Credibility of Volcanic Ash Thicknesses Reported by the Media and Local Residents Following the 2014 Eruption of Kelud Volcano, Indonesia
Setsuya Nakada*, Akhmad Zaennudin**, Fukashi Maeno*, Mitsuhiro Yoshimoto***, and Natsumi Hokanishi*
*Earthquake Research Institute, The University of Tokyo
1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
**Center for Volcanology and Geological Hazard Mitigation, Badan Geologi, Indonesia
***Mount Fuji Research Institute, Yamanashi Prefectural Government, Japan
Ash thicknesses reported by the media and witnessed by local residents may be exaggerated. A good example of such exaggeration is ash thicknesses reported following the Plinian eruption on February 13, 2014 at Kelud volcano, East Java, Indonesia. Volcanic ash thicknesses reported by the media and local residents were generally by 2–7 times larger than the actual values measured by volcanologists. Sensational news reports and strong fresh impressions may cause such exaggeration, or these exaggerated values may simply represent abnormal concentrations of volcanic ash. It is important to pay careful attention to the parameters that are being documented by the media and by people who do not have scientific backgrounds when utilizing such reports in scientific analyses.
-  C. G. Newhall and S. Self, “The Volcanic Explosivity Index (VEI): an estimate of explosive magnitude for historical volcanism,” Jour. Geophys. Re., Vol.87, C2, pp. 1231-1238, 1982.
-  D. M. Pyle, “Sizes of volcanic eruptions,” H. Sigurdsson et al.. (Eds.), “Encyclopedia of Volcanoes,” Academic Press, London, pp. 263-269, 2000.
-  T. Chiba and T. Inoue, “High altitude airborne LiDAR at south east edge of Shimoedake-crater in Kirishima Volcano, Japan,” Abstract of Japan Geoscience Union Meeting 2011, Makuhari, Chiba, Japan, SVC070-P26, 2011 (in Japanese).
-  Y. Nakano, T. Shimizu, T. Yamakoshi, H. Kisa, and T. Ishizuka, “Application of DInSAR technique to estimating an area and a thickness of volcanic ash using ALOS/PALSAR,” J. Japan Soc. Erosion Control Engineer., Vol.66, pp. 41-47, 2013 (in Japanese with English abstract).
-  NIED (National Research Institute for Earth Science and Disaster Preservation), “Thickness of volcanic ash estimated from PASAR/InSAR result,” Report of the National Coordination Committee of Volcanic Eruptions Prediction, Vol.108, pp. 227-230, 2011 (in Japanese), http://www.data.jma.go.jp/svd/vois/data/tokyo /STOCK/kaisetsu/CCPVE/Report/108/kaiho_108_40.pdf#search= %27Thickness+of+volcanic+ash+estimated+from+PALSAR%2 FInSAR+result%27 [accessed Dec. 3, 2015]
-  L. Siebert, T. Simkin, and P. Kimberly, “Volcanoes of the World. Third Edition,” University of California Press and Smithsonian Institution, p. 551, 2010.
-  Global Volcanism Program, “Report on Kelut (Indonesia),” R. Wunderman (Ed.), Bulletin of the Global Volcanism Network, 39:2, Smithsonian Institution, http//dx.doi.org/10.5479/si.GVP. BGVN20142-263280, 2014.
-  K. Ishihara, Surono, M. Hendrasto, and S. Hidayati, “Long-term forecasting of volcanic eruption in case of Kelud volcano, Indonesia,” Annuals Disast. Prev. Res. Inst., Kyoto Univ., Vol.54B, pp. 209-214, 2011.
-  K. Jeffery, B. O’Driscoll, H. Humaida, and J. P. Chadwick, “The pre-eruptive magma plumbing system of the 2007-2008 dome-forming eruption of Kelut volcano, East Java, Indonesia,” Contrib. Mineral. Petrol., Vol.166, pp. 275-308, doi10.1007/s00410-013-0875-4, 2013.
-  H. L. Tanaka, M. Iguchi, and S. Nakada, “Numerical simulations of volcanic ash plume dispels from Kelud volcano in Indonesia on February 13, 2014,” J. Disaster Res, Vol.11, No.1, pp. 31-42, Feb., 2016.
-  BeritaSatu.com, “Erupsi Kelud, penerbangan dari bandara juanda ditunda,” 2014, http://www.beritasatu.com/nusantara/166207-erupsi-kelud-penerbangan-dari-bandara- juanda-ditunda.html newline [accessed Feb. 18, 2014]
-  Liputan6com, “Tebal abu Gunung Kelud di ngantang capai 50 centimeter,” 2014, http://news.liputan6.com/read/828161/tebal-abu-gunung-kelud-di-ngantang-capai-50-c entimeter [accessed Feb. 18, 2014]
-  MetroTVnews.com, “Abu letusan Gunung Kelud. Sampai ke Surabaya dan Yogyakarta,” 2014, http://www.metrotvnews.com/linebreak metronews/read/2014/02/14/6/215869/Abu-Letusan-Gunung-Kelud-Sampai-ke-Surabaya-dan-Yogyakarta [accessed Feb. 18, 2014]
-  Solopos.com, “Gunung Kelud meletus: Kediri diselimuti abu vulkanik, 3 jam ketebalan 5 cm,” 2014, http://www.solopos.com/linebreak 2014/02/14/gnung-kelud-meletus-kediri-diselimuti-abu-vulkanik-3-jam-ketebalan-5-cm-489409 [accessed Feb. 18, 2014]
-  Solopos.com, “Gunung Kelud meletus: abu vulkanik Kelud selimuti Jawa,” 2014, http://www.solopos.com/2014/02/14/gunung-kelud-meletus-abu-vulkanik-kelud-selim uti-jawa-489722 newline [accessed Feb. 18, 2014]
-  NHK World News, “Mount Ontake volcanic eruption,” 2014, http:// www3.nhk.or.jp/nhkworld/english/news/mountontakevolcano/linebreak 2014093001.html [accessed Sep. 5, 2015]
-  T. Kaneko, F. Maeno, and S. Nakada, “Ontake 2014 eruption: Characteristics of the phreatic eruption as inferred from aerial observations,” Earth Planets Space (in review).
-  F. Maeno, S. Nakada, T. Oikawa, M. Yoshimoto, J. Komori, Y. Ishizuka, Y. Takeshita, T. Shimano, T. Kaneko, and M. Nagai, “Reconstruction of a phreatic eruption on 27 September 2014, at Ontake volcano, Central Japan, based on proximal PDC and fallout deposits,” Earth Planets Space (in review).