dot
Detailansicht
Katalogkarte GBA
Katalogkarte ISBD
Suche präzisieren
Drucken
Download RIS
Hier klicken, um den Treffer aus der Auswahl zu entfernen
Titel Ionosperic anomaly due to seismic activities – Part 1: Calibration of the VLF signal of VTX 18.2 KHz station from Kolkata and deviation during seismic events
VerfasserIn S. Sasmal, S. K. Chakrabarti
Medientyp Artikel
Sprache Englisch
ISSN 1561-8633
Digitales Dokument URL
Erschienen In: Natural Hazards and Earth System Science ; 9, no. 4 ; Nr. 9, no. 4 (2009-08-11), S.1403-1408
Datensatznummer 250006902
Publikation (Nr.) Volltext-Dokument vorhandencopernicus.org/nhess-9-1403-2009.pdf
 
Zusammenfassung
VLF signals are long thought to give away important information about the lithosphere-ionosphere coupling. In order to establish co-relations, if any, between the ionospheric activities and the earthquakes, we need to understand what the reference signals are, throughout the year. The best opportunity to do this is during the period of solar minimum where the number of flares and sunspots are negligible and the data would be primarily affected by the sun and variation would be due to normal sunset and sunrise effects. In this paper, we present the result of the sunrise and sunset terminators as a function of the day of the year for a period of four years, viz, 2005–2008 when the solar activity was very low. The terminators are for the 18.2 KHz VTX signal of the Indian Navy as observed from Indian Centre for Space Physics receiving station located in Kolkata. A total of 624 days of data have been used to obtain the mean plot. Any deviation of observations from this so-called the standardized calibration curve would point to influences by terrestrial (such as earthquakes) and extra-terrestrial events (such as solar activities). We present examples of deviations which occur in a period of 16 months and show that the correlation with seismic events is significant and typically the highest deviation takes place up to a couple of days prior to the seismic event. Simultaneous observations of such deviations from more than one station could improve the predictability of earthquakes.
 
Teil von