Qiliang Sun, Vittorio Maselli, X Wang, Shucheng Xie
Submarine landslides can generate catastrophic cascading hazards, including tsunamis. Tectonics and climate have long been hypothesized to influence slope instability, but how they control repeated slope failures over geological time scales is still unclear. In this study from the South China Sea, we find that >90% of the ∼1900-m-thick Plio-Quaternary succession consists of repeated submarine landslide deposits, and they commenced suddenly at about 5.5 Ma. We demonstrate that uplift of the Red River basin and associated strengthening of the Indian Summer Monsoon drive a regime shift in sediment supply, characterized by a sustained increase that persists to the present, steepening the margin slope and promoting sediment overpressure, thereby triggering widespread mass wasting. This study demonstrates a teleconnection between continental tectonic-climatic changes and submarine landslide activity, thereby advancing our understanding of repeated slope-instability phenomena within a source-to-sink stratigraphic framework and contributing to the reconstruction of Earth's history.