Probabilistic Seismic Hazard Assessments for Northern Southeast Asia

We present the evaluation of the 2018 Northern Southeast Asia Seismic Hazard Model (NSAHM18) based on combination of smoothed seismicity, subduction zone, and fault models. The smoothed seismicity is used to model observed distributed seismicity from largely unknown sources in current study area. In addition, due to short instrumental earthquake catalog, slip rate and characteristic earthquake magnitudes are incorporated through fault model. In order to achieve this objective, the compiled earthquake catalog and updated active fault database in this region were reexamined and mutually decided to utilize these input parameters. To take into account epistemic uncertainty, logic tree analysis has been implemented incorporating basic quantities such as different three tectonic regions ground-motion models (GMMs) for Shallow Active, Subduction Interface, and Subduction Intraslab, maximum magnitude, and earthquake magnitude frequency relationships. The seismic hazard results are presented in peak ground acceleration maps at 475 and 2475 year return periods.