GLOBAL WARMING, GLACIER MELTING, RIVER INCISION, AND ALTYN TAGH FAULT EARTHQUAKES DURING THE EARLY PLIOCENE WARMTH

Global warming may have been causing a series of disaster chain responses but our understanding of them is incomplete. Climate changed from being cool to warm at the early Pliocene at ~5 Ma, somewhat similar to the last glacial to the future. Thus, disaster chain responses of this interval may inform risks of disaster chain responses from the last glacial to the future. Here we demonstrate rapid kilometer-scale downward erosion in the Altyn Tagh Fault area synchronous with early Pliocene climate warmth, which we attribute to alpine glacier melting and associated downward river incision. River incision may have decreased the overburden of the Altyn Tagh Fault and triggered strike-slip earthquakes, resulting in tens of kilometers of left lateral movements since then. If the early Pliocene warming is an analog to the near future climate as many suggest, it suggests that active earthquakes may have been accumulating at the several thousands of km long Altyn Tagh fault and other faults bounding alpine glaciers. Furthermore, considering the mountain ranges bounding the Tarim Basin were mostly uplifted by the mid-Miocene time, we propose that the Taklimakan Desert formed due to abundant sand supplies by abrupt meltwater erosion at ~5 Ma, rather than the rise of surrounding mountains.