Shallow Creep on the Laohushan Segment of the Haiyuan Fault, Northeastern Tibetan Plateau, Detected With Dense Near‐Field GPS Measurements

Abstract

Abstract While shallow creep along the Haiyuan fault is a key element in estimating earthquake potential, both the creep rate and spatial distribution inferred from InSAR and repeating earthquakes are still controversial. In this study, we resolve two potentially separated creeping patches along the Laohushan fault (LHSF) based on dense near‐field GPS measurements of 39 stations. The largest creeping patch, which extends ∼20 km along‐strike and ∼9 km down‐dip with a slip rate of 4.2 mm/yr, spatially correlates with seismicity, especially repeating earthquakes. The locked segment is capable of producing an earthquake of Mw 7.3 ± 0.1, with moment rate of (1.08 ± 0.39) × 1017 N⋅m/yr, possibly following the cycle since the 1092 M8 event. The lack of GPS measurements in the near‐field makes it unclear whether the 8 km section between these two patches is slowly creeping below detection threshold or has relocked due to change in environmental condition.

Keywords

• shallow creep
• laohushan fault
• haiyuan fault
• GPS measurement
• earthquake potential
• seismic moment rate