Influence of seasonal soil temperature variation and global warming on the seismic response of frozen soils in permafrost regions

Abstract

AbstractThere has been growing interest in seismic hazards in permafrost regions as development in those regions has increased. Because major infrastructure, such as natural gas pipelines, has been constructed in permafrost regions, it is necessary to evaluate the seismic safety of such a network system. As frozen soil's dynamic properties differ from those of its unfrozen state, the characteristics of seismic waves propagated through frozen soil layers in permafrost differ from those propagated through unfrozen soil. Thus, the dynamic properties and composition of frozen soil layers located between bedrock and the ground surface need to be realistically considered in evaluating the seismic hazards of permafrost regions. The frozen soil layer's composition greatly depends on soil temperatures which vary seasonally and are gradually increasing due to global warming, therefore it is necessary to consider soil temperature variation. In this study, comprehensive parametric site response analysis was carried out based on measured data regarding seasonal and annual temperature variation to investigate seismic hazards. The soil temperature variation between summer and winter and temperature increases due to global warming were the main considerations. The analysis results clearly show that the soil temperature variation significantly impacts seismic hazards in the permafrost region, leading to different site response characteristics than those in the non‐permafrost region.