Investigating Sea-Level Sediment Transport And The Summer Monsoon Season

The International Ocean Discovery Program (IODP) is one of the most an influential marine research collaboration programs that explores the Earth’s history and dynamics using ocean-going research platforms to recover data recorded in seafloor sediments and rocks and to monitor sub-seafloor environments. The IODP Expedition 355 (Arabian Sea Monsoon) started in Colombo, Sri Lanka, from March 31 to May 30, 2015, aiming to better understand the co-evolution of the Tibetan plateau uplift, Indian summer monsoon evolution, weathering, and erosion of Himalaya through multiple time scales.

Long-term marine sediment archives deposited in the deep-sea fan are key materials to study the sensitivity of sediment dynamics in responding to monsoon precipitation evolution and sea-level variations. Previous studies suggest that both Indian summer monsoon precipitation and sea-level are playing important roles in determining the sediment transportation from the large river basin to the deep-sea fan in the Asia area.

On the orbital timescale, both the spectra of East Asian summer monsoons and sea level proxies indicate dominant 100-kyr eccentricity bands during the Late Quaternary in the East Asia marginal seas (such as the South China Sea), making it difficult to decipher the different influence of these two processes on the sediment transportation. However, this is not the case in the South Asian area. In the Arabian Sea, the Indian summer monsoon precipitation is mainly forced by the 23-kyr precession cycles, while the sea-level is conservative at 100-kyr eccentricity cycles. Therefore, it is possible to use this different dominant orbital cycles to estimate the different influence of Indian summer monsoon precipitation and sea-level on sediment transportation in the Arabian Sea.

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