VOLCANIC ACTIVITY ON WHITE ISLAND

Chronicle (Levin), 3 February 1947, Page 3

VOLCANIC ACTIVITY ON WHITE ISLAND

-White island, wiiere there is volcanic activity so.hot that steam eannot ccmdense into geysers and a pebble tossed iiitO' a: fumarole comes back iike a booinerang \VHs recently visited by a group oi' observers from the Depaftnient of Scientific and Industrial ReSearch. . • Their six-day stay is likely to lead to .reports of significance ff om the point of .yiew of science, industry and rc■seafeh- into>the life of the birds which irihabit the pohutukawa-clad fringes of the island.. ...The expedition has marked the changes in hydro-thermal activity sinee the island was last visited by scientists 20 years ago.., Among other tasks car,ried out.M a. preliminary exploratiOn of deposits, some of which may decide the 'jijjland 's. geological. Jiistory. ...Some 00 iiiiles. ffoih Tauranga, White Island appeared not so much white as like a highly-decorated Christmas cake, said Mr.- C. A, Flyming, the geologist of the phfty-. • . Ptirts of it were encrusted With ii jiiukish rock and a hetlvy-miner-alisCd steam • caused a snake-like trail of sulphur-tinted water out to sea. - The island was a blaze of the yellow df sulpliur,' the red of hematite, and the whitte' of gypsum. The only natural green was the far fringes of the pohutukawa fofest. Ashore there were places where it was necessary to tread so.berly and warily. Bchubert's Fairy, a fumarole so uamed many years ago when an attempt was made to mine the sulphur of the island, was still a sight which wouid make Rotorua look tame, Mr. Fleming said. The Fairy danced many feet above a roarintT blowhole. The sulphur -

ous gas escaped at such heat and pressure that it was invisible for many feet. When it condensed, the Fairy appeared in dancing bluish sulphur flame, .wliile far above her soared the steam oloud. . Describing some of the changes since the last visit, he said that Little Donald, one of the blowholes formerly mapped, had now become quiet. Big Don--ald, however, was again the centre of a boiling green lake. This was not nearly so large as the lake which formerly occupied much of the crater, but it was strongly acid. After a strong hapuku line had been in it for a few minutes, the tlireads could be pulled apart. When an attempt was made to examine one fumarole, a thermometer reading up to1 350 degrees centigrade buckled and broke. Knives corroded overnight and a gunmetal watchcase, carried in the pocket of . one of the party, was now completely black. The remains of the sulphur mill of 20-odd years ago showed strong evidence or the corrosive atmospliere. Everything steel and iron had been heavily corroded and the concrete was buckled fiom the expansion of its reiuforcements. The asbestos xoof was also considerably affected. The scientists' opinion is that the extent of the hydro-thermal activity on the island cannot be judged by the steam cloud. This is shown to be greatly affected by the atmosphere when the activity of pools and vents remained constant. Asked whether the gypsum deposits could be used to relieve the shortage in the New Zealand buildi'ng trade, Mr. Fleming declined to comment. He said, however, that samples had been collected for analysis and report. Gypsum, he added, appeared to be the most obvious product of the island 's hydro-thermal activity. It was showing in narrow seams and crystals in a great many places in the crater bed. These deposits, however, were scattered and Some were obvionsly impurec