Regional ice flow piracy following the collapse of Midgaard Glacier in Southeast Greenland

Abstract

Abstract The collapse of Midgaard Glacier in Southeast Greenland initiated a series of dynamic changes in neighbouring catchments. Understanding the evolution of this collapse, along with the numerous flow reorganizations that have transpired, is of paramount significance. This study delves into this extended retreat and drawdown since the end of the Little Ice Age, along with multiple flow reorganisations and their ripple effects on adjacent catchments. Here, we construct a comprehensive timeline, unveiling previously undisclosed complexities in glacial history. This is the first study documenting and investigating ice flow piracy and flow reorganisation in Greenland. We underscore the vital role of comprehending long-term ice dynamics, bed topography, ice-ocean interactions, and the significance of drainage basin piracy for precise predictions and models, especially in the context of climate change's impact on Greenland's ice sheet. The transformations witnessed at Midgard Glacier triggered both large (basin-wide) and local-scale dynamic shifts, affecting the flow direction of Glacier de France, and subsequently instigating dynamical adjustments within Pourquoi-Pas Glacier. This reinforces the imperative need for an interconnected basin approach when modelling dynamic changes on the ice sheet.