|
Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams Entry ID: hulbe_0440670 |
|||
|
[
Update this Record
]
|
Summary
|
Abstract:
This award supports a three year project to develop the tools required to interpret complex patterns of flow features on the Ross Ice Shelf, which record the discharge history the ice streams flowing east off of the West Antarctic Ice Sheet. This work builds on previous research that used flow features visible in satellite image mosaics and numerical models of ice shelf flow to detect changes in grounding zone dynamics and redirection of ice stream outlets over hundreds of years.
Purpose: Recently observed changes on Whillans Ice Stream fit within this framework. The pattern of redirection is driven by the influence of rapid downstream thinning on the basal thermal gradient in the ice and associated "sticky spot" (ice rise) formation. In pursuing this work, the investigators recognized other records of discharge variation on the shelf that can be used to build a more complete history and understanding of ice-stream discharge variability. The intellectual merit of the proposed work lies in the fact that these records, including fracture patterns and spatial variation in ice thickness, when understood in the proper context, will yield quantitative information about the timing and dynamics of ice stream slowdowns, grounding line retreat, and the relative history of discharge between the ice streams. New tools will help further constrain this history. The laser altimeter on NASA's IceSAT has improved our knowledge of the surface elevation of Antarctic ice. IceSAT surface elevations provide a high-resolution map of ice-shelf thickness that, along with provenance maps from ice-shelf image mosaics, will be used to estimate the volumes of ice involved in past ice-stream discharge events (slowdowns, redirections, and so on). This project will develop new numerical models for fracture propagation; these will allow past variations in ice-shelf stress state to be investigated. Together, the dynamic and volume-flux histories will provide a powerful set of observations for understanding past variations in ice stream discharge and the underlying physical processes. The broader impacts of this project center on how it contributes to the ability to estimate West Antarctic contributions to global sea level rise and to answer outstanding questions about the causes of millennial and longer-scale evolution of ice streams. This work will provide a history of the most complex record of ice discharge known. |
Related URL
|
Link:
VIEW RELATED INFORMATION
Description: The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program. |
Location Keywords
|
CONTINENT
> ANTARCTICA
GEOGRAPHIC REGION > POLAR |
Science Keywords
| CRYOSPHERE >SNOW/ICE >ICE MOTION [Definition] |
| CRYOSPHERE >GLACIERS/ICE SHEETS >ICE SHEETS [Definition] |
| CRYOSPHERE >SNOW/ICE [Definition] |
| CRYOSPHERE >GLACIERS/ICE SHEETS [Definition] |
| CRYOSPHERE >GLACIERS/ICE SHEETS >ABLATION ZONES/ACCUMULATION ZONES [Definition] |
| CRYOSPHERE >GLACIERS/ICE SHEETS >GLACIER MASS BALANCE/ICE SHEET MASS BALANCE [Definition] |
| CRYOSPHERE >GLACIERS/ICE SHEETS >GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY [Definition] |
| CRYOSPHERE >GLACIERS/ICE SHEETS >GLACIER MOTION/ICE SHEET MOTION [Definition] |
ISO Topic Category
|
CLIMATOLOGY/METEOROLOGY/ATMOSPHERE
|
Platform
| LABORATORY [Information] |
| FIELD INVESTIGATION [Information] |
Keywords
| Antarctica |
| Fracture Patterns |
| Grounding Line Migration |
| Ice Streams |
| Kamb Ice Streams |
| Whillans Ice Streams |
Data Set Progress
| COMPLETE |
Originating Center
| Portland State University, Department of Geology |
Data Center
|
National Snow and Ice Data Center
[Information]
Data Center URL: http://nsidc.org
| |||
|
NSIDC Antarctic Glaciological Data Center
[Information]
Data Center URL: http://nsidc.org/agdc/
| |||
Personnel
|
CHRISTINA
HULBE Role: INVESTIGATOR Phone: 503-725-3388 Email: chulbe at pdx.edu Contact Address: Portland State University Department of Geology PO Box 751 City: Portland Province or State: OR Postal Code: 97202 Country: USA |
|
NSIDC AGDC
USER SERVICES Role: TECHNICAL CONTACT Phone: +1 (303) 492-6199 Fax: +1 (303) 492-2468 Email: nsidc at nsidc.org Contact Address: National Snow and Ice Data Center CIRES, 449 UCB University of Colorado City: Boulder Province or State: CO Postal Code: 80309-0449 Country: USA |
Creation and Review Dates
DIF Creation Date:
2011-07-02
Last DIF Revision Date:
2011-07-07
| [ Update this Record ] |
