CRATER CHANGE

Wanganui Chronicle, Volume 89, Issue 268, 13 November 1945, Page 4

CRATER CHANGE

RUAPEHU’S ACTIVITY NEW DEVELOPMENTS Wellington, Nov. 12 The crater of Mount Ruapehu seems to be changing very rapidly, says Mr. A. C. Beck, in a report to the Director of the Geological Survey (Mr. M. Ongley), received in Wellington to-day. The floor has risen approximately 100 feet in the last moult.

Mr. Beck stated that the crater had been enlarged southwards by five or six chains, through the melting of the ice wall. The vent had also increased in that direction, and now appeared to be gliptical in shape, and extended to about the position of the former ice wall.

“The activity is very strong,” Mr. Beck reported, “the volume of ashladen steam being very large, possibly greater than ever before, but owing to the increased size of the vent It Is not issuing under any great pressure, and rocks are not being thrown ou any more than.up to 300 or 400 feet in the air. There seem to be two separate orifices within the vent, from which the gas is emitted independently, as when observed for a period the gas issues from one spot, and then from the other. Sometimes they blow off together. The one at the northern end is the more violent in eruption.” When the northern vent was quiet and emitting steam only, various coloured gas clouds could be seen rising from the centre, pink, reddishbrown, pale yellow, and a dirty green. This colour had not previously been observed. Heavy explosions had made fresh holes up to six feet deep in the glacier. Some of the rocks were still warm 12 to 16 hours after they had been emitted. Of late the explosions had averaged two daily. “The quantity of gas escaping and the size of the vent,” says Mr. Beck, “seem to indicate that the worst is not yet over u and that the eruption has not reached its ciimax. - - On November 6 he observed the most spectacular eruption he had seen. “The vent consisted of only one blowhole, which was shooting up rocks over 1000 feet above the floor. The day was almost calm, and we had a very good view of the form of the crater. The inside of the vent seems roughly si ratified into bands of large rocks, and small rocks or ash.” The rocks thrown up from the vent had a jagged appearance as they flew through the air, and when thrown clear of the main ash column, trailed a thick cloud behind them of bluish white (like cigarette smoke). A steam cloud with a pale green tinge was observed from the north lisure. Subsequently, the large black spurts that contain large rocks were seen quite clearly from Chateau Tongariro, and they were followed at night by “a terrillic burst of red-hot rocks and ash. The whole cloud as it rose from the crater was red hot,” he wrote “witn boulders rising and falling In the centre. This possibily was au* to a much more forcible ejection of boulders than had occurred during the afternoon.”