April 7, 2022

Novosilski Glacier, South Georgia Retreat Causes Separation

Posted by Mauri Pelto

Novosilski Glacier in Landsat images from 2020 and 2022. Note the retreat near Point A in particular. The terminus that extended from Point B-C developed an embayment reaching Point A.

Novosilski Glacier is a large tidewater outlet glacier on the west (cloudier) coast of South Georgia terminating in Novosilski Bay It shares a divide with the rapidly retreating Ross and Hindle Glacier on the east coast.  Gordon et al. (2008) observed that larger tidewater and calving outlet glaciers generally remained in relatively advanced positions from the 1950’s until the 1980s. After 1980 most glaciers receded; some of these retreats have been dramatic, such as at Neumayer Glacier. The west coast has featured much less retreat than the east coast.  The change in glacier termini position have been documented by Cook et al (2010) at British Antarctic Survey in a BAS retreat map,  identified that 212 of the Peninsula’s 244 marine glaciers have retreated over the past 50 years and rates of retreat are increasing. Pelto (2017) documented the retreat of 11 of these glaciers during the 1989-2015 period.  NASA Earth  piggy backed on the retreat of some east coast glaciers seen in Landsat images.

Novosilski Glacier in Landsat images from 20o3 and 2022. Note the retreat from Point D  in 2003 to Point A in 2022  ed from Point B-C developed an embayment reaching Point A.

In 2003 Novosilski Glacier terminated in shallow water just east of a small island that acted as a pinning point, Point D.  By 2009 the glacier had retreated only a minor amount from this island into deeper water.  A rapid retreat ensued and by 2016 the glacier had retreated into a narrower fjord reach. The north and south margins featured remnant ice that was based above tidewater, Point B and C.  By 2016 the 2 km wide calving front had retreated 2.5 km from the 2003 position.  There was no significant retreat from 2016 to 2020.  By March of 2022 the glacier has retreated 1 km in the glacier center further leading to separation of the glacier into a northern and southern arm separated by the the Point A rock rib. The retreat also has led to a 6 km2 expansion of Novosilski Bay. The glacier slope at the terminus is steep and active, suggesting retreat may slow again.

Novosilski Glacier in Landsat images from 2016 and 2022. Note the retreat near Point A in particular. The terminus that extended from Point B-C developed an embayment reaching Point A.