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For the first time, a numerical comparison of the General Seismic Zoning (GSZ) maps with the effect of earthquakes that actually occurred after the publication of the maps was carried out. The area of zones of expected intensity on the GSZ map is compared with the area of isoseists from actual earthquakes. It turned out that the isoseist area is on average by an order less than expected according to the GSZ. This paper describes possible reasons for such an overestimation and proposes ways to improve seismic hazard assessments. [ABSTRACT FROM AUTHOR]

Risk assessment of seismic landslides in potential earthquake zones is important for construction in mountainous areas. To present a new method for conducting risk assessment of landslides, data of 720 landslides caused by the Ludian Ms6.5 earthquake, which occurred in 2014, are taken as a sample, and five impact factors are selected as risk assessment indexes; these factors include the slope, slope direction, elevation, strata lithology, and peak ground acceleration. Fractal theory and the result of the landslide distribution analysis of the Ludian earthquake are adopted to calculate the weight of each impact factor. The proposed risk assessment method is established by calculating the landslide distribution density. Under an assumed earthquake, the method is used for conducting risk assessment in the Dayong Expressway region; the topography and geology of this region are very similar to those of the Ludian County. The landslide risk zoning in the region can be obtained using the K-means cluster method to classify the risk level after the assignment of the landslide risk index. The result shows that a 2.25-km route of the Dayong Expressway has the highest risk of geological disasters with an occurrence probability of 1.1% considering the influence of the Chenghai fault. The assessment results can provide a scientific basis for disaster prevention in the Dayong Expressway area. [ABSTRACT FROM AUTHOR]

On 3 July 2015, the Mw 6.5 Pishan earthquake occurred at the junction of the southwestern margin of the Tarim Basin and the northwestern margin of the Tibetan Plateau. To understand the seismogenic mechanism and the post-seismic deformation behavior, we investigated the characteristics of the post-seismic deformation fields in the seismic area, using 9 Sentinel-1A TOPS synthetic aperture radar (SAR) images acquired from 18 July 2015 to 22 September 2016 with the Small Baseline Subset Interferometric SAR (SBAS-InSAR) technique. Postseismic LOS deformation displayed logarithmic behavior, and the temporal evolution of the post-seismic deformation is consistent with the aftershock sequence. The main driving mechanism of near-field post-seismic displacement was most likely to be afterslip on the fault and the entire creep process consists of three creeping stages. Afterward, we used the steepest descent method to invert the afterslip evolution process and analyzed the relationship between post-seismic afterslip and co-seismic slip. The results witness that 447 days after the mainshock (22 September 2016), the afterslip was concentrated within one principal slip center. It was located 5–25 km along the fault strike, 0–10 km along with the fault dip, with a cumulative peak slip of 0.18 m. The 447 days afterslip seismic moment was approximately 2.65 × 1017 N m, accounting for approximately 4.1% of the co-seismic geodetic moment. The deep afterslip revealed that a creeping process from steady-state "secondary" creeping to accelerating "tertiary" creep in the deep of fault. The future seismic hazard deserves further attention and research. [ABSTRACT FROM AUTHOR]