Collaborative Research: Sonic Logging the NEEM Corehole, Greenland

Past deep ice cores recovered from the Greenland Ice Sheet (GrIS) have failed to obtain intact Eemian ice, ice from the last interglacial period. The recent North Greenland Eemian Ice Drilling effort (NEEM) has successfully recovered ~150 m of such ice. The proposed continuous sonic monitoring of the ice fabric will resolve small scale variability that is missed by the traditional techniques used in thin section analyses of ice cores, which tend to under-sample the core. The scales to be recovered with the sonic sampling are more comparable to those that can be observed with new gas-sampling technologies. The proposed work would add to the physical data set required to fully interpret data being recovered from the NEEM ice core, such as the gas content analyses used to infer past atmospheric conditions. The presence of a special USGS winch this summer, a winch required for the operation of University of Washington instrument proposed for deployment, and the planned abandonment of the NEEM field camp after the summer of 2012, make this proposal appropriate for a RAPID award.