Pope, Smith, and Kohler glaciers, in the Amundsen Sea Embayment of West Antarctica, have experienced enhanced ocean-induced ice-shelf melt, glacier acceleration, ice thinning, and grounding line retreat in the past thirty years, in a glaciological setting with retrograde bedrock slopes conducive to marine ice sheet instability. Here we present observations of the grounding line retreat of these glaciers since 2014 using a constellation of interferometric radar satellites with a short revisit cycle combined with precision surface elevation data. We find that the glacier grounding lines develop spatially-variable, km-sized, tidally-induced migration zones. After correction for tidal effects, we detect a sustained pattern of retreat coincident with high melt rates of un-grounded ice, marked by episodes of more rapid retreat. In 2017, Pope Glacier retreated 3.5 km in 3.6 months, or 11.7 km/yr. In 2016-2018, Smith West retreated at 2 km/yr and Kohler at 1.3 km/yr.  While the retreat slowed down in 2018-2020, these retreat rates are faster than anticipated by numerical models on yearly time scales. We hypothesize that the rapid retreat is caused by un-represented, vigorous ice-ocean interactions acting within newly-formed cavities at the ice-ocean boundary.

This Dataset contains InSAR double difference interferograms over Pope, Smith and Kohler glaciers in the Amundsen Sea Embayment, West Antarctica. 

Data have been acquired by the COSMO-SkyMed constellation and cover the period 2016-2020.

A shapefile with the mapped grounding lines is also included in this dataset.

Additional dataset:

Ice Thickness and height above flotation derived from Bed Machine Antarctica version 2020_06_18. 

Velocity map derived from Sentinel-1A/B Pixel Offsets for the year 2018-2019