Hello everyone! My name is Courtney Shafer, I’m a 2nd-year, first-generation Geology PhD student at the University at Buffalo working with Dr. Kristin Poinar. I am building a model that will predict the formation and evolution of moulins on the Greenland Ice Sheet. I’m also a recipient of the 2021 DOE Computational Science Graduate Fellowship. With their support, I hope to extend the capability of the moulin model to work with large, deterministic ice sheet models.
Prior to coming to Buffalo, I worked with Dr. Dan Martin at the Lawrence Berkeley National Laboratory on ice sheet modeling using the BISICLES (https://commons.lbl.gov/display/bisicles/BISICLES) ice sheet model. I was specifically interested in how BISICLES handled different approximations to the Stokes equations (Shallow Shelf Approximation, Shallow Ice Approximation, L1L2, etc.) and how model results using these approximations compared with each other. Approximations in ice sheet modeling are a necessary part of modeling since solving a full system model is usually computationally heavy. Ice sheet model comparisons seek to understand these differences between models and are an integral part of confirming the efficacy of these models.
I’ve investigated the BISICLES contribution to both the MISMIP3D and MISMIP+ intercomparison projects to see how the SSA approximation compares with the L1L2 approximation.
Moulins are large vertical tunnels that transport meltwater from the surface down to the bed of an ice sheet, and the water that reaches the bed can then lubricate the ice and has a direct impact on the overall dynamics of ice sheet flow. Current ice sheet models lack the physics needed to describe these intricate processes, which is necessary for ensuring accurate predictions of ice sheet flow and, ultimately, sea-level rise. This is an important puzzle to solve, especially as surface melt rates continue to grow in tandem with a warming climate.
September 2022 – Field work to Helheim!
From September 2nd to September 15th, I participated in fieldwork in southeast Greenland to investigate a perennial firn aquifer at Helheim Glacier, one of the largest flowing outlet glaciers in the southeast region. Specifically, I used “seismoelectric” methods to measure the top and bottom of the firn aquifer in the region to determine the thickness of the aquifer.
We collected measurements of the aquifer at two different sites. To create the seismic waves, we used two different methods: striking the surface of the snow with a large rubber hammer, or by creating a small explosion at a meter depth within the snow. The strength of the sources used to generate the seismic waves allow you to “see” to certain depth, that hammer generating a more shallow signal, whereas the explosion creates a more deeper signal
With the hammer strikes, we were able to “see” the top and the bottom of the firn aquifer and determined a thickness of about 19m.
Landing in Keflavik, Iceland 
Exploring Reykjavik 
Resting on baggage at Reykjavik airport, waiting to fly to Kulusuk! 
Finally in Kulusuk! 
Iceberg says hello on the way from Kulusuk to Tasiilaq
Beautiful Tasiilaq
February 2023
I received the SUNY GREAT award!
April 2023
Traveled to Maine for the first time to present my poster on my seismoelectric fieldwork at the 2023 Northeast Glaciology Meeting!