Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521
The West Antarctic Ice Sheet (WAIS) is currently thinning and retreating because shifting oceanic currents are transporting warmer waters to the ice margin, which could lead to a collapse of the ice sheet and global sea level rise. International Ocean Discovery Program (IODP) Expedition 374 sailed t...
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ftunivmassamh:oai:scholarworks.umass.edu:masters_theses_2-1988 2024-04-28T08:02:03+00:00 Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 Seidenstein, Julia 2020-07-15T18:08:02Z application/pdf https://scholarworks.umass.edu/masters_theses_2/937 https://doi.org/10.7275/17658004 https://scholarworks.umass.edu/context/masters_theses_2/article/1988/viewcontent/Seidenstein_Julia_MS_Thesis_v12.pdf unknown ScholarWorks@UMass Amherst https://scholarworks.umass.edu/masters_theses_2/937 doi:10.7275/17658004 https://scholarworks.umass.edu/context/masters_theses_2/article/1988/viewcontent/Seidenstein_Julia_MS_Thesis_v12.pdf Masters Theses Paleoceonography Foraminifera Ross Sea Antarctica Plio-Pleistocene Geology text 2020 ftunivmassamh https://doi.org/10.7275/17658004 2024-04-03T14:59:02Z The West Antarctic Ice Sheet (WAIS) is currently thinning and retreating because shifting oceanic currents are transporting warmer waters to the ice margin, which could lead to a collapse of the ice sheet and global sea level rise. International Ocean Discovery Program (IODP) Expedition 374 sailed to the Ross Sea in 2018 to study the history of the WAIS over the last 20 million years. Previous geologic drilling projects into Ross Sea sediments that record the history of the WAIS (DSDP Leg 28, RISP, MSSTS, Cape Roberts Drilling Project, ANDRILL), as well as modeling studies, show considerable variability of ice-sheet extent during the Neogene and Quaternary including ice sheet collapse during times of extreme warmth. The purpose of this study is to reconstruct paleoenvironments on the Ross Sea and confirm modeling studies that show warming waters in the Southern Ocean led to the loss of Antarctic ice in the past. Site U1523 is a key site as it is located close to the shelf break and therefore sensitive to warm water incursions from modified Circumpolar Deep Water (mCDW) onto the Ross Sea continental shelf as the Antarctic Slope Current weakens with a changing climate. Shelf sites U1522 and U1521 provide perspective for what was happening closer to the Ross Ice Shelf. Multiple incursions of subpolar or temperate planktic foraminifera taxa occurred during the latest Pliocene and early Pleistocene prior to ~1.8 Ma at Site U1523 indicating times of warmer than present conditions and less ice in the Ross Sea. Especially high abundances of foraminifera are recorded in the late Pleistocene associated with Marine Isotope Stage (MIS) 31, MIS 11, and MIS 5e might also indicate reduced ice and relatively warmer conditions. The interval of abundant foraminifera around MIS 31 (MIS 37 to 21) suggests multiple warmer interglacials during the Mid-Pleistocene Transition (MPT). A change in benthic foraminiferal assemblages and a large increase in foraminiferal fragments after the MPT (~800 ka) indicate stronger currents at the ... Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Ross Sea Southern Ocean University of Massachusetts: ScholarWorks@UMass Amherst |
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Open Polar |
collection |
University of Massachusetts: ScholarWorks@UMass Amherst |
op_collection_id |
ftunivmassamh |
language |
unknown |
topic |
Paleoceonography Foraminifera Ross Sea Antarctica Plio-Pleistocene Geology |
spellingShingle |
Paleoceonography Foraminifera Ross Sea Antarctica Plio-Pleistocene Geology Seidenstein, Julia Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 |
topic_facet |
Paleoceonography Foraminifera Ross Sea Antarctica Plio-Pleistocene Geology |
description |
The West Antarctic Ice Sheet (WAIS) is currently thinning and retreating because shifting oceanic currents are transporting warmer waters to the ice margin, which could lead to a collapse of the ice sheet and global sea level rise. International Ocean Discovery Program (IODP) Expedition 374 sailed to the Ross Sea in 2018 to study the history of the WAIS over the last 20 million years. Previous geologic drilling projects into Ross Sea sediments that record the history of the WAIS (DSDP Leg 28, RISP, MSSTS, Cape Roberts Drilling Project, ANDRILL), as well as modeling studies, show considerable variability of ice-sheet extent during the Neogene and Quaternary including ice sheet collapse during times of extreme warmth. The purpose of this study is to reconstruct paleoenvironments on the Ross Sea and confirm modeling studies that show warming waters in the Southern Ocean led to the loss of Antarctic ice in the past. Site U1523 is a key site as it is located close to the shelf break and therefore sensitive to warm water incursions from modified Circumpolar Deep Water (mCDW) onto the Ross Sea continental shelf as the Antarctic Slope Current weakens with a changing climate. Shelf sites U1522 and U1521 provide perspective for what was happening closer to the Ross Ice Shelf. Multiple incursions of subpolar or temperate planktic foraminifera taxa occurred during the latest Pliocene and early Pleistocene prior to ~1.8 Ma at Site U1523 indicating times of warmer than present conditions and less ice in the Ross Sea. Especially high abundances of foraminifera are recorded in the late Pleistocene associated with Marine Isotope Stage (MIS) 31, MIS 11, and MIS 5e might also indicate reduced ice and relatively warmer conditions. The interval of abundant foraminifera around MIS 31 (MIS 37 to 21) suggests multiple warmer interglacials during the Mid-Pleistocene Transition (MPT). A change in benthic foraminiferal assemblages and a large increase in foraminiferal fragments after the MPT (~800 ka) indicate stronger currents at the ... |
format |
Text |
author |
Seidenstein, Julia |
author_facet |
Seidenstein, Julia |
author_sort |
Seidenstein, Julia |
title |
Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 |
title_short |
Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 |
title_full |
Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 |
title_fullStr |
Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 |
title_full_unstemmed |
Plio-Pleistocene Paleoceonography of the Ross Sea, Antarctica Based on Foraminifera from IODP sites U1523, U1522, and U1521 |
title_sort |
plio-pleistocene paleoceonography of the ross sea, antarctica based on foraminifera from iodp sites u1523, u1522, and u1521 |
publisher |
ScholarWorks@UMass Amherst |
publishDate |
2020 |
url |
https://scholarworks.umass.edu/masters_theses_2/937 https://doi.org/10.7275/17658004 https://scholarworks.umass.edu/context/masters_theses_2/article/1988/viewcontent/Seidenstein_Julia_MS_Thesis_v12.pdf |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Ross Sea Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Ross Sea Southern Ocean |
op_source |
Masters Theses |
op_relation |
https://scholarworks.umass.edu/masters_theses_2/937 doi:10.7275/17658004 https://scholarworks.umass.edu/context/masters_theses_2/article/1988/viewcontent/Seidenstein_Julia_MS_Thesis_v12.pdf |
op_doi |
https://doi.org/10.7275/17658004 |
_version_ |
1797573542825426944 |