The Southern Apennines chain is related to the west‐dipping subduction of the Apulian lithosphere. The strongest seismic events mostly occurred in correspondence of the chain axis along normal NW–SE striking faults parallel to the chain axis. These structures are related to mantle wedge upwelling beneath the chain. In the foreland, faulting develops along E–W strike‐slip to oblique‐slip faults related to the roll‐back of the foreland. Similarly to other historical events in Southern Apennines, the I0 = XI (MCS intensity scale) 23 July 1930 earthquake occurred between the chain axis and the thrust front without surface faulting. This event produced more than 1400 casualties and extensive damage elongated approximately E‐W. The analysis of the historical waveforms provides the chance to study the fault geometry of this “anomalous” event and allow us to clarify its geodynamic significance. Our results indicate that the MS = 6.6 1930 event nucleated at 14.6 ± 3.06 km depth and ruptured a north dipping, N100°E striking plane with an oblique motion. The fault propagated along the fault strike 32 km to the east at about 2 km/s. The eastern fault tip is located in proximity of the Vulture volcano. The 1930 hypocenter, similarly to the 1990 (MW = 5.8) Southern Apennines event, is within the Mesozoic carbonates of the Apulian foredeep and the rupture developed along a “blind” fault. The 1930 fault kinematics significantly differs from that typical of large Southern Apennines earthquakes, which occur in a distinct seismotectonic domain on late Pleistocene to Holocene outcropping faults. These results stress the role played by pre‐existing, “blind” faults in the Apennines subduction setting.

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On 30 October 1930, an M w 5.8 earthquake hit the northern Marche coastal area (central Italy), causing significant damage (I 0 VIII-IX degree Mercalli-CancaniSieberg) along a 40 km stretch of the Adriatic coast between Pesaro and Ancona, centered on the town of Senigallia. This area is characterized by relatively infrequent and moderate-sized earthquakes and by elusive active faults. In spite of the presence of wellknown northwest-southeast-trending, northeast-verging fault-propagation folds forming the outer thrusts of the Apennines, the current level of activity, and the kinematics of these coastal structures are still controversial.We present a multidisciplinary analysis of the source of the 30 October 1930 Senigallia earthquake, combining instrumental and macroseismic data and elaborations with available evidence from geological and tectonic investigations. We determine the main seismic parameters of the source, including the earthquake location, its magnitude, and, for the first time, its focal mechanism, providing the first instrumental evidence for thrust faulting along the northern Marche coastal belt.Our findings provide conclusive evidence for the current activity of the northern Marche coastal thrusts. As such they have significant implications for the seismic hazard of the area, a densely populated region that hosts historical heritage, tourism facilities, industrial districts, and key transportation infrastructures.Online Material: Description of method used for moment tensor computation, tables of focal mechanisms and recording stations, and figures of seismic flux and uncertainty maps for macroseismic epicenters.

We present a method for the rapid determination of the moment tensor suitable for application to regional earthquakes up to 3000 km distance. The algorithm is based on the inversion of long‐period waveforms in the time‐domain and is routinely applied to significant events of the Mediterranean, from Iran to the Azores, using digital data recorded by the MedNet regional network. We show results for 20 significant earthquakes of 1990–1992, including the large shocks in Romania (May 30, 1990), Iran (June 20, 1990), Caucasus (April 29, 1991), Turkey (March 13, 1992) and Egypt (October 12, 1992), the damaging Italian earthquakes of Potenza (May 5, 1990) and Siracusa (December 13, 1990), unusual events in the Southern Mediterranean (November 11, 1990) and Holland (April 13, 1992) and the recent shocks of October 23, 1992 in Morocco and Caucasus. The comparison with published focal mechanisms and Centroid Moment Tensors show our results to be consistent with those retrieved using global data and local networks, proving that an advanced regional seismic network is capable of providing accurate, rapid control of regional seismicity.

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