Observations on the rotational seismic wavefield recorded in the Campi Flegrei volcanic area.

In recent years, the use of rotational seismometers has been improved to investigate the full wavefield of earthquakes through the joint use of transational and rotational components of motion. The preliminary results shown in the present communication refer to the analisys carried out on the data recorded by a rotational seismometer installed in the Campi Flegrei volcanic area. Starting from the first months of the year 2021, the first rotational seismometer (Lunitek Tellus R based on magnetichydrodynamic technology) was installed close to a broad band sensor Guralp CMG40T (60 s) and an Episensor Kinemetrics. The collected data is composed by the low magnitude local seismicity ({$MDmax = 3.6$) with hypocentral depths between 0.3 and 4 km b.s.l. For the selected earthquakes ({$MD$ > $1.7$), coherence and cross-correlation methodologies were applied to obtain directional features of incoming recorded wavefield. The joint use of rotational and accelerometric sensors confirmed the possibility of estimating directinal features of the incoming wavefront and highlighted correlated phases on the coda of seismograms providing useful indications about the diffuse wavefield recorded in the investigated area.