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Preseismic ionospheric electron enhancements revisited
| Title: | Preseismic ionospheric electron enhancements revisited |
| Authors: | Heki, Kosuke Browse this author →KAKEN DB | | Enomoto, Yuji Browse this author →KAKEN DB |
| Keywords: | ionosphere | | preseismic anomaly | | 2011 Tohoku-oki earthquake | | GPS | | TEC | | geomagnetism |
| Issue Date: | 3-Oct-2013 |
| Publisher: | American Geophysical Union |
| Journal Title: | Journal of Geophysical Research: Space Physics |
| Volume: | 118 |
| Issue: | 10 |
| Start Page: | 6618 |
| End Page: | 6626 |
| Publisher DOI: | 10.1002/jgra.50578 |
| Abstract: | [1] Possible enhancement of ionospheric Total Electron Content (TEC) immediately before the 2011 Tohoku-oki earthquake (Mw9.0) has been reported by Heki (2011). Critical responses to it often come in two stages; they first doubt the enhancement itself and attribute it to an artifact. Second (when they accept the enhancement), they doubt the significance of the enhancement among natural variability of space weather origin. For example, Kamogawa and Kakinami (2013) attributed the enhancement to an artifact falsely detected by the combined effect of the highly variable TEC under active geomagnetic condition and the occurrence of a tsunamigenic ionospheric hole. Here we closely examine the time series of vertical TEC before and after the 2011 Tohoku-oki earthquake. We first demonstrate that the tsunami did not make an ionospheric hole, and next confirm the reality of the enhancement using data of two other sensors, ionosonde and magnetometers. The amplitude of the preseismic TEC enhancement is within the natural variability, and its snapshot resembles to large-scale traveling ionospheric disturbances. However, distinction could be made by examining their propagation properties. Similar TEC anomalies occurred before all the M ≥ 8.5 earthquakes in this century, suggesting their seismic origin. |
| Rights: | Copyright [2013] American Geophysical Union. |
| Relation: | http://www.agu.org/pubs/authors/pdf/copyright.pdf | | http://publications.agu.org/author-resource-center/usage-permissions/ |
| Type: | article |
| URI: | http://hdl.handle.net/2115/54787 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 日置 幸介
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