There is a serious lack of knowledge of physical processes within and beneath glaciers and ice sheets, at a time when modeling needs are acute for predicting ice sheet and glacier movement, and associated sea-level changes. Under this grant, a network of wirelessly interconnected geophysical sensors (so-called "geobricks") will be developed that will simultaneously include: seismic reflection and refraction imaging, radar imaging at high- and low-frequencies, and a dense array of continuously operating GPS receivers. Along with the "geobricks", a source, both radar and seismic, will be developed which can be towed by snowmobiles. With this network, measurements can be made of: basal roughness, subglacial sedimentary and hydrologic conditions, englacial crystal fabric, accumulation rate variability, and the "4D" (time and space) variability of the ice sheet flow field
