Ronne Ice Shelf

Ronne Ice Shelf
Name	Ronne Ice Shelf
Location	Weddell Sea, Antarctica
Coordinates	78°S 40°W
Area	~430,000 km²
Thickness	up to 600 m
Status	Retreating

Ronne Ice Shelf is a major Antarctic ice shelf bordering the Weddell Sea and the Filchner-Ronne Ice Shelf system near Queen Elizabeth Land and Coats Land. It fringes the Antarctic Peninsula region and buttresses ice streams draining the East Antarctic Ice Sheet into the Southern Ocean, playing a key role in regional sea level contributions and ocean-cryosphere interactions.

Geography and Physical Characteristics

The ice shelf occupies embayments adjacent to Filchner Ice Shelf, Alexander Island, Berkner Island, and the Shackleton Range, with seaward fronts facing the Weddell Sea, Scotia Sea, and the Southern Ocean. Its grounding line connects to inland features including the Slessor Glacier, Foundation Ice Stream, Support Force Glacier, and the Kohler Glacier, and overlies bathymetry such as the Weddell Basin and Maud Rise. Surface elevations and ice thickness are mapped by missions like Operation IceBridge, ICESat, and CryoSat-2, revealing flow patterns influenced by subglacial topography beneath the Fimbul Ice Shelf margin. The shelf interacts with polynyas near McMurdo Sound and fronts typical of the Antarctic Convergence and the Weddell Gyre.

History of Exploration and Naming

Early sightings occurred during voyages by expeditions such as the Belgian Antarctic Expedition (1897–99), United States Antarctic Service Expedition (1939–41), and Operation Highjump. Major mapping was completed by the Ronnie and Ellsworth era surveys and later by the British Antarctic Survey and U.S. Geological Survey. The feature was named in honor of Finn Ronne, whose work during the Antarctic exploration of the 1940s and service in the United States Navy advanced reconnaissance of the region. Subsequent aerial photography and satellite reconnaissance by Landsat, NOAA, European Space Agency, and research programs like SCAR refined cartography and nomenclature debates resolved at meetings of the Advisory Committee on Antarctic Names and the Scientific Committee on Antarctic Research.

Glaciology and Ice Dynamics

Flow dynamics are dominated by ice streams feeding from the East Antarctic Ice Sheet and modulated by pinning points such as Berkner Island and submerged ridges like the South Orkney microcontinent features. Studies by institutions including NASA, NSF, British Antarctic Survey, Alfred Wegener Institute, and Lamont–Doherty Earth Observatory use models from PISM and observations from GPS and radar campaigns to quantify shear margins, basal sliding, and calving processes. Ocean-driven basal melting driven by Circumpolar Deep Water incursions, and buttressing loss linked to rift propagation similar to events at Larsen Ice Shelf and Pine Island Glacier influence mass balance. Ice-core records from areas adjacent to the shelf tie to paleoclimate reconstructions coordinated through IPCC assessments and regional palaeoglaciological syntheses.

Climate Change and Recent Retreat

Recent satellite time series from ERS-1, ERS-2, Envisat, Sentinel-1, and ICESat-2 document thinning, grounding line migration, and calving events analogous to those affecting Thwaites Glacier and Amundsen Sea Embayment. Oceanographic campaigns by Weddell Sea Expedition teams and analyses led by University of Cambridge, University of Washington, University of Maine, and Columbia University report enhanced basal melt related to warming of Antarctic Bottom Water and altered circulation in the Weddell Gyre. Prognostic runs using CMIP6 forcings and ice-sheet models indicate potential contributions to global sea level comparable to impacts from destabilization in the West Antarctic Ice Sheet over multi-century horizons. Policy and assessment bodies such as IPCC and Scientific Committee on Antarctic Research incorporate these findings into risk analyses for coastal infrastructure and United Nations climate deliberations.

Ecology and Marine Environment

The marginal ice zone and sub-ice-shelf cavities support microbial communities studied by teams from Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, Alfred Wegener Institute, and British Antarctic Survey. Food webs link to megafauna including krill aggregations, emperor penguin colonies, Adélie penguin populations, and marine mammals such as Weddell seal and southern elephant seal which forage in polynyas and along ice fronts. Nutrient fluxes and primary productivity are influenced by iron and nutrient delivery from ice melt and upwelling related to the Antarctic Circumpolar Current and the Weddell Gyre; studies contribute to global biogeochemical models and are cited in programs like WOA and GEOTRACES.

Human Activity and Research Stations

Human activity is limited to scientific field camps and logistical support from stations including Rothera Research Station, Halley Research Station, Neumayer-Station III, and seasonal field camps deployed by National Science Foundation, British Antarctic Survey, Alfred Wegener Institute, and British Antarctic Survey logistics contractors. Air and ship operations are coordinated through Antarctic Treaty consultative meetings and logistics managed by national programs like United States Antarctic Program and Australian Antarctic Division. Research focuses on ice-ocean interactions, borehole access projects inspired by BAS and WHOI collaborations, and autonomous platforms such as Argo floats adapted for polar deployment and autonomous underwater vehicles employed beneath the shelf.

Category:Ice shelves of Antarctica Category:Geography of the Weddell Sea