Air-Fall Ash from the Main Crater of Asama Volcano on August 7, 2019, and its Water-Soluble Components
Muga Yaguchi*,, Akihiko Terada**, and Yasuo Ogawa**
*Volcanology Research Department, Meteorological Research Institute, Japan Meteorological Agency
1-1 Nagamine, Tsukuba, Ibaraki 305-0052, Japan
**Volcanic Fluid Research Center, School of Science, Tokyo Institute of Technology, Tokyo, Japan
We collected volcanic ash immediately following the eruption of Mt. Asama on August 7, 2019, observed the characteristics of ash particles, and analyzed the water-soluble components. The volcanic ash consisted mostly of altered fragments, and no clear evidence of essential materials was found. The volcanic ash contained large amounts of water-soluble components, Cl and SO4 at concentrations of 8,710 mg/kg and 49,100 mg/kg, respectively. These results indicate that this eruption was caused by the phreatic explosion and that part of the volcanic edifice of Mt. Asama was fractured and emitted.
-  Japan Meteorological Agency, “Volcanic Warning (Near the crater),” https://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/volinfo/VJ20190807223000_306.html (in Japanese) [accessed August 14, 2019]
-  Japan Meteorological Agency, “Volcanic Activity of Asama Volcano (Sep.2000–Apr.2003),” Rep. Coord. Commit. Pred. Volc. Eruption, Vol.85, pp. 35-52, 2003 (in Japanese).
-  Japan Meteorological Agency, “Abstract of Volcanic Activities of Asama in 2004,” Rep. Coord. Commit. Pred. Volc. Eruption, Vol.89, pp. 11-23, 2005 (in Japanese).
-  Japan Meteorological Agency, “Volcanic Activity of Asamayama Volcano From June 2008 to October 2008,” Rep. Coord. Commit. Pred. Volc. Eruption, Vol.101, pp. 54-61, 2010 (in Japanese).
-  Japan Meteorological Agency, “Volcanic Activity of Asamayama Volcano (from October 2008 to February 2009),” Rep. Coord. Commit. Pred. Volc. Eruption, Vol.102, pp. 34-48, 2010 (in Japanese).
-  Japan Meteorological Agency, “Volcanic Activity of Asamayama Volcano (June 2015–October 15, 2015),” Rep. Coord. Commit. Pred. Volc. Eruption, Vol.122, pp. 108-127, 2015 (in Japanese).
-  Japan Meteorological Agency, “Descriptive Report of Volcanic Activity on Asama volcano (August 8, 2019 at 00:30),” https://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/monthly_v-act_doc/tokyo/19m08/201908080030_306.pdf, p. 5, 2019 (in Japanese).
-  K. Kazahaya, J. Hirabayashi, H. Mori, M. Odai, Y. Nakahori, K. Nogami, S. Nakada, H. Shinohara, and K. Uto, “Volcanic Gas Study of the 2000 Miyakejima Volcanic Activity: Degassing Environment Deduced from Adhered Gas Component on Ash and SO2 Emission Rate,” J. Geography, Vol.110, No.2, pp. 271-279, doi: 10.5026/jgeography.110.2_271, 2001 (in Japanese with English abstract).
-  A. Tomiya, I. Miyagi, H. Hoshizumi, T. Yamamoto, Y. Kawanabe, and H. Satoh, “Essential material of the March 31, 2000 eruption of Usu Volcano: Implication for the mechanism of the phreatomagmatic eruption,” Bull. Geol. Surv. Japan, Vol.52, No.4-5, pp. 215-229, doi: 10.9795/bullgsj.52.215, 2001 (in Japanese with English abstract).
-  T. Oikawa, T. Oba, A. Fujinawa, and H. Sasaki, “Geological study of phreatic eruptions” J. Geol. Soc. Japan, Vol.124, No.4, pp. 231-250, doi: 10.5575/geosoc.2017.0071, 2018 (in Japanese with English abstract).
-  M. Yaguchi, T. Ohba, N. Numanami, and R. Kawaguchi, “Constituent Mineral and Water-soluble Components of Volcanic Ash from the 2018 Eruption of Mt. Motoshirane of Kusatsu-Shirane Volcano, Japan,” J. Disaster Res., Vol.14, No.7, pp. 991-995, doi: 10.20965/jdr.2019.p0991, 2019.
-  Geographical Survey Institute of Japan, https://maps.gsi.go.jp/#13/36.387226/138.475542/&base=std&base_grayscale=1&ls=std%2C0.6%7Chillshademap%2C0.75&blend=1&disp=11&lcd=hillshademap&vs=c1j0h0k0l0u0t0z0r0s0m0f2&d=vl,2019 (in Japanese) [accessed August 14, 2019]
-  M. Yoshimoto, T. Shimano, S. Nakada, E. Koyama, H. Tsuji, A. Iida, M. Kurokawa, Y. Okayama, M. Nonaka, T. Kaneko, H. Hoshizumi, Y. Ishizuka, R. Furukawa, K. Nogami, S. Onizawa, K. Niihori, T. Sugimoto, and M. Nagai, “Mass Estimation and Characteristics of Ejecta from the 2004 Eruption of Asama Volcano,” Bull. Volcanol. Soc. Japan, Vol.50, No.6, pp. 519-533, doi: 10.18940/kazan.50.6_519, 2005 (in Japanese with English abstract).
-  Y. Suzuki, A. Furukawa, S. Nakada, T. Fujii, A. Watanabe, and E. Koyama, “Juvenile ash of an small eruption at Mt. Asama on August 10, 2008,” Programme and Abstracts Volcanol. Soc. Japan 2008, p. 106, doi: 10.18940/vsj.2008.0_106, 2008 (in Japanese).
-  K. Nogami, S. Onizawa, and J. Hirabayashi, “Geochemical Observation on the 2004 Eruption of Asama Volcano through Analysis of Water-soluble Components on the Ash,” Bull. Volcanol. Soc. Japan, Vol.53, No.2, pp. 69-77, doi: 10.18940/kazan.53.2_69, 2008 (in Japanese with English abstract).
-  J. Ossaka, K. Nogami, and J. Hirabayashi, “Water-soluble Components on Volcanic Ashes from Tokachi-dake Volcano, Hokkaido, Japan during the 1988–1989 Eruption,” Bull. Volcanol. Soc. Japan, Vol.43, No.1, pp. 25-31, doi: 10.18940/kazan.43.1_25, 1998 (in Japanese with English abstract).
-  M. Yaguchi, T. Ohba, and M. Sago, “The nature and source of the volcanic ash during the 2015 small phreatic eruption at Hakone volcano, central Japan,” Geochem. J., Vol.53, No.3, pp. 209-217, doi: 10.2343/geochemj.2.0560, 2019.
-  K. Nogami, J. Hirabayashi, T. Ohba, J. Ossaka, M. Yamamoto, S. Akagi, T. Ozawa, and M Yoshida, “Temporal variations in the constituents of volcanic ash and adherent water-soluble components in the Unzen Fugendake eruption during 1990–1991,” Earth Planets and Space, Vol.53, No.7, pp. 723-730, doi: 10.1186/BF03352400, 2001.
-  J. Ossaka and J. Hirabayashi, “The 1982, 1983 eruptions of the Asama Volcano from the geochemical point of view” Programme and Abstracts Volcanol. Soc. Japan 1983, p. 422, doi: 10.18940/kazanc.28.4_422_1, 1983 (in Japanese).
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 International License.