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 |
| Summary: | 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. |
|---|