Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica
Changes in the discharge of West Antarctic ice streams are of potential concern with respect to global sea level. The six relatively thin, fast-flowing Ross ice streams are of interest as low-slope end-members among Antarctic ice streams. Extensive research has demonstrated that these "rivers o...
Main Authors: | , , |
---|---|
Format: | Text |
Language: | unknown |
Published: |
PDXScholar
2003
|
Subjects: | |
Online Access: | https://pdxscholar.library.pdx.edu/geology_fac/30 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1029&context=geology_fac |
id |
ftportlandstate:oai:pdxscholar.library.pdx.edu:geology_fac-1029 |
---|---|
record_format |
openpolar |
spelling |
ftportlandstate:oai:pdxscholar.library.pdx.edu:geology_fac-1029 2023-05-15T13:58:46+02:00 Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica Parizek, Byron R. Alley, Richard B. Hulbe, Christina L. 2003-01-01T08:00:00Z application/pdf https://pdxscholar.library.pdx.edu/geology_fac/30 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1029&context=geology_fac unknown PDXScholar https://pdxscholar.library.pdx.edu/geology_fac/30 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1029&context=geology_fac Geology Faculty Publications and Presentations Ice sheets -- Antarctica Glaciers -- Antarctica Ice shelves -- Antarctica Glaciers -- Antarctica -- Ross Ice Shelf Geology text 2003 ftportlandstate 2022-01-09T19:24:25Z Changes in the discharge of West Antarctic ice streams are of potential concern with respect to global sea level. The six relatively thin, fast-flowing Ross ice streams are of interest as low-slope end-members among Antarctic ice streams. Extensive research has demonstrated that these "rivers of ice" have a history of relatively high-frequency (óO(100) years), asynchronous discharge variations with evolving lateral boundaries. Amidst this variability, a ~1300 km grounding-line retreat has occurred since the Last GlacialMaximum. Numerical studies of Ice Stream D (Parizek and others, 2002) indicate that a proposed thermal-regulation mechanism(Clarke and Marshall, 1998; Hulbe and MacAyeal,1999; Tulaczyk and others, 2000a,b), which could buffer the West Antarctic ice sheet against complete collapse, may be over-ridden by latent-heat transport within meltwater from beneath inland ice. Extending these studies to Ice Stream A,Whillans Ice Stream and Ice Stream C suggests that further grounding-line retreat contributing to sea-level rise is possible thermodynamically. However, the efficiency of basal water distribution may be a constraint on the system. Because local thermal deficits promote basal freeze-on (especially on topographic highs), observed short-term variability is likely to persist. Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Ice Stream A Ice Stream C Ice Stream D Ross Ice Shelf West Antarctica Whillans Ice Stream Portland State University: PDXScholar Antarctic West Antarctica West Antarctic Ice Sheet Ross Ice Shelf Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) Whillans Ice Stream ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
institution |
Open Polar |
collection |
Portland State University: PDXScholar |
op_collection_id |
ftportlandstate |
language |
unknown |
topic |
Ice sheets -- Antarctica Glaciers -- Antarctica Ice shelves -- Antarctica Glaciers -- Antarctica -- Ross Ice Shelf Geology |
spellingShingle |
Ice sheets -- Antarctica Glaciers -- Antarctica Ice shelves -- Antarctica Glaciers -- Antarctica -- Ross Ice Shelf Geology Parizek, Byron R. Alley, Richard B. Hulbe, Christina L. Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica |
topic_facet |
Ice sheets -- Antarctica Glaciers -- Antarctica Ice shelves -- Antarctica Glaciers -- Antarctica -- Ross Ice Shelf Geology |
description |
Changes in the discharge of West Antarctic ice streams are of potential concern with respect to global sea level. The six relatively thin, fast-flowing Ross ice streams are of interest as low-slope end-members among Antarctic ice streams. Extensive research has demonstrated that these "rivers of ice" have a history of relatively high-frequency (óO(100) years), asynchronous discharge variations with evolving lateral boundaries. Amidst this variability, a ~1300 km grounding-line retreat has occurred since the Last GlacialMaximum. Numerical studies of Ice Stream D (Parizek and others, 2002) indicate that a proposed thermal-regulation mechanism(Clarke and Marshall, 1998; Hulbe and MacAyeal,1999; Tulaczyk and others, 2000a,b), which could buffer the West Antarctic ice sheet against complete collapse, may be over-ridden by latent-heat transport within meltwater from beneath inland ice. Extending these studies to Ice Stream A,Whillans Ice Stream and Ice Stream C suggests that further grounding-line retreat contributing to sea-level rise is possible thermodynamically. However, the efficiency of basal water distribution may be a constraint on the system. Because local thermal deficits promote basal freeze-on (especially on topographic highs), observed short-term variability is likely to persist. |
format |
Text |
author |
Parizek, Byron R. Alley, Richard B. Hulbe, Christina L. |
author_facet |
Parizek, Byron R. Alley, Richard B. Hulbe, Christina L. |
author_sort |
Parizek, Byron R. |
title |
Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica |
title_short |
Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica |
title_full |
Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica |
title_fullStr |
Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica |
title_full_unstemmed |
Subglacial thermal balance permits ongoing grounding line retreat along the Siple Coast of West Antarctica |
title_sort |
subglacial thermal balance permits ongoing grounding line retreat along the siple coast of west antarctica |
publisher |
PDXScholar |
publishDate |
2003 |
url |
https://pdxscholar.library.pdx.edu/geology_fac/30 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1029&context=geology_fac |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-64.250,-64.250,-84.450,-84.450) ENVELOPE(-155.000,-155.000,-82.000,-82.000) ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
geographic |
Antarctic West Antarctica West Antarctic Ice Sheet Ross Ice Shelf Siple Whillans Siple Coast Whillans Ice Stream |
geographic_facet |
Antarctic West Antarctica West Antarctic Ice Sheet Ross Ice Shelf Siple Whillans Siple Coast Whillans Ice Stream |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Ice Stream A Ice Stream C Ice Stream D Ross Ice Shelf West Antarctica Whillans Ice Stream |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Ice Stream A Ice Stream C Ice Stream D Ross Ice Shelf West Antarctica Whillans Ice Stream |
op_source |
Geology Faculty Publications and Presentations |
op_relation |
https://pdxscholar.library.pdx.edu/geology_fac/30 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1029&context=geology_fac |
_version_ |
1766267100532310016 |