NSF Award Search: Award # 0944597 - Collaborative Research: Byrd Glacier Flow Dynamics

National Science Foundation

Award Abstract # 0944597

Collaborative Research: Byrd Glacier Flow Dynamics

NSF Org:	OPP Office of Polar Programs (OPP)
Awardee:	UNIVERSITY OF KANSAS CENTER FOR RESEARCH, INC.
Initial Amendment Date:	August 26, 2010
Latest Amendment Date:	August 26, 2010
Award Number:	0944597
Award Instrument:	Standard Grant
Program Manager:	Julie Palais OPP Office of Polar Programs (OPP) GEO Directorate For Geosciences
Start Date:	August 15, 2010
End Date:	July 31, 2014 (Estimated)
Total Intended Award Amount:	$412,381.00
Total Awarded Amount to Date:	$412,381.00
Funds Obligated to Date:	FY 2010 = $412,381.00
History of Investigator:	Leigh Stearns (Principal Investigator) stearns@ku.edu (785)864-4202 Cornelis van der Veen (Co-Principal Investigator)
Awardee Sponsored Research Office:	University of Kansas Center for Research Inc 2385 IRVING HILL RD Lawrence KS US 66045-7552 (785)864-3441
Sponsor Congressional District:	02
Primary Place of Performance:	University of Kansas Center for Research Inc 2385 IRVING HILL RD Lawrence KS US 66045-7552
Primary Place of Performance Congressional District:	02
DUNS ID:	076248616
Parent DUNS ID:	007180078
NSF Program(s):	ANT Glaciology, EPSCoR Co-Funding
Primary Program Source:	040100 NSF RESEARCH & RELATED ACTIVIT 040100 NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s):	0000, 9150, OTHR
Program Element Code(s):	5116, 9150
Award Agency Code:	4900
Fund Agency Code:	4900
CFDA Number(s):	47.078

ABSTRACT

Stearns/0944597

This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier's flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society's need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

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Van der Veen, C. J. L. A. Stearns J. Johnson B. Csatho "Flow dynamics of Byrd Glacier, East Antarctica" Journal of Glaciology , v.60 , 2014 , p.1053 10.3189/2014JoG14J052

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

The Intellectual Merit of this project is to improve prognostic ice sheet models by understanding the sensitivity of Antarctic outlet glaciers to a range of dynamic processes. We achieved this goal through detailed modeling of the trunk of Byrd Glacier, finding several new results.

Dynamics in the across-flow direction are more complicated than originally believed, suggesting a possible connection to basal erosion rates.
The grounding line of Byrd Glacier is located in a region where the bed slopes inland. However, unlike other glaciers with this configuration (e.g. Pine Island Glacier), the grounding line at Byrd Glacier did not retreat when the glacier accelerated 10% following the drainage of two subglacial lakes in the catchment area. This result suggests that, while Byrd Glacier may be sensitive to changes at its basal boundary, it is not doomed for irreversible retreat like other glaciers in Antarctica.

We were surprised to find numerous crevasse fields on the East Antarctic Plateau, a region where ice is under low-stresses. By mapping the location of crevasse fields above 2500 m elevation using satellite mosaics, we identified that crevasses are associated with area of persistent wind-glaze, and that stress is not a good indicator for crevasse initiation. Instead, we hypothesize that crevasses are growing from macro-cracks known to be forming within glazed surfaces, and which can extend to depths of over 20 m. This work points to local environmental and climatological conditions as a primary control on crevassing in the East Antarctic Plateau, which is unlike current hypotheses on crevasse initiation. Given the large scale of the crevasses and the low accumulation rates surrounding them, modern atmosphere may be actively mixing into the pores of ice that is hundreds or thousands of years old. The low accumulation and cold temperatures of glacial maxima might permit extensive crevassing over the ice sheet, which could explain apparent ice-air age differences in deep ice cores.

Results from this study provide important information about the stability of Byrd Glacier. The Broader Impacts of this work include improvements of current ice sheet models that need information regarding the flow dynamics of East Antarctic outlet glaciers. This project supported a PhD student and an undergraduate student worker. Through this grant they gained valuable field experience and strengthened their skills in computer programming, satellite remote sensing, numerical modeling and radar interpretation.

Last Modified: 10/29/2014
Modified by: Leigh A Stearns

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