Research Objectives:
Ice from the West Antarctic Ice Sheet (WAIS) flows to the sea through a number of ice streams but the factors controlling the flow of the ice streams are not well understood. Prior work demonstrated the surprisingly sensitive response of the Siple Coast ice streams' flow speed to tide height beneath the Ross Ice Shelf.
Measuring the response of the ice streams to the rise and fall of the tide is an excellent natural experiment that researchers can use to improve understanding of controls on the ice streams, and improve their to model the WAIS. To measure in detail the flow-speed response to tidal forcing project team members will install an array of GPS receivers on the ice plain of Whillans Ice Stream up to tributaries B2 and B1. They will conduct ground geophysics (seismics and radar) in conjunction with GPS to continuously monitor the state of the base of ice stream.
This second season of the TIDES project will focus on the high frequency, fine scale motion of Whillans Ice Stream. Working in two groups, Team One will operate from Siple Dome to install the "backbone" array of GPS receivers and cache snowmobiles, sleds, science equipment and fuel at B140 and B010 for use by Team Two. Team Two will conduct ground geophysical experiments at B140 including a tight GPS array, a seismic array, and ground radar at various locations on the ice plain of Whillans Ice Stream. At the end of the field season, Team Two will retrieve the backbone array and retro all equipment and trash to Siple Dome for return to McMurdo.
Improved knowledge of ice-stream behavior will contribute to researchers' ability to assess the potential for rapid ice-sheet change affecting global sea levels. Results will be disseminated through scientific publications and talks at professional meetings, as well as contacts with the press, university classes, visits to schools and community groups, and other activities.
