Glaciers provide climate change clues

The GLACIRECON (Reconstruction of the post ꞌLittle Ice Ageꞌ geomorphological processes in glacial environments - sedimentological and morphological record of glacial land systems' reactions to environmental changes) project studied the marginal zones of selected modern glaciers. They intended to map and quantify land form development within glacial forelands and evaluate the most important processes responsible for landscape change.

Researchers combined field work with the analysis of remote sensing data using GPS to aid in the processing of aerial images. They also conducted surveys of ice-marginal zones, used unmanned aerial vehicles to collect high resolution images and performed geomorphological mapping and analysed sediments.

Debris flows were found to be the most important re-sedimentation processes, leading to transformation of the active parts of the forelands. However, their distribution and intensity varied during the glaciation period. It was also found that some parts of the stable landscape could be subsequently altered again due to the effects of streams or meltwaters. This could lead to mass movement processes and further slope instability, thereby generating the flow of debris.

Several moraine sites in Iceland and the Arctic archipelago of Svalbard were studied and found to be composed of large amounts of dead-ice. They occur when the glacier stops and melts in situ, getting covered in a relatively thin veneer of debris. During glaciation, these ice-covered landforms are subjected to various re-sedimentation processes, finally leading to the creation of a more stable landscape.

Results revealed a switching between stable and active conditions over time. The changes of volume were very diverse and largely related to local conditions such as slope gradient and meltwater rather than climate changes. Recognition of drivers related to changes from stable to active conditions was valuable for managing the Arctic landscape.

GLACIRECON's findings were especially important for reconstruction of the glacial systems as well as a proper understanding of the glacial records. The results of these reconstructions will help scientists gain a better understanding of how climatic changes affect glacier and ice-sheet behaviour and global sea-level.