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Volume 67 (2013)
- Issue 6 Pages 183-
- Issue 5 Pages 159-
- Issue 4 Pages 119-
- Issue 3 Pages 89-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 67, Issue 4
Displaying 1-4 of 4 articles from this issue
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Yusuke YAGI, Yoshiaki TAINOSHOArticle type: Article
2013 Volume 67 Issue 4 Pages 119-129
Published: July 25, 2013
Released on J-STAGE: May 16, 2017
JOURNAL OPEN ACCESSAtmospheric soil particles were collected in the Asian dust-storm period by using low pressure andersen impacter in Kobe city in April 2003 to investigate the characteristics of the Asian dust-storm particles. These samples were analyzed by field emission scanning electron microscopy (FE-SEM) equipped with an energy dispersive X-ray spectrometer. These soil particles were divided into five groups based on characteristics of their chemical compositions such as Si-rich, SiAl-rich, SiAl+Na/K/Ca, SiAlK+Fe/Mg and SiAl+Na/K/Ca/Mg particles. Morphology and compositional characteristics of all the individual soil particles were examined by FE-SEM. The soil particles contained sulfur, chlorine and heavy metal elements were found in the Asian dust-storm period in many case. The maximum amount of the soil particles in the Asian dust-storm period occurred in the 1.17μm to 3.45μm size fraction. The amount of the soil particles in this size were around 38%, while that of the soil particles in same size range in non-Asian dust-storm period were around 15%. The distribution of the number of the soil particles in air are strongly influenced by the soil particles derived from the Asian dust-storm from these results. Asian dust-storm particles are mainly composed of the compound of minute soil particles with sea salt, Fe ball and sulfate particle etc. These soil particles are mutually attached to make single slightly large soil particle. These facts suggest that the Asian dust-storm particles were generated by mutually attachment of minute soil particles during the Asian dust-storm transportation process.View full abstractDownload PDF (20977K) -
Erika SANO, Hiroaki ISHIGA, Yoshikazu SAMPEI, Tetsuya SAKAI, Toshiaki ...Article type: Article
2013 Volume 67 Issue 4 Pages 131-144
Published: July 25, 2013
Released on J-STAGE: May 16, 2017
JOURNAL OPEN ACCESSThe large-scale tsunami created by the 2011 off the Pacific Coast of the Tohoku Earthquake struck far-flung regions of the Pacific coastline. Description of recently deposited tsunami sediments is significant for future research of both past and modern tsunami. Samples were collected in Miyagi Prefecture of northeast Japan by coring with an acrylic pipe. This allowed observation of sedimentary features. Geochemical analysis of tsunami and pre-tsunami sediments is useful for discrimination of both types of sediments. The tsunami sediments were divided into sandy or muddy sediments, based on their characteristic distribution in the coastal area. Lithologic contrasts were related to the geographic features of the sandy beaches, and the inland areas inundated by the tsunami waves. Both sandy and muddy sediments commonly formed thin layers, less than 15 cm thick. Sandy sediments were distributed along the coastline, up to 5km from the shore. Muddy sediments dominated in the northern side of the Ishinomaki district, where the bay has a more concave shape than the other areas examined. Muddy sediments were deposited on the surfaces of paddy fields and on the foundations of destroyed houses and other structures. Some of the sand deposits exhibited parallel lamination and layered concentrations of iron sands. The tsunami sediments are enriched in Pb, Zn, Cu, TS (total sulfur), Br, and Cl compared to the pre-tsunami sediments. The enrichments in these elements are related to the organic matter which was accumulated in the adjacent bays and/or estuaries. Previously reported geochemical map data for fluvial and marine sediments in this area were used for characterization of original provenance signatures. The results indicate that the tsunami sediments are more similar to those of fluvial sediments, rather than the marine sediments. This suggests the tsunami sediments were deposited mostly by backwash waves, rather than from transportation by run-up waves. The similarity of the geochemical compositions of the tsunami sediments and on-land sediments could be related to historic recurrence of large-scale tsunami in this region.View full abstractDownload PDF (19999K) -
Yoshiaki SUGAMORIArticle type: Article
2013 Volume 67 Issue 4 Pages 145-147
Published: July 25, 2013
Released on J-STAGE: May 16, 2017
JOURNAL OPEN ACCESSDownload PDF (485K) -
Toshio KUSUNOKI, Michio KIJI, Teiji MIKAMI, Mamoru MURATAArticle type: Article
2013 Volume 67 Issue 4 Pages 149-154
Published: July 25, 2013
Released on J-STAGE: May 16, 2017
JOURNAL OPEN ACCESSDownload PDF (13851K)
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