2011 Arctic

This project will develop a new, international (8-nation), broadband seismic capability for Greenland - the GreenLand Ice Sheet monitoring Network (GLISN) - a real-time sensor array of 25 stations which enhances and upgrades the performance of the scarce existing Greenland seismic infrastructure for detecting, locating, and characterizing glacial earthquakes and other cryo-seismic phenomena, and contributing to our understanding of Ice Sheet dynamics. In support of this project, IDP will drill one borehole for the seismometers. In addition to drilling the hole, which must be dry and vertical, IDP will assist with the installation of the seismometers by using the drilling rig to lower the instrumentation and data cables.

The goal of this project is to investigate snow accumulation in the south-eastern sector of the Greenland ice sheet. Snow accumulation rates on the Greenland ice sheet have been significantly underestimated and the missing mass prevents accurate estimates of the overall ice sheet mass balance. The south-eastern sector of the ice sheet contains the largest proportion of the missing mass. Consequently, this study will measure snow accumulation using new and existing firn cores along two transects in the south-east Greenland data void and, by combining the firn core records with ground-penetrating radar surveys, develop continuous accumulation transects between 2500 m and 500 m elevation.

This project is investigating the physical properties and state of snow and firn along a traverse from Thule to Summit Greenland. The scientists will accompany the resupply traverse from Thule to Summit, and make detailed observations of grain size, density and stratigraphy in 1 m deep snow pits and 10 m deep boreholes in firn along a route that crosses all the facies (ablation facies, soaked facies, percolation facies, dry snow facies) of the ice sheet. Techniques to be applied in the field include near infra-red photography, borehole optical stratigraphy, and a neutron-scattering probe. A ground-penetrating radar operated along the traverse will provide stratigraphic data that links the stratigraphic information obtained in the snow pits and boreholes. Two shallow ice cores obtained at the beginning and end of the traverse, and snow samples, will be returned to the laboratory for examination of microstructure using micro-computed tomography and brightness temperature using optical and near-infrared photography.

The goal of this project is to analyze firn cores from McCall Glacier in the eastern Brooks Range of Alaska to better understand the processes of internal accumulation of ice within firn. The study will involve extracting firn cores from McCall Glacier to study their change over time to better understand the processes of internal accumulation of ice within firn and the effects of this process on the paleoclimate proxies they are using to interpret a previously drilled deep ice core. The plan is to take about 30 meters of core per year, as a series of about 5 m deep triplicate cores from 2 nearby locations.

The stable isotopic records from the Greenland Ice Sheet are the gold standard for understanding climate variations in the Arctic on decadal to millennial scales. While the basic tenets that underlie interpretation of isotopic information appear robust in a mean sense, meteorological and glaciological processes can confound simple interpretations. Processes of concern are variations in moisture sources, cloud processes, surface ablation, blowing snow and vapor diffusion in the firn. Continuous measurements of the isotopic composition of water vapor and daily measurements of the isotopic composition of freshly-fallen and blowing snow will be made at Summit (Greenland), Eureka (Ellesmere Island) and Reykjavik (Iceland). These will be combined with measurements of the amount, size distribution, and approximate habit of falling and blowing snow, turbulence measurements to evaluate snow lofting, surface latent heat flux (ablation and frost) and energy balance, and remote sensing of polar clouds and atmospheric structure. High-resolution firn cores will be drilled to reconcile the detailed isotopic measurements and modeling with glaciological records.