We present the first geology-based, multi-scale stress maps derived from approximately 8,000 Plio-Quaternary fault-striation pairs across Peninsular Italy’s seismogenic extensional belt. Stress-field inversions were performed at structural site, fault system, and crustal domain scales, allowing high-resolution mapping of long-term stress orientations while preserving local complexity. Results show dominant, near-pure extensional kinematics, with minor local oblique or strike-slip components. The minimum principal stress axes (σ₃) exhibit radial patterns along major bent faults and outward-convex arcs in the Central-Northern Apennines and the Southern Apennine–Calabrian ridge. These stress arcs flank two thinned crustal domains: the Tuscan–Northern Tyrrhenian and the Southern Tyrrhenian regions. While the stress regime remains consistently extensional along the belt, stress ratio (Φ) values exhibit a north-to-south transition from uniaxial tension (prolate ellipsoid) to radial tension (oblate ellipsoid). This gradient is likely controlled by crustal thickness and composition variations, topographic elevation, heat flow, and/or inherited structural anisotropies. Finally, we integrate stress inversion results with geodetic and seismological datasets using a hybrid gridded model of extensional directions. This cross-disciplinary synthesis validates the geological stress field and provides new insight into seismogenic processes and transient phenomena not always captured in seismic records.
First geology-based multi-scale Quaternary stress maps along Peninsular Italy’s seismic heartland
Andrenacci C.;Bello S.;Brozzetti F.;Pietrolungo F.;De Nardis R.;Lavecchia G. ¹⁻²
2025-01-01
Abstract
We present the first geology-based, multi-scale stress maps derived from approximately 8,000 Plio-Quaternary fault-striation pairs across Peninsular Italy’s seismogenic extensional belt. Stress-field inversions were performed at structural site, fault system, and crustal domain scales, allowing high-resolution mapping of long-term stress orientations while preserving local complexity. Results show dominant, near-pure extensional kinematics, with minor local oblique or strike-slip components. The minimum principal stress axes (σ₃) exhibit radial patterns along major bent faults and outward-convex arcs in the Central-Northern Apennines and the Southern Apennine–Calabrian ridge. These stress arcs flank two thinned crustal domains: the Tuscan–Northern Tyrrhenian and the Southern Tyrrhenian regions. While the stress regime remains consistently extensional along the belt, stress ratio (Φ) values exhibit a north-to-south transition from uniaxial tension (prolate ellipsoid) to radial tension (oblate ellipsoid). This gradient is likely controlled by crustal thickness and composition variations, topographic elevation, heat flow, and/or inherited structural anisotropies. Finally, we integrate stress inversion results with geodetic and seismological datasets using a hybrid gridded model of extensional directions. This cross-disciplinary synthesis validates the geological stress field and provides new insight into seismogenic processes and transient phenomena not always captured in seismic records.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
