Mount Hoei

A flank volcano located in the northeastern part of Shizuoka Prefecture, southeast of the summit of Mt. Fuji. Its elevation is 2,693 meters. It is part of Gotemba City, Shizuoka Prefecture. The eruption in 1707 (4th year of the Hoei era) created three craters aligned in a north-northwest to south-southeast direction. The first crater is elliptical, measuring 1,300 meters in length and 1,000 meters in width, and is called Shinnai-in. The second and third craters are much smaller. The protruding part is shoulder-shaped and is called Akaiwa, and the reddish-brown pyroclastic flow deposits are considered to be part of the Old Fuji Volcano. Mt. Hoei's activity did not result in lava flow, but rather in the ejection of large amounts of volcanic ash, with ash falling as far as the center of Edo city.

[Kitagawa Mitsuo]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

静岡県北東部、富士山山頂の南東部に位置する側火山。標高2693メートル。静岡県御殿場市(ごてんばし)に属する。1707年（宝永4）の噴火活動によって生じた火口は北北西から南南東方向に三つ並び、第1火口は長径1300メートル、短径1000メートルの楕円(だえん)形で新内院とよばれる。第2、第3火口はこれよりずっと小さい。突出部は肩状の形態をもって赤岩とよばれ、赤褐色の火砕流堆積(たいせき)物は古富士火山の一部とされている。宝永山の活動は、溶岩は流出せず火山灰の噴出が多く、江戸市中まで降灰があった。

［北川光雄］

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