Options
Long-term influence of giant earthquakes: backward empirical evidence and forward test
Language
English
Obiettivo Specifico
3.1. Fisica dei terremoti
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
3/98 (2008)
Publisher
Seismological Society of America
Pages (printed)
1102–1112
Issued date
June 2008
Abstract
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.
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.
Type
article
File(s)
Loading...
Name
BSSA2007203_marzocchi_selva.pdf
Description
Main article
Size
363.18 KB
Format
Adobe PDF
Checksum (MD5)
c303bcc35e950639a23afb44c8101fa6