The Kunlun Fault is a major left-lateral strike-slip fault stretching more than 1,500 kilometres across the northern Tibetan Plateau in Qinghai Province, roughly parallel to the Altyn Tagh Fault to its northwest. Like its neighbour, it helps accommodate the eastward extrusion of Tibetan crust driven by the ongoing collision of India with Asia.
The fault slips at around 10 to 12 millimetres per year and is one of the fastest-moving structures within the plateau interior. Its long, continuous traces cross high, remote terrain, allowing single ruptures to extend for hundreds of kilometres.
Its most famous event is the magnitude 7.8 Kunlun (Kokoxili) earthquake of 2001, which tore an extraordinary surface rupture roughly 400 kilometres long, one of the longest ever documented. Because the region is sparsely inhabited, that giant quake caused relatively few casualties despite its enormous size.