- 著者
- Hiroyuki GOTO Yoshiya HATA Yasuko KUWATA Hidekazu YAMAMOTO Hitoshi MORIKAWA Shunichi KATAOKA
- 出版者
- 公益社団法人 土木学会
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.1, no.1, pp.329-342, 2013 (Released:2013-11-20)
- 参考文献数
- 94
- 被引用文献数
- 3 6
The 2011 off the Pacific coast of Tohoku earthquake brought severe damage caused not only by the tsunami but also by the ground motions. The present manuscript summarizes the source mechanism/process and the characteristics of ground motions around eastern Japan during the earthquake. For the last two years after the earthquake, many researchers have devoted their efforts to analyzing and discussing the source and ground motions. New findings from some recent works are also cited. We, furthermore, introduce characteristics of ground motions at some typical damaged sites, where no records of ground motions were obtained during the main shock, using time histories of after shocks.
- 著者
- Hajime KAYANNE Chuki HONGO Ken OKAJI Yoichi IDE Takeshi HAYASHIBARA Hidekazu YAMAMOTO Nobuo MIKAMI Kiyoshi ONODERA Takaaki OOTSUBO Hiroyuki TAKANO Makoto TONEGAWA Shogo MARUYAMA
- 出版者
- 日本サンゴ礁学会
- 雑誌
- Galaxea, Journal of Coral Reef Studies (ISSN:18830838)
- 巻号頁・発行日
- vol.14, no.1, pp.73-95, 2012 (Released:2013-02-04)
- 参考文献数
- 37
- 被引用文献数
- 1 7 1
Ninety-three coral species have been identified at Okinotorishima (Okinotori Island), an isolated table reef located in the center of the Philippine Sea. The species composition of the island is similar to that of other islands in the northwestern Pacific, but the number of species is small in comparison with surrounding islands. The coral fauna at the island is characterized by a unique species composition that is independent of the Ryukyu Islands, mainland Japan, Palau, and the Mariana Islands. No endemic species were found, but the dominant Acropora species (A. aculeus, A. sp. aff. divaricata, and A. globiceps) were morphologically different from corresponding species at the Ryukyu Islands. The relatively low species diversity at the island despite the close proximity to an area of high diversity is explained by its small habitat diversity and isolation from other islands. The island is located in a subtropical gyre and is isolated from major currents. Thus, only coral larvae with a long competency period (as long as 70 days) can settle at the island from surrounding islands. This unique species composition seems to have been maintained for at least the last 7600 years, since the last stage of sea level rise in the post-glacial period (Holocene).