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北海道大学地球物理学研究報告 = Geophysical bulletin of Hokkaido University >
第69号 >
2004年スマトラ島沖大地震で発生した地球周回表面波
Title: | 2004年スマトラ島沖大地震で発生した地球周回表面波 |
Other Titles: | Muti-orbit surface waves generated by the 2004 great Sumatra earchquake |
Authors: | 吉澤, 和範1 Browse this author |
Authors(alt): | YOSHIZAWA, Kazunori1 |
Issue Date: | 15-Mar-2006 |
Publisher: | 北海道大学大学院理学研究科地球惑星科学専攻(地球物理学) |
Journal Title: | 北海道大学地球物理学研究報告 |
Journal Title(alt): | Geophysical bulletin of Hokkaido University |
Volume: | 69 |
Start Page: | 15 |
End Page: | 21 |
Abstract: | The great Sumatra earchquake on December 26, 2004, which devastated the coastal areas of the Indian Ocean by the subsequent tsunami, generated tremendous numbers of surface-wave trains which traveled around the globe for many times. We analyse vertical-component seismograms of the event recorded by the F-net broadband seismic network in Japan, which has been deployed and maintained by NIED (National Research Institute for Earth Science and Disaster Prevention, Japan). By applying a band-pass filter between 3 and 5 mHz, we extract the long-period Airy phase of the fundamental-mode Rayleigh wave. The long period records display a magnificent series of multi-orbit Rayleigh wave trains that have circumnavigated the Earth for more than 6 times; i.e., we are able to observe clear signals up to R13-R14 phases. Although much later arrival phases than R14 become less visible mainly due to lateral heterogeneities in the Earth as well as dispersions of surface waves, we are still able to detect some smaal signals up to R18. |
Type: | bulletin (article) |
URI: | http://hdl.handle.net/2115/21497 |
Appears in Collections: | 北海道大学地球物理学研究報告 = Geophysical bulletin of Hokkaido University > 第69号
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