Subglacial bedforms are commonly used to reconstruct past glacial dynamics and investigate processes occuring at the ice–bed interface. Using analogue modelling and geomorphological mapping, we demonstrate that ridges with undulating crests, known as subglacial ribbed bedforms, are ubiquitous features along ice stream corridors. These bedforms provide a tantalizing glimpse into (1) the former positions of ice stream margins, (2) the ice lobe dynamics and (3) the meltwater drainage efficiency.

We map visible traces of subglacial meltwater flow across Keewatin, Canada. Eskers are commonly observed to form within meltwater corridors up to a few kilometres wide, and we interpret different traces to have formed as part of the same integrated drainage system. In our proposed model, we suggest that eskers record the imprint of a central conduit while meltwater corridors represent the interaction with the surrounding distributed drainage system.

We map series of aligned mounds (esker beads) across central Nunavut, Canada. Mounds are interpreted to have formed roughly annually as sediment carried by subglacial rivers is deposited at the ice margin. Chains of mounds are formed as the ice retreats. This high-resolution (annual) record allows us to constrain the pace of ice retreat, sediment fluxes, and the style of drainage through time. In particular, we suggest that eskers in general record a composite signature of ice-marginal drainage.

During the last 2.6 million years, the Earth's climate has cycled between cold glacials and warm interglacials, causing the growth and retreat of ice sheets. These ice sheets can be independently reconstructed using numerical models or from dated evidence that they leave behind (e.g. sediments, boulders). Here, we present a tool for comparing numerical model simulations with dated ice-sheet material. We demonstrate the utility of this tool by applying it to the last British–Irish ice sheet.

We use the deglaciation of the last British–Irish Ice Sheet as a valuable case to examine the processes of contemporary ice sheet change, using an ice sheet model to simulate the Minch Ice Stream. We find that ice shelves were a control on retreat and that the Minch Ice Stream was vulnerable to the same marine mechanisms which threaten the future of the West Antarctic Ice Sheet. This demonstrates the importance of marine processes when projecting the future of our contemporary ice sheets.

Scattered observations suggest that subglacial meltwater routes drive ice stream dynamics and ice sheet stability. We use a new experimental approach to reconcile such observations into a coherent story connecting ice stream life cycles with subglacial hydrology and bed erosion. Results demonstrate that subglacial flooding, drainage reorganization, and valley development can control an ice stream lifespan, thus opening new perspectives on subglacial processes controlling ice sheet instabilities.

Knowledge of ice sheet bed topography and surrounding sea floor bathymetry is integral to the understanding of ice sheet processes. Existing elevation data products for Greenland underestimate fjord bathymetry due to sparse data availability. We present a new method to create physically based synthetic fjord bathymetry to fill these gaps, greatly improving on previously available datasets. This will assist in future elevation product development until further observations become available.

We mapped and analysed nearly 2000 large valleys that were formed by meltwater flowing under a former ice sheet. Our results demonstrate that valleys tend to cluster together in distinctive networks. The valleys themselves are typically < 20 km long, and 0.5–3 km wide, and their morphology is strongly influenced by local bed conditions (e.g. topography) and hydrology. We suggest valleys formed gradually, with secondary contributions from flood drainage of water stored on top of or under the ice.