The rate and scale of future marine terminating glacier retreat in Greenland's (and the Arctic) represents a significant unknown for estimating future sea level contributions, and the planning of future shipping routes and polar infrastructure (e.g. mines, ports/harbours, hydropower installations). As noted by Greenlandic PM Mute Egede (http://tiny.cc/EgedeSpeech), Greenland is set to be a key location for this as the UK and governments globally look for: (1) better constraint on future sea level change; (2) fast, safe, politically stable shipping routes between the Atlantic and Pacific; (3) alternative forms of renewable energy (e.g. hydrogen extracted through hydropower); (4) and obtaining rare earth minerals sourced in an environmentally and socially responsible manner. This Renewal proposal will build on progress made in the first stage of the fellowship on the development of computationally simple approaches to assessing glacier stability, and advances made by the glaciological community in the generation of near real-time data. It will achieve this by building the first ever "Glaciological Digital Twin" (GDT). This will be openly accessible, and use data obtained in near-real time to assess the likelihood of glacier change and the potential downstream impacts of this on shipping, infrastructure and local communities. In addition to this, we will build on the establishment of the Liverpool-Asiaq Glacier Observatory (LAGO) to understand present and future risks to Nuuk - Greenland's largest port, and a potentially vital location for future UK trade through the opening of the Northwest Passage. Nuuk's major Sikuk Harbour (meaning "ice free" in Greenlandic) has ironically had to close 5 times in the last year due to increased incursions of ice that originated from Narsap Sermia. In this project we will combine data from LAGO with satellite imagery and computer simulations of glacier behaviour to advance our understanding of what is driving changes at this glacier and understand how much of a risk it poses to Nuuk and the future planned development of Sikuki Harbour. Communicating the results of our work to UK and international stakeholders forms a key component of this project, and to maximise meaningful uptake of this work we have partnered with Asiaq Greenland Survey (the Greenland Government's geoscience consultancy); Ramboll Engineering (responsible for ensuring the resilience of multiple marine infrastructure projects in Greenland to future change); the Greenland Business Association (GBA; representing 330 Greenlandic businesses who employ >30% of the Greenlandic working age population); and the UK All Party Parliamentary Group for Polar Regions. Stakeholder engagement will take the form of meetings and workshops facilitated by the GBA while working alongside Asiaq and Ramboll at their offices in Nuuk. Events will also be held and briefing notes produced for the APPG for Polar Regions, to communicate findings and insight from the project to UK MPs and Peers regarding how glacier and iceberg change in Greenland can and will impact the environment, trade and security of the UK. Taken together, this project will help to advance our understanding of the short (sub-seasonal) and long term (multi-decadal) responses of Greenland's MTGs to future climate change from the scale of individual glaciers to the entire ice sheet. In doing so, it will deliver improved estimates of future sea level contribution, and contribute to a safer and more secure environment for its people, industry and governments within and beyond the Arctic.

This fellowship will transform our understanding of how the ice sheets and glaciers at both poles will contribute to future sea level change, and anticipate future iceberg risks impacting the people, businesses and governments in these regions. Building on my recent work (Lea, 2018), significant cloud computing resources will be used to facilitate automated analysis of the unprecedented volume of Arctic and Antarctic satellite imagery that is generated every day. This is the first time that analysis at such scales will be undertaken, and would be otherwise unachievable using current glacier monitoring approaches. Using results from this real-time updated analysis, a combination of new physically based and empirically based machine learning models will provide the first global assessment of glacier stability and framework to monitor this. This will allow significant improvements to short (<1 year) and long term (decadal) plans for infrastructure, industry projects and security as Arctic sea ice declines and both poles undergo major environmental changes. These factors are especially important for the UK as it impacts: - The environment and security of UK administered territories in Antarctica and the Southern Ocean. - UK business making informed decisions on future project viability in polar regions, where icebergs pose a major hazard to shipping and infrastructure such as ports, rigs and subsea pipelines. - The anticipated opening of the Northwest and Northeast Passage trade routes, offering UK business opportunities to significantly reduce the length and environmental impact of shipping. The future viability of these routes due to sudden glacier retreat and changing iceberg risks will have major implications for future UK supply chains between the Pacific and Atlantic Oceans. The UN Intergovernmental Panel on Climate Change have highlighted that the stability of marine terminating ice margins is a major uncertainty in global sea level change projections, and by extension iceberg risk. The existing barriers to achieving a global assessment of glacier stability are that: - Current approaches to data collection (even for individual glaciers) can be extremely time intensive. - The considerable computational power required by numerical models of glacier stability limits researchers to exploring only a few potential future scenarios. Consequently only a handful of the 100s-1000s of these glaciers at each pole have been studied in detail, leaving our knowledge of future glacier and ice sheet stability woefully incomplete and poorly constrained. This fellowship's innovative image and stability analyses will directly address these challenges. Ensuring that these novel findings have impact is built in as a key objective of this fellowship. Support from project partners will allow substantial and rarely achievable levels of engagement with the UK Government on objectives highlighted in the Foreign and Commonwealth Office's recent publication 'Beyond the Ice: UK policy towards the Arctic' (2018), including: Projecting global influence; Protecting people and the environment; and Promoting prosperity. Three stakeholder events spanning the fellowship will also allow UK business to directly highlight their key concerns and help direct the generation of data products. These will be designed to allow UK business to make better informed decisions on the viability of ongoing and future projects in the polar regions. Informed decision making relating to infrastructure at key locations is also in the UK's long term interest for the successful development of future trade routes. To this end, a three month placement at the Greenland Government's geoscience consultancy (Asiaq Greenland Survey) and regular trips as part of fieldwork to Greenland's largest city and deepwater port, Nuuk, will allow regular engagement with policymakers and industry at a pivotal location for the future development of the Northwest Passage shipping route.

Subglacial hydrology is a critical control on mass loss from the Greenland Ice Sheet via its impact on ice motion in the ablation zone and frontal ablation of marine terminating glaciers. Subglacial lakes are a key component of this subglacial hydrological system. Sediments that accumulate on lake beds are potential archives of past ice sheet configurations, paleoenvironmental and palaeoclimate change, and the presence of life. Subglacial lake water provides a habitat for microbial communities and an analogue for life on other planetary bodies. The localised storage and downstream drainage of large volumes of water modulates basal hydrology and biogeochemical cycles/processes, and can trigger calving at the ice margin and transient (weeks to months) and long-term ice-flow variations. Drainage events can also form channels, cut up into the ice or down into the bed, and transport large volumes of water and sediment downstream. Finally, outburst floods onto the glacier foreland present a major hazard to downstream life and infrastructure. Although it is well documented that hundreds of subglacial lakes exist beneath the Antarctic Ice Sheet, in Greenland, subglacial lakes have until recently received little attention because the geometry of the ice sheet led to the assumption that they were scarce. However, recent work from members of our team demonstrate that lakes are widespread beneath the Greenland Ice Sheet and moreover, can be highly dynamic features that, in contrast to Antarctica, are fed by melt from the ice surface and can drain rapidly in a matter of weeks. They therefore represent an important end-member for how subglacial lakes in both Greenland and Antarctica will behave in a warmer world as surface melting becomes more prevalent, accesses a wider portion of the bed, and lake drainage becomes more vigorous. Yet the key processes controlling subglacial lake formation and dynamics, and their impact on basal hydrology and ice flow in Greenland have yet to be identified. What is needed therefore is detailed field data integrated with numerical modelling to accurately determine the properties of these environments and assess their influence on ice sheet subglacial hydrology and ice dynamics. The project will assemble a world-leading multidisciplinary team to undertake the first field-based characterisation and monitoring of multiple fast-draining subglacial lakes in Greenland, which will be used to constrain and test a state-of-the-art subglacial hydrological model. It benefits from the confirmed discovery of three fast-draining subglacial lakes beneath Isunnguata Sermia, which are the most accessible on the planet and therefore provide an opportunity to conduct high-reward discovery science with logistical economy and low risk. The aim is to quantify the role of fast-draining subglacial lakes on the hydrology and dynamics of the Greenland Ice Sheet to: (i) improve our understanding of the role of subglacial lakes in modulating subglacial hydrology and dynamics in Greenland; (ii) provide insight into their future impact in both Greenland and Antarctica, (iii) generate data to enable ice sheet and hydrological modellers to improve their predictions of the future contribution of the GrIS to sea level rise, and (iv) develop the scientific basis for future subglacial lake exploration in Greenland for investigating past ice and climate change and exploring subglacial biology and biogeochemical fluxes.