High-resolution crustal structure in the area of the 2016-2017 seismic sequence of Central Italy: insights from Receiver Function analysis

Author(s)

Nicola Piana Agostinetti, Claudio Chiarabba

Abstract

The 2016-2017 seismic sequence of Central Italy has been characterized

by the occurrence of medium to large magnitude events along a complex

fault system with diffuse seismicity distributed at different depth

levels. It has been shown that the rupture of the largest event

propagated along two different fault segments potentially associated to

complex shallow crustal seismic geometries. Moreover, along-strike

profiles of microseismicity clearly depict an heterogeneous

depth-distribution of hypocenters, suggesting that such complex

structure can extend to the mid-crustal level. Despite the huge amount

of seismic data available from active and passive seismic surveys, a

clear picture of the entire crust is still lacking. In this study, for

the first time, we depict the geometry of the main crustal seismic

discontinuities across the area of the 2016-2017 seismic sequence of

Central Italy. High-resolution receiver function (RF) have been computed

for about 70 temporary and permanent seismic stations deployed during

the sequence, with an inter-station distance between 5 and 10 km. Such

passive seismic data-set is used to (a) image the complex shallow

crustal structure associated to the multi-segmented events via CCP

migration, and (b) reconstruct a pseudo 3D S-wave velocity model of the

area based on single-station RF inversions. Our results provide new

constraints in terms of geometry of crustal seismic discontinuities and

S-wave velocity measurements for the entire area, to be compared with,

e.g. results from local earthquake tomography, seismicity relocation and

ambient noise measurements.

Organisation(s)

Department of Geology

External organisation(s)

Istituto Nazionale di Fisica Nucleare (INFN), Roma

Pages

13779

Publication date

04-2018

Peer reviewed

Yes

Austrian Fields of Science 2012

105102 General geophysics

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