Assessment of Strong Earthquake Risk in Maqin–Maqu Segment of the Eastern Kunlun Fault, Northeast Tibet Plateau

Abstract

The East Kunlun Fault Zone, as a highly seismically active fault, has witnessed five earthquakes with magnitudes exceeding M7.0 to the west of Animaqing Mountain since 1900. Conversely, the historical records for the Maqin–Maqu segment in the east of Animaqing Mountain show no M7.0 or above earthquakes, designating it as a distinctive seismic gap within this fault zone. We analyzed the tectonic background and structural features of the Maqin–Maqu segment within the East Kunlun Fault Zone to evaluate its potential seismic capacity. Utilizing a new established probability recurrence model, we calculated the seismic hazard for both segments over the next 100 years. The results indicate that the probability of M7.0 or above earthquake occurring in the Maqu segment in the next 100 years is 11.47%, classified as a moderate probability event. The joint probability of at least one M7.0 or above strong earthquake occurring in the entire Maqin–Maqu segment in the next 100 years is 16.14%, also classified as a moderate probability event, while the probability for the Maqin segment alone is 5.36%, classified as a low probability event. Considering the uncertainty of the probability model, a qualitative hazard classification for each segment was further conducted. The comprehensive evaluation suggests a low risk of a major earthquake occurring in the Maqin segment in the next 100 years, while the Maqu segment is assessed to have a higher risk.