Proposed Survey Objectives

We propose to address a major fundamental objective of the ASE Science Plan by conducting comprehensive aerogeophysical surveys covering the entirety of the major glacial drainage basins of the ASE. These surveys will have sufficient coverage to include the entirety of the catchments for both the Pine Island and Thwaites Glaciers and the hypothesized boundaries of all of the major crustal blocks bounding the Byrd Subglacial Basin beneath the ASE drainages. Our surveys will also have sufficient density to identify critical ice dynamic transitions within the ASE. These surveys are the critical next step in the sequence suggested by the ASE Science Plan for advancing understanding of the ASE sector and are required to address the science objectives. Providing these geophysical results to the broader ASE research community is the primary objective of our proposed research.

Results from these surveys will include:

* Flow-line parallel radar and laser profiles to support detailed flow-band modeling.

* Profiles of surface elevations for validation and/or change detection with anticipated ICESAT laser altimetry measurements.

* Fully gridded maps of ice sheet volume characteristics (surface elevation, ice thickness and accumulation rate) to support future map-plane and 3D ice dynamics modeling.

* Maps of englacial characteristics (surface and bottom crevasses, internal layer topography) and of subglacial interface characteristics (roughness statistics and radar reflectivity) to identify critical regions of ice dynamic transition.

* Maps of bed elevation to identify the distribution of any preexisting marine sedimentary drape (that is a controllingfactor for Siple Coast ice streams).

* Maps of subglacial geophysical characteristics (free-air/Bouguer gravity and magnetic field anomaly) to support geologic classification and the estimation of geothermal heat flux for modeling of ice sheet dynamics.

Our objectives and timetable for dissemination of our aerogeophysical results:

* The ASE research community will need timely access to our preliminary results in order to plan follow-on studies. We will supply preliminary maps and grids of surface elevation, ice thickness, free-air gravity and geomagnetic anomalies to funded ASE investigators within seven months of their collection. These maps and grids will enable planning for operations in the subsequent field season.

* The broader community will require access to these data to stimulate research and prepare proposals. To accomplish this, we will provide to the National Snow and Ice Data Center and the National Geophysics Data Center appropriate maps, grids and profiles of surface elevation, bed elevation, ice thickness, free-air gravity and geomagnetic anomalies within 19 months of completion of each survey.

* We will also integrate our results with those of our BAS colleagues within six months of the completion of the PIB survey; present results at the NSF WAIS Workshops held in the autumn of each year; assemble and package our raw profile-based data for access via the web within two years of their collection; and prepare data acquisition and analysis manuscripts for publication within 19 months of the completion of each survey.