Unveiling the hidden source of major historical earthquakes: A multi-scale, trans-disciplinary approach to the 1456 and 1688 Sannio earthquakes (Mw 7.0, southern Italian Apennines)
Year: 2025
Type: article
Abstract: The southern Apennine chain ranks among Europe's regions with the highest historical seismicity, yet its seismogenic structures remain poorly defined or completely unknown, including those of highly destructive Mw ∼7.0, 1456 and 1688 Sannio earthquakes, which are examined in this study. Using a multi-scale, interdisciplinary approach - combining detailed field investigations (stratigraphic, geomorphological, structural, and paleoseismological analyses), tephrochronological and OSL dating, and reassessment of macroseismic intensity distribution from archival sources - this study identifies a possible source for these earthquakes. It corresponds to a ∼45 km normal fault system composed by two main branches (Eastern Calore Fault and Western Calore Fault) with primary segments trending E-W to ESE-WNW and dipping N- to NNE. Segments extend along the southern border of both eastern and western Calore River sub-basins and are partially connected by NNW-SSE to N-S trending, east-dipping, transfer zone fault splays. Although the morphostructural evidence of Quaternary tectonic activity is unevenly expressed in both sub-basins, they share a similar Middle Pleistocene-to-Holocene morpho-sedimentary evolution, suggesting a common driving factor, ascribable to the sub-coeval activity of the fault segments delimiting both sub-basins. On a short-time scale, this study provides the first evidence of a post-14 ka occurrence of a paleoearthquake with a surface displacement ≳0.7 m, as well as of a decametric off-set affecting post-9 ka sediments. These coseismic surface ruptures have an estimated recurrence time of approximately 1400 years, with the two more recent events likely corresponding to the Mw ∼7.0, 1456 and 1688 Sannio earthquakes. Further detailed paleoseismological investigations are recommended to uncover direct evidence of co-seismic displacement linked to the 1456, 1688, and earlier earthquakes. • The Quaternary sedimentary infill of the Calore River basin exhibits an asymmetric geometry. • A 45-km long fault system led the morpho-sedimentary evolution of the Calore basin. • A ∼14 ka coseismic surface faulting (≥70 cm) occurred along the Calore fault. • Over the past 14 kyr, the same fault likely caused ten similar surface displacements. • The last two faulting events likely caused the Mw 7, 1456 and 1688 Sannio earthquakes.
Source: Quaternary Science Reviews
Institutions: University of Molise, University of Sannio, Institute of Environmental Geology and Geoengineering, National Research Council, Dipartimento della Protezione Civile, University of Naples Federico II, Istituto Nazionale di Geofisica e Vulcanologia, INGV Osservatorio Vesuviano, Université de Versailles Saint-Quentin-en-Yvelines, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Laboratoire des Sciences du Climat et de l'Environnement, Université Paris-Saclay, Geosciences Paris-Saclay
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,920
OpenAlex ID: W4408140662