Macroseismic intensities assessment of the August 21, 2017 Casamicciola earthquake at the Ischia volcanic Island (southern Italy)

Abstract

On August 21, 2017 at 20:57 (Local Time) a very shallow earthquake (ca 1.2 km depth) of Md=4.0 hit the Ischia island (Southern Italy) heavily damaging the Casamicciola Terme village and also the Lacco Ameno village, causing two fatalities and about 40 people injured. Soon after the mainshock we surveyed the area and collect macroseismic data in order to assess the MCS intensity and the ESI‐07 intensity values. We assigned the maximum intensity value I= VIII MCS at Casamicciola Terme on the basis of the damage to buildings and we assessed the epicentral intensity value I= VII ESI‐07 on the basis of primary and secondary coseismic ground effects. We point out that the Casamicciola volcano‐tectonic earthquake (Md=4), has had catastrophic consequences on local communities, therefore this study can provide relevant implications for seismic hazard evaluation and land use planning in the Ischia island.