Evolution and variability of the Asian monsoon and its potential linkage with uplift of the Himalaya and Tibetan Plateau

Abstract

Uplift of the Himalaya and Tibetan Plateau (HTP) and its linkage with the evolution of the Asian monsoon has been regarded as a typical example of a tectonic-climate linkage. Although this linkage remains unproven because of insufficient data, our understanding has greatly advanced in the past decade. It is thus timely to summarize our knowledge of the uplift history of the HTP, the results of relevant climate simulations, and spatiotemporal changes in the Indian and East Asian monsoons since the late Eocene. Three major pulses of the HTP uplift have become evident: (1) uplift of the southern and central Tibetan Plateau (TP) at ca. 40-35 Ma, (2) uplift of the northern TP at ca. 25-20 Ma, and (3) uplift of the northeastern to eastern TP at ca. 15-10 Ma. Modeling predictions suggest that (i) uplift of the southern and central TP should have intensified the Indian summer monsoon (ISM) and the Somali Jet at 40-35 Ma; (ii) uplift of the northern TP should have intensified the East Asian summer monsoon (EASM) and East Asian winter monsoon (EAWM), as well as the desertification of inland Asia at 25-20 Ma; and (iii) uplift of the northeastern and eastern TP should have further intensified the EASM and EAWM at 15-10 Ma.We tested these predictions by comparing them with paleoclimate data for the time intervals of interest. There are insufficient paleoclimate data to test whether the ISM and Somali Jet intensified with the uplift of the southern and central TP at 40-35 Ma, but it is possible that such uplift enhanced erosion and weathering that drew down atmospheric CO 2 and resulted in global cooling. There is good evidence that the EASM and EAWM intensified, and desertification started in inland Asia at 25-20 Ma in association with the uplift of the northern TP. The impact of the uplift of the northeastern and eastern TP on the Asian monsoon at 15-10 Ma is difficult to evaluate because that interval was also a time of global cooling and Antarctic glaciation that might also have influenced the intensity of the Asian monsoon.

Mid‐Miocene initiation of E‐W extension and recoupling of the Himalaya

“…The initial drop in convergence rates approximately coincides with the beginning of widespread cessation of ductile motion on the South Tibetan detachment system (Godin, Grujic, Law, & Searle, ; Kellett et al, ) and the initiation of the first N‐S graben (Mitsuishi et al, ; this study), while the further reduction in convergence rate in the middle Miocene is coeval with the final termination of the South Tibetan detachment system and widespread development of brittle E‐W extensional structures (Ratschbacher et al, ). The middle Miocene slow down also coincides with greater sediment flux into basins (Clift et al, ), and peak strength of the monsoon system (Sun & Wang, ; Tada, Zheng, & Clift, ). The paired increase in sediment flux and monsoon strengthening could reflect formation of significant topography and during renewed deformation/mountain building (e.g.…”

Distinct control mechanism of fine‐grained sediments from Yellow River and Kyushu supply in the northern Okinawa Trough since the last glacial

“…IODP Site U1429 (31°37.04'N, 128°59.85'E) is located in the northern Okinawa Trough in water depths of 732 m (Figure a). Three holes were cored to a composite depth below seafloor (CCSF‐D) of 200 m [ Tada et al ., ]. For this study, we focused on the upper 20.99 m, which spans from the late last glacial to the Holocene.…”

The Asian Monsoon and its Future Change in Climate Models: A Review

“…Modeling studies suggest that the first uplift corresponded to an intensification of the Indian summer monsoon, and the second and the third caused intensification of the East Asian summer and winter monsoons. There is good evidence for a link between the second uplift and monsoon behavior: the East Asian summer and winter monsoon intensified and inland desertification started at 25-20 Ma, associated with uplift of the northern Tibetan Plateau (Tada et al 2016). Therefore, the Himalayas (or the southern Tibetan Plateau) intensify the Indian summer monsoon while the northern Tibetan Plateau intensifies the East Asian summer monsoon as well as the East Asian winter monsoon.…”

“…Geological evidence indicates three successive stages of uplift of the Himalayas and the Tibetan Plateau at (1) 40-35 Ma (southern and central Tibetan Plateau), (2) 25-20 Ma (northern Tibetan Plateau), and (3) 15-10 Ma (northeastern to eastern Tibetan Plateau) (Tada et al 2016). Recent modeling studies have demonstrated the different roles of the Himalayas and various regions of Tibetan Plateau uplift on Asian monsoons (Zhang et al 2012).…”