Non-volcanic tremor beneath the Central Range in Taiwan triggered by the 2001 Mw 7.8 Kunlun earthquake

Non-volcanic tremor (NVT) is an extended-duration and non-impulsive seismic signal observed away from volcanic regions. Although NVT has been found along the circum-Pacific subduction zones and the transform plate boundary in California, it is not clear whether NVT occurs in other tectonic environments. NVT is often associated with slow-slip events, and can be triggered instantaneously during the surface waves of teleseismic events. However, the underlying mechanisms of tremor generation remain mysterious. Here we show clear evidence of NVT beneath the Central Range (CR) in Taiwan triggered by the 2001 M-w 7.8 Kunlun earthquake in northern Tibet. Tremor occurs when the Love wave displacement is to the southwest (the lateral motion direction for the CR), suggesting a simple frictional response to the driving force. We hypothesize that tremor occurred on the weak basal detachment fault beneath the CR. Our observations indicate that tremor may exist at a wide range of active tectonic environments.