by pumice. This research is integrated in project PERMANTAR (FCT) and is part of the IPY projects ANTPAS and TSP.