190 



G. H. KALLIGAN. 



show that a warm sub-surface current, about 400 miles 

 wide, and about 250 fathoms deep, flows in an easterly 

 direction off Gape Northumberland on the Victorian coast. 

 At Cape Leuwin it is a surface current, but at Cape Nor- 

 thumberland it is about 150 fathoms below, and has cooled 

 to the extent of about 16° Fan. 



As the great Southern Ocean current of less temperature 

 than 62° approaches the south-west coast of Australia it 

 meets this warm southerly drift from the Indian* Ocean, 

 and its water being the heavier, it dips below the warmer 

 stream, and flows as a sub-surface current until it meets 

 the shore line. It bifurcates probably from 400 miles to 

 500 miles south-west of Oape Leuwin, one part flowing 

 northwards along the western coast of West Australia, as 

 far north as Sharks Bay, and the other flows easterly along 

 the South Coast as far as Bass' Strait. The branch which 

 flows northward dips under the warm southerly drift from 

 the Indian Ocean before referred to, but upwells in the 

 immediate vicinity of the shore line, forming a cold belt, 

 which varies in width according to the strength and dura- 

 tion of the off shore winds. 



There is not sufficient information available to enable us 

 to say how far it extends as a sub-surface current to the 

 west. The oceanic isotherm of 62° approaches the west 

 coast approximately in an east and west direction, on about 

 the latitude of Perth, until within from 50 to 200 miles 

 from the shore line, according to the season, and then bends 

 sharply to the south. Towards the end of June it is at its 

 greatest distance (about 200 miles) south of Oape Leuwin, 

 and it approaches to within a few miles of the shore line 

 at the end of September. The waters adjacent to the shore 

 between Eucla and North West Cape of West Australia, 

 are reported to be about 5° colder than the water in the 

 offing, and this is probably due to an upwelling of the water 

 of the Southern Ocean current. 1 



1 Report by J. J. East to the West Aust. Govt., August, 1912. 



