Earth:Shirasu-Daichi
| シラス台地 | |
 Extent pyroclastic flow from Ito eruption, Aira Caldera (red outline), Kyushu, Japan as represented by approximate Ito Ignimbrite distribution (yellow)[1] | |
| Location | Southern Kyūshū, Japan |
|---|---|
| Coordinates | [ ⚑ ] : 31°41′00″N 130°52′00″E / 31.6833333°N 130.8666667°E |
| Formed by | Volcanic action |
| Geology | Volcanic plateau |
Shirasu-Daichi (シラス台地) is a broad pyroclastic plateau in southern Japan . It covers almost all of southern Kyūshū, which was formed by pyroclastic flows. It covers more than half of Kagoshima Prefecture, as well as 16% of Miyazaki Prefecture.[2] The Japanese Shirasu (シラス) is a local name of the pumiceous sediments in Kagoshima Prefecture, Japan. The term has been recommended to be used just for the non-welded ignimbrite component in the Japanese geological literature.[3] Daichi (台地) means plateau.
Geology
A major three phase eruption of the Aira Caldera formed in the first phase the Osumi pumice fall, had a second phase Tsumaya pyroclastic flow and in the third Ito eruption phase produced the widely distributed Aira-Tn tephra that has been dated at 29,428 to 30,148 years calibrated before present.[4][5] The Aira-Tn tephra falls from this eruption were up to 0.800 m (2 ft 7.5 in) thick extending to significant depth that would have affected plant life in south eastern South Korea and Honshu.[1] This and Ito Ignimbrite up to 160 m (520 ft) thick, are the most significant pyroclastic deposits of the plateau.[6] However an eruption about 11,000 years before present did result in the Satsuma pumice fall[3] and there have been multiple relatively minor ash falls since from the local active volcanoes.
References
- ↑ 1.0 1.1 "Publication of the distribution maps of large-volume ignimbrites in Japan - geological data show the impact of large-scale eruptions". GSJ/AIST. 2022-01-25. https://www.gsj.jp/en/research/topics/pr20220125.html.
- ↑ 寺園貞夫 「シラスの堆積とその浸食地形」 『シラス台地研究』
- ↑ 3.0 3.1 Iwamatsu, Akira; Fukushige, Yasuo; Koriyama, Sakae (1989). "Applied Geological Problems of Shirasu (シラスの応用地質学的諸問題)". 地学雑誌 (Earth Science Magazine). doi:10.5026/jgeography.98.4_379. https://www.jstage.jst.go.jp/article/jgeography1889/98/4/98_4_379/_article/-char/ja/.
- ↑ Smith, Victoria C.; Staff, Richard A.; Blockley, Simon P.E.; Ramsey, Christopher Bronk; Nakagawa, Takeshi; Mark, Darren F.; Takemura, Keiji; Danhara, Toru (2013). "Identification and correlation of visible tephras in the Lake Suigetsu SG06 sedimentary archive, Japan: chronostratigraphic markers for synchronising of east Asian/west Pacific palaeoclimatic records across the last 150 ka". Quaternary Science Reviews 67: 121–137. doi:10.1016/j.quascirev.2013.01.026. ISSN 0277-3791. https://www.sciencedirect.com/science/article/pii/S0277379113000413.
- ↑ Miyairi, Y.; Yoshida, K.; Miyazaki, Y.; Matsuzaki, H.; Kaneoka, I. (2004). "Improved 14 C dating of a tephra layer (AT tephra, Japan) using AMS on selected organic fractions". Nuclear Instruments and Methods in Physics Research B 223–224: 555–559. doi:10.1016/j.nimb.2004.04.103. ISSN 0168-583X. https://www.researchgate.net/publication/245072458.
- ↑ Baer, E. M.; Fisher, R. V.; Fuller, M.; Valentine, G. (1997). "Turbulent transport and deposition of the Ito pyroclastic flow: Determinations using anisotropy of magnetic susceptibility". Journal of Geophysical Research: Solid Earth 102: 22565–22586. doi:10.1029/96JB01277. https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/96JB01277.
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