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Vol. 12 (2009 year), No. 2
Namgaladze A.A., Zolotov O.V., Zakharenkova I.E., Shagimuratov I.I., Martynenko O.V.
Ionospheric total electron content variations observed before earthquakes: Possible physical mechanism and modeling
Some experiments have been carried out by phase association and infrasonic sources location using the Apatity infrasound array and Finnish-Swedish acoustic network. Several events from the area of Plesetsk spaceport have been detected and located. The analysis of variation of backazimuth estimations has been done basing on signals from repeating military explosion in Northern Finland. Estimations of the location accuracy for the explosions have been obtained. It has been confirmed that cause-effect relation exists between facts of presence or absence of infrasonic wave first arrivals and weather conditions.
(in English, стр.8, fig. 6, tables. 0, ref 29, Adobe PDF, Adobe PDF 0 Kb)
Vol. 13 (2010 year), No. 4
Zolotov O.V., Prokhorov B.E.
Morphological features of the total electron content variations before the Whenchuan earthquake, 2008
The paper presents the investigation and description of the main morphological features of the total electron content (TEC) variations before the Whenchuan earthquake of May 12, 2008, M 7.9, D 19 km, (31.0N;103.4E). The observed TEC disturbances were strongly linked to the near-epicenter and have been treated by the authors as manifestation of the "lithosphere–atmosphere–ionosphere" coupling processes.
(in Russian, стр.4, fig. 2, tables. 0, ref 12, Adobe PDF, Adobe PDF 0 Kb)
Vol. 15 (2012 year), No. 2
Karpov M.I., Zolotov O.V., Namgaladze A.A.
Modeling of the ionosphere response on the earthquake preparation
Seismo-ionosphere coupling processes have been investigated considering the GPS observed anomalous ionospheric Total Electron Content (TEC) variations before strong earthquakes as their precursors. The numerical simulations' results of the TEC response on the vertical electric currents flowing between the Earth and ionosphere during the earthquake (EQ) preparation time have been performed. Model experiments have been carried out using the Upper Atmosphere Model. The following currents' parameters were varied in: (i) direction (to or from the ionosphere); (ii) latitudinal zone of the sources' (EQ epicenters) location; (iii) currents' configuration: (1) grid nodes with "straight" currents were surrounded by "border" grid points with currents of opposite direction ("return" currents); (2) the "return" currents were spread out over the globe; (3) without "return" currents. Numerical simulations have shown that electric currents with density of 4?10-8 A/m2 over the area of about 200 km in longitude and 2500 km in latitude produce both positive and negative TEC disturbances with magnitude up to 35 % in agreement with GPS TEC observations before EQs.
(in English, стр.6, fig. 4, tables. 0, ref 27, Adobe PDF, Adobe PDF 0 Kb)
Vol. 15 (2012 year), No. 2
Romanovskaya Yu.V., Namgaladze A.A., Zolotov O.V., Starikova N.A., Lopatiy V.Z.
Searching for seismo-ionospheric earthquakes precursors: Total electron content disturbances before 2005-2006 seismic events
During earthquakes preparation periods significant disturbances in the ionospheric plasma density are often observed. These anomalies are caused by lithosphere-atmosphere-ionosphere interaction, particularly by the seismic electric field penetrating from the ground surface into the ionosphere. The seismic electric field produces electromagnetic ЕВ drift changing plasma density over the epicenter region and magnetically conjugated area. The paper is devoted to analysis of regular Global Positioning System observations and revelation of seismo-ionospheric precursors of earthquakes in Total Electron Content (TEC) of the ionosphere. Global and regional relative TEC disturbances maps (%) have been plotted for 2005-2006 M6, D<60 km seismic events and analyzed in order to determine general features of precursors. The obtained results agree with the recent published case-study investigations.
(in English, стр.5, fig. 2, tables. 0, ref 29, Adobe PDF, Adobe PDF 0 Kb)
Vol. 15 (2012 year), No. 3
Zolotov O.V., Namgaladze A.A., Prokhorov B.E.
Total electron content disturbances prior to Great Tohoku March 11, 2011 and October 23, 2011 Turkey Van earthquakes and their physical interpretation
This paper discusses the GPS (Global Positioning System) observed TEC (Total Electron Content) variations prior to the M 9.0 Great Tohoku (Japan, Sendai) March 11, 2011 and M 7.1 Oct. 23, 2011 Turkey Van earthquakes as possible seismo-ionosphere precursors. We have formulated a set of the TEC phenomenological features often reported as precursors to strong earthquakes based on our experience and publications' analysis. This feature-set has been applied to the relative TEC deviations for time intervals March 08-11, 2011 and Oct. 20-23, 2011 preceding M 9.0 Great Tohoku (Japan) March 11 and Turkey Van Oct. 23 earthquakes, respectively. In both cases there have been revealed strong local long-living (of about several hours) TEC disturbances at the near-epicenter and magnetically conjugated areas. These disturbances may be treated as seismo-ionospheric precursors. The physical mechanism for the observed TEC structures for these two as well as for other cases of recent strong seismic events has been proposed. The anomalies have been interpreted and explained on the base of this physical mechanism from the origin hypothesis point of view in terms of electromagnetic lithosphere-ionosphere coupling.
(in English, стр.12, fig. 3, tables. 0, ref 63, Adobe PDF, Adobe PDF 0 Kb)
Vol. 15 (2012 year), No. 3
Karpov M.I., Namgaladze A.A., Zolotov O.V.
Three-dimensional structure of the seismo-electromagnetic ionospheric electron density disturbances
The paper presents the three-dimensional structure of the ionospheric electron density disturbances triggered by the vertical electric currents flowing between the Earth and ionosphere over the faults before the strong earthquakes. The results were obtained using the global numerical Earth's Upper Atmosphere Model (UAM). The vertical electric currents flowing between the Earth and ionosphere over the faults were used as lower boundary conditions for the UAM electric potential equation. The UAM calculated 3D structure of the ionospheric electron density disturbances demonstrates an importance of all three ionospheric plasma drift movements – vertical, meridional and zonal but not only vertical one.
(in English, стр.9, fig. 9, tables. 0, ref 26, Adobe PDF, Adobe PDF 0 Kb)