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| Lescarmontier, L.; Legresy, B.; Young, N. W.; Coleman, R.; Testut, L.; Mayet, C.; Lacroix, P. |
| We investigated the evolution of two major rifts cutting across Mertz Glacier Tongue, East Antarctica, using a combination of satellite images and 60 day sets of GPS data from two stations deployed either side of the western rift in 2007. The eastern rift began to open in the early 1990s, and the western rift initiated in 2002 in conjunction with the collision of a large iceberg with the tongue. Velocity time series derived from the 2007 GPS data exhibited strong variations at tidal periods modulated by sea-surface height and sea-surface slope and reproduced here with a conceptually simple model. We found that opening of the western rift in 2002 leads to a dramatic change in behavior of the tongue as the large range in velocity (700-2400 m a(-1)) observed... |
| Tipo: Text |
Palavras-chave: Antarctic glaciology; Calving; Crevasses; Glacier flow; Glacier mechanics. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00489/60023/63276.pdf |
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| Charrassin, J. -b.; Hindell, M.; Rintoul, S. R.; Roquet, Fabien; Sokolov, S.; Biuw, M.; Costa, D.; Boehme, L.; Lovell, P.; Coleman, R.; Timmermann, R.; Meijers, A.; Meredith, M.; Park, Y. -h.; Bailleul, F.; Goebel, M.; Tremblay, Y; Bost, C. -a.; Mcmahon, C. R.; Field, I. C.; Fedak, M. A.; Guinet, C. |
| Polar regions are particularly sensitive to climate change, with the potential for significant feedbacks between ocean circulation, sea ice, and the ocean carbon cycle. However, the difficulty in obtaining in situ data means that our ability to detect and interpret change is very limited, especially in the Southern Ocean, where the ocean beneath the sea ice remains almost entirely unobserved and the rate of sea-ice formation is poorly known. Here, we show that southern elephant seals (Mirounga leonina) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice... |
| Tipo: Text |
Palavras-chave: Antarctic circumpolar current; Instrumentation; Marine predators; Ocean observation; Sea-ice modeling. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00241/35239/33750.pdf |
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| Galton-fenzi, B. K.; Maraldi, C.; Coleman, R.; Hunter, J.. |
| Ocean circulation under ice shelves and associated rates of melting and freezing are strongly influenced by the shape of the sub-ice-shelf cavity. We have refined an existing method and used additional in situ measurements to estimate the cavity shape under the Amery Ice Shelf, East Antarctica. A finite-element hydrodynamic ocean-tide model was used to simulate the major tidal constituents for a range of different sub-Amery Ice Shelf cavity water-column thicknesses. The data are adjusted in the largely unsurveyed southern region of the ice-shelf cavity by comparing the complex error between simulated tides and in situ tides, derived from GPS observations. We show a significant improvement in the simulated tides, with a combined complex error of 1.8 cm, in... |
| Tipo: Text |
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| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00238/34899/34556.pdf |
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| Lescarmontier, L.; Legresy, B.; Coleman, R.; Perosanz, F.; Mayet, C.; Testut, L.. |
| At the time of its calving in February 2010, Mertz Glacier, East Antarctica, was characterized by a 145km long, 35km wide floating tongue. In this paper, we use GPS data from the Collaborative Research into Antarctic Calving and Iceberg Evolution (CRAC-ICE) 2007/08 and 2009/10 field seasons to investigate the dynamics of Mertz Glacier. Twomonths of data were collected at the end of the 2007/08 field season from two kinematic GPS stations situated on each side of the main rift of the glacier tongue and from rock stations located around the ice tongue during 2008/09. Using Precise Point Positioning with integer ambiguity fixing, we observe that the two GPS stations recorded vibrations of the ice tongue with several dominant periods. We compare these results... |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00140/25136/23246.pdf |
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