Glaciologist Emily Stevenson is enchanted by the frozen world and alarmed at its catastrophic thaw.
Above: at the top of the Taku-B nunatak on the Juneau Icefield, Alaska
By Emily Stevenson (St John’s, DPhil 2012)
Glacial landscapes are just breathtaking; the whites and blues of the ice, the peripheral raw ground rock and huge turbulent rivers that flow from the base of the ice. I’m an earth scientist, and my research into glacial systems takes me to stunning ice sheets and glaciers around the northern hemisphere. Unfortunately, glaciated catchments are environments that are among the most vulnerable to climate change, and ice-sheet retreat is presently taking place at an unprecedented level. That’s demonstrated in the 2013 report from the Intergovernmental Panel on Climate Change (IPCC) and the World Glacier Monitoring Survey, for example. Glacier National Park in the northern USA is predicted to have no more glaciers by 2030.
While many fundamental and crucial scientific projects are currently focused on constraining the mass, flux and volume of ice and/or water loss from ice sheets to the oceans, very few are concerned with uncovering the nutrient and/or chemical composition of this water, what primarily determines its composition, and how it varies between geographically distinct ice masses.
Above: Emily goes to collect water at the Nuuk glacier terminus in Greenland
As an undergraduate I studied chemistry at the University of Edinburgh and had a passion for the outdoors, taking up mountaineering and heading out on international expeditions on the Andes in South America. Based in these incredible mountainous regions and glaciated landscapes, I saw how fragile these environments are and how frighteningly fast they are changing and receding. I realised I wanted to use my degree to investigate earth surface processes, so in 2005 I applied to undertake a DPhil at Oxford’s Department of Earth Sciences.
Whilst my geological knowledge was somewhat lacking (!), my solid background in chemistry and my analytical abilities allowed me to pursue a DPhil in isotope geochemistry. The fantastic multi-disciplinary department welcomed me and allowed me to collaborate with great professors and researchers who constantly helped and encouraged me. After leaving Oxford in 2012, I was awarded the highly competitive Turner Postdoctoral Fellowship at the University of Michigan and was able finally to pursue my research into what determines the composition of glacial runoff and how this may be changing.
The Earth’s surface has been dominated by cycles of glacial advance for more than two million years. Processes occurring at the glacier bed exert a fundamental control on the release of bioavailable elements to rivers and oceans and the evolution of the Earth’s surface, hydrosphere and atmosphere. Beneath vast ice sheets and glaciers lies the poorly understood (and well-hidden) environment where ice at the base of the glacier grinds against bedrock producing vast amounts of freshly ground rock, silt and sand. As melt water passes through these environments it picks up and dissolves these tiny particulates, enriching glacial melt waters with the nutrients and elements needed to support life downstream in rivers and oceans, stimulating oceanic primary producers and promoting the drawdown of carbon dioxide from the atmosphere.
Earlier this year I was awarded a prestigious Marie Curie fellowship by the European Commission, to study precisely this — nutrient export from glacial environments. The overarching goal is to investigate the redox conditions (i.e. the availability of oxygen within these individual systems) that control vital nutrient and elemental release through a study of glaciated regions which vary fundamentally in size, hydrology and bedrock composition in Greenland, Iceland, the Canadian Rockies and French Alps.
Fieldwork is vital to my research as it allows direct sampling and places each outflow in context and, however it can also represent a fundamental challenge. Gaining direct access to glacial melt water drainage pathways can be challenging, often to locations that have never before been explored, let alone used for obtaining samples. I have meticulously planned field campaigns making it logistically possible to approach and sample from previously inaccessible environments in Greenland.
Looking for an upwelling through the ice
Through a collaborative effort with a fellow glaciologist and a professional photographer, I have helped make some of these places accessible to the adventurous general public (www.bigchilladventure.com). Raising awareness of the frailty and beauty of these rapidly vanishing glaciated environments is vital if we are to continue this essential research, to place it at the forefront of policymaking and in the clear sight of the wider industrial, scientific and public communities.
You can follow Dr Stevenson’s research and photographs on Twitter, @dreistevenson.
Main image courtesy of Emily Stephenson / Juneau Icefield Research Program. Nuuk glacier image © Mindy Cambiar. Remaining images © John Weall.