GIA summer school

Sea level doesn’t only increase when the sea rises, but also when the land subsides! In the end, it’s all relative. To learn more about vertical land motion, Carolina and I attended the Glacial Isostatic Adjustment training school at Lantmäteriet in Gävle, the Swedish mapping, cadastral and land registration authority.

Glacial Isostatic Adjustment, or GIA for short, refers to the adjustment of the Earth to the loading and unloading of large ice sheets. The adjustment leads to land uplift underneath former ice sheets, and subsidence around its margins. Sweden has many examples of GIA: you can find beaches that have been raised to heights of 200m over the past thousands of years. Once you could swim here, but now the sea is kilometers away!

The training school held at Lantmäteriet was well organized, with very interesting lectures covering land uplift, sea-level change, geodetic observations, ice sheet dynamics and more. It was a great experience!

[written by Tim Hermans]

 [photo credit: Daniel Vallin]