Macroseismic intensity investigation of the November 2014, M=5.7, Vrancea (Romania) crustal earthquake

Abstract

On November 22, 2014, at 21:14:17 local time (19:14:17 GMT) an earthquake of local magnitude ML=5.7 occurred in the proximity of Marasesti city in Vrancea county (Romania) in the lower crust (39 km depth). It was the largest event recorded since 120 years in this area (the maximum magnitude was estimated at Mw 5.9 for an event occurred on March 1, 1894). The main shock was followed by more than 200 aftershocks detected and located by the Romanian seismic network during two months. Immediately after the main shock was recorded, the National Institute for Earth Physics (NIEP) sent macroseismic questionnaires to all affected areas, in order to define the macroseismic field of ground shaking. According to the macroseismic questionnaires survey, the intensity reached VI MSK in the epicentral area, and the seismic event was felt up to a distance of 600 km from the epicenter (practically in all the extra- Carpathian area). Also, this intensity value was estimated at 25 localities. The earthquake caused general panic, but the building damage was minor to moderate only. According to macroseismic observations, the damage area was extended mostly to the east and north from epicenter. After the collection of the macroseismic data and the evaluation of the macroseismic effects of this earthquake, an intensity dataset has been obtained for 680 sites. The main purpose of this paper is to investigate the macroseismic effects associated to this earthquake using the MSK-64 intensity scale in order to evaluate the impact on the regional seismic hazard assessment.