A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic
Climate during the last glacial period was marked by abrupt instability on millennial timescales that included large swings of temperature in and around Greenland (Daansgard–Oeschger events) and smaller, more gradual changes in Antarctica (AIM events). Less is known about the existence and nature of...
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Copernicus Publications
2023
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Online Access: | https://doi.org/10.5194/cp-19-607-2023 https://doaj.org/article/cb19140ae34548988981f552f7c5d839 |
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ftdoajarticles:oai:doaj.org/article:cb19140ae34548988981f552f7c5d839 2023-05-15T14:13:33+02:00 A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic D. A. Hodell S. J. Crowhurst L. Lourens V. Margari J. Nicolson J. E. Rolfe L. C. Skinner N. C. Thomas P. C. Tzedakis M. J. Mleneck-Vautravers E. W. Wolff 2023-03-01T00:00:00Z https://doi.org/10.5194/cp-19-607-2023 https://doaj.org/article/cb19140ae34548988981f552f7c5d839 EN eng Copernicus Publications https://cp.copernicus.org/articles/19/607/2023/cp-19-607-2023.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-19-607-2023 1814-9324 1814-9332 https://doaj.org/article/cb19140ae34548988981f552f7c5d839 Climate of the Past, Vol 19, Pp 607-636 (2023) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2023 ftdoajarticles https://doi.org/10.5194/cp-19-607-2023 2023-03-19T01:30:18Z Climate during the last glacial period was marked by abrupt instability on millennial timescales that included large swings of temperature in and around Greenland (Daansgard–Oeschger events) and smaller, more gradual changes in Antarctica (AIM events). Less is known about the existence and nature of similar variability during older glacial periods, especially during the early Pleistocene when glacial cycles were dominantly occurring at 41 kyr intervals compared to the much longer and deeper glaciations of the more recent period. Here, we report a continuous millennially resolved record of stable isotopes of planktic and benthic foraminifera at IODP Site U1385 (the “Shackleton Site”) from the southwestern Iberian margin for the last 1.5 million years, which includes the Middle Pleistocene Transition (MPT). Our results demonstrate that millennial climate variability (MCV) was a persistent feature of glacial climate, both before and after the MPT. Prior to 1.2 Ma in the early Pleistocene, the amplitude of MCV was modulated by the 41 kyr obliquity cycle and increased when axial tilt dropped below 23.5 ∘ and benthic δ 18 O exceeded ∼3.8 ‰ (corrected to Uvigerina ), indicating a threshold response to orbital forcing. Afterwards, MCV became focused mainly on the transitions into and out of glacial states (i.e. inceptions and terminations) and during times of intermediate ice volume. After 1.2 Ma, obliquity continued to play a role in modulating the amplitude of MCV, especially during times of glacial inceptions, which are always associated with declining obliquity. A non-linear role for obliquity is also indicated by the appearance of multiples (82, 123 kyr) and combination tones (28 kyr) of the 41 kyr cycle. Near the end of the MPT ( ∼0.65 Ma), obliquity modulation of MCV amplitude wanes as quasi-periodic 100 kyr and precession power increase, coinciding with the growth of oversized ice sheets on North America and the appearance of Heinrich layers in North Atlantic sediments. Whereas the planktic δ 18 O of Site U1385 ... Article in Journal/Newspaper Antarc* Antarctica Greenland North Atlantic Directory of Open Access Journals: DOAJ Articles Shackleton Greenland Climate of the Past 19 3 607 636 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 D. A. Hodell S. J. Crowhurst L. Lourens V. Margari J. Nicolson J. E. Rolfe L. C. Skinner N. C. Thomas P. C. Tzedakis M. J. Mleneck-Vautravers E. W. Wolff A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Climate during the last glacial period was marked by abrupt instability on millennial timescales that included large swings of temperature in and around Greenland (Daansgard–Oeschger events) and smaller, more gradual changes in Antarctica (AIM events). Less is known about the existence and nature of similar variability during older glacial periods, especially during the early Pleistocene when glacial cycles were dominantly occurring at 41 kyr intervals compared to the much longer and deeper glaciations of the more recent period. Here, we report a continuous millennially resolved record of stable isotopes of planktic and benthic foraminifera at IODP Site U1385 (the “Shackleton Site”) from the southwestern Iberian margin for the last 1.5 million years, which includes the Middle Pleistocene Transition (MPT). Our results demonstrate that millennial climate variability (MCV) was a persistent feature of glacial climate, both before and after the MPT. Prior to 1.2 Ma in the early Pleistocene, the amplitude of MCV was modulated by the 41 kyr obliquity cycle and increased when axial tilt dropped below 23.5 ∘ and benthic δ 18 O exceeded ∼3.8 ‰ (corrected to Uvigerina ), indicating a threshold response to orbital forcing. Afterwards, MCV became focused mainly on the transitions into and out of glacial states (i.e. inceptions and terminations) and during times of intermediate ice volume. After 1.2 Ma, obliquity continued to play a role in modulating the amplitude of MCV, especially during times of glacial inceptions, which are always associated with declining obliquity. A non-linear role for obliquity is also indicated by the appearance of multiples (82, 123 kyr) and combination tones (28 kyr) of the 41 kyr cycle. Near the end of the MPT ( ∼0.65 Ma), obliquity modulation of MCV amplitude wanes as quasi-periodic 100 kyr and precession power increase, coinciding with the growth of oversized ice sheets on North America and the appearance of Heinrich layers in North Atlantic sediments. Whereas the planktic δ 18 O of Site U1385 ... |
format |
Article in Journal/Newspaper |
author |
D. A. Hodell S. J. Crowhurst L. Lourens V. Margari J. Nicolson J. E. Rolfe L. C. Skinner N. C. Thomas P. C. Tzedakis M. J. Mleneck-Vautravers E. W. Wolff |
author_facet |
D. A. Hodell S. J. Crowhurst L. Lourens V. Margari J. Nicolson J. E. Rolfe L. C. Skinner N. C. Thomas P. C. Tzedakis M. J. Mleneck-Vautravers E. W. Wolff |
author_sort |
D. A. Hodell |
title |
A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic |
title_short |
A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic |
title_full |
A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic |
title_fullStr |
A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic |
title_full_unstemmed |
A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic |
title_sort |
1.5-million-year record of orbital and millennial climate variability in the north atlantic |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/cp-19-607-2023 https://doaj.org/article/cb19140ae34548988981f552f7c5d839 |
geographic |
Shackleton Greenland |
geographic_facet |
Shackleton Greenland |
genre |
Antarc* Antarctica Greenland North Atlantic |
genre_facet |
Antarc* Antarctica Greenland North Atlantic |
op_source |
Climate of the Past, Vol 19, Pp 607-636 (2023) |
op_relation |
https://cp.copernicus.org/articles/19/607/2023/cp-19-607-2023.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-19-607-2023 1814-9324 1814-9332 https://doaj.org/article/cb19140ae34548988981f552f7c5d839 |
op_doi |
https://doi.org/10.5194/cp-19-607-2023 |
container_title |
Climate of the Past |
container_volume |
19 |
container_issue |
3 |
container_start_page |
607 |
op_container_end_page |
636 |
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1766286002090934272 |