 |
| Titel |
Phenomena of electrostatic perturbations before strong earthquakes (2005–2010) observed on DEMETER |
| VerfasserIn |
X. Zhang, X. Shen, M. Parrot, Z. Zeren, X. Ouyang, J. Liu, J. Qian, S. Zhao, Y. Miao |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 12, no. 1 ; Nr. 12, no. 1 (2012-01-09), S.75-83 |
| Datensatznummer |
250010406
|
| Publikation (Nr.) |
 copernicus.org/nhess-12-75-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| During the DEMETER operating period in 2004–2010, many strong earthquakes took
place in the world. 69 strong earthquakes with a magnitude above 7.0 during
January 2005 to February 2010 were collected and analysed. The orbits,
recorded in local nighttime by satellite, were chosen by a distance of 2000 km
to the epicentres during the 9 days around these earthquakes, with 7 days before
and 1 day after. The anomaly is defined when the disturbances in the electric
field PSD increased to at least 1 order of magnitude relative to the normal
median level about 10−2μV2/m2/Hz at 19.5–250 Hz frequency band,
and the starting point of perturbations not exceeding 10° relsupative to the
epicentral latitude. Among the 69 earthquakes, it is shown that electrostatic
perturbations were detected at ULF-ultra low frequency and ELF-extremely low
frequency band before the 32 earthquakes, nearly 46%. Furthermore, we
extended the searching scale of these perturbations to the globe, and it can
be found that before some earthquakes, the electrostatic anomalies were
distributed in a much larger area a few days before, and then they
concentrated to the closest orbit when the earthquake would happen one day
or a few hours later, which reflects the spatial developing feature during
the seismic preparation process. The results in this paper contribute to a
better description of the electromagnetic (EM) disturbances at an altitude
of 660–710 km in the ionosphere that can help towards a further understanding of the
lithosphere-atmosphere-ionosphere (LAI) coupling mechanism. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|