CLIMATIC CHANGES

New Zealand Herald, Volume LXXI, Issue 21792, 5 May 1934, Page 14

CLIMATIC CHANGES

WEATHER 3000 YEABS AGO EFFECT OF GLACIAL AGES . SCIENTIST'S INVESTIGATIONS The South Island to-day prides itself on its winter resorts, on its snowcapped mountains and on its snow and ice sports, but not long ago as geologists reckon time —a mere two or three thousand years—it could, with equal justice, have prided itself on its seabathing, on its mild winters and on a climate almost sub-tropical iu its warmth. Some three thousand years ago the climate of New Zealand was very much hotter and drier than at present, but between tho years 1000 B.C. and 500 8.C., for a reason that is as yet imperfectly understood, tho average temperature in both the Northern and Southern Hemispheres fell sharply, creating the climates now known. This is ono of the conclusions arrived at by Dr. C. C. Caklenius, lecturer in geology at the University of Stockholm. For the last seven months he has been engaged on an investigation of the glacial and post-glacial deposits of tho South Island, his object being the constructing of a geological and meteorological time-scale for the Southern Hemisphere. His work is a part of tho general labours of the Geo-Chrono-logical Institute of Stockholm, which is preparing a detailed time-scale based on geological observations of tho climatic changes which have affected the world at various periods in its history. The principal object of tho time-scale is to determine tho times at which tho various glacial periods in the world's history occurred, how long they lasted and what was their subsequent influence on climate. These periods have been intensively studied in the Northern Hemisphere for many years, but Dr. Caklenius' present investigations are the first that have been made in New Zealand. A scale has already been prepared for the Northern Hemisphere, and Dr. Caklenius says he believes that his investigations i New Zealand show that the dim; tic changes already proved in the Northern occurred simultaneously with those in the Southern Hemisphere. The final stages of Dr. Caldenius' New Zealand investigations were carried out in tho country round Lake Wakatipu, Lake Manapouri, and Lake Tekapo, and in the peat bogs near Mossburn and Otautau and Swampy Hill in Otago. A study of the deposits left in the old lake beds in these districts and in the peat bogs enabled the scientist, by his observations of the annual layers of silt left by the flow of glacial rivers in the warm seasons,, to estimate the temperature of the season, since glacial rivers naturally flow more freely in hot summers than in cold ones.

It is by observations of these annual layers in all parts of tho world that the Geo-Chronological Institute's table is being constructed. Dr. Caldenius himself has already visited South America and made observations there, and after leaving New Zealand he will visit Australia to study the permo-carboni r -: ous glacial deposits in the Newcastle district. All his observations so far indicate that the climatic changes of the Southern Hemisphere occurred contemporaneously with those in the north. Dr. Caldebius will remain in Christchurch until the end of next week. He will then visit Dunedin and lecture at the University of Otago, and will leave for Australia on May 18. "Although I have not been able to get everything I wanted in New Zealand," he remarked in an interview in Christchurch this week, "I am, on the whole very pleased with the results of mv work here."