Dynamical control on the response of Pine Island Glacier
Lead Research Organisation:
University of Cambridge
Department Name: Scott Polar Research Institute
Abstract
It is expected that sea-level rise will impact coastal communities worldwide over the coming decades to centuries. In the UK, the vulnerability of coastal communities and assets is best characterised in terms of the likely frequency of the over-topping of sea-defences. For example, when they were built, the sea-defences for the city of London (including the Thames Barrier) were designed to protect London from all except the 1-in-1000 year flood event. A rise of 50 cm in global sea level will reduce this level of protection to 1-100 years, and a rise of 100 cm would reduce it to 1-in-10 years.
Pine Island Glacier is one of five glaciers in West Antarctica that are currently contributing sea-level rise at a significant and accelerating rate. The portion currently affected by thinning contains sufficient ice to raise global sea-level by around 25 cm - its neighbours account for another 50 cm.
Given the rate of ice-loss and the potential implications for sea-defence planning there is a clear requirement to understand and predict the future of Pine Island Glacier and its neighbours. However, as highlighted by the Intergovernmental Panel on Climate Change (IPCC, 2007), understanding the way that dynamic changes are transmitted through the glaciers draining ice sheets is so poorly understood that the IPCC believed it was the least well understood, and potentially the largest, contribution to sea-level rise in the coming century.
ISTAR-C will directly address this lack of knowledge, by seeking to understand the processes that are responsible for transmitting the effect of thinning of the floating ice shelf, upstream such that thinning can now be seen on much of the trunk and tributaries of Pine Island Glacier.
ISTAR-C will also use the most up-to-date methods available to measure the properties (rock-type and water-content) of the bed beneath several locations on Pine Island Glacier to determine their influence on the propagation of thinning. We will test the hypothesis that it is these bed conditions that are responsible for the fact that the tributaries of Pine Island Glacier appear to be thinning at different rates. Testing this hypothesis will give us a much better understanding on which to predict the future magnitudes of ice-thinning rates for the glacier.
To achieve these objectives we will collect data from Pine Island Glacier during two field seasons. These will include precise measurement of variations in ice-flow from the ice-shelf up the glacier and into its tributaries. We will image the bed of the glacier using radar and seismic techniques, and use satellite remote sensing to measure the changing configuration of the glacier in areas that cannot be accessed on the ground. We will use the data we have collected to drive and verify a set of computer simulations of the dynamics of Pine Island Glacier. Each of these will test a particular aspect of the glacier flow, and allow us to test our current knowledge and hypotheses against real data. The models that emerge from the exercise will be demonstrably more reliable in simulating past changes on the glacier, and thus have reduced uncertainty in predicting the future evolution of such changes, and the consequential contribution to sea-level rise.
Overall, this programme will deliver significant improvements in understanding of how glaciers in general interact with their beds, and very specific lessons about one of the most rapidly-changing and significant glaciers on the planet, Pine Island Glacier.
Pine Island Glacier is one of five glaciers in West Antarctica that are currently contributing sea-level rise at a significant and accelerating rate. The portion currently affected by thinning contains sufficient ice to raise global sea-level by around 25 cm - its neighbours account for another 50 cm.
Given the rate of ice-loss and the potential implications for sea-defence planning there is a clear requirement to understand and predict the future of Pine Island Glacier and its neighbours. However, as highlighted by the Intergovernmental Panel on Climate Change (IPCC, 2007), understanding the way that dynamic changes are transmitted through the glaciers draining ice sheets is so poorly understood that the IPCC believed it was the least well understood, and potentially the largest, contribution to sea-level rise in the coming century.
ISTAR-C will directly address this lack of knowledge, by seeking to understand the processes that are responsible for transmitting the effect of thinning of the floating ice shelf, upstream such that thinning can now be seen on much of the trunk and tributaries of Pine Island Glacier.
ISTAR-C will also use the most up-to-date methods available to measure the properties (rock-type and water-content) of the bed beneath several locations on Pine Island Glacier to determine their influence on the propagation of thinning. We will test the hypothesis that it is these bed conditions that are responsible for the fact that the tributaries of Pine Island Glacier appear to be thinning at different rates. Testing this hypothesis will give us a much better understanding on which to predict the future magnitudes of ice-thinning rates for the glacier.
To achieve these objectives we will collect data from Pine Island Glacier during two field seasons. These will include precise measurement of variations in ice-flow from the ice-shelf up the glacier and into its tributaries. We will image the bed of the glacier using radar and seismic techniques, and use satellite remote sensing to measure the changing configuration of the glacier in areas that cannot be accessed on the ground. We will use the data we have collected to drive and verify a set of computer simulations of the dynamics of Pine Island Glacier. Each of these will test a particular aspect of the glacier flow, and allow us to test our current knowledge and hypotheses against real data. The models that emerge from the exercise will be demonstrably more reliable in simulating past changes on the glacier, and thus have reduced uncertainty in predicting the future evolution of such changes, and the consequential contribution to sea-level rise.
Overall, this programme will deliver significant improvements in understanding of how glaciers in general interact with their beds, and very specific lessons about one of the most rapidly-changing and significant glaciers on the planet, Pine Island Glacier.
Planned Impact
The research undertaken in iSTAR-C will improve understanding of the causes of rapid change observed in parts of the West Antarctic ice sheet (WAIS) and how these may contribute to sea-level rise in future. While production of sea-level rise projections is not included within iSTAR-C, this programme will deliver understanding that underpins such projections, and will reduce uncertainty, and increase confidence, in those projections. Thus, the most significant economic and societal impacts of iSTAR-C will be realised as the science outcomes from iSTAR-C are taken up by beneficiaries beyond the immediate colleagues of the Co-Is; there are researchers and non-research scientists and engineers, who are directly undertaking sea-level rise projections.
Within this group we identify several key beneficiaries who will be users of iSTAR-C outcomes.
1. Academic researchers: (e.g., Proudman Oceanographic Institute, UK Climate Impacts Programme) who have a role in producing local, regional and global sea-level projections, and delivering to users.
2. Intergovernmental Panel on Climate Change (IPCC). The IPCC is by far the most influential group synthesising and delivering sea-level rise projections to policy-makers.
3. Governmental and non-governmental advisors. (E.g.; Dept. of Energy and Climate Change, UK Environment Agency) closely monitor science regarding sea-level protection and are influential in bringing science in the agenda of policy-makers.
Engaging with these and similar groups will maximise the value of iSTAR-C.
In an even wider frame, iSTAR-C and projects like it, which seek to improve the underlying science on which we base our projections of future state of the planet, should play an important role in re-establishing public confidence in science. The nature of the iSTAR-C programme, which focuses on an exciting work in an inspiring area, and on current and unarguable changes in the Earth System, will draw the attention of many people not normally turned on by science. This will give iSTAR-C a great opportunity to engage with individuals and we will not squander this opportunity. We will seek to present and frame iSTAR-C outcomes without policy-prescriptive implications, but in a spirit of informing rational evidence-based debate. We will seek a dialogue with groups and individuals who share this goal.
Within this group we identify several key beneficiaries who will be users of iSTAR-C outcomes.
1. Academic researchers: (e.g., Proudman Oceanographic Institute, UK Climate Impacts Programme) who have a role in producing local, regional and global sea-level projections, and delivering to users.
2. Intergovernmental Panel on Climate Change (IPCC). The IPCC is by far the most influential group synthesising and delivering sea-level rise projections to policy-makers.
3. Governmental and non-governmental advisors. (E.g.; Dept. of Energy and Climate Change, UK Environment Agency) closely monitor science regarding sea-level protection and are influential in bringing science in the agenda of policy-makers.
Engaging with these and similar groups will maximise the value of iSTAR-C.
In an even wider frame, iSTAR-C and projects like it, which seek to improve the underlying science on which we base our projections of future state of the planet, should play an important role in re-establishing public confidence in science. The nature of the iSTAR-C programme, which focuses on an exciting work in an inspiring area, and on current and unarguable changes in the Earth System, will draw the attention of many people not normally turned on by science. This will give iSTAR-C a great opportunity to engage with individuals and we will not squander this opportunity. We will seek to present and frame iSTAR-C outcomes without policy-prescriptive implications, but in a spirit of informing rational evidence-based debate. We will seek a dialogue with groups and individuals who share this goal.
Publications
Siegert M
(2017)
Antarctic subglacial groundwater: a concept paper on its measurement and potential influence on ice flow
in Geological Society, London, Special Publications
Bougamont M
(2019)
Contrasting Hydrological Controls on Bed Properties During the Acceleration of Pine Island Glacier, West Antarctica
in Journal of Geophysical Research: Earth Surface
Bougamont M
(2015)
Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica
in Geophysical Research Letters
Christoffersen P
(2014)
Significant groundwater contribution to Antarctic ice streams hydrologic budget CHRISTOFFERSEN ET. AL.; HYDROLOGIC BUDGETS FOR ICE STREAMS
in Geophysical Research Letters
Description | Pine Island Glacier is one of Earth's largest, and one which has influenced sea level over the last several decades disproportionately. It's acceleration has, for instances, greatly increased the mass loss in West Antarctica. In this grant, the research in Cambridge showed that acceleration of Pine Island was accompanied by significant changes in the basal environment. The central part of the glacier has become weaker while its margins have become stronger. The research has identified flow of water beneath the glacier as a central process in the glaciers's flow and dynamical character. |
Exploitation Route | The numerical model developed in this grant is publically available and free to use by other researchers. |
Sectors | Environment Government Democracy and Justice |
Description | The iSTAR programme has, as a whole, delivered significant public outreach and widening participation. The research in Cambridge was communicated to school groups and members of the public who visited the Polar Museum in the Scott Polar Research Institute. |
First Year Of Impact | 2017 |
Sector | Environment,Government, Democracy and Justice |
Impact Types | Societal |
Description | Bridging grant from the Isaac Newton Trust |
Amount | £42,609 (GBP) |
Funding ID | 12.22(i) |
Organisation | University of Cambridge |
Sector | Academic/University |
Country | United Kingdom |
Start | 08/2012 |
End | 09/2014 |
Title | Ice flow model output for Pine Island Glacier (West Antarctica), from numerical inversions of ice surface velocities observed in 1996 and 2014 |
Description | This data contains the model output of three numerical inversions of Pine Island Glacier ice surface velocities performed with the Community Ice Sheet Model (CISM2.0). The first and second simulations are inversions of the 1996 and 2014 velocity, respectively. The third simulation is a sensitivity experiment on the 2014 inversion. The gridded data consists of the ice surface velocity, basal velocity, basal stress, basal melt rates, and basal water fluxes, calculated for Pine Island Glacier catchment area. |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Description | Cambridge - Canterbury international research collaboration |
Organisation | University of Canterbury |
Department | Gateway Antarctica |
Country | New Zealand |
Sector | Academic/University |
PI Contribution | This collaboration provided a new network of scientists from UK and New Zealand. The scientists are collaborating on developing new geophysical techniques for exploration of glaciers and ice shelves in Antarctica. |
Collaborator Contribution | The partner provided financial support to Dr Poul Christoffersen and Dr Marion Bougamont, who were awarded international scholarships and spent five months at Gateway Antarctica in Christchurch, New Zealand, in 2017. |
Impact | During the visit, Dr Christoffersen gave three seminars, one conference presentation and one public lecture. Dr Bougamont gave two seminars and one conference presention. |
Start Year | 2017 |
Description | Coupling basal mechanics and ice flow in the Community Ice Sheet Model |
Organisation | Los Alamos National Laboratory |
Country | United States |
Sector | Public |
PI Contribution | In this collaboration, the Cambridge group was responsible for integrating a model of subglacial processes in the higher-order Community Ice Sheet Model. |
Collaborator Contribution | The partner at the Los Alamos National Laboratory contributed with their expertise on numerical ice sheet modelling. The Community Ice Sheet Model is primarily developed at the Los Alamos National Laboratory. |
Impact | This collaboration has increased the dynamic capability of the CISM. Outcomes were reported in conference papers as well as articles published in peer-reviewed journals of high international standard. A good example is: Bougamont*, M., S. Price**, P. Christoffersen, A. J. Payne, Dynamic patterns of ice stream flow in a 3D higher-order ice sheet model with plastic bed and simplified hydrology, Journal of Geophysical Research - Earth Surface, 2011, doi:10.1029/2011JF002025***. * Postdoctoral Researcher at the Scott Polar Research Institute ** Partner at Los Alamos National Laboratory *** THIS ARTICLE WAS SELECTED AS A RESEARCH HIGHLIGHT BY EDITORS OF THE AMERICAN GEOPHYSICAL UNION AND FEATURED AS RESEARCH SPOTLIGHT IN THE EOS NEWSLETTER. |
Start Year | 2008 |
Description | Coupling hydrology and ice flow in the Community Ice Sheet Model |
Organisation | University of California, San Diego (UCSD) |
Country | United States |
Sector | Academic/University |
PI Contribution | In this collaboration, the Cambridge group integrated hydrological processes in the Community Ice Sheet Model, which they use to simulate the flow of glaciers and ice sheets in Antarctica and Greenland. |
Collaborator Contribution | The collaborators at the Scripps Institution of Oceanography provided a validated hydrological model. |
Impact | The collaboration with Prof. Helen Fricker and her research group at the Scripps Institution of Oceanography has so far produced three significant peer-reviewed journal articles: Bougamont, M., P. Christoffersen, A. L. Hubbard, A. A. Fitzpatrick, S. H. Doyle, and S. P. Carter, Sensitive response of the Greenland Ice Sheet to surface melt drainage over a soft bed, Nature Communications, 5, 5052-5052, doi:10.1038/ncomms6052, 2014. HIGH IMPACT RESEARCH OUTPUT WITH ALTMETRIC SCORE OF 144 ONE MONTH AFTER PUBLICATION. OUTPUT REPORTED IN 17 NEWS OUTLETS. Christoffersen, P., *M. Bougamont, S. P. Carter, H. A. Fricker, and S. Tulaczyk, Significant groundwater contribution to Antarctic ice streams hydrologic budget, Geophysical Research Letters, 41(6), 2003-2010, doi:10.1002/2014gl059250, 2014. SELECTED AS RESEARCH HIGHLIGHT BY AGU EDITORS AND FEATURED AS RESEARCH SPOTLIGHT IN EOS NEWSLETTER. Beem, L. H., S. M. Tulaczyk, M. A. King, *M. Bougamont, H. A. Fricker, and P. Christoffersen, Variable deceleration of Whillans Ice Stream, West Antarctica, Journal of Geophysical Research-Earth Surface, 119(2), 212-224, doi:10.1002/2013jf002958, 2014. SELECTED AS RESEARCH HIGHLIGHT BY AGU EDITORS AND FEATURED AS RESEARCH SPOTLIGHT IN EOS NEWSLETTER. |
Start Year | 2011 |
Title | 2D iceberg calving parameterisation for the Elmer/ICE finite element package |
Description | A 2D iceberg calving parameterisation was implemented in the Full Stokes Elmer/ICE (open source) finite element package. |
Type Of Technology | Software |
Year Produced | 2016 |
Open Source License? | Yes |
Impact | The model can be used at no cost by those using the Elmer/ICE model to study glaciers numerically. |
URL | http://elmerice.elmerfem.org/ |
Title | 3D calving parameterisation implemented in Elmer/Ice (open source) finite-element model |
Description | The process whereby icebergs break off glaciers where implemented in Elmer/Ice finite element package and is now available through open source licensing. |
Type Of Technology | Software |
Year Produced | 2018 |
Open Source License? | Yes |
Impact | The software allows users to simulate marine-terminating glaciers with a free-moving boundary applied on their front. The new solution allows for simulation of the effect of submarine melting and other types of ocean forcing. This is a significant improvement over previous models in which the front of glaciers either remained fixed or moved in response to the ice flow alone. |
Description | Panel debate ("ICE") on BBC's "The Forum" broadcast on World Service and Radio 4 |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | In this 45-minute programme, I was able to carefully explain my work in polar regions to the listeners while debating the consequences of climate change with the presenter and the other panelists. This radio programme reached a lot of listeners in the UK and abroad via multiple broadcasts on BBC Radio 4 and the BBC World Service. A Christmas repeat on BBC Radio 4 (Saturday 28 December 2013) shows wide public interest. |
Year(s) Of Engagement Activity | 2013 |
URL | http://www.bbc.co.uk/programmes/b03m8612 |
Description | Research on ice-sheet stability featured as highlight in Nature Climate Change |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | The article "Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica" by Bougamont et al. was selected as a Research Highlight by the editors of Nature Climate Change. The article's main findings was summarised as a Research Highlight in Nature Climate Change (vol. 5) under the title: "West Antarctic ice stability". |
Year(s) Of Engagement Activity | 2015 |
URL | http://www.nature.com/nclimate/journal/v5/n11/full/nclimate2857.html |
Description | Research on ice-stream flow featured as highlight in Eos Magazine |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | The article "Variable deceleration of Whillans Ice Stream, West Antarctica" by Beem et al. was selected as a Research Highlight by the editors of Journal of Geophysical Research. The article's main findings was summarised as a Research Spotlight in Eos magazine (vol. 95 no. 21) under the title "Antarctica's Whillans Ice Plain ice flows are highly variable". |
Year(s) Of Engagement Activity | 2014 |
URL | http://onlinelibrary.wiley.com/doi/10.1002/2014EO210015/full |
Description | Research on subglacial lakes featured as highlight in Eos Magazine |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | The article - Significant groundwater contribution to Antarctic ice streams hydrologic budget - by Christoffersen et al. was selected as a Research Highlight by the editors of Geophysical Research Letters. The article's main findings was summarised as a Research Spotlight in Eos magazine (vol. 95 no. 35) under the title: Tracking the sources and sinks of Antarctica's subglacial waterways. |
Year(s) Of Engagement Activity | 2014 |
URL | http://onlinelibrary.wiley.com/doi/10.1002/2014EO350021/full |