Mirjam Bilker-Koivula (Finnish Geospatial Research Institute) and Holger Steffen (Lantmäteriet, Sweden), will present

“The Whys and Hows of Dealing with Glacial Isostatic Adjustment in a Mapping Authority”

Glacial isostatic adjustment (GIA) affects among others vertical datums, sea-level measurements, GNSS heights, and crustal motion models. Hence, it creates technical and practical challenges for mapping agencies. They have to address them in their daily work by updating geodetic reference frames, modeling vertical land motion, adjusting elevation datasets, communicating changes to users, maintaining long-term stability of coordinates and more. We will present some examples how two authorities, Lantmäteriet in Sweden and the Finnish Geospatial Research Institute (FGI), handle GIA. We will focus on deformation and gravity change, but also provide snapshots of Lantmäteriet’s communication efforts and FGI’s GIA-related investigations in Antarctica.