Large-Scale Interseismic Crustal Deformation, Fault Slip Rate, Coupling and Earthquake Potential in the Upper Yellow River Basin

Abstract

Abstract

The Upper Yellow River Basin (UYRB) is one of the most tectonically complex and seismically active regions in China, but the detailed crustal deformation and interseismic fault couplings, providing the essential parameters for geodynamics and seismic hazard analysis, are still unclear in this region. We thus adopt Sentinel-1 Synthetic Aperture Radar images to form frame-based line-of-sight velocity maps, and then derive a high-resolution surface deformation map around the UYRB. Slip rates and coupling states are further inverted for some active yet less-investigated faults. For instance, we estimate a right-lateral strike-slip motion of ~2.3–3.5 mm/yr along the Riyueshan Fault, and a thrust rate of ~2.0–3.5 mm/yr across the Lajishan Fault. Finally, the seismic moment budgets and the potential magnitudes are calculated based on the fault slip deficits and historical earthquakes. The accumulated moment deficit could produce earthquakes of MW ≥ 6.0 in most active faults, and up to MW ≥ 7.0 along the Dongdatan-Xidatan and Maqin-Maqu segments of the East Kunlun Fault and the Jinqianghe segment of the Haiyuan Fault. Our inverted slip rates, interseismic coupling states, and potential seismic moment on the active faults provide a basis for understanding kinematic processes and assessing seismic hazards within the UYRB.