Surface Rupture Zone Discovered for First Time After Tibet’s Baqing Earthquake

October 26, 2026 — A field team from the China Earthquake Administration has identified a surface rupture zone for the first time following the magnitude-7.0 earthquake in Baqing County, Nagqu City, in the Xizang Autonomous Region of southwestern China. The discovery provides important field evidence for studying fault activity, ground deformation and the geological impacts of the earthquake.

According to the administration, the field team located the rupture zone on October 25, approximately 15 kilometers east of the epicenter and about 20 kilometers from Maru Township in Baqing County. Investigations indicate that the earthquake involved primarily normal-fault rupture, accompanied by left-lateral strike-slip movement.

The rupture surface was nearly vertical, with vertical displacement of approximately 3.5 meters and localized horizontal displacement of about 0.9 meters. The rupture zone measured roughly 8 to 30 meters wide, and the fault extended north and south toward mountainous areas covered by snow.

Investigators also identified several areas of soil liquefaction and ground cracking. These features suggest that the earthquake caused substantial ground deformation and a range of geological impacts. Systematic measurements of these effects will help researchers analyze the fault-rupture process, the release of seismic energy and the way earthquake damage varies with local terrain.

The earthquake struck Baqing County at 10:33 p.m. local time on October 22, at a reported focal depth of approximately 10 kilometers. Reports available as of October 26 said that 16 people had died and 76 had been injured. Aftershocks continued following the main shock. According to China’s earthquake monitoring network, more than 2,000 aftershocks had been recorded by 8 a.m. on October 26, with the strongest measuring magnitude 5.7.

A surface rupture zone forms when fault movement during a strong earthquake reaches and deforms the ground surface. Its location, width and displacement are important measurements in earthquake geology. The newly identified rupture will provide baseline data for further research into fault geometry, damage assessment and regional seismic hazards.

Researchers are expected to combine field observations with geological mapping, remote-sensing imagery and geophysical measurements to develop a more complete understanding of the earthquake. Further analysis will be needed to clarify the rupture process and determine the full extent of its geological effects.

Continued aftershock monitoring and geological hazard inspections remain important in the affected area. The high-altitude terrain and changeable weather can complicate emergency operations, while ground cracks and unstable slopes may pose additional risks. Authorities will need to maintain inspections, monitoring and post-disaster assessments to protect residents and rescue personnel.

The first discovery of the surface rupture zone offers a significant new clue to understanding the Baqing earthquake. As more observations become available, researchers may be able to characterize the fault’s behavior more precisely and improve assessments of earthquake hazards across the Tibetan Plateau.