Variations of the ionospheric electron density during the Bhuj seismic event
Ionospheric perturbations by natural geophysical activity, such as volcanic eruptions and earthquakes, have been studied since the great Alaskan earthquake in 1964. Measurements made from the ground show a variation of the critical frequency of the ionosphere layers before and after the shock. In th...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2004-12-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/22/4123/2004/angeo-22-4123-2004.pdf |
| _version_ | 1819056886984474624 |
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| author | A. Trigunait M. Parrot S. Pulinets F. Li |
| author_facet | A. Trigunait M. Parrot S. Pulinets F. Li |
| author_sort | A. Trigunait |
| collection | DOAJ |
| description | Ionospheric perturbations by natural geophysical activity, such as volcanic eruptions and earthquakes, have been studied since the great Alaskan earthquake in 1964. Measurements made from the ground show a variation of the critical frequency of the ionosphere layers before and after the shock. In this paper, we present an experimental investigation of the electron density variations around the time of the Bhuj earthquake in Gujarat, India. Several experiments have been used to survey the ionosphere. Measurements of fluctuations in the integrated electron density or TEC (Total Electron Content) between three satellites (TOPEX-POSEIDON, SPOT2, SPOT4) and the ground have been done using the DORIS beacons. TEC has been also evaluated from a ground-based station using GPS satellites, and finally, ionospheric data from a classical ionospheric sounder located close to the earthquake epicenter are utilized. Anomalous electron density variations are detected both in day and night times before the quake. The generation mechanism of these perturbations is explained by a modification of the electric field in the global electric circuit induced during the earthquake preparation.
<br><br><b>Key words.</b> Ionosphere (ionospheric disturbances) – Radio
Science (ionospheric physics) – History of geophysics (seismology) |
| first_indexed | 2024-12-21T13:30:33Z |
| format | Article |
| id | doaj.art-0820546a787c4c089b733f764f5f0386 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-21T13:30:33Z |
| publishDate | 2004-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-0820546a787c4c089b733f764f5f03862022-12-21T19:02:19ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762004-12-01224123413110.5194/angeo-22-4123-2004Variations of the ionospheric electron density during the Bhuj seismic eventA. Trigunait0M. Parrot1S. Pulinets2F. Li3Laboratoire de Physique et Chimie de l’Environnement, Centre National de la Recherche Scientifique, Orléans, FranceLaboratoire de Physique et Chimie de l’Environnement, Centre National de la Recherche Scientifique, Orléans, FranceInstituto de Geofísica, UNAM, Ciudad Universitaria, Delegacíon de Coyoacán, 04510, México D.F., MexicoLaboratoire de Physique et Chimie de l’Environnement, Centre National de la Recherche Scientifique, Orléans, FranceIonospheric perturbations by natural geophysical activity, such as volcanic eruptions and earthquakes, have been studied since the great Alaskan earthquake in 1964. Measurements made from the ground show a variation of the critical frequency of the ionosphere layers before and after the shock. In this paper, we present an experimental investigation of the electron density variations around the time of the Bhuj earthquake in Gujarat, India. Several experiments have been used to survey the ionosphere. Measurements of fluctuations in the integrated electron density or TEC (Total Electron Content) between three satellites (TOPEX-POSEIDON, SPOT2, SPOT4) and the ground have been done using the DORIS beacons. TEC has been also evaluated from a ground-based station using GPS satellites, and finally, ionospheric data from a classical ionospheric sounder located close to the earthquake epicenter are utilized. Anomalous electron density variations are detected both in day and night times before the quake. The generation mechanism of these perturbations is explained by a modification of the electric field in the global electric circuit induced during the earthquake preparation. <br><br><b>Key words.</b> Ionosphere (ionospheric disturbances) – Radio Science (ionospheric physics) – History of geophysics (seismology)https://www.ann-geophys.net/22/4123/2004/angeo-22-4123-2004.pdf |
| spellingShingle | A. Trigunait M. Parrot S. Pulinets F. Li Variations of the ionospheric electron density during the Bhuj seismic event Annales Geophysicae |
| title | Variations of the ionospheric electron density during the Bhuj seismic event |
| title_full | Variations of the ionospheric electron density during the Bhuj seismic event |
| title_fullStr | Variations of the ionospheric electron density during the Bhuj seismic event |
| title_full_unstemmed | Variations of the ionospheric electron density during the Bhuj seismic event |
| title_short | Variations of the ionospheric electron density during the Bhuj seismic event |
| title_sort | variations of the ionospheric electron density during the bhuj seismic event |
| url | https://www.ann-geophys.net/22/4123/2004/angeo-22-4123-2004.pdf |
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