Surface ruptures database related to the 26 December 2018, MW 4.9 Mt. Etna earthquake, southern Italy

Abstract

We provide a database of the surface ruptures produced by the 26 December 2018 Mw 4.9 earthquake that struck the eastern flank of Mt. Etna volcano in Sicily (southern Italy). Despite its relatively small magnitude, this shallow earthquake caused about 8 km of surface faulting, along the trace of the NNWtrending active Fiandaca Fault. Detailed field surveys have been performed in the epicentral area to map the ruptures and to characterize their kinematics. The surface ruptures show a dominant right-oblique sense of displacement with an average slip of about 0.09 m and a maximum value of 0.35 m. We have parsed and organized all observations in a concise database, with 932 homogeneous georeferenced records. The Fiandaca Fault is part of the complex active Timpe faults system affecting the eastern flank of Etna, and its seismic history indicates a prominent surface-faulting potential. Therefore, this database is essential for unravelling the seismotectonics of shallow earthquakes in volcanic areas, and contributes updating empirical scaling regressions that relate magnitude and extent of surface faulting.

A New Way to Explore Volcanic Areas: QR-Code-Based Virtual Geotrail at Mt. Etna Volcano, Italy

“…In detail, the following morphologies can be observed: eruptive vents and fissures, spatter ramparts and cones, bombs, breccias, aa lava flows and few pahoehoe lava flows, in the proximity of the vents, and lava flow levees and ogives in aa lava flows. Etna, with the eastern flank characterized by instability (a and b modified after Villani et al [34]). (c) The geological map of the eastern flank is shown here, modified from Branca et al [35]; the de- [34]).…”

High-resolution surface faulting from the 1983 Idaho Lost River Fault Mw 6.9 earthquake and previous events

“…High-resolution surface deformation datasets from normal faults are limited to a few recent earthquakes 24 – 28 . Baize et al .…”

“…Information about surface faulting is used for seismic hazard studies in similar tectonic contexts in the world. Comparing of our database with similar databases 25 , 27 , 28 could help define probabilistic estimates to refine scaling laws 72 , 76 , 107 – 109 , and could integrate worldwide databases 29 , improving knowledge of global earthquake properties.…”

Database of Italian present-day stress indicators, IPSI 1.4

“…In both cases, the results are consistent within the error of each quality category. With regard to fault data, the collected field measurements are affected by uncertainties owing to qualitative and quantitative factors, such as environmental conditions, representativeness of the measured object and instrument maintenance, precision and accuracy 61 . With regard to the earthquake data, we refer to different worldwide catalogues (Italian CMT dataset, European Mediterranean RCMT catalogue, quick regional moment tensors and the TDMT-INGV catalogue) and to compare the results of the analysis before their inclusion in the database.…”