The impact of loading-induced stress variation on the seismicity of active faults

Licentiate thesis, 2023

Surface loads such as the ocean, atmosphere, and continental water, constantly modify the stress field of the Earth’s crust. Most earthquakes occur at tectonic plate boundaries and such stress perturbations on the active faults at the plate boundaries may trigger earthquakes. Several previous studies reported that tides or hydrological loading could modulate seismicity in some areas. We elaborate on this idea and further investigate the accumulative effect of various loadings.

In this work, we compute the total Coulomb stress change created by hydrological loading, atmospheric loading, and non-tidal ocean loading from 2011 to 2016 in the Kamchatka-Kuril Islands-Japan region, and then compare it to the background earthquakes in the same period. This thesis contributes to our understanding of the complex interactions between surface loading and induced seismicity, which has important implications for earthquake hazard assessment and risk mitigation.