Seismotectonic model backing the PSHA and seismic zoning of Republic of Macedonia for National Annex to MKS EN 1998-1:2012 Eurocode 8

Abstract

The seismicity in Macedonia is associated with recent tectonic movements along normal faults. The normal fault tectonics is a consequence of extensional processes that started at the end of the Early Miocene, which affected the larger part of the Balkan region and still is present today. These vertical differential faulting processes, distinguished also as neotectonic, divided the terrains into uplifting (horsts) and subsiding blocks (grabens). The movements along some of those faults are active even today, particularly along the superimposed faults stretching east-west (EW) to northeast-southwest (NE-SW), which transversally cross the geological units and tectonic structures, representing areas of dominant seismic activity in Macedonia. The seismic activity of destructive nature, which affects the territory of Macedonia, is modeled by 10 seismotectonic zones with predominant EW and NE-SW orientation. With the proposed new seismotectonic model, we have fundamentally redefined the existing seismicity models of Macedonia. The paper presents and discusses in all necessary details the construction and elements of the seismotectonic model developed and adopted by Milutinovic et al. (2016) for the development of a seismic zoning map of Macedonia for National Annex FN MKC EN 1998-1:2012/NA:2018 to MKS EN 1998-1:2012 Eurocode 8.