Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays
Abstract The Shimosa Group, a Middle- to Late-Pleistocene sedimentary succession, has been the focus of stratigraphic attention because it lies beneath the Tokyo metropolitan area of central Japan. It is also of palaeoclimatic significance because it contains important interglacial marine strata of...
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ftdoajarticles:oai:doaj.org/article:8cc64caf19864635924ef5ec126acb92 2023-05-15T18:00:57+02:00 Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays Hiroto Kajita Tsutomu Nakazawa Masayuki Utsunomiya Naohiko Ohkouchi Miyako Sato Naomi Harada Hodaka Kawahata 2022-07-01T00:00:00Z https://doi.org/10.1186/s40645-022-00499-y https://doaj.org/article/8cc64caf19864635924ef5ec126acb92 EN eng SpringerOpen https://doi.org/10.1186/s40645-022-00499-y https://doaj.org/toc/2197-4284 doi:10.1186/s40645-022-00499-y 2197-4284 https://doaj.org/article/8cc64caf19864635924ef5ec126acb92 Progress in Earth and Planetary Science, Vol 9, Iss 1, Pp 1-13 (2022) Alkenone palaeothermometer Interglacial periods Shimosa Group Geography. Anthropology. Recreation G Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.1186/s40645-022-00499-y 2022-12-30T23:16:18Z Abstract The Shimosa Group, a Middle- to Late-Pleistocene sedimentary succession, has been the focus of stratigraphic attention because it lies beneath the Tokyo metropolitan area of central Japan. It is also of palaeoclimatic significance because it contains important interglacial marine strata of the past 450,000 years. Because the marine strata of the Shimosa Group were formed in the shallow inner bay known as the Palaeo-Tokyo Bay, rare occurrences of planktonic foraminifera make it difficult to quantitatively reconstruct the palaeo-sea surface temperatures (SSTs). Here, we extracted long-chain alkenones (LCAs) from the core GS-UR-1 penetrating the Shimosa Group to Marine Isotope Stage (MIS) 11. We found that the alkenone unsaturation ratio appears to reflect the SST of the Palaeo-Tokyo Bay formed during the peaks of MISs 5e, 7e, 9, and 11, which was consistent with the inflowing water mass changes inferred from the benthic foraminiferal assemblages. The palaeo-SSTs during each interglacial period were 2–3 °C higher than the pre-industrial levels of Tokyo Bay and seemed to reach a level similar to that of the Holocene thermal maximum. The findings of this study demonstrate that the LCA-based proxy, which has not before been utilised in studies on the Shimosa Group, has strong potential to provide palaeoceanic and stratigraphic information. Article in Journal/Newspaper Planktonic foraminifera Directory of Open Access Journals: DOAJ Articles Inner Bay ENVELOPE(-37.967,-37.967,-54.017,-54.017) Progress in Earth and Planetary Science 9 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Alkenone palaeothermometer Interglacial periods Shimosa Group Geography. Anthropology. Recreation G Geology QE1-996.5 |
spellingShingle |
Alkenone palaeothermometer Interglacial periods Shimosa Group Geography. Anthropology. Recreation G Geology QE1-996.5 Hiroto Kajita Tsutomu Nakazawa Masayuki Utsunomiya Naohiko Ohkouchi Miyako Sato Naomi Harada Hodaka Kawahata Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays |
topic_facet |
Alkenone palaeothermometer Interglacial periods Shimosa Group Geography. Anthropology. Recreation G Geology QE1-996.5 |
description |
Abstract The Shimosa Group, a Middle- to Late-Pleistocene sedimentary succession, has been the focus of stratigraphic attention because it lies beneath the Tokyo metropolitan area of central Japan. It is also of palaeoclimatic significance because it contains important interglacial marine strata of the past 450,000 years. Because the marine strata of the Shimosa Group were formed in the shallow inner bay known as the Palaeo-Tokyo Bay, rare occurrences of planktonic foraminifera make it difficult to quantitatively reconstruct the palaeo-sea surface temperatures (SSTs). Here, we extracted long-chain alkenones (LCAs) from the core GS-UR-1 penetrating the Shimosa Group to Marine Isotope Stage (MIS) 11. We found that the alkenone unsaturation ratio appears to reflect the SST of the Palaeo-Tokyo Bay formed during the peaks of MISs 5e, 7e, 9, and 11, which was consistent with the inflowing water mass changes inferred from the benthic foraminiferal assemblages. The palaeo-SSTs during each interglacial period were 2–3 °C higher than the pre-industrial levels of Tokyo Bay and seemed to reach a level similar to that of the Holocene thermal maximum. The findings of this study demonstrate that the LCA-based proxy, which has not before been utilised in studies on the Shimosa Group, has strong potential to provide palaeoceanic and stratigraphic information. |
format |
Article in Journal/Newspaper |
author |
Hiroto Kajita Tsutomu Nakazawa Masayuki Utsunomiya Naohiko Ohkouchi Miyako Sato Naomi Harada Hodaka Kawahata |
author_facet |
Hiroto Kajita Tsutomu Nakazawa Masayuki Utsunomiya Naohiko Ohkouchi Miyako Sato Naomi Harada Hodaka Kawahata |
author_sort |
Hiroto Kajita |
title |
Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays |
title_short |
Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays |
title_full |
Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays |
title_fullStr |
Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays |
title_full_unstemmed |
Long-chain alkenones in the Shimosa Group reveal palaeotemperatures of the Pleistocene interglacial Palaeo-Tokyo Bays |
title_sort |
long-chain alkenones in the shimosa group reveal palaeotemperatures of the pleistocene interglacial palaeo-tokyo bays |
publisher |
SpringerOpen |
publishDate |
2022 |
url |
https://doi.org/10.1186/s40645-022-00499-y https://doaj.org/article/8cc64caf19864635924ef5ec126acb92 |
long_lat |
ENVELOPE(-37.967,-37.967,-54.017,-54.017) |
geographic |
Inner Bay |
geographic_facet |
Inner Bay |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
Progress in Earth and Planetary Science, Vol 9, Iss 1, Pp 1-13 (2022) |
op_relation |
https://doi.org/10.1186/s40645-022-00499-y https://doaj.org/toc/2197-4284 doi:10.1186/s40645-022-00499-y 2197-4284 https://doaj.org/article/8cc64caf19864635924ef5ec126acb92 |
op_doi |
https://doi.org/10.1186/s40645-022-00499-y |
container_title |
Progress in Earth and Planetary Science |
container_volume |
9 |
container_issue |
1 |
_version_ |
1766170238191140864 |