The interaction between active normal faulting and large scale gravitational mass movements revealed by paleoseismological techniques: a case study from central Italy.

Abstract

Paleoseismological techniques have been applied to characterize the kinematic behavior of large-scale gravitational phenomena located in proximity of the seismogenic fault responsible for the Mw 7.0, 1915 Avezzano earthquake and to identify evidence of a possible coseismic reactivation. The above mentioned techniques were applied along the surface expression of the main sliding planes of the Mt. Serrone gravitational deformation - located in the southeastern border of the Fucino basin (central Italy) - allowing us to detect instantaneous events of deformation along the uphill-facing scarp. These events are testified by the presence of faulted deposits and by colluvial wedges. The identified and chronologically-constrained episodes of rapid displacement can be probably correlated with seismic events determined by the activation of the Fucino seismogenic fault, affecting the toe of the gravitationally unstable rock mass. Indeed this fault can produce strong, short-term dynamic stresses able to trigger the release of local gravitational stress accumulated by Mt. Serrone’s large-scale gravitational phenomena.