Ross Embayment

The continent of Antarctica has two major divisions; West Antarctica in mostly western longitudes and East Antarctica in mostly eastern longitudes. East Antarctica is the larger and has a higher average elevation. Separating the two subcontinents is a lower elevation topographic region occupied by the Ross Ice Shelf and the Ross Sea. This region is referred to as the Ross Embayment. The embayment comprises an area of approximately {{convert|1137000|km2|sqmi}}. It includes the Ross Sea ({{Convert|637000|km2|sqmi}}){{Cite news|url=https://www.niwa.co.nz/fisheries/the-ross-sea-trophic-model/about-the-ross-sea|title=About the Ross Sea|date=2012-07-27|work=NIWA|access-date=2018-02-23|language=en}} and the Ross Ice Shelf (as of 2013, {{Convert|500809|km2|sqmi}}).{{Cite journal|last1=Rignot|first1=E.|last2=Jacobs|first2=S.|last3=Mouginot|first3=J.|last4=Scheuchl|first4=B.|date=2013-07-19|title=Ice-Shelf Melting Around Antarctica|journal=Science|language=en|volume=341|issue=6143|pages=266–270|doi=10.1126/science.1235798|issn=0036-8075|pmid=23765278|bibcode=2013Sci...341..266R |s2cid=206548095|url=http://www.escholarship.org/uc/item/0jm230gv|doi-access=free}} The name is most commonly used in the scientific literature,{{Cite journal|last1=Fitzgerald|first1=Paul G.|last2=Sandiford|first2=Michael|last3=Barrett|first3=Peter J.|last4=Gleadow|first4=Andrew J.W.|year=1986|title=Asymmetric extension associated with uplift and subsidence in the Transantarctic Mountains and Ross Embayment|journal=Earth and Planetary Science Letters|volume=81|issue=1|pages=67–78|doi=10.1016/0012-821x(86)90101-9|bibcode=1986E&PSL..81...67F }}{{Cite journal|last1=Webb|first1=Peter-Noel|last2=Harwood|first2=David M.|year=1991|title=Late Cenozoic glacial history of the Ross embayment, Antarctica|journal=Quaternary Science Reviews|volume=10|issue=2–3|pages=215–223|doi=10.1016/0277-3791(91)90020-u|bibcode=1991QSRv...10..215W }}{{Cite journal|last1=McKay|first1=Robert|last2=Browne|first2=Greg|last3=Carter|first3=Lionel|last4=Cowan|first4=Ellen|last5=Dunbar|first5=Gavin|last6=Krissek|first6=Lawrence|last7=Naish|first7=Tim|last8=Powell|first8=Ross|last9=Reed|first9=Josh|year=2009|title=The stratigraphic signature of the late Cenozoic Antarctic Ice Sheets in the Ross Embayment|journal=Geological Society of America Bulletin|volume=121|issue=11–12|pages=1537–1561|doi=10.1130/b26540.1|bibcode=2009GSAB..121.1537M }} at times along with the West Antarctic Rift System, which is of larger extent and has geologic meaning.{{Cite journal|last1=Behrendt|first1=J. C.|last2=LeMasurier|first2=W. E.|last3=Cooper|first3=A. K.|last4=Tessensohn|first4=F.|last5=Tréhu|first5=A.|author-link5=Anne Tréhu|last6=Damaske|first6=D.|date=1991-12-01|title=Geophysical studies of the West Antarctic Rift System|journal=Tectonics|language=en|volume=10|issue=6|pages=1257–1273|doi=10.1029/91tc00868|bibcode=1991Tecto..10.1257B |issn=1944-9194}} Because the rift system includes the embayment, the latter is considered to lie in West Antarctica.

The informal use of the name 'Ross Embayment' tends to denote a smaller region than the rift system. The embayment extends from Northern Victoria Land and the Transantarctic Mountains on the west (in East Antarctica) to the Edward VII Peninsula, Shirase Coast, and Siple Coast on the east (Marie Byrd Land in West Antarctica), and south to the grounding line of the Ross Ice Shelf.

File:Ross Ice Shelf PS.jpg). North at top. A giant iceberg on the left (west) has broken off the front of the Ross Ice Shelf. The Transantarctic Mountains cross the image from left to lower right. Original file from Commons was image-enhanced. ]]

The low elevation marine characteristic of the Ross Embayment formed since the Jurassic period.{{Cite journal|last=Barrett|first=P.J.|year=1981|title=History of the Ross Sea region during the deposition of the Beacon Supergroup 400-180 million years ago|journal=Journal of the Royal Society of New Zealand|volume=11|issue=4|pages=447–458|doi=10.1080/03036758.1981.10423334|doi-access=free}} Before that time and earlier East and West Antarctica had similar elevations and the Ross Embayment did not exist.Barrett, P. J., D. H. Elliot, and J. F. Lindsay (2013), The Beacon Supergroup (Devonian-Triassic) and Ferrar Group (Jurrasic) in the Beardmore Glacier Area, Antarctica, in Geology of the Central Transantarctic Mountains, edited by M. D. Turner and J. E. Splettstoesser, pp. 339–428, American Geopysical Union, {{doi|10.1029/AR036p0339}}.{{Cite journal|last1=Bialas|first1=Robert W.|last2=Buck|first2=W. Roger|last3=Studinger|first3=Michael|last4=Fitzgerald|first4=Paul G.|date=2007-08-01|title=Plateau collapse model for the Transantarctic Mountains–West Antarctic Rift System: Insights from numerical experiments|journal=Geology|language=en|volume=35|issue=8|pages=687–690|doi=10.1130/G23825A.1|bibcode=2007Geo....35..687B |issn=0091-7613}} The breakup of the eastern sector of Gondwana in Cretaceous time resulted in crustal extension, thinning and subsidence to form the Ross Embayment.{{Cite book|title=The West Antarctic Ice Sheet: Behavior and Environment|last1=Dalziel|first1=I. W. D.|last2=Lawver|first2=L. A.|date=2001|publisher=American Geophysical Union|isbn=9781118668320|editor-last=Alley|editor-first=Richard B.|pages=29–44|language=en|doi=10.1029/ar077p0029|editor-last2=Bindschadle|editor-first2=Robert A.}} The mechanism of crustal stretching and subsidence in the Ross Embayment has been attributed to detachment faulting.{{Cite journal|last=Fitzgerald, P.G. and Baldwin, S.L.|year=1997|title=Detachment fault model for the evolution of the Ross Embayment|journal=The Antarctic Region: Geological Evolution and Processes|pages=555–564}} Extension between East and West Antarctica totals about 500 kilometers. Half of this occurred prior to sea floor spreading that separated the New Zealand microcontinents (Zealandia) from Antarctica beginning at 85 million years.{{Cite journal|last=Lawver, L.A. and Gahagan, L.M.|year=1994|title=Constraints on timing of extension in the Ross Sea region|journal=Terra Antartica|volume=1|issue=3|pages=545–552}} The remaining extension occurred in the Central Trough, Northern Basin, and Victoria Land Basin in the western Ross Sea before late Miocene time.{{Cite journal|title=Tectonic History of Mid-Miocene to Present Southern Victoria Land Basin, Inferred from Seismic Stratigraphy in McMurdo Sound, Antarctica; USGS Open-File Report 2007-1047, Short Research Paper 049|journal=Tectonic History of Mid-Miocene to Present Southern Victoria Land Basin, Inferred from Seismic Stratigraphy in Mcmurdo Sound, Antarctica|volume=2007|issue=1047srp049|last=Henrys, S., T. Wilson, J.M. Whittaker, C. Fielding, J. Hall, and T. Naish|year=2007|doi=10.3133/of2007-1047.srp049}} Subsidence continued as mantle under the Ross Embayment cooled.{{Cite journal|last1=Wilson|first1=Douglas S.|last2=Luyendyk|first2=Bruce P.|date=2009-08-01|title=West Antarctic paleotopography estimated at the Eocene-Oligocene climate transition|journal=Geophysical Research Letters|language=en|volume=36|issue=16|pages=L16302|doi=10.1029/2009gl039297|bibcode=2009GeoRL..3616302W |s2cid=163074|issn=1944-8007}}

• Ross Island
• McMurdo Station
• Scott Base
• Roosevelt Island, Antarctica
• Iceberg B-15
• Iceberg C-19

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Category:Geography of Antarctica