The Electromagnetic Geophysics Laboratory at the Lamont-Doherty Earth Observatory of Columbia University develops and applies electromagnetic geophysical imaging techniques to study Earth processes in offshore, onshore and glacial environments.
Four person Team consisted of Columbia graduate student Chloe Gustafson, Columbia Prof. Kerry Key, Colorado School of Mines Prof. Matt Siegfried and mountaineer Meghan Seifert, spent the first three weeks at Camp 20 while surveying the grounding zone.
During November 2018 to January 2019 we carried out an extensive geophysical survey on the Whillans Ice Stream in West Antarctica. Our survey is the first to use magnetotelluric (MT) imaging to map subglacial groundwater water beneath an ice stream. We collected a total of 44 passive MT stations, as well as several active-source electromagnetic (EM) stations using a large loop transmitter system. These data will be used to study the distribution of groundwater at the base of the ice stream at both the grounding line where the ice stream turns into the Ross Ice Shelf and at Subglacial Lake Whillans. We also serviced a few long term GPS stations that have been recording data for several years and that have been used to track transient changes in ice velocity associated with basal water filling and draining in subglacial lakes. Our project is in collaboration with Matt Siegfried (Colorado School of Mines) and Helen Fricker (Scripps Institution of Oceanograpahy, UC San Diego). Both EM and MT methods and the rationale for their use are described in our feasibility study paper.
See the video shot during 30-40 knot winds at Camp 20 during the SALSA EM survey.
More info at: https://emlab.ldeo.columbia.edu/index…