Sliding velocity fluctuations and subglacial hydrology over the last two decades on Argentière glacier, Mont Blanc area - Environnement, Dynamiques et Territoires de la Montagne Accéder directement au contenu
Article Dans Une Revue Journal of Glaciology Année : 2016

Sliding velocity fluctuations and subglacial hydrology over the last two decades on Argentière glacier, Mont Blanc area

Résumé

The subglacial observatory beneath the Argentiere glacier provides a rare opportunity to study the interactions between glacier sliding velocity and subglacial runoff. The sliding velocity has been monitored in this cavity almost continuously since 1997 and the resulting data indicate a decrease in annual sliding velocities over the last two decades. We found close relationships between annual surface velocity, sliding velocity and ice thickness. These relationships indicate that the ice-flow velocity changes do not depend on subglacial water runoff changes at the annual timescale. The seasonal magnitudes of sliding also show a decrease over the last two decades. At the seasonal timescale, sliding velocity increases before or simultaneously with the large runoff increase in May, indicating a distributed drainage system. Conversely, at the end of the melt season, sliding velocity continues to decrease after the runoff returns to low winter values. The simultaneous increases of runoff and sliding velocity occur mainly before the spring transition. Later, sliding velocity generally appears not to be related to water inputs coming from the surface, except for some large accelerations after midAugust that are always associated with periods of rapidly increasing water inputs to the subglacial drainage system.
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Dates et versions

hal-02009228 , version 1 (22-11-2021)

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Paternité - Pas d'utilisation commerciale - Pas de modification

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  • HAL Id : hal-02009228 , version 1

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Christian Vincent, Luc Moreau. Sliding velocity fluctuations and subglacial hydrology over the last two decades on Argentière glacier, Mont Blanc area. Journal of Glaciology, 2016, 62 (235), pp.805-815. ⟨hal-02009228⟩
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