PULSATING LAKES

New Zealand Listener, Volume 31, Issue 801, 26 November 1954, Page 5

PULSATING LAKES

Sir,-In the recent article "The Spell of the Lakes" reference was made to the generally accepted pulsation of the surface of Lake Wakatipu, which is frequently reported as rising and falling by some inches with a period of roughly five minutes. Pulsations of a similar kind are well known on other lakes, and were first investigated in detail by Forel,

who made an especial study of Lake Geneva about 1880. The term "seiche" is generally used to describe such oscillations, which are believed to be caused by the atmospheric pressure and wind tilting the surface of the lake a few inches from the horizontal so that it then vibrates rather like the water swinging from side to side in a hand basin. There is very little easily accessible data dealing with the behaviour of Lake Wakatipu, and no detailed scientific investigation appears to have been made of the amplitude and the periodicity. The Otago University Science Students’ Association is conducting an inquiry into the phenomenon on Lake Wakatipu, and are anxious to collect first-hand descriptions of the various effects noticed. The unusual shape and depth of Lake Wakatipu may produce effects not noticed elsewhere, and it is hoped that a fuller investigation with proper instruments may be made at an early date. We should be extremely grateful for any information relevant to the matter, such as date and place of .occurrence, rise and fall, duration, .and weather, which readers can let us have, The value of the inquiry will depend considerably upon the number of accounts obtained, and correspondents are assured of a re~ ply. Letters may be sent to Lake Wakatipu Inquiry. University of Otago. Dune

edin.

R. R.

MARPLES

Secretary of Science Students’ Association,