Basal Properties of the Greenland Ice Sheet (BPoG)

The single most important boundary condition for modelling ice sheet evolution is bed topography, from which - in conjunction with surface elevations - ice thickness can be determined. This importance is demonstrated by the facts that ice motion due to deformation is very sensitive to ice thickness-the thicker the ice the more it deforms-and that the point at which the ice sheet is contact with the ocean is also very sensitive to thickness and bed profile. Small changes in ice thickness and basal stickiness (friction) at this contact point can result in large change in ice discharge.

Advances in our knowledge of ice thickness and bedrock topography in Greenland have been made since the last comprehensive study was published over ten years ago. The most recent bed data set, published in 2013, possesses more complete coverage of the ice sheet interior and margins and was sufficient to resolve a huge ancient canyon, carved by a river tens of thousands of years ago, and now buried beneath the several kilometres of ice. The canyon extends for more than 750 km, and is possibly the longest in the world yet has only just been discovered. Close to the ice sheet margins, however, gaps in observations are still prevalent due to the steep relief and warm ice in these areas. This is particularly true for the numerous outlet glaciers that control ice discharge into the ocean. Outlet glaciers are where ice is flowing fastest, where the greatest ice mass losses have been observed and where models are most sensitive to small changes, or errors, in bed geometry. Furthermore, the topography of the seafloor (the bathymetry) in the fjords that the glaciers flow into is, currently, poorly known. Uncertainties of hundreds of metres in bathymetry exist while numerical modelling studies have shown that the bathymetry has a strong influence on the interaction of the ocean with the glaciers. These big errors in the bathymetry mean that the models will have difficulty simulating the behaviour of this interaction because the errors will feed into the results. It is the problem of "garbage in, garbage out". The models are limited by the quality of the data that are used to drive them. This project aims to address all these limitations by producing the "next generation" bed elevation data set for Greenland and the coastal area including bathymetry. It will also provide key information on the properties of the ice/bed interface: in particular whether there is water at the bed or not. The result of this work will be data sets that will greatly advance our understanding of the sensitivity of the ice sheet to changes in atmospheric and oceanic forcing.

There are three broad categories of user groups who will benefit from the results and activities of the project in addition to scientists working directly on ice sheets and sea level rise. These are i) the climate change policy community including NGOs, ii) mineral exploration companies and iii) the general public, (including schools).


i) Climate change policy community.
We have direct links with the several organizations who have benefited from previous related research and who will benefit from this work. The list below is not meant to be exhaustive but to illustrate the type of beneficiary in this category with an indication of how they might benefit:
UK Met Office & DECC: coordinating the AVOID programme (a DECC/DEFRA funded project, http://www.avoid.uk.net/) Public Interest Research Centre (http://www.pirc.info/) provides climate policy documents for the public and UNFCC.
UN Environment Programme: provides information about climate change and sea level rise to general public and educational establishments. Past experience indicates that this category of end user has greatly benefited from a strong interaction and involvement with the experts doing the work.

ii) The oil and gas industry is surveying the shelf seas west and east of Greenland for exploration and possible exploitation of hydrocarbons, while mining companies are looking to exploit various mineral resources in Greenland (see e.g. Greenland Minerals and Energy Ltd; http://www.ggg.gl/). Both these sectors would benefit from improved knowledge of fjord bathymetry, marginal bed topography and the vulnerability of marine terminating margins to climate change.


iii) The general public. Arctic research has huge potential for capturing the public imagination and engaging students at both primary and secondary level in issues related to climate change, environmental policy, glaciology and polar processes. Because of the profound societal impacts of sea level rise, the vulnerability of the Arctic to climate change, and the dramatic impacts of climate change already occurring in the Arctic and Greenland specifically, the general public are an important beneficiary of this work. This includes those witnessing the changes such as the Greenlandic inhabitants.

JLB and MJS currently undertake talks to local schools and also to a Geography teacher training programme run by the Princes Teaching Institute. JLB was until recently head of undergraduate admissions for Geography at UoB and, in this capacity, developed a number of widening participation activities which he is still involved with. The PI and Co-Is have a long record of working with the media. Britain's only dedicated Polar Museum is located in the Scott Polar Research Institute, University of Cambridge, while the media and outreach activities associated with the Lake Ellsworth project (http://www.ellsworth.org.uk/) were widely reported and followed including social media outlets.