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author Kim, Ji-Eun
Khim, Boo-Keun
Ikehara, Minoru
Lee, Jongmin
author_facet Kim, Ji-Eun
Khim, Boo-Keun
Ikehara, Minoru
Lee, Jongmin
collection Datos científicos de ciencias marinas y ambientales
contents Denitrification in the Arabian Sea is closely related to the monsoon-induced upwelling and subsequent phytoplankton production in the surface water. The δ15N values of bulk sediments collected at Site U1456 of the International Ocean Discovery Program (IODP) Expedition 355 reveal the orbital-scale denitrification history in response to the Indian Monsoon. Age reconstruction based on the correlation of planktonic foraminifera (Globigerinoides ruber) δ18O values with the LR04 stack together with the shipboard biostratigraphic and paleomagnetic data assigns the study interval to be 1.2 Ma. Comparison of δ15N values during the last 800 kyrs between Site U1456 (Eastern Arabian Sea) and Site 722B (Western Arabian Sea) showed that δ15N values were high during interglacial periods, indicating intensified denitrification, while the opposite was observed during glacial periods. Taking 6‰ as the empirical threshold of denitrification, the Eastern Arabian Sea has experienced a persistent oxygen minimum zone (OMZ) to maintain strong denitrification whereas the Western Arabian Sea has undergone OMZ breakdown during some glacial periods. The results of this study also suggests that five principal oceanographic conditions were changed in response to the Indian Monsoon following the interglacial and glacial cycles, which controls the degree of denitrification in the Arabian Sea.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_911694
institution PANGAEA
language en
publishDate 2020
publisher PANGAEA
record_format pangaea
spellingShingle Nitrogen isotope ratio and oxygen isotope ratio from Arabian Sea IODP Site 355-U1456
Kim, Ji-Eun
Khim, Boo-Keun
Ikehara, Minoru
Lee, Jongmin
355-U1456A; 355-U1456C; AGE; Arabian Sea; Carbon, total; Chromium reduction destillation, hot single step; Denitrification; Depth, composite; DEPTH, sediment/rock; DRILL; Drilling/drill rig; Event label; Exp355; Globigerinoides ruber, δ13C; Globigerinoides ruber, δ18O; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; IODP Depth Scale Terminology; Isotope ratio mass spectrometry; Joides Resolution; Monsoon; Nitrogen, total; nitrogen isotope; oxygen isotope; Oxygen minimum zone; Sample code/label; δ15N, bulk sediment
Denitrification in the Arabian Sea is closely related to the monsoon-induced upwelling and subsequent phytoplankton production in the surface water. The δ15N values of bulk sediments collected at Site U1456 of the International Ocean Discovery Program (IODP) Expedition 355 reveal the orbital-scale denitrification history in response to the Indian Monsoon. Age reconstruction based on the correlation of planktonic foraminifera (Globigerinoides ruber) δ18O values with the LR04 stack together with the shipboard biostratigraphic and paleomagnetic data assigns the study interval to be 1.2 Ma. Comparison of δ15N values during the last 800 kyrs between Site U1456 (Eastern Arabian Sea) and Site 722B (Western Arabian Sea) showed that δ15N values were high during interglacial periods, indicating intensified denitrification, while the opposite was observed during glacial periods. Taking 6‰ as the empirical threshold of denitrification, the Eastern Arabian Sea has experienced a persistent oxygen minimum zone (OMZ) to maintain strong denitrification whereas the Western Arabian Sea has undergone OMZ breakdown during some glacial periods. The results of this study also suggests that five principal oceanographic conditions were changed in response to the Indian Monsoon following the interglacial and glacial cycles, which controls the degree of denitrification in the Arabian Sea.
title Nitrogen isotope ratio and oxygen isotope ratio from Arabian Sea IODP Site 355-U1456
topic 355-U1456A; 355-U1456C; AGE; Arabian Sea; Carbon, total; Chromium reduction destillation, hot single step; Denitrification; Depth, composite; DEPTH, sediment/rock; DRILL; Drilling/drill rig; Event label; Exp355; Globigerinoides ruber, δ13C; Globigerinoides ruber, δ18O; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; IODP Depth Scale Terminology; Isotope ratio mass spectrometry; Joides Resolution; Monsoon; Nitrogen, total; nitrogen isotope; oxygen isotope; Oxygen minimum zone; Sample code/label; δ15N, bulk sediment
url https://doi.org/10.1594/PANGAEA.911694