Fig. 1

Geodynamic setting of the Ionian Sea-Calabrian Arc subduction. a The Tindari Letojanni (TL) and Palinuro STEP fault system are from refs. ^{19, 20, 27}. The 2002–2017 earthquakes are from http://cnt.rm.ingv.it/ and the focal mechanisms of earthquakes with hypocentral depth <30 km and Md > 4 are from http://www.eas.slu.edu/eqc/eqc_mt/MECH.IT/, respectively. b Location of the high and low Vp anomalies along the crustal profile A–A′ traced in a (data extracted from ref. ²¹); the top of the Ionian slab is also reported as dashed line. c Location of the high and low Vp/Vs anomalies along the crustal profile B–B′ traced in a (data extracted from ref. ²²)