This footage of Mt. Aso's continuing eruption is referred to in the following statement:
"An aerial observation on Dec. 23 from an Asahi Shimbun helicopter showed the diameter of the vent, formed at the bottom of the crater and through which magma and rock fragments erupted, having expanded by 30 meters since the eruption to measure about 50 meters."
http://ajw.asahi.com/article/behind_news/social_affairs/AJ201412240066
http://youtu.be/zDFR0VTPxlo
阿蘇山噴火から1カ月、観光に打撃 キャンセル相次ぐ
21年ぶりの本格的なマグマ噴火が始まって12月25日で1カ月になる阿蘇山中岳。 【記事はこちら】http://www.asahi.com/articles/ASGDQ6VTQGDQTIPE02C.html ※朝日新聞社の動画の改ざんや、許可なく商用・営利目的で利用することを禁じます。