Correlation of terrestrial surface oscillations and ionosphere disturbances during the earthquakes according to laser interferometer and GPS data
Abstract
Process of earthquakes preparation occupies, as a rule, the significant period of time and consequently demands carrying out the long observations above the possible earthquake focus. The existing network of ground navigating stations allows performing such observations in the ionosphere state. It also enables to determine the ionospheric effects of earthquakes based on the analysis of an electron density of F2 layer. The navigating systems GPS and Glonass despite the complexity of detecting ionospheric variations caused by seismic effects can be adapted in the best way to the realization of the ionosphere monitoring. Large-scale spatial and temporal disturbances of the earth strain and the total electron contents (TEC) in the ionospheric F2 layer have been recently detected by our underground laser strainmeters and microwave ionospheric profile-meter based on the GPS data [1]. Here the technique of long-base laser interferometry measurements and dual frequency GPS data acquisition are presented and new results of data analysis are discussed. We have compared the strain-barometric variations recorded by the laser interferometers of 100 m and 300 m length at the IRE RAS testing site (Moscow region), and TEC drifts according to the local (distance up to 100-200 km) and remote (being 2000-7000 km apart) GPS stations. The utmost sensitivity of laser interferometers was dL/L=10(-11) to the earth strain and dP=10(-4) mbar to the barometric variations. The ionospheric data have been calculated with radio translucence algorithms application. The connection of undulating strain-barometric oscillations of a surface and atmospheric pressure in 1-10 mHz frequency band and synchronously recorded TEC variations was found during earthquakes (Japan 25.09.03, Ms=8.4 and Altai 27.09.03 Ms=7.3 - 6.7) and the velocities of the disturbances propagation have been determined. [1] M.N. Dubrov and V.M. Smirnov, IUGG2003, 30.06-11.07.2003, Sapporo, Japan, JSA02.
- Publication:
-
European Planetary Science Congress 2008
- Pub Date:
- September 2008
- Bibcode:
- 2008epsc.conf..733D