Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios

Jawad El Hawari; Mohamed El Ghachi

doi:doi:10.11648/j.advances.20230404.11

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Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios

Jawad El Hawari, Mohamed El Ghachi

Published in Advances (Volume 4, Issue 4)

Received: 11 September 2023 Accepted: 4 October 2023 Published: 14 October 2023

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Abstract

This study was conducted on the GeoB8601-3 core, collected off the southwest coast of Morocco, to reconstruct the variations in oceanic temperatures over the past 2000 years. Geochemical analyses of planktonic foraminifera G. bulloides in the core provided Mg/Ca ratios, as well as stable carbon (δ13C) and oxygen (δ18O) isotopes. The distribution of Mg/Ca ratios with respect to core depth exhibited significant variations, with the lowest values recorded at a depth of 90-91.5 cm and the highest values observed at depths of 110-111.5 cm and 135-136.5 cm. Through specific calibrations, Mg/Ca values were converted to temperatures, allowing for the reconstruction of oceanic temperatures off southwest Morocco over the 2000-year period. The results indicated a significant temperature increase during certain periods, particularly between ±2112 and ±1681 years BP, as well as between ±1191 and 233 years BP. Relatively cooler temperatures were observed from approximately 165 years BP to the present, with a notable cooling event around 1351 years BP. Comparative analysis of the records obtained, through the two calibration methods, revealed a general trend of decreasing sea surface temperatures over the past 2000 years. It is important to note that these findings are based on the specific study of the GeoB8601-3 core and G. bulloides foraminifera. Further research and additional data are necessary to confirm these observations and gain a better understanding of oceanic temperature variations in this region during the studied period.

Published in	Advances (Volume 4, Issue 4)
DOI	10.11648/j.advances.20230404.11
Page(s)	116-123
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Southwest Morocco, Oceanic Temperatures, Mg/Ca Ratios, G. bulloides Foraminifera, Reconstruction, Last 2000 Years

References

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[2]	Barker, S., Greaves, M., & Elderfield, H. (2003). A study of cleaning procedures used for foraminiferal Mg/Ca paleothermometry. Geochemistry, Geophysics, Geosystems, 4, 8407.
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[5]	Bleil (2004). Report and Preliminary Results of Meteor Cruise M 58/2: Las Palmas-Las Palmas (Canary Islands, Spain), 15.05.-08.06. 2003. Geowissenschaften, Universitat Bremen, Fachbereich 5.
[6]	Boyle, E. A., & Keigwin, L. D. (1985). Comparison of Atlantic and Pacific paleochemical records for the last 215,000 years - Changes in deep ocean circulation and chemical inventories. Earth and Planetary Science Letters, 76, 135-150.
[7]	Bryan, K. (1962). Measurements of meridional heat-transport by ocean currents. Journal of Geophysical Research, 67 (9), 3403-3414.
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[9]	Elderfield, H., & Ganssen, G. (2000). Past temperature and δ18O of surface ocean waters inferred from foraminiferal Mg/Ca ratios. Nature, 405 (6785), 442-445.
[10]	Fairbanks, R. G., Mortlock, R. A., Chiu, T. C., Cao, L., Kaplan, A., Guilderson, T. P., Fairbanks, T. W., Bloom, A. L., Grootes, P. M., Nadeau, M. J., et al. (1980). Late Pleistocene variations in atmospheric carbon-14 content inferred from coral records. Nature, 285 (5763), 624-626.
[11]	Ganssen, G., Sarnthein, M., & Zamuner, E. (2000). Mid-Pleistocene origin of Neogloboquadrina pachyderma sinistral morphotypes inferred from ancestral atlantic records. Marine Micropaleontology, 40 (1-2), 29-53.
[12]	Karrouk, M. S. (2003). Dynamique des climats du Maroc. Thèse de doctorat d’état, Université Ben M’Sick - Casablanca (Maroc).
[13]	Kuhlmann, H., Freudenthal, T., Helmke, P., & Meggers, H. (2004). Reconstruction of paleoceanography off NW Africa during the last 40,000 years: Influence of local and regional factors on sediment accumulation. Marine Geology, 207, 209-224.
[14]	Lea, D. W., & Boyle, E. A. (1991). Cadmium in coral aragonite: Implications for reconstructing seawater Cd using coral skeletons. Paleoceanography, 6 (6), 677-698.
[15]	Mashiotta, T. A., Lea, D. W., & Spero, H. J. (1999). Glacial-interglacial changes in Subantarctic sea surface temperature and δ18O-water using foraminiferal Mg. Earth and Planetary Science Letters, 170, 417-432.
[16]	Rosenthal, Y. (2004). Interlaboratory comparison study of Mg/Ca and Sr/Ca measurements in planktonic foraminifera for paleoceanographic research. Geochemistry, Geophysics, Geosystems, 5 (4), Q04D09.

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APA Style

Jawad El Hawari, Mohamed El Ghachi. (2023). Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios. Advances, 4(4), 116-123. https://doi.org/10.11648/j.advances.20230404.11

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ACS Style

Jawad El Hawari; Mohamed El Ghachi. Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios. Advances. 2023, 4(4), 116-123. doi: 10.11648/j.advances.20230404.11

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AMA Style

Jawad El Hawari, Mohamed El Ghachi. Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios. Advances. 2023;4(4):116-123. doi: 10.11648/j.advances.20230404.11

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@article{10.11648/j.advances.20230404.11,
  author = {Jawad El Hawari and Mohamed El Ghachi},
  title = {Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios},
  journal = {Advances},
  volume = {4},
  number = {4},
  pages = {116-123},
  doi = {10.11648/j.advances.20230404.11},
  url = {https://doi.org/10.11648/j.advances.20230404.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.advances.20230404.11},
  abstract = {This study was conducted on the GeoB8601-3 core, collected off the southwest coast of Morocco, to reconstruct the variations in oceanic temperatures over the past 2000 years. Geochemical analyses of planktonic foraminifera G. bulloides in the core provided Mg/Ca ratios, as well as stable carbon (δ13C) and oxygen (δ18O) isotopes. The distribution of Mg/Ca ratios with respect to core depth exhibited significant variations, with the lowest values recorded at a depth of 90-91.5 cm and the highest values observed at depths of 110-111.5 cm and 135-136.5 cm. Through specific calibrations, Mg/Ca values were converted to temperatures, allowing for the reconstruction of oceanic temperatures off southwest Morocco over the 2000-year period. The results indicated a significant temperature increase during certain periods, particularly between ±2112 and ±1681 years BP, as well as between ±1191 and 233 years BP. Relatively cooler temperatures were observed from approximately 165 years BP to the present, with a notable cooling event around 1351 years BP. Comparative analysis of the records obtained, through the two calibration methods, revealed a general trend of decreasing sea surface temperatures over the past 2000 years. It is important to note that these findings are based on the specific study of the GeoB8601-3 core and G. bulloides foraminifera. Further research and additional data are necessary to confirm these observations and gain a better understanding of oceanic temperature variations in this region during the studied period.},
 year = {2023}
}

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TY - JOUR
T1 - Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios
AU - Jawad El Hawari
AU - Mohamed El Ghachi
Y1 - 2023/10/14
PY - 2023
N1 - https://doi.org/10.11648/j.advances.20230404.11
DO - 10.11648/j.advances.20230404.11
T2 - Advances
JF - Advances
JO - Advances
SP - 116
EP - 123
PB - Science Publishing Group
SN - 2994-7200
UR - https://doi.org/10.11648/j.advances.20230404.11
AB - This study was conducted on the GeoB8601-3 core, collected off the southwest coast of Morocco, to reconstruct the variations in oceanic temperatures over the past 2000 years. Geochemical analyses of planktonic foraminifera G. bulloides in the core provided Mg/Ca ratios, as well as stable carbon (δ13C) and oxygen (δ18O) isotopes. The distribution of Mg/Ca ratios with respect to core depth exhibited significant variations, with the lowest values recorded at a depth of 90-91.5 cm and the highest values observed at depths of 110-111.5 cm and 135-136.5 cm. Through specific calibrations, Mg/Ca values were converted to temperatures, allowing for the reconstruction of oceanic temperatures off southwest Morocco over the 2000-year period. The results indicated a significant temperature increase during certain periods, particularly between ±2112 and ±1681 years BP, as well as between ±1191 and 233 years BP. Relatively cooler temperatures were observed from approximately 165 years BP to the present, with a notable cooling event around 1351 years BP. Comparative analysis of the records obtained, through the two calibration methods, revealed a general trend of decreasing sea surface temperatures over the past 2000 years. It is important to note that these findings are based on the specific study of the GeoB8601-3 core and G. bulloides foraminifera. Further research and additional data are necessary to confirm these observations and gain a better understanding of oceanic temperature variations in this region during the studied period.
VL - 4
IS - 4
ER -

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Author Information

Jawad El Hawari

Department of Geography, University of Sultan Moulay Slimane, Beni Mellal, Morocco
Mohamed El Ghachi

Department of Geography, University of Sultan Moulay Slimane, Beni Mellal, Morocco

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APA Style

Jawad El Hawari, Mohamed El Ghachi. (2023). Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios. Advances, 4(4), 116-123. https://doi.org/10.11648/j.advances.20230404.11

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ACS Style

Jawad El Hawari; Mohamed El Ghachi. Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios. Advances. 2023, 4(4), 116-123. doi: 10.11648/j.advances.20230404.11

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AMA Style

Jawad El Hawari, Mohamed El Ghachi. Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios. Advances. 2023;4(4):116-123. doi: 10.11648/j.advances.20230404.11

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@article{10.11648/j.advances.20230404.11,
  author = {Jawad El Hawari and Mohamed El Ghachi},
  title = {Reconstructing 2000-Year, Oceanic Temperature Changes off Southwest Morocco Using G. bulloides Foraminifera Mg/Ca Ratios},
  journal = {Advances},
  volume = {4},
  number = {4},
  pages = {116-123},
  doi = {10.11648/j.advances.20230404.11},
  url = {https://doi.org/10.11648/j.advances.20230404.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.advances.20230404.11},
  abstract = {This study was conducted on the GeoB8601-3 core, collected off the southwest coast of Morocco, to reconstruct the variations in oceanic temperatures over the past 2000 years. Geochemical analyses of planktonic foraminifera G. bulloides in the core provided Mg/Ca ratios, as well as stable carbon (δ13C) and oxygen (δ18O) isotopes. The distribution of Mg/Ca ratios with respect to core depth exhibited significant variations, with the lowest values recorded at a depth of 90-91.5 cm and the highest values observed at depths of 110-111.5 cm and 135-136.5 cm. Through specific calibrations, Mg/Ca values were converted to temperatures, allowing for the reconstruction of oceanic temperatures off southwest Morocco over the 2000-year period. The results indicated a significant temperature increase during certain periods, particularly between ±2112 and ±1681 years BP, as well as between ±1191 and 233 years BP. Relatively cooler temperatures were observed from approximately 165 years BP to the present, with a notable cooling event around 1351 years BP. Comparative analysis of the records obtained, through the two calibration methods, revealed a general trend of decreasing sea surface temperatures over the past 2000 years. It is important to note that these findings are based on the specific study of the GeoB8601-3 core and G. bulloides foraminifera. Further research and additional data are necessary to confirm these observations and gain a better understanding of oceanic temperature variations in this region during the studied period.},
 year = {2023}
}

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