Research progress of the Tibetan Plateau - Bay of Bengal “source-sink” system since the Last Glacial Maximum

In the last two decades, significant approach has been made in the study on the Tibetan Plateau (TP) - Bay of Bengal (BoB) “source-sink” system since the Last Glacial Maximum (LGM). To track the research frontiers and provide new ideas on the source-sink process of the Northeast Indian Ocean under the guidance of the thought of the earth system science, we summarized the latest progress in several aspects such as weathering and erosion, sediment provenance, sedimentary patterns, and source-sink system responses, and pointed out the breakthrough directions in the future. The physical erosion process in the Ganges-Brahmaputra (G-B) basin is primarily influenced by monsoon climate change, while the chemical weathering process exhibits a complex relationship with the monsoon climate. Temperature, precipitation, vegetation, and glaciers may all play significant roles in controlling these processes in specific times. The sediments in the BoB are mostly weathered products transported by surrounding rivers, particularly from the Ganges-Brahmaputra (G-B) River that transports great amounts of materials from the TP, and partially from Myanmar and Indian Peninsula. The TP has consistently contributed >70% terrigenous materials to the BoB with little changes since the LGM. However, contributions from each provenance varied significantly on a millennial scale. The BoB shelf developed typical storm-controlled delta-shelf deposits. As two most-significant regional transport driving forces, the bottom turbidity current and surface circulation had a crucial impact on the composition and distribution of deep-sea fan sediments. In general, the evolution of the TP - BoB “source-sink” system since the LGM is mainly controlled by the Indian Summer Monsoon (ISM) and sea level changes. In the future, more attention shall be paid to develop the joint land-sea long-term observation of modern deposition processes, and focus on the accurate interpretation of environmental signals in sedimentary records and response mechanism of weathering processes to monsoon climate change. With numerical simulation technology and marine big data, the evolution and environmental impacts of TP - BoB “source-sink” system under the fast global changes deserve more investigations. Meanwhile, comparative studies on other typical source-sink systems in the continental margins of the world shall be strengthened.