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RESEARCH PRODUCT

Quantification of sediment transport into Kongsfjorden due to the glacier melt dynamics of Austre Lovenbreen using terrestrial laser scanning

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International audience; Climate warming causes a decrease of glaciers in Svalbard. This results in sig-nificant changes of the geomorphology of areas in glacier catchments where iceand permafrost is melting. In particular the snout of the glacier melts drasticallyand the water outflow of the glacier changes sometimes its direction. Sedimentand bed load transport forms new river beds in the moraine, and the sedimentsinvolved are transported downstream into the fjords. In recent years terrestriallaser scanning technology has developed significantly, so it is possible to mea-sure the surface of a whole glacier catchment such as the Austre Lovenbreen inhigh resolution just in a few days or even in one day. The measuring range of6000 m combined with a very low beam divergence of the laser beam allows fastand accurate measurements of an area of 4 km2just from one scan position. Thisadvances made it possible that we could track all surface changes via differenti-ating digital surface models of the Austre Lovenbreen catchment using repeatedterrestrial laser scanning surveys in 20 cm resolution and with 10 cm accuracy.In this work we show how the geomorphology of the scanned area changed injust 2 years from 2016 to 2017. In this time frame the glacier outflow changedits riverbed and significant amounts of sediments where transported through themoraine into the fjord, which changed the morphology of the coastline as well.Reflectance values of the laser allowed us to distinguish between snow, ice androck material. In our presentation we explain the methodology of the terrestriallaser scanning surveys and discuss the results of how much material was removedin the new river bed throughout the moraine, how much sediments where accu-mulated at the coast line and how much of the material disappeared in the fjord.