Publication Date:
2021-03-01
Description:
Seismic hazard studies have been undertaken at Etna volcano in the last
years with the aim of estimating the potential of local fault’s activity in generating destructive
earthquakes. The target is the mid-term assessment (30, 20, 10 and 5 yrs), as the identification
of zones that are exposed to the recurrent seismic shaking may be important for land planning
at a local scale, and it represents a valuable complement to establish priority criteria for seismic
risk reduction action.
The methodologies applied at Mt. Etna area include probabilistic approaches based on the
use of historical macroseismic data (the “site approach” by the software code SASHA, see
Azzaro et al., 2008) and fault-based time-dependent models in which occurrence probabilities
of major earthquakes are estimated through the Brownian Passage Time (BPT) function and
the time lapsed since the last event (Azzaro et al., 2012b, 2013b). Mean return period of major
earthquakes - strong to destructive events with epicentral intensity I0 ≥ VIII EMS, considered
as “proxies” of “characteristic” earthquakes – have been obtained by the fault seismic histories,
i.e. the associations “earthquake-seismogenic fault” derived from the historical catalogue of
Etnean earthquakes (CMTE Working Group, 2014). Inter-time statistics of major earthquakes
have been applied to the Timpe tectonic system, considered as a homogeneous seismotectonic
domain (Azzaro et al., 2013b), obtaining a mean recurrence time (Tmean) of 71.3 years, and an
aperiodicity factor α (σTmean/Tmean) = 0.42, typical of semi-periodic processes.
In the present study we present the preliminary results of an analysis aimed at verifying the
variability of the mean occurrence times of major earthquakes generated by the main tectonic
systems at Etna (Pernicana and Timpe faults) by using a geological approach based on geometrickinematic
parameters (3D dimensions, slip-rates etc) representative of fault activity.
Method and input data.
Description:
Published
Description:
Bologna, Italy
Description:
3T. Pericolosità sismica e contributo alla definizione del rischio
Description:
open
Keywords:
Seismic rate, faults
;
04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Extended abstract
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