Publication Date:
2017-04-04
Description:
Earthquakes deliver in few seconds the elastic energy accumulated in hundreds of years. Where and
when will be the next earthquake remains a difficult task due to the chaotic behaviour of seismicity
and the present lack of available tools to measure the threshold of the crustal strength.
However, the analysis of the background strain rate in Italy and the comparison with seismicity shows
that larger earthquakes occur with higher probability in areas of lower strain rate. We present a statistical
study in which a relationship linking the earthquake size (magnitude) and the total strain rate (SR) is
found. We combine the information provided by the Gutenberg–Richter law (GR) of earthquake occurrence
and the probability density distribution of SR in the Italian area. Following a Bayesian approach,
we found a simple family of exponential decrease curves describing the probability that an event of a
given size occurs within a given class of SR. This approach relies on the evidence that elastic energy accumulates
in those areas where faults are locked and the SR is lower. Therefore, in tectonically active areas,
SR lows are more prone to release larger amount of energy with respect to adjacent zones characterised
by higher strain rates. The SR map of Italy, compared with 5 years seismicity supports this result and may
become a powerful tool for identifying the areas more prone to the next earthquakes.
Description:
Published
Description:
67-75
Description:
3.1. Fisica dei terremoti
Description:
JCR Journal
Description:
restricted
Keywords:
Strain rate
;
Magnitude
;
Gutenberg–Richter law
;
Bayesian analysis
;
Seismic hazard
;
Italian area
;
L’ Aquila Emilia earthquakes
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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