Publication Date:
2023-10-26
Description:
This article has been accepted for publication in Geophysical Journal International ©:The Author(s) 2020. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Uploaded in accordance with the publisher's self-archiving policy.
All rights reserved
Description:
The application of a physics-based earthquake simulator to Central Italy allowed the
compilation of a synthetic seismic catalogue spanning 100 000 yr, containing more than
300 000 M ≥ 4.0 simulated earthquakes, without the limitations that real catalogues suffer in
terms of completeness, homogeneity and time duration. The seismogenic model upon which
we applied the simulator code was derived from version 3.2.1 of the Database of Individual
Seismogenic Sources (DISS; http://diss.rm.ingv.it/diss/), selecting, and modifying where appropriate,
all the fault systems that are recognized in the portion of Central Italy considered
in this study, with a total of 54 faults. Besides tectonic stress loading and static stress transfer
as in the previous versions, the physical model on which the latest version of our simulation
algorithm is based also includes the Rate and State constitutive law that helps to reproduce
Omori’s law. One further improvement in our code was also the introduction of trapezoidalshaped
faults that perform better than known faults. The resulting synthetic seismic catalogue
exhibits typical magnitude, space and time features which are comparable to those in real
observations. These features include the total seismic moment rate, the earthquake magnitude
distribution, and the short- and medium-term earthquake clustering. A typical aspect of the
observed seismicity in Central Italy, aswell as across thewhole Italian landmass and elsewhere,
is the occurrence of earthquake sequences characterized by multiple main shocks of similar
magnitude. These sequences are different from the usual earthquake clusters and aftershock
sequences, since they have at least two main shocks of similar magnitude. Therefore, special
attentionwas devoted to verifyingwhether the simulated catalogue includes this notable aspect.
For this purpose, we developed a computer code especially for this work to count the number
of multiple events contained in a seismic catalogue under a quantitative definition. We found
that the last version of the simulator code produces a slightly larger number of multiple events
than the previous versions, but not as large as in the real catalogue. A possible reason for this
drawback is the lack of components such as pore-pressure changes due to fluid-diffusion in
the adopted physical model.
Description:
Published
Description:
526–542
Description:
6T. Studi di pericolosità sismica e da maremoto
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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