Denman Glacier, located in East Antarctica retreated about 5 km in the past 20 years, critically the grounding line rests now on a 5 km wide, 1,800 m deep canyon, which goes even deeper farther inland, down to astonishing 3500 meters, the lowest point on the planet not covered by liquid water.
Significant changes have taken place on Denman Glacier and Shackleton Ice Shelf. The floating section of the glacier experiences vigorous ice melt in contact with the ocean, which suggests the presence of Circumpolar Deep Water. However, there is no historical oceanographic data near the glacier. https://www.pnas.org/content/116/4/1095