Many Changes in Crater of Ngauruhoe

Grey River Argus, 25 February 1949, Page 7

Many Changes in Crater of Ngauruhoe

WANGANUI, February 24,

Considerable changes in the crater of Mt. Ngauruhoe, involving the partial filling of the only previous vent and the opening of a new’ one, have been discovered by Mr L. R. Allen, of the Geological Survey. Mr /tlleii made a quick circuit of the lip of the crater and descended again, “as quickly as possible, because I didn’t know when she was going up again”. Previously the only vent in the volcano was in the southern sector of the crater, and, whereas this was surrounded by sheer 100 ft walls, it is now possible to descend a gentle rubble slope of about 30 feet to the vent itself, which now’ has a surface of hard scum.

Mr Allen believes from his observation that only ash and steam have come from this vent in recent activity. There is probably lava in the vent, headded, but none has been ejected. NEW VENT OPENED The most interesting discovery of his quick inspection wps the development of a new vent in the small north-west sector of the crater. Like the other, this vent now carries a solid scum, but it was from there that all the lava had been ejected. The entire crater is now ringed with ash and hot boulders, most of which have been hurled out several times only to fall back into the vent.

Mr Allen suggested that this regurgitation was explained by the fact that the vent pointed directly upwards. The total quantity of matter thrown out of the depth of the volcano was probably relatively small. Descending by way of the lava stream on the north-west face, Mr Allen inspected several very small vents in the stream, from which lava had trickled. Everything indicated that they w r ere directly connected with the new' major vent. For the past couple of days, the mountain, according to Mr Allen, “has been turning on only a mediocre show”.