Active faulting and continental slope instability in the Gulf of Patti (Tyrrhenian side of NE Sicily, Italy): a field, marine and seismological joint analysis

Abstract

The Gulf of Patti and its onshore sector represent one of the most seismically\ud active regions of the Italian Peninsula. Over the period 1984–2014, about 1800 earthquakes\ud with small-to-moderate magnitude and a maximum hypocentral depth of 40 km occurred\ud in this area. Historical catalogues reveal that the same area was affected by several strong\ud earthquakes such as the Mw = 6.1 event in April 1978 and the Mw = 6.2 one in March\ud 1786 which have caused severe damages in the surrounding localities. The main seismotectonic\ud feature affecting this area is represented by a NNW–SSE trending right-lateral\ud strike-slip fault system called ‘‘Aeolian–Tindari–Letojanni’’ (ATLFS) which has been\ud interpreted as a lithospheric transfer zone extending from the Aeolian Islands to the Ionian\ud coast of Sicily. Although the large-scale role of the ATLFS is widely accepted, several\ud issues about its structural architecture (i.e. distribution, attitude and slip of fault segments)\ud and the active deformation pattern are poorly constrained, particularly in the offshore. An\ud integrated analysis of field structural geology with marine geophysical and seismological\ud data has allowed to better understand the structural fabric of the ATLFS which, in the study\ud area, is expressed by two major NW–SE trending, en-echelon arranged fault segments.\ud Minor NNE–SSW oriented extensional structures mainly occur in the overlap region\ud between major faults, forming a dilatational stepover. Most faults display evidence of\ud active deformation and appear to control the main morphobathymetric features. This aspect, together with diffused continental slope instability, must be considered for the\ud revaluation of the seismic and geomorphological hazard of this sector of southern\ud Tyrrhenian Sea

Hybrid GMPEs for Region-Specific PSHA in Southern Italy

“…In the upper plate, the Tindari-Letojanni Line is an important 6 of 33 NNW-trending dextral-or oblique-strike-slip system that was associated with the Mw 6.1, April 15, 1978, earthquake. This separates the extension along the Calabria western coast from the contraction for the southern Tyrrhenian coast ( [29,30], and references therein).…”

“…earthquake. This separates the extension along the Calabria western coast from the contraction for the southern Tyrrhenian coast ( [29,30], and references therein). Tectonic processes in Sicily appear to be more directly affected by the Africa and Eurasia convergence that according to current kinematic plate models acts along a N-NW to NW direction, at 3 mm/y to 8 mm/y (e.g., [31]).…”

Multiscale processes to describe the Eastern Sicily Seismic Sequences

“…Similarly, many other strong earthquakes in eastern Sicily during historic time were not associated reliably and unequivocally to a seismogenic fault: 1542 (M = 6.6), 1624 (M = 5.6), 1818 (M = 6.2), 1848 (M = 5.5), and 1990 (M = 5.3) Rovida et al, 2016]. The knowledge of the seismic sources is inevitably poorer in the Ionian and Tyrrhenian offshore where only in the very last years some more accurate studies were carried out [Argnani et al, 2009;Polonia et al, 2011Polonia et al, , 2012Cultrera et al, 2017;Gutscher et al, 2016].…”

Three‐Dimensional Modeling of Mount Etna Volcano: Volume Assessment, Trend of Eruption Rates, and Geodynamic Significance

“…The red dashed lines represent the Benioff‐Wadati contours of the slab (Sartori, ). Slab edge deformation is expressed by an array of NW‐SE trending oblique faults running from the southern Tyrrhenian Sea (ATLFS‐Aeolian‐Tindari‐Letojanni Fault System, see Barreca et al, , ; Cultrera et al, ) to the Ionian offshore (IF, Ionian Fault; NAF, North Alfeo Fault; see Gutscher et al, ; Polonia et al, ).,. (b) Geological and structural sketch map of the Etna volcano (modified from Branca, Coltelli, Groppelli, & Lentini, ) showing the distribution of volcanic products erupted during the main volcanic phases (a) Milo and Chiancone volcaniclastic deposits.…”