Publication Date:
2021-01-29
Description:
eriods of accelerated seismicity have been
observed during the preparation process of many large earthquakes.
This accelerating seismicity can be detected by the Accelerated
Moment Release (AMR) method and its recent Revised version (RAMR)
when the two techniques are applied to earthquake catalogues.
The main aim of this study is to investigate the seismicity
preceding large mainshocks and possibly increase our comprehension
of the underlying physics. In particular, we applied both
the AMR and R-AMR to the seismicity preceding 14 large
worldwide shallow earthquakes, i.e. with focal depth less than
40 km, with magnitude M[6 for Mediterranean area, and M
C 6.4 in the rest of the world, occurred from 2014 to 2018. Twelve
case studies were analysed in the framework of SwArm For
Earthquake study project funded by ESA, comprising the period
2014–2016; two additional cases were also considered to confirm
the goodness of the methodology outside the period of the project
catalogues. In total, R-AMR shows better performances than AMR,
in 11 cases out of 14. In particular, in four out of 14 cases (i.e.
28.6%), the R-AMR method shows that acceleration exists due to
an evident clustering in time–space on the faults, thus guiding the
convergence of the fit; in seven cases (i.e. 50%) the R-AMR discloses
acceleration, although no clustering around the fault is
present; the remaining three cases (i.e. 21.4%) show no emerging
acceleration from background. Finally, when R-AMR is compared
with simulations, we verify that in most of the cases the acceleration
is real and not casual.
Description:
Published
Description:
4057–4087
Description:
7T. Variazioni delle caratteristiche crostali e precursori sismici
Description:
JCR Journal
Keywords:
earthquake
;
precursory acceleration
;
accelerated moment release
;
time to failure
;
04.06. Seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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