 |
| Titel |
Multi-point ground-based ULF magnetic field observations in Europe during seismic active periods in 2004 and 2005 |
| VerfasserIn |
G. Prattes, K. Schwingenschuh, H. U. Eichelberger, W. Magnes, M. Boudjada, M. Stachel, M. Vellante, V. Wesztergom, P. Nenovski |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 8, no. 3 ; Nr. 8, no. 3 (2008-05-16), S.501-507 |
| Datensatznummer |
250005528
|
| Publikation (Nr.) |
 copernicus.org/nhess-8-501-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| We present the results of ground-based Ultra Low Frequency (ULF) magnetic
field measurements observed from June to August 2004 during the Bovec
earthquake on 12 July 2004. Further we give information about the seismic
activity in the local observatory region for an extended time span 2004 and
2005. ULF magnetic field data are provided by the South European Geomagnetic
Array (SEGMA) where the experience and heritage from the CHInese
MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The
intensities of the horizontal H and vertical Z magnetic field and the
polarization ratio R of the vertical and horizontal magnetic field intensity
are analyzed taking into consideration three SEGMA observatories located at
different close distances and directions from the earthquake epicenter. We
observed a significant increase of high polarization ratios during strong
seismic activity at the observatory nearest to the Bovec earthquake
epicenter. Apart from indirect ionospheric effects electromagnetic noise
could be emitted in the lithosphere due to tectonic effects in the
earthquake focus region causing anomalies of the vertical magnetic field
intensity. Assuming that the measured vertical magnetic field intensities
are of lithospheric origin, we roughly estimate the amplitude of
electromagnetic noise in the Earths crust considering an average electrical
conductivity of <σ>=10−3 S/m and a certain distance of
the observatory to the earthquake epicenter. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|