Special DLS Lecture – Kristel Chanard (University of Paris, IPGP)

“Insights into the Geodetic Signature of Continental Hydrology”

Understanding how the Earth’s shape, gravity field and rotation change in response to shifting hydrological and oceanic mass loads at its surface holds great potential for regional and global monitoring of our rapidly evolving water resources. Recent advances in the field of hydrogeodesy, have required hand-in-hand development and improvement of observational techniques and of our understanding of the solid Earth interactions with surface and groundwater. The presentation will first focus on innovative data-driven methods aimed at refining observations of the Earth’s gravity field through satellite missions like GRACE and GRACE-Follow On satellite. These approaches provide unprecedented insights into spatial and temporal Earth’s gravity field at timescales ranging from months to decades. However, interpreting these signals in terms of water mass redistribution presents challenges due to the inherently integrated nature of gravity measurements. We will explore the potential of combining measurements of the Earth’s gravity field with additional geodetic measurements, including deformation of the solid Earth by GNSS and InSAR, to identify contributions from the solid Earth and separate signals from various hydrological reservoirs such as surface waters, aquifers or glaciers and ice sheets. Moreover, I will discuss the underlying physical processes shaping the geodetic signature of continental hydrology, providing a foundational understanding for leveraging geodetic measurements in addressing water-related issues and offering crucial insights into the mechanics of solid Earth deformation.

Questions? djwright@mit.edu