Pohutu Geyser’s Long Quiescence

Manawatu Times, Volume 62, Issue 32, 8 February 1937, Page 5

Pohutu Geyser’s Long Quiescence

POSSIBLE CAUSES DISCUSSED. ROTORUA, Feb. 3. The thousands of visitors to Rotorua during the Christinas and New Year ! holidays and since nave been disap- j pointed when they visited the thermal j regions at Whakarewarewa expecting to see the famous Pohutu Geyser in action. During the winter months of 193 G Pohutu established new records for the 1 number of shots during a certain period, and now, at the height of the summer ( season, it shows no signs of activity and has not played since November. Two other small geyers in close proximity to the major vent have been particularly active during the two months when pohutu has been quiet, and it was a popular belief that perhaps these *wo small vents had an effect on Pohutu. Escape of Steam. When the matter was referred to Dr. L. Day, head of the Geophysical Laboratory of the Carnegie Institution, Washington, who is a leading world authority on hot springs and geysers, he said that it was possible that the big chamber beneath Pohutu where pressure was generated for the forcing of tho boiling water up through the vent had cracked, allowing the steam to escape into the neighbouring chambers, thus accounting for the activity of the two small geysers. This, however, would be only a surmise and was not based on investigation. When the question of the effect of the level of Lake Rotorua on the geyser was put to Dr. Hay ho said that as far as he was aware it had never been delinitely established that there was any connection between the lake and tho geyser, but if there was any such connection as had been suggested then the high state of the lake might make the atmosphere in the Pohutu chamber too heavy, thus decreasing the pressure, which would account for the inactivity of the geyser. Effect of Crack. If there was a crack in the chamber, continued Dr. Day, it would probably be years before the geyser would play again because the process of mending would be very slow. However, Dr. Day was not inclined to belief that there was a crack. Soap could be applied to act as a trigger if the pressure was too high in the chamber without any effect to the geyser. The belief that soap was injurious to the vents was untrue, the soap only acting to release the steam. Sand would have the same effect, but would probably tend to block the subterranean tubes feeding the chamber. The Tourist Department has installed a floodlight adjacent to the Malfroy Geyser, which lies nearer the Rachel Pool in the Government Gardens. Tho illumination is supplied by a special blue mercury light fitting and gives most attractive and unusual effects when focussed upon the rising steam of the geyser. A temporary standard has been erected to carry the floodlight, but it is proposed to replace this by a less conspicuous fitting.