Current and Upcoming Fieldwork
Greenland: Refreezing in the Firn of the Greenland Ice Sheet
This project will collect several shallow firn cores from the southwestern sector of the Greenland Ice Sheet to investigate the stratigraphy, density, temperature and liquid water content of the firn cover and investigate spatial and temporal variations (the latter by comparing to previous cores from the literature in some of the sites). The aim of the project is to better understand how the surface meltwater generated in the summer makes its way from its location on the ice sheet to the ocean. Two competing but not mutually exclusive theories are 1) the meltwater percolates into the ice sheet pores and is stored for a relatively long time. 2) The initial infiltrating meltwater refreezes at shallow depth in the firm, forming a hard pan that prohibits further infiltration. The project will test these two hypotheses through a combination of field work, remote sensing from satellites, and modeling.
Greenland: Quantifying Heat/Mass Structure and Fluxes through the Full Thickness of Greenland's Percolation Zone
The goal of the project is to quantify the structure, thermal state, and heat fluxes through the full thickness of the firn column across a transect spanning western Greenland's percolation zone. The project will achieve these objectives by drilling a combination of shallow and deep cores/boreholes at a series of sites between Swiss Camp and Crawford Point. Deep (up to 100 meters) boreholes will be drilled using hot water methods via with a drill that is being developed by the investigators. These deep boreholes will be augmented with a number of shallow cores to quantify density and provide access for temperature logging of the shallow firn thickness. The shallow cores will be drilled with a IDDO Hand Auger and Sidewinder.
Svalbard: Genetic, Phylogenetic and Functional Microbial Diversity in permanently frozen aquatic sediments over geological time
This project will use a SIPRE Hand Auger with a gas engine to collect two 4-meter long permafrost cores from Ny- Ålesund, Svalbard. The goal of the project is to investigate whether microbes embedded in permafrost are extinct, representing ancient terrestrial surface or marine communities preserved through time, or actively living communities that have been evolving since being buried. To determine how long microbial communities can live in permafrost, this project will study permafrost collected from the oldest known sediments of the Northern Hemisphere, which occur in Siberia.
Alaska: Measuring snow compaction on ice sheets to better quantify ice-sheet changes
This project, funded by Columbia University, will conduct a pilot study in Juneau Ice Field, Alaska, to demonstrate the use of phase-sensitive ice-penetrating radar system (ApRES) for measuring firn densities and compaction rates. Within the accumulation area of Juneau Ice Field, the investigators will use a IDDO Hand Auger and Sidewinder to drill shallow firn cores to 40 meters depth and measure snow and firn density for comparison with the ApRES-derived densities. The goal of the project is to develop a new capability to rapidly measure the density and rate of densification of firn using ApRES.
Canada/St. Elias Mountains: Geophysical reconnaissance to expand ice core hydroclimate reconstructions in the Northeast Pacific
The purpose of the field season is to collect firn cores covering the 2002-2018 time period from the Divide camp in the St. Elias Mountains, Yukon Territory, Canada. The investigators will use the Stampfli 2-Inch Drill to recover one 50 meter firn core and at least two 20 meter firn cores. The investigators have maintained automatic weather stations at the Divide camp since 2002, which represents an unprecedented observational record of snow accumulation and associated weather conditions in this glaciated region. By collecting a firn core to ~50 meters depth and analyzing stratigraphy (melt layers) and samples for stable water isotopes, the investigators will calibrate the ice core-based snow accumulation, temperature, and hydroclimate signals using the automatic weather station data. The investigators will also collect ground penetrating radar (GPR) data at the Divide camp to investigate glacier geometry and spatial snow accumulation patterns, and will ground truth the GPR data using the shallow (~20 meter depth) firn cores on a gridded basis.