GNGTS 2015 - Atti del 34° Convegno Nazionale

between z and the resonance frequency (hereinafter f 0 ) by means of seismic noise measurements and by using the HVNSR method (e.g., D’Amico et al. , 2008; Gosar and Lenart, 2010, Ibs-von Seht and Wohlenberg, 1999), by using the HVNSR method (e.g., Mucciarelli 1998; Nakamura 1989). The z vs f 0 empirical equation is as follows: z = a . f 0 b , where a and b are two parameters calculated from best fitting technique (Ibs-von Seht and Wohlenberg, 1999). Western L ’ Aquila Plain geological setting. In this paper, we report the above empirical correlation and the Quaternary sedimentary cover thickness mapping for the Western L’Aquila Plain (hereinafter WAP), struck by an earthquake on April 6, 2009 (Mw: 6.3) (e.g., Galli et al. , 2010; Milana et al. , 2011). WAP is a typical WNW-ESE trending Quaternary basin of the central Apennines thrust and fold belt placed here in the lower Pliocene-upper Miocene times. WAP originates from Quaternary activity of the S-dipping extensional master fault of the Pettino Mt. (Galli et al. , 2010). Its activity produced a graben filled with Quaternary-upper Pliocene (?) clayey-sandy- gravelly deposits of lacustrine, fluvial and slope environments (unit C, Fig. 1) which rests on the Meso-Cenozoic carbonate bedrock (unit D, Fig. 1) (Gruppo di Lavoro MS–AQ, 2010; Tallini et al ., 2012). Moreover, the hill of downtown L’Aquila is characterized by 100-m thick calcareous breccia (unit B, Fig. 1) laying on the C unit as testified by deep boreholes (Del Monaco et al. , 2013). The unit A (Fig. 1) consists of Holocene-Upper Pleistocene alluvial- colluvial-slope deposits characterized by a gravelly-sandy-clayey lithologies, which lay upon the above-mentioned units (Del Monaco et al ., 2013). Fig. 1 – Western L’Aquila Plain (WAP) simplified geological map. 1- alluvial, colluvial and slope deposits (unit A) (Holocene - Upper Pleistocene); 2- Calcareous breccia (unit B) (Middle Pleistocene); 3- fluvial and lacustrine pelite and sand (unit C) (Lower Pleistocene); 4- Meso-Cenozoic bedrock (unit D); 5- main boreholes used for z vs f0 relationship (red number refers to bedrock depth, blue abbreviation refers to borehole in Fig. 1); 6- seismic reflection profile in Tallini et al. (2012). 82 GNGTS 2015 S essione 2.2