By Maryna Mullerman ’20

Climate change is leaving observable effects on our planet. Mette Bendixen, along with other researchers from the University of Copenhagen in Denmark, explored the impact of climate change on the Arctic coastal zone in Greenland. The researcher hypothesized that the evolution of deltas is driven by both terrestrial and marine factors. They assessed the progradation – increase in sizes – of Greenland’s deltas, as well as the effects of temperature increase on open water periods. Their findings can improve scientists’ understanding of Arctic coastal evolution and the impact of ice mass loss on Greenland’s deltas.

The researchers extracted the evidence of delta progradation from aerial and satellite imagery, including historical imagery from the 1940s. They carefully investigated the changes in coastal morphology, with more than 120 Greenlandic deltas being examined for erosional processes. Structural equation modeling (SEM) was used to analyze the impact of terrestrial and marine drivers of delta evolution.

Significant changes were evident in the average delta size from the 1980s to the 2010s. The SEM analysis showed that higher air temperatures had an indirect effect on delta progradation. Elevated temperatures increased freshwater runoff from the Greenland Ice sheet and prolonged open-water period, a time when water absorbs heat and keeps the lower atmosphere warm. Moreover, the researchers suggested that high water runoff increased the amount of sediment flux, which would also be associated with Greenland delta progradation.

The research suggested major alterations in the Arctic coastal zone of Greenland, as the changes in delta sizes and open-water periods shared positive correlations with increasing freshwater runoff and sediment flux. The researchers predicted that this trend would continue in the future, affecting the environment and the inhabitants of the local areas. The study was limited to Greenland deltas, and more research is needed to investigate the effects of the fast-changing environment in other parts of the Arctic.

References:

1. M. Bendixen, et. al., Delta progradation in Greenland driven by increasing glacial mass loss. Nature 550, 101-104 (2017). doi: 10.1038/nature23873.
2. J. Overland, et al., Open water means a warm Arctic. National Snow and Ice Data Center, (2012).
3. Image retrieved from: https://www.pexels.com/photo/climate-cold-glacier-iceberg-2969/