Depth Distribution of Earthquakes in the Kuril–Kamchatka Subduction Zone

Depth distribution is an important parameter of regional seismicity. In this paper, we examine the feasibility of using two-parameter analytical functions to approximate the distribution of earthquake depths relative to a slab in the Kuril-Kamchatka subduction zone and the distribution of absolute earthquake depths for shallow crustal events in the Okhotsk and Pacific plates. It is shown that the wealth of instrumental seismic monitoring data acquired over half a century combined with the new Earth’s structure models (SLAB 2.0) have now made it possible to describe the observed the depth distribution data analytically. Depth distributions were obtained independently for intraslab, interplate, and shallow events. According to our estimates, normal distribution relative to the slab interface is optimal for intraslab and interplates events, while the Weibull distribution proved to be the best fit for shallow events.