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Pre-seismic Geomagnetic and Ionosphere Signatures Related to the Mw5.7 Earthquake Occurred in Vrancea Zone on September 24, 2016

Stanica D. A., Stanica D., Błęcki J., Ernst T., Jóźwiak W, Słomiński J.

Acta Geophysica

2018

Vol. 66, no. 2

167--177

To emphasize the relationship between the pre-seismic geomagnetic signals and Vrancea seismicity, in this work it is hypothesized that before an earthquake initiation, the high stress reached into seismogenic volume generates dehydration of the rocks and fracturing processes followed by release of electric charges along the faulting systems, which lead to resistivity changes. These changes were explored on September 2016 by the normalized function Bzn obtained from the geomagnetic data recorded in ULF range (0.001-0.0083 Hz). A statistical analysis was also performed to discriminate on the new Bzn* time series a pre-seismic signature related to the Mw5.7 earthquake. Significant anomalous behavior of Bzn* was identified on September 21, with 3 days prior to the onset of the seismic event. Similar information is provided by registrations of the magnetic and electron concentration variations in the ionosphere over the Vrancea zone, by Swarm satellites, 4 days and 1 day before the earthquake.

Influence of ionospheric storm on positioning precision

Baran L., Krankowski A., Shagimuratov I.

Reports on Geodesy

2001

z. 2/57

231-236

In the paper results of analysis of the influence of ionospheric storm on positioning precision are presented. The analysis rely on studying of repeatability of vectors` coordinates. Different vector lengths (250 km-1300km) were studied. These vectors were investigated during the ionospheric storms.The permanent observations from IGS/EUREFstations were analysed. Those stations connect Borowiec, Borowa Góra, Lamkowo, Onsala, Mendeleevo, Kotwijk, Matera and Metsahovi. Their latitudes range from 41(st.)N to 60 (st.)N. Software Bernese ver. 4.0 was used for the analysis of observational data of the six and twelve-hours sessions. Results were refered to those otained from 24-hours sessions.

Evaluation of ionospheric effects on SAR interferometry in Antarctica

Al Bayari O.

Reports on Geodesy

2000

z. 8/54

24-31

The influence of atmospheric inhomegeneities on SAR signal has been recently investigated by several authors with interest particularly focused on the tropospheric layer, that is modelled starting from tbe main meteorological parameters observed on site. Phase shift due to the propagation of waves through the medium (troposphere and ionospbere) can be misinterpreted as deformation processes or topographical effects on the interferogramme from SAR image pairs. This paper deals with the influences of the dispersive ionospheric layer on SAR signal in Antarctica. The phenomenon is highly variable in time and space, due to the vicinity of the geomagnetic pole and is directly related to the Total Electron Content (TEC) values. Quantitative information on TEC values, at the time of the interferometrie images pair acquisition from the radar sensor, can be eventually obtained from locally acquired GPS measuremcnts or by ionospheric sounding. The magnitude of phase shift and the possible presence of "ionospheric" fringes can be then estimated.