ITaly HAzards from CApable faulting

Document Actions
ITaly HAzards from CApable faulting
Italy is one of most active regions of the Mediterranean area in terms of active tectonics and seismicity. Several historical catastrophic earthquakes (e.g., 1693 Eastern Sicily, 1783 Calabria, 1805 Molise, 1908 Messina and 1915 Fucino events) recorded MCS intensities up to XI (magnitude ca. or slightly above 7). Paleoseismological studies have been able to find and characterize the causative faults of these events, and have demonstrated that latest Pleistocene-to-Holocene displacements have affected many structures that previously were considered inactive.
The estimation of hazard derived from earthquakes and surface faulting that typically occur for magnitudes >6 is an important issue especially in densely populated and industrialized areas like the Italian territory. Consequently, mapping and characterizing capable faults assume a key role for the risk mitigation. To this purpose, the Geological Survey of Italy - ISPRA (Italian National Institute for Environmental Protection and Research) has developed the ITHACA project (ITaly HAzard from CApable faults), aimed at collecting and analyzing all available information on active tectonic structures in Italy. ITHACA is an important tool for a) environmental and seismic hazards analysis, b) understanding of evolving landscape, c) land-use planning, d) management of Civil Protection emergencies.
Moreover, it provides further elements for research studies focused on the analysis of geodynamic processes.
Capable faults are mapped and characterized in ITHACA based on available information in literature, after a careful and critical review. Consequently, the ITHACA database:
  • is always under revision and can never be considered complete and definitive;
  • does not represent the entire set of capable faults potentially affecting the national territory, but only those that have been characterized in literature, even if at a very low scale;
  • its coverage is not homogenous in the Italian territory. In fact, the level of detail depends on the quality of investigations (ranked in the field “Study quality” of the form associated to each fault) and on mapping scale (reported in the field “mapping scale”).
Specifically concerning microzonation studies, ISPRA disclaims any responsibility on the use of information collected in ITHACA for the detailed characterization of fault displacement hazard. Nevertheless, ISPRA is available to provide technical assistance to local Administrations, for a better knowledge of capable faults affecting their territory.
Furthermore, although capable faults are frequently also seismogenic structures, ITHACA database cannot be used to characterize the seismogenic source in terms of seismic shaking and ground motion. For these purpose, it is recommended to consult databases specifically focused on this topic (e.g. DISS – Database of Individual Seismogenic Sources).
A glossary containing the main definitions agreed at international level of the elements collected in ITHACA is available at the following link (pages 157-167).
The consultation of ITHACA from the Geological Portal through GeoMapViewer can be done by activating a specific service that allows to query the database (geographic and by attribute) providing to the user web forms containing specific information for each fault. For further information it is possible to contact the group of competence at ithaca@isprambiente.it