Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China.
Department of Earth Sciences, Royal Holloway, University of London, Egham, TW20 0EX, Surrey, UK.
Sci Rep. 2021 Jan 15;11(1):1562. doi: 10.1038/s41598-020-79941-4.
The North Pacific subtropical gyre (NPSG) plays a major role in present global ocean circulation. At times, the gyre has coursed through the South China Sea, but its role in the evolutionary development of that Sea remains uncertain. This work systematically describes a major shift in NPSG paleo-circulation evident from sedimentary features observed in seismic and bathymetric data. These data outline two contourite depositional systems-a buried one formed in the late Miocene, and a latest Miocene to present-day system. The two are divided by a prominent regional discontinuity that represents a major shift in paleo-circulation during the latest Miocene (~ 6.5 Ma). The shift coincides with the further restriction of the South China Sea with respect to the North Pacific due to the formation of the Luzon Strait as a consequence of further northwest movement of the Philippine Sea plate. Before that restriction, data indicate vigorous NPSG circulation in the South China Sea. Semi-closure, however, established a new oceanographic circulation regime in the latest Miocene. This work demonstrates the significant role of recent plate tectonics, gateway development, and marginal seas in the establishment of modern global ocean circulation.
北太平洋亚热带回旋（NPSG）在当前全球海洋环流中起着重要作用。有时，该回旋流经南海，但它在南海的演化发展中的作用仍不确定。本工作系统地描述了从地震和水深数据中观察到的沉积特征中明显的 NPSG 古环流重大转变。这些数据勾勒出两个等深流沉积系统——一个是中新世晚期形成的埋藏系统，另一个是中新世晚期至今的系统。两者由一个显著的区域不连续带分隔开，该不连续带代表了中新世晚期（约 650 万年前）古环流的重大转变。这种转变与由于菲律宾海板块进一步向西北移动而形成的吕宋海峡，使得南海相对于北太平洋的进一步限制相一致。在此限制之前，数据表明 NPSG 在南海的环流十分活跃。然而，半封闭状态建立了一个新的海洋环流体系，这种新的体系在最新的中新世出现。这项工作表明了近期板块构造、海峡发展和边缘海在建立现代全球海洋环流中的重要作用。
