Work package 1 in RESPONDER produced technological innovation. By integrating carrier-phase GPS into bespoke, custom-designed UAV systems the project pioneered a new and novel approach, which allows photogrammetric reconstruction of the ice sheet surface with extremely high (10 cm) spatial resolution and equally high accuracy. With multiple surveys conducted when a supraglacial lake drained rapidly in 2018, the team captured the ice sheet’s response as a hydrological connection was between surface and bed was made. This work was published in the Proceedings of the National Academy of Science and reported widely in global news, including National Geographic, Scientific American, CNN, Washington Post and The Times.
This project advanced radio-echo sounding techniques by showing that internal geometry and the base of ice sheets can be captured in 3D. The first record of basal melting from Greenland was a ground-breaking discovery in this project. This finding, also reported in the Proceedings of the National Academy of Science, was reported in >100 global news agencies, including The Times, CNN and Vox. The project also proved the sun can be used as a radio source for basal echo detection and ice thickness measurements.
In work package 2, ten boreholes were drilled at two sites on Sermeq Kujalleq (Store Glacier). Seven boreholes connected with a hydrological system at the glacier base at depths of 953 – 1,043 m below surface. These deep boreholes enabled – for the first time – direct access for instrumentation and observations at the basal interface of a fast-moving outlet glacier in Greenland. Fibre-optic sensing in one of the deep boreholes was a major project success, revealing ice of different types and age as well as the sedimentary nature of the glacier bed. Fibre-optic sensing also produced the most detailed temperature profile to be collected on the Greenland Ice Sheet to date. This discovery was published in Science Advances and reported in global news media.
By bringing together observations and models in work package 3, the RESPONDER project brought new light of the ice flow mechanism. The modelling work introduced a new geostatistical technique, which improved the model resolution and the realisation of ice sheet motion beyond the state of the art. Hence, the project has significantly improved fundamental concepts and the best way in which ice flow can be parameterised theoretically in models.
The team also developed a hydrologically coupled ice flow model. This catchment-scale hydrological model stores water in a distributed cavity system as well as channels, which form and evolve according to the input of meltwater from the surrounding cavities. With feedbacks between i) surface melt, ii) cavity and channel sizes, iii) mechanical friction, iv) ice flow and fracturing, and v) iceberg production, the model offers very realistic simulations and is arguably the most process-rich model to ever be produced.
Over the course of the project, the PI arranged several exhibitions in the Polar Museum in Cambridge, with displays, photographs and scientific instruments. The PI hosted a delegation of 15 Greenlandic youths for the opening of the exhibition: ‘Uummannaq’, which was visited by 25,000 members of the public. A second exhibition (‘Ice from above’) featured drones and aerial imagery acquired in Greenland. Excellent and impactful outreach was made in annual contributions to the Sutton Trust summer school, which is set up to address educational disadvantage and improve social mobility in the UK.
