GNGTS 2017 - 36° Convegno Nazionale

58 GNGTS 2017 S essione 1.1 and induced several environmental effects (Alessio et al. , 1996; Cubellis and Luongo, 1998; Violante et al., 2003; Esposito et al. , 2006). Following the mainshock on August 21, 2017 also the EMERGEO Working Group (http:// emergeo.ingv.it/ ) activated immediately in order to survey the possible surface coseismic effects. In this paper we present the data collected in the field and the preliminary results of the observed coseismic features. Field data survey. A composite surveying team (INGV and CNR / IAMC) activated since August 22 to report the first cosmic effects at the surface. The Emergeo working group investigated the epicentral area and surroundings for a total length of about 2 km between the Fango (Lacco Ameno), to the west, and Bagni (Casamicciola), to the east, covering a total area of ​2.5 km 2 . So far, about 50 observation points have been collected as different geological coseismic effects (Fig. 2). Field mapping and data management was mainly performed using the standard procedures adopted in previous Emergeo surveys (Emergeo Working Group, 2012, 2016). In general, the whole investigated area shows different fractures on both manufactures and ground, on road and on ground cover, with direction from WNW-ESE to E-W and WSW-ENE (Fig. 2), and lengths up to some tens of meters. In addition, some fractures in the soil are fairy with openings of about 3 cm, and in some cases a vertical component of appreciable displacement with lowering of the ground Northward. Widespread sliding phenomena of drywalls were also observed, with direction of movement from south to north, as well as modest gravitational phenomena such as small size collapses of several m 3 , and small landslides in volcanoclastic deposits. The area characterized by these gravitational phenomena is again along the northern slope of Mt. Epomeo. Fig. 2 - Coseismic surface effects: a) and b) surface rupture in via Crateca, Fango (Lacco Ameno) locality; c) surface rupture in via Montecito (Casamicciola); d) landslides in volcanoclastic deposits in via S. Barbara (Casamicciola); e) landslides in volcanoclastic deposits and sliding phenomena of drywalls in via Nizzola (Casamicciola).