The Impact of Changes in Sea Level and East Asian Monsoon on Sediment Transport on the Sunda Shelf Since the Last Deglaciation
Year: 2023
Type: article
Abstract: The Sunda Shelf plays a key role in the sedimentation of the southern South China Sea (SCS). However, the impact of past climate changes on sediment transfer to the Sunda Shelf and the southern SCS is still unresolved. Here, we present new data on grain size, clay mineralogy, and Sr‐Nd isotopes of three marine cores, river sediments, and surface sediments of the Sunda Shelf. The results indicate that clay fractions of the central Sunda Shelf and the Gulf of Thailand derived mainly from the Mekong River and the rivers of northern Thailand since the last deglaciation. Significant changes in sediment sources are observed at 7.5 cal ka BP. From 13.3 to 7.5 cal ka BP, sediments in the Gulf of Thailand mainly originated from the rivers of northern Thailand, with contributions from the Mekong River increasing after 7.5 cal ka BP. An opposite shift is observed in the central Sunda Shelf. Such variations in the spatial distribution result from a combination of sea level and East Asian monsoon effects. After 7.5 cal ka BP, less Mekong River sediments were transported southeastwards into the southern SCS, and more sediments were gradually trapped within the delta and transported in a southwesterly direction into the Gulf of Thailand due to intense East Asian winter monsoon, which forced a strong southwestward coastal current. Our results demonstrate the important impact of East Asian winter monsoon strengthening and sea level rise in the mid‐Holocene, which can change sediment sources and transport processes on the Sunda Shelf.
DOI: 10.1029/2023jf007335
Institutions: Ministry of Natural Resources, First Institute of Oceanography, Laoshan Laboratory, Centre National de la Recherche Scientifique, Université Paris-Saclay, Geosciences Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA Paris-Saclay - Etablissement de Saclay, Laboratoire des Sciences du Climat et de l'Environnement, Tongji University, State Key Laboratory of Marine Geology, National University of Malaysia, Department of Marine and Coastal Resources
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid: $3,700
Funders: Universiti Kebangsaan Malaysia, Taishan Scholar Project of Shandong Province, Qingdao National Laboratory for Marine Science and Technology, Basic Scientific Fund for National Public Research Institutes of China, National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers, National Program on Global Change and Air-Sea Interaction
OpenAlex ID: W4386851259