Geothermal Surrey Almost Completed

Press, Volume XCIX, Issue 29235, 20 June 1960, Page 17

Geothermal Surrey Almost Completed

"The Press" Special Service

AUCKLAND, June 19. The Rotorua office of the Geological Survey has almost completed the mapping of 980 geothermal wrings at Orakeikorako, on the Waikato river. Some time this year, 70 per cent, of the springs will be submerged when the water level rises «0 feet at that point to form the new Lake Ohakuri. It is expected that the rise in level will bring about interesting and possibly spectacular changes in the upper banks of the geothermal area. The face of the resort has been constantly changing and the survey is anxious to obtain a clear picture of its history to ascertain which changes will be natural and which will be induced by the new lake when it is formed. "We have a pretty fair idea of what has happened since 1937,” said survey technician, Mr E. F. Lloyd. “We are a bit vague about what it was like before. What we want is old photographs of the area—of any kind. “I am particularly anxious to aee photographs by Mr D. L Barron, who snapped the area some time, we think, in the 1870 s or 1880’s, and there must be hundreds of snapshots about of the great Orakeikorako geyser, which was blowing about 1940. I haven’t see one of them yet.” As an example of the difficulties under which the survey was working, Mr Lloyd' said he was able to trace 33 documents referring to the district published ’ in the last cetotury, but only nine published between 1900 and 1940. , He asked if people who had any old snapshots of the area could send them to the Department of Scientific and Industrial Research • in Rotorua, where they would be i copied and returned. I Silica forms unique in New II Zealand will be drowned by the | new lake. Some geysers will disI appear; but the effect of the lake Lis expected to be the most interI esting li A peak period of activity at |i Orakeikorako had corresponded | with a six-foot rise in the river I level some years ago. Heavy rain | had fallen before that and it was

not dear which had increased the activity.

In preparation for the flooding, the survey has obtained rainfall data as far back as 1880 and river levels since 1905. Springs have been mapped and heat flows measured all over the mile-long area.

Now technicians are working on the geological structure of the area. If, with the help of photographs; they Can obtain a clear picture of its thermal history, they will then be ready to record and analyse coming changes.