Radiostratigraphy of the Greenland Ice Sheet
Project Goals: This is a two-part project (each part seperately funded by NASA and NSF) to use the radar-derived internal layers in Greenland to understand the thermal state of the bed (NASA) and to use the layers as boundary conditions in ice sheet models.
Objectives: Understanding the history and evolution of ice sheets in response to climate change is an area of active research, motivated by the need to improve estimates of their contribution to modern sea-level rise. The Greenland Ice Sheet (GIS), a major component of the Arctic system, is particularly vulnerable to climate change due to both its physical setting and direct ocean– atmosphere–ice interactions. Both its variability in extent across glacial–interglacial cycles and recent observations of surface-melt-induced acceleration emphasize this sensitivity. Predictive ice-sheet models are our best tools for understanding the cumulative effects of these and other processes upon the GIS. However, these models lack detailed knowledge of the GIS basal boundary condition, which is a critical control upon ice flow. They also do not take advantage of the wealth of information contained with its internal radiostratigraphy, but that will soon change and become a key component of their validation and application as predictive tools.
To address this need for new constraints on ice-sheet models, we will develop, validate, and analyze a new radiostratigraphic database of the GIS. The database will be derived from existing (e.g., PARCA, CReSIS) and ongoing (e.g., IceBridge) airborne radar-sounding campaigns. Our research objectives are as follows:
- Development of novel automated layer-picking techniques
- Holocene surface and basal mass balance determination of the GIS
- Development of a dated radiostratigraphic model of the GIS
- Detection of regions of basal melting and sliding across the GIS
- Delineation of frozen and thawed regions across the GIS bed