A 500,000 year record of Indian summer monsoon dynamics recorded by eastern equatorial Indian Ocean upper water-column structure

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doi: 10.1016/j.quascirev.2013.07.031
Author(s): Bolton, Clara T.; Chang, Liao; Clemens, Steven C.; Kodama, Kazuto; Ikehara, Minoru; Medina-Elizalde, Martin; Paterson, Greig A.; Roberts, Andrew P.; Rohling, Eelco J.; Yamamoto, Yuhji; Zhao, Xiang
Author Affiliation(s): Primary:
University of Southampton, National Oceanography Centre, Southampton, United Kingdom
Brown University, United States
Kochi University, Japan
Volume Title: Quaternary Science Reviews
Source: Quaternary Science Reviews, Vol.77, p.167-180. Publisher: Elsevier, International. ISSN: 0277-3791
Note: In English. 116 refs.; illus., incl. 1 table
Summary: The Indian Summer Monsoon (ISM) is an inter-hemispheric and highly variable ocean-atmosphere-land interaction that directly affects the densely populated Indian subcontinent. Here, we present new records of paleoceanographic variability that span the last 500,000 years from the eastern equatorial Indian Ocean, a relatively under-sampled area of ISM influence. We have generated carbon and oxygen stable isotope records from three foraminiferal species from Ocean Drilling Program Site 758 (5°N, 90°E) to investigate the oceanographic history of this region. We interpret our resultant Δδ18O (surface-thermocline) record of upper water-column stratification in the context of past ISM variability, and compare orbital phase relationships in our Site 758 data to other climate and monsoon proxies in the region. Results suggest that upper water-column stratification at Site 758, which is dominated by variance at precession and half-precession frequencies (23, 19 and 11 ka), is forced by both local (5°N) insolation and ISM winds. In the precession (23 ka) band, stratification minima at Site 758 lag Northern Hemisphere summer insolation maxima (precession minima) by 9 ka, which is consistent with Arabian Sea ISM phase estimates and suggests a common wind forcing in both regions. This phase implicates a strong sensitivity to both ice volume and Southern Hemisphere insolation forcing via latent heat export from the southern subtropical Indian Ocean. Additionally, we find evidence of possible overprinting of millennial-scale events during glacial terminations in our stratification record, which suggests an influence of remote abrupt climate events on ISM dynamics. Abstract Copyright (2013) Elsevier, B.V.
Year of Publication: 2013
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; C-13/C-12; Carbon; Cenozoic; Chemostratigraphy; Climate forcing; Cores; Eastern Indian Ocean; Equatorial region; Foraminifera; Indian Ocean; Invertebrata; Isotope ratios; Isotopes; Leg 121; Lithostratigraphy; Marine sediments; Microfossils; Monsoons; Ninetyeast Ridge; O-18/O-16; ODP Site 758; Ocean Drilling Program; Orbital forcing; Oxygen; Paleoclimatology; Paleohydrology; Productivity; Protista; Quaternary; Sediments; Stable isotopes; Upper Quaternary
Coordinates: N052302 N052303 E0902141 E0902140
Record ID: 2014061778
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands