Deep structure of the crust in the area of the 2016-2017 Central Italy
seismic sequence from receiver function analysis
We compute a high-resolution topographic model of the Moho beneath the
faulting system activated during the 2016-2017 Central Italy seismic
sequence, using Receiver Function (RF) analysis. We document that Ps
conversions recorded in RF data-set varies abruptly at very short
distance across the crustal lineament called Ancona-Anzio Line (AAL).
Moho depth varies from about 20-30 km in the Tyrrhenian domain on the
West to 35-40 km in the Adriatic domain in the East. Where the two
domains are juxtaposed along the AAL, Moho depth values cluster around
50 km depth, in a stripe-like area 20 km wide. Such unique features
marks the deformation zone in the lithosphere and testifies the abrupt
change in delamination style in the two sectors of the Apennines.
Intermittent large normal faulting earthquakes driven by across-belt
extension break through such inherited strong structural changes
although conditioned by localized barriers to fluids migration and