Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios
Proxy records from Arctic Ocean sediment cores show that major paleogeographic changes occurred during the last glacial-interglacial cycle, but there is minimal data on Arctic Ocean temperature history. Mg/Ca ratios in the calcitic shells of Krithe, a benthic marine ostracode characteristic of deep-...
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ftoceanrep:oai:oceanrep.geomar.de:13078 2023-05-15T14:27:28+02:00 Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios Cronin, T. M. Dwyer, G. S. Briggs, W. M. Jr. Farmer, J. Bauch, Henning A. Jakobsson, Martin Spielhagen, Robert F. Stepanova, Anna 2011 https://oceanrep.geomar.de/id/eprint/13078/ http://www.geogr.msu.ru/structure/labs/notl/nauchd/downloads/Abstracts_2011_APEX_Longyearbyen.pdf unknown Cronin, T. M., Dwyer, G. S., Briggs, W. M. J., Farmer, J., Bauch, H. A. , Jakobsson, M., Spielhagen, R. F. and Stepanova, A. (2011) Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios. [Talk] In: APEX Fifth International Conference and Workshop: Quaternary Glacial and Climate Extremes. , 01.06.-04.06. 2011, Longyearbyen, Svalbard, Norway . APEX Fifth International Conference and Workshop: Quaternary Glacial and Climate Extremes / hosted by The University Centre in Svalbard (UNIS). pp. 57-58 . Conference or Workshop Item NonPeerReviewed 2011 ftoceanrep 2023-04-07T15:01:47Z Proxy records from Arctic Ocean sediment cores show that major paleogeographic changes occurred during the last glacial-interglacial cycle, but there is minimal data on Arctic Ocean temperature history. Mg/Ca ratios in the calcitic shells of Krithe, a benthic marine ostracode characteristic of deep-sea and Arctic continental shelf environments, have been used to reconstruct bottom water temperature (BWT) in the North Atlantic (Dwyer et al. 1995, Cronin et al. 1996). We analyzed Mg/Ca and Sr/Ca ratios in more than 500 specimens of K. glacialis and K. minima from 114 coretops in the Arctic Ocean and Nordic Seas to improve the Mg/Ca–temperature calibration and to evaluate the influence of other factors on Mg/Ca and Sr/Ca ratios (e.g. vital effects, carbonate ion concentration). Mg/Ca concentrations range from 6 to 13 mmol/mol and exhibit a positive correlation to temperature from -1.5 to 0.5ºC (r 2=0.4) with a sensitivity of 0.471 mmol/mol/ºC. Temperature, or temperature-related factors affecting physiology, molting and/or calcification processes, appear to be an influence on Mg/Ca variability. Carbonate ion shows no apparent relationship to Mg/Ca at ∆[CO3-2] values from -20 to 70 μmol/kg, however Sr/Ca ratios are positively correlated to ∆[CO3-2] (r2=0.5). We applied Mg/Ca paleothermometry for K. glacialis and K. minima to 32 sediment cores from the central Arctic Ocean (Lomonosov, Mendeleyev, Gakkel Ridges) and the Iceland Plateau. Marine Isotope Stage 3 (MIS3, 60-25 ka) Mg/Ca ratios at mid-depth sites (1000-2600 m water depth) average 2 to 8 mmol/mol higher than those in the late Holocene suggesting MIS3 BWTs were 1-3 ̊C warmer. In contrast, at core sites below 3000 meters, Mg/Ca ratios indicate little or no BWT change during MIS 3. Warmer mid-depth MIS 3 BWTs are consistent with oxygen isotope evidence for glacial-age elevated BWTs in the Iceland Sea (Bauch t al. 2001). Mid-depth Arctic Ocean warming most likely involves changes in the depth, circulation or temperature of the warm Atlantic Layer (AL). Possible ... Conference Object Arctic Arctic Arctic Ocean Iceland Nordic Seas North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean Dwyer ENVELOPE(65.050,65.050,-70.183,-70.183) Iceland Plateau ENVELOPE(-12.000,-12.000,69.500,69.500) Mendeleyev ENVELOPE(14.517,14.517,-71.900,-71.900) |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
unknown |
description |
Proxy records from Arctic Ocean sediment cores show that major paleogeographic changes occurred during the last glacial-interglacial cycle, but there is minimal data on Arctic Ocean temperature history. Mg/Ca ratios in the calcitic shells of Krithe, a benthic marine ostracode characteristic of deep-sea and Arctic continental shelf environments, have been used to reconstruct bottom water temperature (BWT) in the North Atlantic (Dwyer et al. 1995, Cronin et al. 1996). We analyzed Mg/Ca and Sr/Ca ratios in more than 500 specimens of K. glacialis and K. minima from 114 coretops in the Arctic Ocean and Nordic Seas to improve the Mg/Ca–temperature calibration and to evaluate the influence of other factors on Mg/Ca and Sr/Ca ratios (e.g. vital effects, carbonate ion concentration). Mg/Ca concentrations range from 6 to 13 mmol/mol and exhibit a positive correlation to temperature from -1.5 to 0.5ºC (r 2=0.4) with a sensitivity of 0.471 mmol/mol/ºC. Temperature, or temperature-related factors affecting physiology, molting and/or calcification processes, appear to be an influence on Mg/Ca variability. Carbonate ion shows no apparent relationship to Mg/Ca at ∆[CO3-2] values from -20 to 70 μmol/kg, however Sr/Ca ratios are positively correlated to ∆[CO3-2] (r2=0.5). We applied Mg/Ca paleothermometry for K. glacialis and K. minima to 32 sediment cores from the central Arctic Ocean (Lomonosov, Mendeleyev, Gakkel Ridges) and the Iceland Plateau. Marine Isotope Stage 3 (MIS3, 60-25 ka) Mg/Ca ratios at mid-depth sites (1000-2600 m water depth) average 2 to 8 mmol/mol higher than those in the late Holocene suggesting MIS3 BWTs were 1-3 ̊C warmer. In contrast, at core sites below 3000 meters, Mg/Ca ratios indicate little or no BWT change during MIS 3. Warmer mid-depth MIS 3 BWTs are consistent with oxygen isotope evidence for glacial-age elevated BWTs in the Iceland Sea (Bauch t al. 2001). Mid-depth Arctic Ocean warming most likely involves changes in the depth, circulation or temperature of the warm Atlantic Layer (AL). Possible ... |
format |
Conference Object |
author |
Cronin, T. M. Dwyer, G. S. Briggs, W. M. Jr. Farmer, J. Bauch, Henning A. Jakobsson, Martin Spielhagen, Robert F. Stepanova, Anna |
spellingShingle |
Cronin, T. M. Dwyer, G. S. Briggs, W. M. Jr. Farmer, J. Bauch, Henning A. Jakobsson, Martin Spielhagen, Robert F. Stepanova, Anna Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios |
author_facet |
Cronin, T. M. Dwyer, G. S. Briggs, W. M. Jr. Farmer, J. Bauch, Henning A. Jakobsson, Martin Spielhagen, Robert F. Stepanova, Anna |
author_sort |
Cronin, T. M. |
title |
Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios |
title_short |
Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios |
title_full |
Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios |
title_fullStr |
Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios |
title_full_unstemmed |
Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios |
title_sort |
arctic ocean temperature history since 60 ka based on ostracode mg/ca ratios |
publishDate |
2011 |
url |
https://oceanrep.geomar.de/id/eprint/13078/ http://www.geogr.msu.ru/structure/labs/notl/nauchd/downloads/Abstracts_2011_APEX_Longyearbyen.pdf |
long_lat |
ENVELOPE(65.050,65.050,-70.183,-70.183) ENVELOPE(-12.000,-12.000,69.500,69.500) ENVELOPE(14.517,14.517,-71.900,-71.900) |
geographic |
Arctic Arctic Ocean Dwyer Iceland Plateau Mendeleyev |
geographic_facet |
Arctic Arctic Ocean Dwyer Iceland Plateau Mendeleyev |
genre |
Arctic Arctic Arctic Ocean Iceland Nordic Seas North Atlantic |
genre_facet |
Arctic Arctic Arctic Ocean Iceland Nordic Seas North Atlantic |
op_relation |
Cronin, T. M., Dwyer, G. S., Briggs, W. M. J., Farmer, J., Bauch, H. A. , Jakobsson, M., Spielhagen, R. F. and Stepanova, A. (2011) Arctic Ocean Temperature History since 60 ka based on ostracode Mg/Ca ratios. [Talk] In: APEX Fifth International Conference and Workshop: Quaternary Glacial and Climate Extremes. , 01.06.-04.06. 2011, Longyearbyen, Svalbard, Norway . APEX Fifth International Conference and Workshop: Quaternary Glacial and Climate Extremes / hosted by The University Centre in Svalbard (UNIS). pp. 57-58 . |
_version_ |
1766301228792283136 |