For our third sustainability research focused student profile we meet Mark Hehlen from Portland, Oregon in the US. Currently studying for a PhD in Polar Research at Churchill College, the aim of Mark’s research is to help constrain the future projections and timing of sea level rise so policy and industry decision makers can do something about it.

To accomplish this, Mark is looking at polar ice sheet mass loss to determine “how much and how fast”, building computer models of ice flow for Thwaites Glacier at the Scott Polar Research Institute as part of the International Thwaites Glacier Collaboration (ITGC) Thwaites Interdisciplinary Shear Margin Evolution (TIME) project. Thwaites is a massive ice stream the size of the island of Britain which accounts for 4% of all global sea level rise leading to its nickname of ‘The Doomsday Glacier’ in the media.

The journey to glaciology

Mark studied mathematics and statistics for his first undergraduate degree but lacked an application for the mathematics he was learning; ‘If algebra is a screwdriver, calculus is a power tool, and mathematics is architecture. The problem was, I didn’t know what I wanted to build.’ The turning point came when a glaciologist inspired him to volunteer at the 2012 Scientific Committee on Antarctic Research (SCAR) open science conference. Mark was introduced to the geophysical surveys of Operation IceBridge, full-Stokes equations for ice flow, and the history of billions of gigatons of delicate ice crystals that act as a barometer of Earth’s climate. He was utterly enthralled by glaciology and polar science as an application for his training in theoretical mathematics but his transition into geoscience was full of hurdles: departments not accepting theoretical mathematicians for graduate study, to student loans piling up, and a saturated job market. It took six long years for Mark to make it back to academia and a second undergraduate degree in Geology, but once he got there, he hit the ground running!

I was commuting 75 miles each way to class, and I needed to prove to myself and my new department that I had the experience and drive to master the fundamentals of geology and prepare myself for graduate study in glaciology.

Mark studied field geology, biogeochemistry, glacial landforms, and remote sensing at the University of Vermont. His senior thesis involved building digital elevation models from spaceborne LiDAR and discovering an unexpected signal of seasonal variation in Antarctic glacier discharge. After graduating, he undertook a two-month field expedition with the Juneau Icefield Research Program to survey below the ice with ground penetrating radar, fly drones to build structure from motion models, and eventually co-authored a paper on the uncertainty in satellite derived ice velocities, which has just been published in Remote Sensing. Under the guidance of academic experts, Mark was finally introduced with hands-on practice to modeling glacier flow.

Cambridge and Churchill College

With the British Antarctic Survey and Scott Polar Research Institute (SPRI) both based in Cambridge, the city was always on Mark’s short list of potential universities to do his PhD. When he saw that Dr. Christoffersen at SPRI had a posting for a PhD candidate for modeling on the ITGC TIME project with the opportunity for field work, he knew this was ideal.

At Cambridge, Mark is technically based in the Geography Department, he identifies more as an earth scientist or glaciologist. Thwaites Glacier, the focus of Mark’s PhD research, is a massive ice stream situated in the middle of West Antarctic Ice Sheet (WAIS). Since 2000, Thwaites has widened its front from 80-120 km and accelerated from 340 m/yr to 4900 m/yr. Mark’s work is to investigate the potential for Thwaites’ eastern shear margin to migrate drastically, influencing the amount of ice loss. He uses high performance computing to solve full-Stokes flow for Thwaites along its eastern shear margin, and couple these flow solutions with temperature evolution, hydrological development, and basal sliding laws. However, as Mark points out, ‘models are only as good as the data they are fed’ so he is also working with the geophysics field team to undertake ice penetrating radar surveys and the first 3D active seismic survey in Antarctica to determine englacial fabrics, water distribution, and high-resolution bed topography. 

When it comes to Mark’s experience of being a postgraduate student at Churchill College, what he enjoys most, other than its close proximity to the British Antarctic Survey and his work, is the space and quiet.

I think it is essential to escape the touristy bustle of city centre and have a wide-open area to clear your mind. At the same time, a bicycle commute across town only takes ten minutes.

Mark’s hobbies usually centre around mountain sports, from cross-country skiing to climbing and hiking but in Cambridge he spends any free time he has playing board games, attending quiz nights or crossing the academic divide and having a pint with the locals.

After his PhD Mark plans to return to the States to pursue post-doctoral research or sign on with a national laboratory. Longer-term, a professorship that would enable him to hybrid his work on modelling with the field and remote sensing would be ideal, but his greatest career aspiration is to pass on knowledge and inspire the next generation to glaciology. 

It is one thing to realise that studying ice is cool, but another to be able to ski across a ‘small’ glacier and understand that as it all goes away, beaches will disappear, ocean salinity will change, land use will change, global energy systems will change, resources will become more scarce, 650 million people will be displaced, wars will break out. All because of these little ice crystals. So, it is imperative to train the next generations of earth and cryospheric scientists so we can hopefully avert what is to come, but if all else fails, prepare for it.


Mark’s PhD is fully funded through the UKRI National Environmental Research Council (NERC), specifically the Cambridge Climate, Life and Earth (C-CLEAR) sciences doctoral training program (DTP). Additionally, Mark is a part of the ITGC TIME grant. ITGC is an international collaboration of US, UK, Australia, Sweden and South Korea, but most funding is from the National Science Foundation [US] and NERC [UK]). This includes logistical support from the British Antarctic Survey and the US Antarctic Program – the latter which houses the science team at McMurdo station, supplies safety personnel, and provides deep field logistics.