Nitrogen isotope ratio and oxygen isotope ratio from Arabian Sea IODP Site 355-U1456 ...

• Main Authors: Kim, Ji-Eun, Khim, Boo-Keun, Ikehara, Minoru, Lee, Jongmin
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Arabian Sea; Denitrification; IODP; Monsoon; nitrogen isotope; oxygen isotope; oxygen minimum zone; Event label; Sample code/label; DEPTH, sediment/rock; Depth, composite; AGE; Globigerinoides ruber, δ18O; Globigerinoides ruber, δ13C; Carbon, total; Nitrogen, total; δ15N, bulk sediment; Drilling/drill rig; Chromium reduction destillation, hot single step; IODP Depth Scale Terminology; Isotope ratio mass spectrometry; Exp355; Joides Resolution; Integrated Ocean Drilling Program / International Ocean Discovery Program IODP; Indian; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.911694; https://doi.pangaea.de/10.1594/PANGAEA.911694

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 ...