Correlation of recent calving front retreat at Pine Island Glacier to bathymetry

• Main Authors: Arndt, Jan Erik, Larter, Robert D., Friedl, Peter, Gohl, Karsten, Höppner, Kathrin
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Antarctic; Pine Island Glacier; West Antarctic Ice Sheet; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Iceberg*; Pine Island
• Online Access: https://epic.awi.de/id/eprint/47493/; https://hdl.handle.net/10013/epic.cc4b7162-30bb-4930-be39-5eb1c1d72f3c

Pine Island Glacier (PIG) currently experiences the largest negative mass balance in comparison to other outlet glaciers in Antarctica and hence is the largest contributor to modern sea-level rise. Due to the glacier’s topographic setting, a bed that deepens beyond the grounding line to the deep interior basin of the West Antarctic Ice Sheet (WAIS), it has been suggested that this increased ice loss may be a precursor of WAIS collapse. Despite the increased mass loss, however, the calving front of PIG remained more or less stable since the earliest observations in the mid-20th century. Large icebergs where calved at intervals of a few years but subsequently the calving front re-advanced close to or even beyond its former position. This pattern changed in 2015 when a calving event resulted in a reoriented (45°-25° clockwise compared to previous calving lines) and most retreated calving line position ever observed. This new calving geometry was confirmed by a calving event in September 2017. In February 2017 we were able to access the formerly ice-shelf covered area during RV Polarstern expedition PS104. Bathymetric data from this area revealed a bathymetric ridge that has acted as a pinning point of PIG in the past. We use these bathymetric data in combination with satellite data from the last decades to investigate the correlation of bathymetric features to the calving dynamics of Pine Island Glacier.