Description: Argnani (2021, hereinafter ARG2021) commented on the paper by Barreca et al. (2021, hereinafter BRC2021) titled: “The Strait of Messina: Seismotectonics and the source of the 1908 earthquake”, in which a new seismotectonic model and constraints on the possible source fault (the so-called W-Fault) for the 1908 disastrous seismic event were provided. Results from BRC2021 led to a revision of most of the previously published papers on the issue. ARG2021 commented both on the recent activity of the W-Fault and even about its existence in the offshore. In fact, according to the author's inferences: “it may belong to a fault system that is no longer active” and, contradictorily, “the offshore occurrence of the W-Fault is not supported by the data”. The comment is mostly based on a new tectonic interpretation that the author performed directly on the BRC2021 figures, where the offshore portion of the W-fault is illustrated. In this reply, we demonstrate that the interpretation provided by ARG2021 is affected by several oversights that led the author to erroneous conclusions about the issue. Accordingly, we strongly confirm both the occurrence of the W-Fault in the offshore and the present-day activity of this structure, the only active fault capable of producing large earthquakes in the Strait of Messina area.

Description: Published

Description: 103962

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: Argnani (2021) provides a commentary (hereafter ARGN) on our paper titled: “Deformation Pattern of the Northern Sector of the Malta Escarpment: Fault Dimension, Slip Prediction, and Seismotectonic Implications,” which was published in the journal Frontiers in Earth Science in January 2021 (Gambino et al., 2021, hereafter GAMB). Through the interpretation of eight new seismic profiles (six of which are reported in Supplementary Figure S1 of GAMB) crossing the Malta Escarpment, GAMB pointed to a better definition of the geometry of three active faults (F1, F2, F3) and their seismic potential by employing slip tendency modeling and forward analysis. The results suggest that F3 is prone to be reactivated under the achieved stress field and has the capacity of generating M 〉 7 earthquakes. ARGN raises concerns about the higher resolution and less penetration of the eight newly acquired high-resolution multichannel reflection seismic profiles and the seismic-stratigraphic pattern proposed by GAMB. According to ARGN, “the seismic profiles analyzed by GAMB belong to different sets and have very different seismic characters and resolution, making seismic facies correlation pretty difficult, also because no tie lines are available. As a result, stratigraphic correlations are highly speculative and the ensuing uncertainties undermine the timing of the tectonic evolution envisaged by GAMB, as well as the age and rate of activity of tectonic structures.” Furthermore, ARGN argues on the hypothesis of an early large-scale slope instability affecting the area. Most of the statements of ARGN seem to be based on his available older multichannel reflection seismic profiles, which have, indeed, a higher penetration but less resolution. We also agree that high-resolution digital multichannel seismic profiles are not easily comparable with low-resolution multichannel seismic lines, but we see the clear advantage of a state-of-the-art technology to image the upper strata of sedimentary systems. The used system proved its robustness in many different settings worldwide and has been successfully used for many pre-site surveys for drilling campaigns for the IODP and ICDP. As a result, we rebut point-by-point ARGN’s comments and stand by our model on the active deformation pattern and seismotectonics of the northern sector of the Malta Escarpment.

Description: Published

Description: 886439

Description: 2T. Deformazione crostale attiva

Description: JCR Journal