Investigating meltwater flow beneath the Greenland Ice Sheet using a multi-tracer approach

Lead Research Organisation: University of Bristol
Department Name: Geographical Sciences

Abstract

The Greenland Ice Sheet is the main reservoir of ice in the northern hemisphere capable of affecting sea level in the 21st Century. Measurements of the elevation of the ice sheet surface from aircraft now provide a much better picture of the whether the ice sheet is graining or losing mass. However, until there is a better understanding of how ice flows from the ice sheet interior to the ocean, models that aim to predict the response of the Greenland Ice Sheet to climate change and the impact on sea level are unlikely to produce accurate estimates. One of the least poorly understood aspects of ice flow is how meltwater lubrication at the ice sheet sole might affect the rate of ice discharge to the ocean. Recent research has shown that the input of surface meltwater to the ice sheet bed in summer causes considerable ice speed up. Exactly how meltwater flows at the bed (does it flow in discrete channels or does it spread out and flow in a more diffuse manner?) is crucial to understanding how the ice sheet might respond to increased melt inputs in a warming climate. Currently, little is known about basal meltwater routing because the vast amounts of meltwater prevent the use of traditional tracing techniques (e.g. dye tracing). This project aims to apply novel tracing methods which will survive large scale dilution, and which can be injected to holes (moulins) on the glacier surface and detected when the water emerges at the ice sheet front. Some of these techniques have been using widely in oceanography to trace currents across ocean basins. Our tracer experiments will provide new information regarding characteristics of meltwater flow paths and their temporal/spatial variations at the bed of the ice sheet and provide detailed measurements (e.g. pressure) of along-flow path characteristics. Comparison of our tracer results (e.g. water flow speeds, pressure conditions in channels) with ice velocity data from the same glacier will help identify linkages between meltwater routing and ice flow mechanisms, and will generate a unique dataset for future numerical modelling studies aimed at quantifying the future contribution of the Greenland Ice Sheet to global sea level rise.level rise.

Publications

10 25 50
 
Description Large efficient channels convey meltwater beneath the Greenland Ice Sheet
Exploitation Route Use for constraining numerical models of ice flow
Sectors Environment

 
Description - findings have advanced understanding of water flow beneath ice sheets -development of low cost electronic tracers for tracing water flow in ice sheets has had wide interest as a technique and is now being adapted for use in UK waterways (see impact accelerator funding)
First Year Of Impact 2010
Sector Environment
Impact Types Economic

 
Description Cryoegg: a novel wireless instrument for exploring deep ice
Amount £232,387 (GBP)
Funding ID EP/R03530X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2018 
End 10/2021
 
Description NERC-CONICYT joint funding scheme
Amount £733,000 (GBP)
Funding ID PII20150106 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 07/2016 
End 04/2019
 
Description Sub-ice sheet weathering: a missing link in the global silicon cycle?
Amount £262,000 (GBP)
Funding ID RPG-2016-439 
Organisation The Leverhulme Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 06/2017 
End 05/2021
 
Description UKIERI: Bio-climatic feedbacks of melting Himalayan Ice
Amount £198,000 (GBP)
Organisation UK-India Education and Research Initiative (UKIERI) 
Sector Academic/University
Country United Kingdom
Start 04/2017 
End 04/2020
 
Title Proglacial discharge measurements, Leverett Glacier, south-west Greenland (2009-2012) 
Description Measurements of water discharge, suspended sediment concentration and electrical conductivity during the melt seasons of 2009, 2010, 2011 and 2012 in the proglacial river draining from the tongue of Leverett Glacier, a land-terminating glacier in the south-west of the Greenland Ice Sheet. The measurements were made in a stable bedrock section approximately 2 km downstream from the glacier terminus. Data loggers recorded measurements every 15 minutes from approximately May to August each year. Water depth (stage) was converted to discharge (Q) using season-specific ratings curves derived from repeat dye-dilution injections undertaken across the stage values. Suspended sediment concentration (SSC) was obtained by calibrating turbidity sensor readings with sediment samples taken in-situ and then filtered, dried and weighed. Electrical conductivity (EC) was recorded using a water conductivity probe; the data were filtered for bad values and corrected for temperature, but no smoothing was applied. These version 2 files are presented as CSV lists, with some summary metadata included as comments at the start of each file; they essentially contain the same data as the previous version files. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Description Collaboration in Greenland 
Organisation Woods Hole Oceanographic Institution
Country United States 
Sector Charity/Non Profit 
PI Contribution Advice on methods and method develop for hydrology work in Greenland
Collaborator Contribution collaborative discussions, one paper published
Impact Bhatia, M. S. Das, M. Charette, J.L. Wadham, E.B. Kujawinski. 2013. Organic carbon export from the Greenland Ice Sheet, Geochimica et Cosmochimica Acta, doi: http://dx.doi.org/ 10.1016/j.gca.2013.02.006
Start Year 2009
 
Description Collaboration with the East Greenland Ice Core Project (EGRIP) 
Organisation University of Copenhagen
Department Niels Bohr Institute
Country Denmark 
Sector Academic/University 
PI Contribution Liz Bagshaw (former PDRA on two technology-led NERC grants led from Bristol) participated in the EGRIP field season, and developed and deployed Etracers and Cryo-Eggs for monitoring processes in firn.
Collaborator Contribution This collaboration would not have been possible without significant in kind backing from the EGRIP team.
Impact Further plans are being developed.
Start Year 2016
 
Description Technology Development 
Organisation Biotrack
Country United Kingdom 
Sector Private 
PI Contribution Development and adaptation of animal tracking equipment for glacier hydrology research
Collaborator Contribution collaboration
Impact Various publications - see publications
Start Year 2009
 
Description Blogs on fieldwork in Greenland (Jon Hawkings, PhD student) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact excellent feedback

stimulation of discussion
Year(s) Of Engagement Activity 2012
URL http://cabot-institute.blogspot.co.uk/2012/08/unprecedented-melting-of-greenland-ice.html
 
Description Invitation to two workshops on "Exploration of Subglacial Lake CECS, Antarctica", Valdivia, Chile 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Wadham was invited to and led discussion of plans to explore Antarctic Subglacial Lake CECs at two international workshops in the Centro Estudio Scientificos, in Valdivia (Chile). This was a UK-Chilean group of scientists and engineers who plan to enter and sample this lake.
Year(s) Of Engagement Activity 2016,2017
 
Description Invited research seminar at Woods Hole Oceanographic Institute 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Wadham invited to give a research seminar at WHOI, based upon her work on Greenland biogeochemistry and sensor development.
Year(s) Of Engagement Activity 2016
 
Description Keynote International Glaciological Society Annual Meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Study participants or study members
Results and Impact Keynote presentation given by Wadham, sparked interest and ideas from researchers in aligner fields
Year(s) Of Engagement Activity 2017
 
Description Keynote at European Geophysical Union Meeting (Vienna) by Wadham 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Wadham was invited to give a keynote presentation about her sensor development work via several NERC funded projects.
Year(s) Of Engagement Activity 2016
 
Description Partnership with the BBC on documentary on BBC4 on "Dangerous Earth: Icebergs" 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Wadham was a lead scientist on this BBC4 documentary, which communicated the impacts of icebergs on the rest of the planet. She participated in filming and appeared in the final product in December 2016.
Year(s) Of Engagement Activity 2016
 
Description Research Seminars - National University of Singapore, Imperial College London 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Follow up correspondence and requests for further info have been made.
Year(s) Of Engagement Activity 2015
 
Description Science presentations at 7 international schools in Hong Kong and China 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Email follow up has happened. Further information has been requested.
Year(s) Of Engagement Activity 2014,2015
 
Description Talks at schools (Schools STEM outreach day, 5th July, Bristol Oasis Marksbury Rd, 30th January by Liz Bagshaw) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Liz Bagshaw, former PDRA on two sensor-focussed research grants, gave talks at local schools in Bristol and Cardiff.
Year(s) Of Engagement Activity 2016
 
Description UoB Bristol Glaciology Centre outreach at Room 13 Hareclive (Bristol Ice Explorers) - Jon Hawkings (PhD student), Professor Martyn Tranter 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact sparked lots of discussion

An art competition for the local school children was launched, focussed on glacial environments
Year(s) Of Engagement Activity 2014
URL http://www.room13hareclive.org.uk/news
 
Description Video documentary work in Greenland (Alex Ingle, MSc student, University of Edinburgh) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact good feedback

stimulated discussion
Year(s) Of Engagement Activity 2011,2012
URL http://www.geos.ed.ac.uk/glaciology/hydrology_dynamics/photo_video.html