In both of these the crater form is very clearly marked.
But experience in other parts of Japan shows that a long quiescent crater may at any moment burst into disastrous activity.
Farrand spent more than a week in the crater trying to get some good photographic views, and Orton has given a graphic description of his experiences in the same place.
In the eruptions of 1823, 1832, 1840 and 1868 the floor of the crater rose on the eve of an eruption and then sank, sometimes hundreds of feet, with the discharge of lava; but since 1868 (in 1879, 1886, 1891, 1894 and 1907; and once, before 1868, in 1855) this action has been confined to Halemaumau and such other pits as at the time existed.
A volcano-promontory at the Pacific end of the Tsugaru Strait: a finely formed cone surrounded on three sides by the sea, the crater breached on the land side.
It was soon found that each mine was in reality a huge vertical funnel or crater descending to an unknown depth, and filled with diamantiferous blue ground.
Eruption in 1905, when the main crater was enlarged to a length of 3000 ft.
This precipice, known as Monte Somma, forms the wall of an ancient prehistoric crater of vastly greater size than that of the present volcano.
Near the centre of the park is Mud Caldron, a circular crater about 40 ft.
A few persons reside on the little island Allegranza, a mass of lava and cinders ejected at various times from a now extinct volcano, the crater of which has still a well-defined edge.