TABLE I BASS STRAIT-Dayhght High Tides -Dec./Jan. \969/7D 



V December reflects Ihe much 

 stronger lidal forces due to full 

 fOOOP coinciding with earth's closes! 

 approach 10 the mhi (perihelion). A 

 similar but reduced effect is seen 

 at the nexl lull moon (22 J.mn.ii v ) 

 when Ihe sun receded from perihelion. 

 What mijjlii have been regarded as 

 a normtil tide wave travel only 

 siowS up Cui 20 human, when the 

 moon's declination is north. 



The figures at the top lefi band 

 corner Oj cell nutp indicate Ihe co- 

 U..I tfrtttft for Portland Ji"d Wan- 

 immhiuil- whose high tides A« often 

 "held up ' lone after the tidal forces 

 have passed. 



fatte II shows similar dnl.i foi Ihe 

 |UVM month commencing 19 June. 

 IWO Hee;.usc Ihe sun hr.s teceded 



June, 1971 



during ihe winler the III hour co- 

 udal lines become very repetitive and 

 re-inforces the view that this simple 

 pattern i» characteristic of Bass 

 Strait. 



Spied and tUreaiov oj Tide Waves 

 Urinmd Tti.sn\utua. 



CHvW that the oncoming tide W8Y« 

 from the east runs approximately on 

 a north-south line it is evident thai 

 Tasmania provides ihe alternates of 

 a path through Bass Strait and a 

 southerly course around Tasmania. 



rig. I shows the extent of the 

 abyssal plains and the continental 

 die|l m the vieimts ol Tasmania and 

 H.,ss Str.ni. li has been shown that 

 i lie speed of travel of a tidal wave 

 fNQI is proportional lo the depth of 



149 



