Climate change and human activities are profoundly reshaping the Earth’s water cycle, driving accelerated ice sheet and glacier melt, increasing precipitation variability, intensifying evaporation, accelerating groundwater depletion, and contributing to rapid sea level change. Understanding these transformations requires integrating complementary observations of water mass redistribution to improve predictions and support evidence-based decision-making for water and coastal risk management.

In this context, modern space geodesy, which measures changes in the Earth’s gravity field and surface deformation, provides a unique way to monitor the redistribution of water across continental hydrology, the cryosphere, and the oceans over spatial scales from local to global and timescales from seasonal to multi-decadal. However, interpreting these observations in terms of water, ice, and ocean redistribution remains challenging due to the integrated nature of geodetic signals.

We will explore the potential of combining multiple geodetic observations, including spatio-temporal variations in the Earth’s gravity field and surface deformation measured by GNSS and InSAR, with in-situ measurements and physics-based models of the solid Earth-water interactions to disentangle solid Earth processes from hydrological, cryospheric, and oceanic signals. This approach not only helps refine estimates of water and ice mass redistribution from space geodesy, but also provides new insights into the mechanical properties of the solid Earth, with implications for a better understanding of other geophysical processes.

Kristel Chanard, IGN/IPGP

Lieu
École normale supérieure – PSL
24 rue Lhomond – aile Erasme
salle Claude Froidevaux – E314