The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations
Huge five earthquakes with magnitude greater than 6.0 took place in Asia (include Philippines, Indonesia, etc.) during the period from the beginning of August 2008 to the end of Junuary 2009, and the corresponding data of subionospheric VLF propagation between the NWC transmitter (Australia, 19.8 kH...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2010-03-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | http://www.nat-hazards-earth-syst-sci.net/10/581/2010/nhess-10-581-2010.pdf |
| _version_ | 1818154458265157632 |
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| author | Y. Kasahara F. Muto Y. Hobara M. Hayakawa |
| author_facet | Y. Kasahara F. Muto Y. Hobara M. Hayakawa |
| author_sort | Y. Kasahara |
| collection | DOAJ |
| description | Huge five earthquakes with magnitude greater than 6.0 took place in Asia (include Philippines, Indonesia, etc.) during the period from the beginning of August 2008 to the end of Junuary 2009, and the corresponding data of subionospheric VLF propagation between the NWC transmitter (Australia, 19.8 kHz) and a few Japanese stations (distance 6~8 Mm) are examined. As the result of our analysis by means of (1) trend (average nighttime amplitude), (2) dispersion, (3) nighttime fluctuation, and (4) atmospheric gravity wave enhancement, three earthquakes from the five taking place within the fifth Frenel zone are found to have accompanied a precursory signature in VLF propagation. On the other hand, there were observed no such precursory signatures for the remaing two earthquakes. One is too deep (>400 km) and another is too distant from the great-circle path. These characteristics of seismo-ionospheric perturbations would be of essential importance in studying the spatial/temporal properties of seismo-ionospheric perturbations for medium-distance propagation. |
| first_indexed | 2024-12-11T14:26:49Z |
| format | Article |
| id | doaj.art-a0340f7be2f648f0a2c40d8b5da4adb3 |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-11T14:26:49Z |
| publishDate | 2010-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-a0340f7be2f648f0a2c40d8b5da4adb32022-12-22T01:02:39ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812010-03-01103581588The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stationsY. KasaharaF. MutoY. HobaraM. HayakawaHuge five earthquakes with magnitude greater than 6.0 took place in Asia (include Philippines, Indonesia, etc.) during the period from the beginning of August 2008 to the end of Junuary 2009, and the corresponding data of subionospheric VLF propagation between the NWC transmitter (Australia, 19.8 kHz) and a few Japanese stations (distance 6~8 Mm) are examined. As the result of our analysis by means of (1) trend (average nighttime amplitude), (2) dispersion, (3) nighttime fluctuation, and (4) atmospheric gravity wave enhancement, three earthquakes from the five taking place within the fifth Frenel zone are found to have accompanied a precursory signature in VLF propagation. On the other hand, there were observed no such precursory signatures for the remaing two earthquakes. One is too deep (>400 km) and another is too distant from the great-circle path. These characteristics of seismo-ionospheric perturbations would be of essential importance in studying the spatial/temporal properties of seismo-ionospheric perturbations for medium-distance propagation.http://www.nat-hazards-earth-syst-sci.net/10/581/2010/nhess-10-581-2010.pdf |
| spellingShingle | Y. Kasahara F. Muto Y. Hobara M. Hayakawa The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations Natural Hazards and Earth System Sciences |
| title | The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations |
| title_full | The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations |
| title_fullStr | The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations |
| title_full_unstemmed | The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations |
| title_short | The ionospheric perturbations associated with Asian earthquakes as seen from the subionospheric propagation from NWC to Japanese stations |
| title_sort | ionospheric perturbations associated with asian earthquakes as seen from the subionospheric propagation from nwc to japanese stations |
| url | http://www.nat-hazards-earth-syst-sci.net/10/581/2010/nhess-10-581-2010.pdf |
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