Modern Approaches for Historical Seismograms: Moment Tensor Inversion of the 1947 Squillace Basin, South Italy, Earthquake

• DOI: 10.1785/0220230423
• Publication Date: 2024-04-11T09:10:16Z
• Authors: Silvia Scolaro; Josep Batlló; Barbara Orecchio; Debora Presti; Daniel Stich; Cristina Totaro
• Keywords: Moment tensor; Seismogram

Abstract The scientific community has become increasingly aware of the importance preserving and recovering historical seismic data, also because their possible use in combination with modern techniques analysis. Seismograms coming from analog recording era cover more than 100 yr activity may have a great relevance, especially for risk evaluations regions struck by destructive events past centuries but characterized minor last decades. In this study we used seismograms to investigate an earthquake presumed magnitude 5.7 that occurred 1947 central Calabria, south Italy, high-seismic region framed complex geodynamic setting led northwest-trending Nubia–Eurasia convergence southeastward Ionian slab rollback. According catalogs, is only M > 5.5 instrumentally recorded area where presence lateral edge been suggested intense debate still open concerning existence, proper location, subduction-transform propagator (STEP) fault zone. To earthquake, selected 15 medium- long-period related instrumental parameters, proceeded vectorization process waveform corrections. A technique specifically developed time-domain moment tensor computation through inversion applied digitized recordings. solution estimated indicates strike-slip mechanism, focal depth 28 km Mw 5.1. obtained hypocentral left-lateral kinematics on about west-northwest–east-southeast-oriented fit well local seismotectonic framework are compatible STEP furnishing new seismological constraint kinematics. Moreover, presented analysis useful sharing data methodological issues seismogram management.