Comparison of methods for macroseismic mapping: A case study of the 2016 Debarca-Plakenska earthquake

Abstract

The isoseismal map can directly reflect the damage degree of an earthquake, and it is an image representation of a seismic influence field or ground motion intensity field. This paper presents a comparative analysis of three methods used for generating macroseismic maps: manual isoseismal drawing, geostatistical interpolation method kriging and deterministic interpolation method natural neighbor. The objective is to test whether more automated methods can support the process of macroseismic mapping and reduce the subjectivity involved in manually drawn isoseismal lines. The analysis is based on data collected from earthquake that occurred on May 21, 2016, in the epicentral area Debarca-Plakenska, in the Republic of North Macedonia. A total of 82 intensity points, based on the European Macroseismic Scale, were supplemented with 17 additional intensity II points to ensure adequate closure of the macroseismic field and enhanced interpolation accuracy. The findings underscore the importance of selecting interpolation methods based on data characteristics. This research highlights the importance of properly collecting complete macroseismic data. Through the calculation examples, the best choice for this case study is the kriging interpolation method, which can be used to directly build a macroseismic field through intensity points.