Multiparametric data analysis for seismic source identification in the Campanian area: merging of seismological, structural and gravimetric data

This paper deals with an interdisciplinary research that has been carried out to
investigate the neotectonic activity of the Campanian plain and surrounding areas
(southern Italy), affected by Plio-Pleistocene tectonics and volcanic activity. Three
thematic data sets have been generated for this area, “fault”, “earthquake” and
“gravimetric” data sets, respectively. These data sets allow an integrated analysis of the
structural, seismic and gravimetric data in GIS environment with the aim of
identifying the active structural lineaments that accommodate the local stress through
seismic activity. In detail, an original map with Plio-Quaternary tectonic structures of
the Campanian plain and its margins, constrained by morpho-structural analysis
and/or geophysical exploration data, is presented. The available earthquake data sets
have been merged in a single data set, including seismicity in the Campanian area
from 217 b.C. to 2010; processing of seismic data for new precise earthquake
locations have been carried out for some clusters of events with poor data, for better
constraining existence and activity of some outcropping and buried tectonic
structures. As regards the gravimetric data set, a Multiscale Derivative Analysis
(MDA) of the gravity field of the area has been performed, relying on the high
resolution properties of the Enhanced Horizontal Derivative (EHD). MDA of gravity
data allowed localization of several linear and close trends, identifying anomaly
sources whose presence was not previously detected. Our integrated analysis shows
that a strong correlation occurs among the new hypocentral locations of the seismic
clusters matching the fault systems of the Massico Mt. and Avella Mts., and the MDA
lineaments from gravity data relative to the same tectonic structures.