Publication Date:
2017-04-04
Description:
We investigate the capability of the strongest earthquakes to modify sig-
nificantly the seismicity in a wide spatiotemporal window. In particular, we show that
the strongest earthquakes of last century were probably able to influence the seismicity
at large spatiotemporal distances, extending their reach over thousands of kilometers
and decades later. We report statistically significant differences in worldwide seismi-
city before and after the occurrence of the strongest earthquakes of the last century,
whose perturbation is modeled by means of coseismic and postseismic stress varia-
tions. This long-term coupling has produced time variations in worldwide seismic
activity that appear related to the physical coupling between the focal mechanism of
source earthquakes and the tectonic setting of each zone. These results could provide
new important insights on seismic hazard assessment because they raise doubts on the
validity of two paradigms; that is, the steadiness of the mainshock rate and the iso-
lation of a seismic region from the surrounding areas. Finally, in addition to this back-
ward analysis, we also provide a formal forward test by forecasting the effects on
global seismicity of the recent Sumatra–Andaman earthquakes; this is maybe a unique
chance to test the long-term hypothesis with an independent dataset that avoids, by
definition, any kind of (often unconscious) optimization of the results that is an un-
avoidable possibility in backward analyses.
Description:
Published
Description:
1102–1112
Description:
3.1. Fisica dei terremoti
Description:
JCR Journal
Description:
open
Keywords:
Long-term earthquake interaction
;
Forward Test
;
04. Solid Earth::04.06. Seismology::04.06.02. Earthquake interactions and probability
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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