Underground Gas Storage as Benchmark for Seismic Attenuation Tomography in a Tectonically Complex Region (North-Eastern Italy)

We present a multiscale seismic attenuation tomography of a seismotectonically complex region in northern Italy hosting the well-characterized Collalto Underground Gas Storage (UGS). Beyond its specific relevance, this site provides a natural laboratory for assessing the ability of attenuation imaging to distinguish fluid-rich zones from highly strained, failure-prone volumes. We integrated scattering and absorption tomography models: scattering anomalies, between the two principal thrusts, highlight localized strain near fault tips; absorption tomography images the shallow UGS and reveals a deeper fluid-saturated volume. Seismicity concentrated around this deeper anomaly, exhibiting a pulsatory temporal pattern, suggests a fluid-driven role in the deformation processes. These findings show that attenuation tomography, combined with multiscale and complementary geophysical models, can resolve critical subsurface features related to fluids and strain. The approach is broadly applicable to geothermal and volcanic contexts and supports seismic hazard assessment in tectonically active regions where natural and anthropogenic processes may interact.