Totten Glacier Explained

Totten Glacier
Photo Width:250px
Map:Antarctica
Mark:Blue_pog.svg
Label:Totten Glacier
Location:Wilkes Land
Coordinates:-67°N 116.3333°W

Totten Glacier is a large glacier draining a major portion of the East Antarctic Ice Sheet, through the Budd Coast of Wilkes Land in the Australian Antarctic Territory. The catchment drained by the glacier is estimated at 538000km2,[1] extending approximately 1100km (700miles) into the interior and holds the potential to raise sea level by at least 3.5m (11.5feet).[2] Totten drains northeastward from the continental ice but turns northwestward at the coast where it terminates in a prominent tongue close east of Cape Waldron. It was first delineated from aerial photographs taken by USN Operation Highjump (1946–47), and named by Advisory Committee on Antarctic Names (US-ACAN) for George M. Totten, midshipman on of the United States Exploring Expedition (1838–42), who assisted Lieutenant Charles Wilkes with correction of the survey data obtained by the expedition.

Totten Ice Shelf is a 6200km2 floating portion of Totten Glacier, laterally bounded by the Aurora Subglacial Basin to the south and Law Dome to the north. The ice shelf exists at the confluence of the two main grounded tributaries of Totten Glacier, its base lies 2500m (8,200feet) below sea level near the grounding line of the western tributary, and the ice shelf surface is characterized by longitudinal channels and transverse fractures.[3] [4] Totten Ice Shelf is of glaciological interest because it buttresses the flow of grounded ice while coupling the ice basin to ocean processes such as ocean warming.[5]

Totten Glacier Tongue (-66.5833°N 121°W) is a small glacier tongue extending seaward from Totten Glacier. Delineated from air photos taken by U.S. Navy Operation Highjump (1946–47) and named by US-ACAN in association with Totten Glacier.

Melt

Totten Glacier drains the Aurora Subglacial Basin, which is largely grounded below sea level[6] and is subject to marine ice sheet instability, meaning melt near the grounding line could lead to runaway glacier retreat and a significant contribution to sea level rise.

Surface altimetry measurements from Interferometric synthetic-aperture radar suggest that Totten Glacier lost mass from 1992 to 2006[7] and gravity measurements obtained by the Gravity Recovery and Climate Experiment satellite indicate mass loss has continued through at least 2016.[8] The ICESat laser altimeter measured surface lowering of the grounded[9] and floating[10] [11] [12] portions of Totten Glacier from 2003 to 2009; however, longer term observations of the floating ice shelf show interannual variability of thickness[13] and velocity.[14] [15] [16]

Totten Glacier loses mass primarily through melt at its ice shelf base, and melt is influenced by the availability of ocean heat entering the cavity below the ice shelf.[17] [18] Warm, modified Circumpolar deep water enters the Totten Ice Shelf cavity through submarine canyons,[19] driven by wind processes at the nearby continental shelf break. Wind processes and sea ice formation along the Sabrina Coast have been linked to variability in Totten Ice Shelf basal melt and calving rates.[20]

A study in 2019 (published 2023) at the outfall of the Totten Glacier in East Antarctica showed that water at depth, above freezing temperature, was melting the under-side of the glacier.[21] [22]

See also

References

-67°N 136°W

Notes and References

  1. Roberts . etal. Jason. Refined broad-scale sub-glacial morphology of Aurora Subglacial Basin and East Antarctica derived by an ice-dynamics-based interpolation scheme. The Cryosphere. 2011. 5. 3. 551–560. 10.5194/tc-5-551-2011. 2011TCry....5..551R. free. 2152/41173. free.
  2. Greenbaum. J. S.. Blankenship. D. D.. Young. D. A.. Richter. T. G.. Roberts. J. L.. Aitken. A. R. A.. Legresy. B.. Schroeder. D. M.. Warner. R. C.. 2015. Ocean access to a cavity beneath Totten Glacier in East Antarctica. Nature Geoscience. En. 8. 4. 294–298. 10.1038/ngeo2388. 1752-0908. 2015NatGe...8..294G.
  3. Greene. C. A.. Blankenship. D. D.. 2018. A Method of Repeat Photoclinometry for Detecting Kilometer-Scale Ice Sheet Surface Evolution. IEEE Transactions on Geoscience and Remote Sensing. 56. 4. 2074–2082. 10.1109/TGRS.2017.2773364. 2018ITGRS..56.2074G. 4348022. 0196-2892.
  4. Dow. Christine F.. Lee. Won Sang. Greenbaum. Jamin S.. Greene. Chad A.. Blankenship. Donald D.. Poinar. Kristin. Forrest. Alexander L.. Young. Duncan A.. Zappa. Christopher J.. 2018-06-01. Basal channels drive active surface hydrology and transverse ice shelf fracture. Science Advances. en. 4. 6. eaao7212. 10.1126/sciadv.aao7212. 2375-2548. 6007161. 29928691. 2018SciA....4.7212D.
  5. Greene. Chad A.. Young. Duncan A.. Gwyther. David E.. Galton-Fenzi. Benjamin K.. Blankenship. Donald D.. 2018-09-06. Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing. The Cryosphere. en. 12. 9. 2869–2882. 10.5194/tc-12-2869-2018. 1994-0416. 2018TCry...12.2869G. free.
  6. Young. Duncan A.. Wright. Andrew P.. Roberts. Jason L.. Warner. Roland C.. Young. Neal W.. Greenbaum. Jamin S.. Schroeder. Dustin M.. Holt. John W.. Sugden. David E.. 2011. A dynamic early East Antarctic Ice Sheet suggested by ice-covered fjord landscapes. Nature. En. 474. 7349. 72–75. 10.1038/nature10114. 21637255. 1476-4687. 2011Natur.474...72Y. 4425075.
  7. Rignot. Eric. etal. 2008. Recent Antarctic ice mass loss from radar interferometry and regional climate modelling. Nature Geoscience. 1. 2019. 106–110. 2008NatGe...1..106R. 10.1038/ngeo102.
  8. Web site: Gravimetric Mass Balance. February 7, 2018.
  9. Pritchard. Hamish D.. Arthern. Robert J.. Vaughan. David G.. Edwards. Laura A.. 2009. Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets. Nature. En. 461. 7266. 971–975. 10.1038/nature08471. 19776741. 1476-4687. 2009Natur.461..971P. 4334500.
  10. Pritchard. H. D.. Ligtenberg. S. R. M.. Fricker. H. A.. Vaughan. D. G.. Broeke. M. R. van den. Padman. L.. 2012. Antarctic ice-sheet loss driven by basal melting of ice shelves. Nature. En. 484. 7395. 502–505. 10.1038/nature10968. 22538614. 1476-4687. 2012Natur.484..502P. 205228290.
  11. Rignot. E.. Jacobs. S.. Mouginot. J.. Scheuchl. B.. 2013-07-19. Ice-Shelf Melting Around Antarctica. Science. en. 341. 6143. 266–270. 10.1126/science.1235798. 0036-8075. 23765278. 2013Sci...341..266R. 206548095. free.
  12. Depoorter. M. A.. Bamber. J. L.. Griggs. J. A.. Lenaerts. J. T. M.. Ligtenberg. S. R. M.. Broeke. M. R. van den. Moholdt. G.. 2013. Calving fluxes and basal melt rates of Antarctic ice shelves. Nature. En. 502. 7469. 89–92. 10.1038/nature12567. 24037377. 1476-4687. 2013Natur.502...89D. 4462940.
  13. Paolo. Fernando S.. Fricker. Helen A.. Padman. Laurie. 2015-04-17. Volume loss from Antarctic ice shelves is accelerating. Science. en. 348. 6232. 327–331. 10.1126/science.aaa0940. 0036-8075. 25814064. 2015Sci...348..327P. 206632749. free.
  14. Greene. Chad A.. Blankenship. Donald D.. Gwyther. David E.. Silvano. Alessandro. Wijk. Esmee van. 2017-11-01. Wind causes Totten Ice Shelf melt and acceleration. Science Advances. en. 3. 11. e1701681. 10.1126/sciadv.1701681. 29109976. 5665591. 2375-2548. 2017SciA....3E1681G.
  15. Li. Xin. Rignot. Eric. Mouginot. Jeremie. Scheuchl. Bernd. 2016-06-28. Ice flow dynamics and mass loss of Totten Glacier, East Antarctica, from 1989 to 2015. Geophysical Research Letters. en. 43. 12. 2016GL069173. 10.1002/2016gl069173. 1944-8007. 2016GeoRL..43.6366L.
  16. Roberts. Jason. Galton-Fenzi. Benjamin K.. Paolo. Fernando S.. Donnelly. Claire. Gwyther. David E.. Padman. Laurie. Young. Duncan. Warner. Roland. Greenbaum. Jamin. Ocean forced variability of Totten Glacier mass loss. Geological Society, London, Special Publications. 461. 1. 175–186. 10.1144/sp461.6. 2018GSLSP.461..175R. 2018. 55567382. free.
  17. Khazendar. A.. Schodlok. M. P.. Fenty. I.. Ligtenberg. S. R. M.. Rignot. E.. Broeke. M. R. van den. 2013-12-05. Observed thinning of Totten Glacier is linked to coastal polynya variability. Nature Communications. En. 4. 2857. 10.1038/ncomms3857. 24305466. 2013NatCo...4.2857K. free.
  18. Gwyther. D. E.. Galton-Fenzi. B. K.. Hunter. J. R.. Roberts. J. L.. 2014-05-06. Simulated melt rates for the Totten and Dalton ice shelves. Ocean Sci.. 10. 3. 267–279. 10.5194/os-10-267-2014. 1812-0792. 2014OcSci..10..267G. free.
  19. Rintoul. Stephen Rich. Silvano. Alessandro. Pena-Molino. Beatriz. van Wijk. Esmee. Rosenberg. Mark. Greenbaum. Jamin Stevens. Blankenship. Donald D.. 16 December 2016. Ocean heat drives rapid basal melt of the Totten Ice Shelf. Science Advances. 2. 12. e1601610. 10.1126/sciadv.1601610. 28028540. 5161426. 2016SciA....2E1610R.
  20. Miles. Bertie W. J.. Stokes. Chris R.. Jamieson. Stewart S. R.. 2016-05-01. Pan–ice-sheet glacier terminus change in East Antarctica reveals sensitivity of Wilkes Land to sea-ice changes. Science Advances. en. 2. 5. e1501350. 10.1126/sciadv.1501350. 27386519. 4928901. 2375-2548. 2016SciA....2E1350M.
  21. https://doi.org/10.1029/2022GL097864 Helicopter-Based Ocean Observations Capture Broad Ocean Heat Intrusions Toward the Totten Ice Shelf
  22. https://www.abc.net.au/news/2023-09-13/antarctic-sea-ice-probes-dropped-from-helicopter-totten-glacier/102844512 Antarctic helicopter mission helps confirm Totten Glacier melting from below due to warm water

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