Landscape Evolution at an Emerging Englacial Esker in Southeast Iceland Over Weekly-to-Annual Timescales

Eskers are used to characterize glacial drainage systems to inform ice sheet modeling. However, the connection between eskers preserved in the paleoglaciologic record and the conditions required to deposit them is not well understood, particularly for englacial eskers. We use uncrewed aerial vehicle data over weekly-to-annual timescales from 2021-2024 at Breiðamerkurjökull in Iceland to investigate how englacial eskers evolve after emerging from the glacier. During the study period, an esker emerged from an englacial conduit, experienced significant modification, and was emplaced on the outwash plain at the edge of a proglacial lake. We find that englacial eskers experience significant erosion and modification as they interact with proglacial lakes or streams and their ice cores melt, implying that englacial eskers are not generally well preserved in the paleoglaciologic record. Both esker morphology and stratigraphy evolved over the study period, indicating that when observed in preserved englacial eskers, they do not necessarily reflect conduit emplacement conditions. Englacial eskers deposited at the edge of overdeepenings may be more likely to be preserved than those deposited elsewhere. Additionally, surface ice topography evolution is assessed to identify structural hazards at an esker-forming glacier margin, which is critical as glacial-related hazards increase in a warming climate.