May 5, 2020
Huron Glacier (H) and Kaliakra Glacier (K) in 2001 and 2020 Landsat images. Extensive retreat at bedrock locations Point A and B with limited retreat at C and D.
Livingston Island, Antarctica is part of the South Shetland Island chain and is primarily covered by glaciers. At the eastern end is Huron Glacier. Huron Glacier and the adjacent Kaliakra Glacier are tidewater outlet glaciers terminating in Moon Bay on the east end of Livingston Island. Molina et al (2007) noted that persistent warming had led to mass loss from 1956-2000 on Johnson and Hurd Glacier further west on the island. Osmanoglu et al (2014) observed the velocity and frontal ablation rates of Livingston Island glaciers. Frontal ablation includes losses from calving and surface melting of the ice face from contact with the ocean and air. They observed that frontal ablation losses were the same magnitude as surface ablation. Huron Glacier had the highest frontal ablation by a significant amount from 2007-2011 and the higest location of velocity at 250 m/year. Here we examine Landsat images from the 2001-2020 period to illustrate the retreat of the glacier fronts in Moon Bay.
In 2001 the icefront is 3 km beyond Point A a bedrock knob at the end of a ridge, 3.5 km beyond Point B also bedrock at the end of a ridge, 1800 m beyond Point C and 1500 m beyond Point D. Snowcover extends to the ice front. In 2004 there is not a significant change in the ice front position and snowcover again extends to the ice front. By 2015 the ice front has retreated to within 1 km of Point A. In March 2018 there is evident ablation in the lowest reaches of Huron Glacier. In February 2020 the ice front has retreated to the bedrock knob at Point A , a 3000 m retreat since 2004. The ice front is 2 km from the bedrock ridge at Point B, a 1500 m retreat since 2004. The ice front retreat on the north side of Kaliakra at Point C has retreated 400 m since 2004. Retreat on the south margin of Huron Glacier at Point D has retreated 500 m. Surface melting is also evident in 2020 from Point B to the ice front, with a lateral moraine exposed as was the case in 2018. The 2020 melt season featured record high temperatures in this region of Antarctica leading to high surface melt, such as at Eagle Island Ice Cap. Surface melt on Livingston Island is less extensive than on the Warsaw Icefield on King George Island (Petlicki et al, 2017). Retreat of Huron Glacier has been more rapid than on other glacier fronts on Livingston Island this is reflective of the higher frontal ablation rate, which is significantly due to its high velocity. Osmanoglu et al (2014) note a significant summer velocity increase on Livingston Island glaciers, will increased melt enhance basal water pressure and velocity or lead to a more mature drainage reducing basal water pressure limiting summer velocity increases? The retreat of the calving front is similar to that of Endurance Glacier on Elephant Island.
Huron Glacier (H) and Kaliakra Glacier (K) in 2018 Landsat image portrayed in Antarctic REMA, note surface melt and lateral moraine material near Point A and B.