1 INTRODUCTION The thermal state of the active layer and permafrost are key indicators of climate change within the cryo- sphere and several international panels and programs (GCOS, IGBP, GTN-P) endeavour to monitor these parameters. The IPA has instigated the Circumpolar Active Layer Monitoring (CALM) program that, until now, has mainly developed in the Arctic. This paper is the first step to create a coordinated program for active layer monitoring in Antarctica. Also the impor- tant biological project “Regional Sensitivity to Climate Change in Antarctic Terrestrial and Limnetic Ecosys- tems” (RiSCC) looks forward to integrating its bio- logical data with the abiotic data of this project. In this paper we present the results of the first years of active layer and near permafrost thermal monitoring. We also illustrate the methodologic problems related to the active layer monitoring that occurs in Antarctica. 2 STUDY AREAS The study sites are all located in Victoria Land (Antarctica) between 77°50'S and 74°44'S at altitudes ranging from 38 to 1100 m a.s.l. The sites include a range of geographical, geomorphological, geological and pedological characteristics (Table 1). The choice of the sites was influenced by the availability of logis- tical facilities with Scott Base, Boulder Clay and Oasi adjacent to New Zealand, or Italian Antarctic stations. The Marble Point, Bull Pass, Mount Keinath and Simpson Crags sites are accessible by helicopter from the main research stations. All the sites were chosen following pedological, geophysical and/or geomor- phological study (Guglielmin et al., 1997a). The sites of Mount Keinath and Oasi are both located on granitic outcrops and differ from the other sites, which are char- acterized by till deposits. CALM grids of 100 m (121 measurements points) at Boulder Clay and Simpson Crags were established in 1998 to monitor the active layer thickness. Permafrost is continuous in all the sites with a thickness of several hundred meters and a ZAA (zero annual amplitude) approximately around 11 m at Boulder Clay (French and Guglielmin, 2000). The ice content within the permafrost is variable. In the Northern Victoria Land the ice-free areas are mainly characterized by massive ice bodies of different ori- gins (Gragnani et al., 1998; Guglielmin et al., 2001) such as at the sites of Boulder Clay and Simpson Crags or ice-rich and ice-bonded permafrost along the raised beaches and within the older till. The gravimetric moisture content of the active layer of soils in Southern Victoria Land is typically between 1 and 10% (Campbell et al., 1994, 1997). There is some seasonal variability at sites where snow-melt has been shown to result in an increase in soil moisture content to values of up to 15% for short periods (up to 14 days, Campbell et al., 1997). Within the underlying per- mafrost in coastal areas, moisture contents are variable ranging from lenses of ice (100% moisture), to mois- ture contents of 10%, with an average of about 40% (Campbell et al., 1998). In dry inland areas, such as the Wright Valley, soil moisture contents, in both the permafrost and the active layer, are generally less than 10%. 337 Towards an Antarctic active layer and permafrost monitoring network M. Guglielmin ArpaLombardia, Milan, Italy M. Balks Department of Earth Sciences, University of Waikato, Hamilton, New Zealand R. Paetzold Natural Resource Conservation Service, United States Department of Agriculture, Lincoln, Nebraska, USA ABSTRACT: This paper is the first step to create a coordinated program for active layer monitoring in Antarctica as instigated by several international panels and programs (GCOS, IGBP). Actually 7 sites located along a latitu- dinal transect in Victoria Land between 77°55'S and 74°26'S are monitored. At all the sites ground temperatures at depths to 7.8 m and some climatic parameters (e.g. air temperature, incoming radiation), are all year round recorded using dataloggers. The climatic significance of GST in four selected sites (Scott Base, Bull Pass, Boulder Clay and Simpson Crags) is illustrated. The active layer thickness shows a large variability both in space and in time. The southern sites show an active layer thicker (ranging between 22 and 55cm) than the northern ones (17–39 cm) despite of a warmer GST in the last. This difference can be explained with the higher ice content of the northern sites. Permafrost, Phillips, Springman & Arenson (eds) © 2003 Swets & Zeitlinger, Lisse, ISBN 90 5809 582 7