| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-21 20:12 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2008 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Short-term prediction of Vrancea (Romania) earthquakes using the geomagnetic method (POSTER)
Authors:
I.A. Moldovan(1), A.S. Moldovan(2), A.O. Placinta(1), D. Enescu(1)
Affiliation:
(1) National Institute for Earth Physics, P.O.Box MG-2, Bucharest-Magurele, RO-077125, Romania
(2) AZEL DESIGNING GROUP LTD, Bucharest-Magurele, Marasesti 12, RO-077125, ROMANIA
E-mail
iren@infp.ro
Keywords:
geomagnetic field, earthquake prediction
Abstract:
Ten years of geomagnetic records, made at Muntele Rosu Observatory (Romania), correlated with seismic and solar data and followed by personal interpretations of the most important geomagnetic anomalies are presented in the paper. The results of the data processing are illustrated in diagrams of the magnetic components and of the magnetic impedance Bz(t)/BH(t). The time variation of Bz(t)/Bx(t) and Bz(t)/By(t) is closely examined in correlation with Vrancea seismic activity, where Bz is the vertical component of the geomagnetic flux density and BH the resultant of Bx and By horizontal components). The theoretical reasons for using ratios Bz(t)/Bx(t) and Bz(t)/By(t)of the geomagnetic flux density components as earthquake prediction tools are first of all provided. We calculated the daily average of the above mentioned ratios and plotted them for each studied year. Every calculated value of the ratios on the diagram refers to midday time. The earthquake marks are accompanied by values of the moment magnitude Mw. The working data are represented by geomagnetic data as recorded at Muntele Rosu Observatory in the period December 1997 – December 2007 and by the data of Vrancea seismic activity in the same period. Seismic data were taken from the seismic bulletins of the National Institute for Earth Physics. The correlation between the time variation of Bz(t)/Bx(t) and Bz(t)/By(t) and Vrancea seismic activity prove that 85% of all earthquakes of magnitudes Mw>Mo (Mo=3.6-4.0, usually Mo=3.9, in the case of subcrustal earthquakes, while in crustal earthquakes Mo=2.8-3.0), were preceded by significant perturbations of the magnetic impedance Bz/Bx. The largest earthquake occurred in this time interval has the moment magnitude Mw=6.3. It seems that the precursor time or the amplitude of the precursory geomagnetic anomaly can be linked reliably with the magnitude of the anticipated earthquake.
|
|
|
|