Scientists have found that preferential ice flow and erosion explain why fjords often extend to depths below sea level, according to research published online in Nature Geoscience this week.
Mark Kessler and colleagues use a two?dimensional numerical model to examine the conditions that lead to the intense glacial erosion that is associated with fjord formation. Starting from a landscape with four shallow valleys, the team found that the ice preferentially flows through the lowest valley. The amount of erosion increases proportionally with increasing ice discharge through each channel, and therefore quickly exaggerates the relief of the landscape. Over a few million years, these small valleys are eroded into the dramatic features we see throughout the Arctic region today, with fjords plunging kilometres below sea level.
In an accompanying News and Views, Johan Kleman says ‘The model clearly shows that the glacial system is extremely relief-enhancing and capable of greatly magnifying subtle height differences in the initial relief. This [