Investigating the seasonal behaviour of tidewater glaciers in southeast Greenland

Abstract

Tidewater glaciers in Greenland have experienced considerable fluctuations in terminus position over the past ~25 years, with wintertime advance and summertime retreat cycles that vary considerably between glaciers. Studying these seasonal cycles is crucial to identifying the environmental forcings that influence glacier sensitivity on interannual timescales. Glaciers exhibiting seasonal retreat in response to submarine melting may be especially vulnerable to sustained retreat under continued climate warming. This thesis investigates 19 tidewater glaciers in southeast Greenland, analysing seasonal terminus behaviour, terminus morphology, and ice velocity in relation to environmental drivers including meltwater runoff, ice mélange presence, and fjord geometry.

The findings reveal substantial variability in terminus behaviour across glaciers, with some glaciers more responsive to meltwater input, while others are modulated by ice mélange dynamics. Terminus morphology is similarly diverse, shaped by factors such as fjord shape and ice dynamics, which play stabilising or destabilising roles depending on glacier-specific settings. Seasonal ice velocity fluctuations, largely influenced by meltwater input, vary significantly across glaciers, likely modulated by responses to meltwater input and inferred subglacial hydrological systems. This research enhances understanding of the complex, glacier-specific responses to environmental forcings in southeast Greenland and provides insights that can improve future projections of ice
loss and the Greenland Ice Sheet’s contribution to sea level rise.

Date of Award	4 Jul 2025
Original language	English
Awarding Institution	University of St Andrews
Supervisor	Tom Cowton (Supervisor), Doug I Benn (Supervisor), Chris R. Stokes (Supervisor) & Rahcel Carr (Supervisor)