144 



PROF. W. J. DAK IN : EXPEDITION TO THE 



Funafuti." Keport of Coral Reef Committee of the Royal Society, Section X. 



p. 17G (1904). 



The mean annual surface tempera- 

 ture of 21 - 1° 0. is much nearer the 

 equator on the west coasts of South 

 America and South Africa than it is 

 on the west coast of Australia. In other 

 words, the water washing the coast of 

 West Australia is warmer than that 

 washing the west coasts of South 

 America and South Africa in the same 

 latitude. 



We really require much more data 

 from this coast before theorising on the 

 effect of such movement of water 

 as a " Kalter Auftrieb." It would 

 appear, however, from the following 

 that Michaelsen's suggestions can 

 scarcely hold good for the region under 

 discussion. East winds are stated to 

 prevail on the west coast of West 

 Australia for a considerable part of each 

 day. " These push the warmer surface 

 water seaward, and so cause the risiug 

 of the colder bottom water to replace 

 the driven water at the surface. The 

 rising of the colder bottom water, 

 ' the cold swell,' takes place quite 

 close to the coast and of course in- 

 fluences mostly the line of tbe coast 

 and its fauna. On the surface the 

 originally colder water soon gets a 

 higher temperature, so that by the time 

 it has been driven by the east winds 

 over the space between the coast and 

 the Abrolhos it has grown warm." We 

 shall refer later to tbe winds on this 

 coast; let us look again at the sea 

 temperatures. If a cold water up- 

 welling, especially of any extent, takes 

 place along the west coast of Australia 

 it is caused by the trade winds (not 

 an offshore local breeze), and it would probably occur along the edge of the 



