Saturday, 24 November 2007

Back on track!

It is great to see that the GPS tracker is back in operation and be able to keep up to date with Mark's movements once again.... After today's cycling, Mark has reached a point about half way down the west coast of the Eyre peninsula. He is cycling on the Flinders Highway which links Ceduna with Port Lincoln at the southern end of the peninsula. The highway (and many geographical features throughout Australia) is named after the British navigator, Matthew Flinders who explored much of the coastline of Australia in the course of two voyages between 1801 and 1803.

It was during the first of these voyages that he charted the coast of South Australia. Flinders is also credited with being the person to give Australia its name!

The image of the Flinders Highway below is from Wikipedia and although it does not specify exact location, it does give a general indication of the kind of road Mark is now on. However, there is one other significant feature - unique power lines poles called Stobie poles which is explained here.Most geographers would describe themselves as either physical or human geographers and, if you haven't yet guessed, I'm at the physical end of the spectrum. This explains why I was really interested today in a stretch of coastline which Mark passed by near to Elliston . Here was a cove , very similar to Lulworth Cove which I visited just a few weeks ago in Dorset. Below are photos of both for comparison....
The similarity in their shapes is not coincidence. The same processes have created coves like these at opposite ends of the world. Both Lulworth and the bay at Elliston have formed on concordant coastlines. These are stretches of coast where the geology is arranged parallel to the coast. Often a harder rock type forms a protective barrier along the edge of the coastline with softer rocks further inland. If the sea breaches the outer barrier, it penetrates through to the softer rocks which are more easily eroded forming the cove behind. Further inland penetration is usually halted by the presence of another line of harder rock at the back of the cove. In both of the images (but especially the one of Elliston bay) , you can make out the remnants of the harder outer layer of rock. The entrance to Elliston Bay is clearly quite tricky! Another reason for the widening of coves relates to refractive wave energy and you can see very clearly on the photo of Elliston Bay how the waves entering the cove 'bend'. This is due to the frictional drag which the headlands at the sides cause. The waves in the middle of the cove proceed to the beach without this drag. The consequence of this is that the erosive energy of the waves is directed at the side of the cove while deposition creates a beach at the back of the cove just as here on Elliston Beach .

South of Elliston the landscape appears to become quite arid and cultivation clearly gives way to extensive sheep grazing. One of the places mentioned on the web diary today is Sheringa which on closer inspections seems to be little more than a homestead with a road leading to 'No Where'!

Finally, it is already the next day in Australia. This is Mt Hope where Mark camped on Saturday evening.... 20.42 GMT .... add on the time difference .... Mark is off on his bike already and we haven't even got to bed!!

1 comment:

Anonymous said...

That was a close shave with the GPS tracker. Those coves were cool shapes and the water was so blue, wish I could go and live there!