Ice dynamics and structural evolution of Jutulstraumen, Queen Maud Land, East Antarctica (1963 – 2022)

Abstract

Jutulstraumen, a major outlet glacier in East Antarctica, drains into the Fimbulisen (∼39,400 km2). Here, we produce the first long term (~ 60 years) record of its behaviour using optical satellite imagery to map changes in its frontal position between 1963 and 2022, together with more recent datasets of ice velocity, surface elevation changes and grounding line position. Our analysis reveals that the ice front has been steadily advancing since its last major calving event in 1967, with a consistent ice flow velocity of ~ 720 ± 20 m yr-1(2000-2022). This has been accompanied by spatially variable ice surface thickening at an average rate of +0.15 ± 0.02 m yr-1 (2003-2020) between 20 km and 120 km inland of the grounding line. We also find evidence to suggest a minor grounding line advance of ~ 200 m (~ 6 m yr- 1) between 1990 and 2022, albeit with large uncertainties. Mapping of the major rifts on Jutulstraumen’s ice tongue from 2003 to 2022 (MODIS) reveals an overall increase in their lengths on both sides of the floating ice tongue, accompanied by some minor calving events. Given present-day ice front advance rates (~ 755 m yr-1), it would take around 31 years for the ice tongue to reach its most recent maximum extent in the mid 1960s, but extrapolation of rift lengthening suggests the next major calving event could take place sooner, possibly as early as the 2040s. Overall, however, there is no evidence of any dynamic imbalance, with ice-tongue advance, inland thickening and grounding line advance mirroring other major glaciers in Dronning Maud Land.