Transient Creep on the Yarlung Zangbo Suture in Southern Tibet Triggered by the 2015 Gorkha (Nepal) Earthquake

Abstract

Large earthquakes often elevate seismicity in surrounding regions, as seen on the Xainza‐Dinggyê rift in southern Tibet after the 2015 M _W 7.8 Gorkha (Nepal) earthquake. In contrast, the EW‐trending Yarlung Zangbo suture (YZS), located directly north of this event, exhibits seismic quiescence. To understand its response, we utilized Sentinel‐1 data to derive a post‐Gorkha deformation field which shows a clear dextral motion on this suture. Pre‐Gorkha data confirmed the absence of this signal, strongly supporting that it was triggered slip by the Gorkha event. Given the lack of associated seismicity, we proposed this transient was primarily aseismic. Although whether the YZS is active is controversial, the triggered slip suggests it also accommodates partial shear strain between central Tibet and the rigid Indian plate. This case also provides us a unique opportunity to examine the diverse responses of faults under stress loading induced by large earthquakes and the following processes.