Diverse landscapes beneath Pine Island Glacier influence ice flow

Area of Science:

• Glaciology
• Earth Science
• Climate Science

Background:

• The Pine Island Glacier (PIG) in West Antarctica is a major contributor to global sea-level rise, with its retreat accelerating in recent decades.
• Accurate projections of future sea-level rise necessitate improved ice-sheet models that incorporate robust parameterization of basal traction.
• Current models often estimate basal traction using surface velocity, lacking detailed understanding of the underlying ice-bed interface processes like friction and form drag.

Purpose of the Study:

• To investigate the detailed subglacial topography of the Pine Island Glacier using high-resolution ice-penetrating radar.
• To assess the impact of diverse subglacial landscapes on ice flow dynamics.
• To highlight challenges for current ice-sheet modeling and future sea-level rise predictions.

Main Methods:

• Acquisition of high-resolution bed topography maps using ice-penetrating radar across key areas of the Pine Island Glacier.
• Analysis of the acquired radar data to characterize the subglacial landscape at the ice-bed interface.
• Comparison of high-resolution topography data with lower-resolution data used in existing ice-sheet models.

Main Results:

• High-resolution radar data reveal a more complex and contrasting subglacial topography than previously represented in ice-sheet models.
• The diverse subglacial landscapes identified have a demonstrable impact on the flow of the Pine Island Glacier.
• Existing models may not adequately capture the influence of detailed bed topography on ice flow.

Conclusions:

• Detailed understanding of subglacial topography is crucial for accurate ice flow modeling.
• The complexity of the Pine Island Glacier's bed presents a significant challenge for current ice-sheet models.
• Improved subglacial data are essential for refining projections of future sea-level rise due to ice-sheet loss.