Japan Geoscience Union Meeting 2016

Presentation information


Symbol O (Public) » Public

[O-02] Poster presentations by senior high school students

Sun. May 22, 2016 1:45 PM - 3:15 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Tatsuhiko Hara(International Institute of Seismology and Earthquake Engineering, Building Research Institute), Miwa Kuri(International Research Institute of Disaster Science, Tohoku University), Keiko Konya(Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology), Hajime Naruse(Department of Geology and Mineralogy, Graduate School of Science, Kyoto University), Kou Yamada(Waseda University)

1:45 PM - 3:15 PM

[O02-P62] The Mechanism of "Red" Matsukawa River.

*Hiroto Manba1, *Ibuki Kamikura1, *Kentaro Nashimoto1, Hiroaki Kuroiwa1 (1.Iiyama High School)

“Matsukawa River” in northern Nagano Prefecture is an acid river and contains much iron. Therefore, it looks red. It is known that this “reddening” phenomenon is caused by the sulfur mine in the source of the river. However, it occurs not near the source of the river but in the lower point, where the River meets the other stream. The concentration of iron goes down after the river meets the stream because the stream doesn’t contain iron. We researched why the reddening phenomenon occurs at the point.The results are as follows: 1st, the following equation shows the reddening phenomenon: 2Fe3+ + 6H2O → Fe2O3·3H2O↓ + 6H+ ; 2nd, either of oxygen and hydrogen sulfide doesn’t affect the reddening phenomenon; 3rd, the reddening phenomenon occurs when acidity of water weakens and when temperature of water rises.Therefore, the reddening phenomenon tend to occur in summer when the river rises and temperature of water rises.