Study of the influence of climate change on the geophysical evolution of Svalbard using space geodesy measurements, in situ data and local Earth modelling (ICEMELTING)

The study of climate change and its impact has become an essential part of research. Over the past 35 years, the mean temperature of both the ocean and the atmosphere has increased of 2°, resulting in changes to ecosystems and the environment. One of the most evident and readily observable indications of climate change is the melting of glaciers, a phenomenon that is particularly pronounced at the poles.

The Svalbard archipelago is not an exception in this regard. With 56% of its surface area covered by glaciers, the ice is melting very quickly, which is inducing deformations of the Earth’s surface and variations in the Earth’s gravitational field. However, it should be noted that global warming has other consequences. We also observe changes in sedimentology, geomorphology and the coastal environment.

The core objective of ICEMELTING project is to comprehend the impact of climate change on various scales in Svalbard.
Firstly, space geodesy allows us to observe the deformation of the Earth’s surface and variations in its gravitational field. These effects are local and regional and depend on current and past events. Svalbard has a glacial history, marked by numerous episodes of glaciation and deglaciation. In particular, the last glacial maximum (LGM), the Little Ice Age (LIA) and currents events.
Glaciers are classified as loadings, indicating that the Earth’s surface exhibits deflection under the pressure exerted by the weight of ice. Should there be a thaw, the Earth will respond by rising. We are able to observe this Earth deformation using GPS 3D positioning time series. Our network of 17 GPS stations across Svalbard has provided us with valuable data on the region’s mean vertical velocity, which we have measured at an average of 10 mm/yr (Figure 1). In this velocity, we observe the accumulation of the Earth’s response to the LGM deglaciation, known as global isostatic adjustment (GIA). This is in addition to the response to the LIA deglaciation and current ice melt. One of the objectives of this project is to ascertain the proportion of the signal attributable to current ice melt and the proportion resulting from past events.

Following on from the initial objective, the second objective is to establish a connection between the space geodesy approach and the studies of sedimentology and coastal environments. Recent research findings indicate that there have been changes in the transfer of sediment from the continental to the marine domains. It should be noted, however, that changes in the dynamics of coastal areas have also been observed, with a shift from progradation to erosion.

The primary challenge of this project is to integrate a range of observations and techniques to comprehensively assess the impact of climate change. It is important to note that the various observations and techniques employed in this project have different levels of resolution and sensitivity.