Recent ice‐contact delta formation in front of Pio XI glacier controls sedimentary processes in Eyre Fjord, Patagonia

Pio XI Glacier (49°S) is the largest and one of the very few advancing glaciers in Patagonia. Satellite data indicate that the main glacier terminus transitioned from calving to land‐based around 2010, effectively resulting in the formation of an ice‐contact delta at the head of Eyre Fjord. Here, we investigate how this ice‐contact delta formation affected sediment transport processes in Eyre Fjord. Sediment cores and seismic profiles collected along the fjord provide evidence for a relatively abrupt increase in the number and magnitude of turbidity currents, coeval with the formation of the ice‐contact delta. This observation is supported by modern summer hydrographic observations and bathymetric data. We posit that the ice‐contact delta formation resulted in sediment input being concentrated at specific subaerial locations across the fjord head, which favoured the development of plume‐triggered turbidity currents. This suggests that a sudden increase in turbidite thickness in fjord sediment records could represent ice‐contact delta development at fjord heads.