Oceanographic Variability induced by Tides, the Intraseasonal Cycle and Warm Subsurface Water intrusions in Maxwell Bay, King George Island (West-Antarctica)

We examine the hydrographic variability induced by tides, winds, and the advance of the austral summer, in Maxwell Bay and tributary fjords, based on two recent oceanographic campaigns. We provide the first description in this area of the intrusion of relatively warm subsurface waters, which have led elsewhere in Antarctica to ice-shelf disintegration and tidewater glacier retreat. During flood tide, meltwater was found to accumulate toward the head of Maxwell Bay, freshening and warming the upper 70 m. Below 70 m, the flood tide enhances the intrusion and mixing of relatively warm modified Upper Circumpolar Deep Water (m-UCDW). Tidal stirring progressively erodes the remnants of Winter Waters found at the bottom of Marian Cove. There is a buoyancy gain through warming and freshening as the summer advances. In Maxwell Bay, the upper 105 m were 0.79 °C warmer and 0.039 PSU fresher in February than in December, changes that cannot be explained by tidal or wind-driven processes. The episodic intrusion of m-UCDW into Maxwell Bay leads to interleaving and eventually to warming, salinification and deoxygenation between 80 and 200 m, with important implications for biological productivity and for the mass balance of tidewater glaciers in the area.

The moss flora of Ostrov Geologov (Geologists Island), Maxwell Bay, King George Island, Antarctica.

Located of the east coast of Fildes Peninsula, South of Ardley Island, at King George Island, Ostrov Geologov (Geologist Islands) is a small island with 0.25 miles long. It only had one plant record published so far. We have conducted extensive fieldwork on the site and provide here a comprehensive checklist and a key for the moss species occurring on the island. Despite its small size, theislandcontains about 35% of all theFildes Peninsula moss flora, six new records were found. The pristine state of the island due to its relative isolation, presence of avian nesting sites and a relatively rich moss flora are strong arguments in favor of protection status for the island.

Geomorphology and landforms distribution in selected ice-free areas in the South Shetland Islands, Antarctic Northern Peninsula region

Ice-free areas cover a small percentage of the land in the South Shetland Islands. However, they are significant as they contain ecosystems highly sensitive to environmental changes and are located within a region affected by global warming. These areas are dominated by periglacial, glacial, fluvial, and coastal processes and landforms, where permafrost is often present. Soil development is observed although vegetation cover is sparse and closely related to the geomorphology. The mapping and monitoring of ice-free areas is important as they are highly sensitive to climate change. The objective of this study was to characterize and map surface landforms in ice-free areas using traditional mapping methods as well as advanced remote sensing techniques. Geomorphological and topographical maps were initially obtained through field measurements and observations, and complemented with existing aerial photography at scales between 1:2000 and 1:25000. Thereafter, satellite-borne data became available and were included in the methodology to further determine the distribution of the landforms. In the Antarctic environment, Synthetic Aperture Radar (SAR) provides the most reliable images as data can be obtained in any weather conditions as well as during the day and night. Fully polarimetric SAR RADARSAT-2 were used to determine seven different terrain classes representing surface landforms in ice-free areas around Maxwell Bay (King George Island). The SAR remote sensing techniques were successfully applied to identify different periglacial, fluvial, glacial, coastal, as well as lithological landforms. Field data from Fildes Peninsula were used to train a supervised classifier to map further areas around Maxwell Bay. In this case, the ice-free areas around Maxwell Bay clearly show the dominance of periglacial landforms and processes. Therefore, these techniques can be used to compare past and future results and to monitor areas affected by changing environmental factors and increasing human activities.

The first report on Amphipoda from Marian Cove, King George Island, Antarctic

This is a first account on amphipods from Marian Cove in Maxwell Bay, near the King Sejong Station, King George Island, the Antarctic. We have conducted a survey in 14 localities in the shallow sublittoral zone. A total of 22 amphipod species belonging to 12 families were identified. Six of these species were new for the whole Maxwell Bay. Our findings increase the amphipod fauna of Maxwell Bay from 55 to 61 species. The dominant species in the shallow sublittoral zone of Marian Cove were: Cheirimedon femoratus and Gondogeneia antarctica, followed by Bovallia gigantea, Orchomenella cf. ultima, Paradexamine fissicauda, Prostebbingia brevicornis, Pariphimedia integricauda, and Jassa wandeli.