 |
| Titel |
Persistent pre-seismic signature detected by means of Na-K-Mg geothermometry records in a saline spring of Vrancea area (Romania) |
| VerfasserIn |
H. Mitrofan, C. Marin, D. Zugrăvescu, F. Chitea, M.-A. Anghelache, L. Besutiu, A. Tudorache |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 10, no. 2 ; Nr. 10, no. 2 (2010-02-09), S.217-225 |
| Datensatznummer |
250007928
|
| Publikation (Nr.) |
 copernicus.org/nhess-10-217-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| A six year-long hydrochemical monitoring operation was conducted in Vrancea
seismic zone (Romania), addressing a saline spring that proved to be suitable
for Na-K-Mg geothermometry diagnosis. During the considered time-interval
(2003–2009), only one important earthquake (mb=5.8) occurred in
Vrancea region, this circumstance providing an unambiguous reference-moment
between pre-seismic and post-seismic periods. On occurrence of that
earthquake, an anomalous fluctuation of the Na-K temperature was detected –
a result largely similar to previous ones recorded worldwide (California,
southwest Egypt, northeast India). Yet such fluctuations may not necessarily
be induced by earthquake-associated processes: they can occur also
"routinely", possibly reflecting some environmental,
meteorologically-induced "noise". It was therefore important to examine
whether the variations observed in the data values could be plausibly related
to a seismogenesis process. By additionally investigating (in a
"scattterplot" diagram) the correlation between the Na-K temperatures and
the values of a so-called "maturity index", a specific pattern emerged,
with pre-seismic data-points plotting in a distinct domain of the diagram;
moreover, those data-points appeared to describe a "drift away" pathway
with respect to the remaining data-points "cluster", recorded during the
subsequent 4 years of post-seismic monitoring. The "drift away" pattern
persistently evolved for at least 18 months, ending just before the
mb=5.8 earthquake and consequently suggesting the existence of some kind of
long-term precursory phenomenon. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|