Sea level changes

Global sea levels are rising mainly due to melting glaciers, ice sheets, and thermal expansion of seawater caused by global warming. However, because of complex mechanisms like glacial isostatic adjustment, changes in ocean currents, and Earth’s gravitational field, the rise is not evenly distributed across the globe.

About the topic

At the Department of Geography, we study past sea-level changes along the Norwegian coast, ranging from modern times back to the late glacial period, when the outer coast first became ice-free. We reconstruct historical sea levels by analyzing landforms and sediments from isolation basins (lakes and bogs that were once submerged below sea level) and salt marshes. By carefully reconstructing how sea levels fluctuated in Norway and comparing this data to global datasets, our goal is to better understand how the various factors influencing sea-level change have operated in the past. This understanding will help predict how sea levels may respond to future climate change at both local and global scales. Current projects at the department focus on postglacial sea-level change from western Norway in the south to Lofoten and VesterĂ¥len in the north.

Fieldwork
Reconstruction of past sea levels requires precise altitude measurements using differential GPS. Photo: Kristian Vasskog
Last updated: 17.11.2025