Study of changes induced by global warming in Svalbard based on spatial geodetic data and in situ geophysical measurements

The Svalbard Archipelago, located in the Arctic region of Norway, is extremely vulnerable to the climate change. With a current increase of 3 at 5°C in average air temperature and a change in precipitation with an increasing proportion of rain, certain negative consequences for the environment and ecosystem are inevitable. One of the most obvious signs of climate change in this region is the melting of ice, which is causing the Earth’s crust to deform. But there are other consequences, such as the loss of sea ice cover, changes in how sediment is transported and also changes in biodiversity.These phenomena are widely studied in this region. For example, deformation of the Earth’s crust is determined using 3D positioning data acquired by GNSS across Svalbard, particularly in Ny-Alesund. Since 2000, daily positioning time series show a strong upward component, with an average vertical velocity of between 8 to 13 mm/yr. This velocity is the Earth’s response to various episodes of glaciation and deglaciation in the past like the last glacial maximum or the Little Ice Age, and to the current melting of ice. This current melting has also been studied a lot at Ny-Alesund station, where glaciers are monitored to measure changes in ice height from one year to the next and calculate the glacier’s surface mass balance. This is the case for the Austre Lovenbreen, for which data has been available since 2007, showing record melting over the last ten years. The same is true for the study of the prodeltas evolution since 2009, which shows a stabilisation of almost all prodeltas since 2016.All these phenomena are largely studied separately, but our analysis consists of interpreting all this data in order to study the possible correlation between these observations which share the same cause: climate change. In our study, we ask how we can link measurements taken at the glacier or in the underwater sediment, along with space geodesy data, to better understand the ongoing geophysical processes that mark the transition between a glacial environment and paraglacial environment.