Reconstitution de l'histoire paraglaciaire d'une marge glaciaire face aux changements climatiques : le cas du glacier Baron au Spitsberg (Paraglacial history of a glacial margin facing global change : the Baronbreen case study, Spitsbergen)

摘要

Polar regions are very sensitive to climate variability. Glacial environments, such as those of Spitsbergen, respond drastically to climate warming by the disintegration of ice masses, release of huge amounts of free water and rapid evolution of terrestrial landforms. Paraglacial studies have shown that sediment yield decreases with time according to a relaxation curve. This study examines the effects of scaling on rhythms of deglaciation and sediment fluxes in a small catchment. It appears that the paraglacial sequence, known as a morphogenic crisis, can be affected by internal small threshold event which are able to mobilize large quantities of sediment. It means that, at small scale, the curve profile is more irregular than suggested by large scale model.