Publication Date:
2017-05-12
Description:
The accurately reconstructed geometry of the subduction interface is a crucial element for seismic and tsunami
hazard studies that require realistic modelling of future earthquake ruptures.
The Calabrian Arc is a cornerstone in the Mediterranean plate-tectonics puzzle and understanding its geometry
and behavior may strongly contribute to estimating the seismic and tsunami hazard in the region. Besides, it has
occasionally be blamed to have generated some past large earthquakes and tsunamis, despite it shows no sign
of significant seismic activity on the shallow portion of the interface. In addition, significant in-slab seismicity
is recorded below 40 km depth and a rate of 1-5 mm/yr characterize the convergence between the two plates
involved, Africa and Europe.
An accurate 3D reconstruction of the Calabrian subduction plate interface based on the interpretation of ca.
9000 km of seismic reflection profiles, provided in the collaborative framework between Spectrum and INGV
(CA-60), allows us to detail the architecture of the shallow part of the subduction interface (〈20 km).
The resulting 3D model images the peculiar features that characterize the Calabrian subduction interface:
1) an external flat at 5-8 km depth located under an accreted Messinian evaporites wedge;
2) a central ramp cutting between 8-14 km depth with high roughness and lateral variations of the dip angle;
3) a deeper flat between 14 and 20 km;
4) the overthrusting over the continental Apulia margin in the northern part;
5) the Subduction Transform Edge Propagator (STEP) fault system guiding the southeastern propagation of the
subduction;
The deeper part of the subducted slab was reconstructed by analysing the seismicity distribution and the
available tomographic data and allows us to highlight the progressive development from north to south of the slab
breakoff at 100-150 km depth.
The detailed 3D reconstruction allows us to also estimate the rock volume involved in the accretionary wedge
building and to compare the geometrical features of the subduction interface with the surficial ongoing processes
(i.e. uplift rates) in the Calabrian Arc.
Description:
The Italian Flagship Project RITMARE; the TSUMAPS-NEAM Project, co-financed by the European Union Civil Protection Mechanism, Agreement Number: ECHO/SUB/2015/718568/PREV26; the INGV Centro per la Pericolosità Sismica (CPS, Seismic Hazard Centre); and the project MASSIMO - Cultural Heritage Monitoring in Seismic Area, PON01/02710 - coordinated by INGV and funded by the Italian Ministry of Education, University and Research. Spectrum Geo Inc. provided the CA99, MEM07, and GT08 seismic profiles under the confidentiality agreement CA-60 with INGV;
Description:
Unpublished
Description:
Wien
Description:
5T. Modelli di pericolosità sismica e da maremoto
Description:
2TR. Ricostruzione e modellazione della struttura crostale
Keywords:
Subduction
;
Calabrian arc
;
Subduction interface
;
3D modelling
;
Seismic interpretation
;
Calabrian arc
;
Accretionary wedge
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Poster session
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