The history of monsoons recorded in marine sediments of the Indian Ocean

Author(s): Niitsuma, Nobuaki
Author Affiliation(s): Primary:
Shizuoka University, Institute of Geosciences, Shizuoka, Japan
Nihon University, Japan
Tokyo Metropolitan University, Japan
Volume Title: Significance of the Himalayan-Tibetan Massif for global changes
Volume Author(s): Ono, Yugo, prefacer; Endo, Kunihiko; Iwata, Shuji
Source: The significance of the Himalayan-Tibetan Massif for global changes, prefaced by Yugo Ono, Kunihiko Endo and Shuji Iwata. Chigaku Zasshi = Journal of Geography, 106( 2(951)), p.226-239. Publisher: Tokyo Chigaku Kyokai, Tokyo, Japan. ISSN: 0022-135X CODEN: CGZAAL
Note: In Japanese with English summary. 24 refs.Special issue; illus., incl. 1 table, sketch map
Summary: The deep sea sediments off Oman contain records of the history of the Southwest Monsoon, as seen from lithology, paleontology, isotopes, geochemistry and magnetostratigraphy. Glacial-interglacial fluctuations in upwelling related to the Southwest Monsoon can be traced back 250 ka. In contrast, from 450 to 250 ka, carbon isotope differences indicating upwelling strength did not show such distinct cyclicity. Upwelling was strong during interglacial stages and had less fluctuation, and was weak during glacial stages with large fluctuation. This upwelling and climate can be traced back to the late Miocene. The strongest upwelling is estimated to have occurred in the Pliocene-Pleistocene time, based on calcareous nannofossil assemblages, isotopic indicators, and organic carbon content. During glacial stages several factors suggest that the Arabian Peninsula was humid, including a very high calculated rate of sedimentation based on oxygen isotope stratigraphy, several to ten times that of interglacial stages, and an increase in the absolute flux of fluvial sediments and variability of lithofacies. The Arabian Peninsula was separated by high mountains along its southwest margin from east Africa, which was arid during glacial stages.
Year of Publication: 1997
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 07 Marine Geology and Oceanography; 24 Surficial Geology, Quaternary Geology; Arabian Peninsula; Asia; C-13/C-12; Carbon; Cenozoic; Foraminifera; Geochemistry; Glacial environment; Glaciomarine environment; Holocene; Indian Ocean; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Leg 117; Marine environment; Marine sediments; Monsoons; O-18/O-16; Ocean Drilling Program; Oman; Oxygen; Paleo-oceanography; Paleoecology; Protista; Quaternary; Sediments; Stable isotopes; Upwelling
Coordinates: N160748 N182912 E0604438 E0572212
Record ID: 1997071809
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