L' Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS
Doi
Abstract
In this paper, we report new GPS measurements which indicate active NE-SW
extension and strain accumulation in the Molise region (Apennines, Italy). The GPS
observations were collected during campaigns on benchmarks of the dense IGM95
network (average distance 20 km), spanning a maximum observation interval of 13
years, and have been integrated with measurements from the available permanent GPS
sites. Considering the differential motion of the GPS sites, located on the Tyrrhenian
and Adriatic coasts, we can evaluate a 4-5 mm/yr extension accommodated across this
part of the Apennines. The velocity field exhibits clusters of sites with homogeneous
velocity vectors, outlining two main divergence areas, both characterized by the
largest velocity gradients: one near Venafro and the other near Isernia where two
primary active faults and several historical earthquakes have been documented. These
results suggest that an active extension in this part of the Apennines can be currently
distributed between the two faults systems associated with the largest earthquakes of
this region