Geographic Setting

Macquarie Island

Macquarie Island is located at latitude 54 38' 40" S. longitude 158 40' 50"E. It is an oceanic island located in the Southern Ocean. The island is 34 by 6 km lying about 1,500 km east of Tasmania and, also, is located halfway between the Australian and Antarctic Continents. It is a part of the Sub-Antarctic Islands which means that it lies South of the Polar Front and experiences cool temperate climate conditions.


Map of Macquarie Island

The temperature varies from around 7 degrees celsius in the summer and 4 degrees celsius in the winter. Cloud cover is experienced often so very little sunlight has a chance to reach the ground. The island experiences some form of precipitation (rain, snow or hail) about 300 days out of the year. It is very windy because it lies within the zone of the West Wind Drift. Unlike other Antarctic islands, it is a plateau shaped from wave movement rather than ice collisions. The altitude reaches 433 meters at its highest point.

Extrusive volcanic rocks (mainly pillow lavas and basaltic dykes) make up 80% of the island crust. There is a central plateau about 300 meters above sea level that is the main topographic feature on the island. It is surrounded on all sides by steep cliffs and glacial drift up to 20 meters thick. There are actually quite a few lakes and smaller pools found on the plateau and the surrounding island terrain.


Macquarie Island Coastline

An interesting fact about Macquarie Island is that it is the best preserved source of oceanic crust which was formed in deep waters and is now above sea level. The island is a part of an exposed ridge complex called the Macquarie Ridge. The Ridge interacts with the Indian-Australian and the Pacific plate creating tectonic movement and constant, but extremely slow, growth of the island. Because of this, Macquarie Island is an area where geoconservation is extremely important.

References:

http://library.thinkquest.org/26442/html/isles/macquar.gif
http://www.eoearth.org/article/MacQuarie_Island,_Australia
http://www.alasdairmcgregor.com.au/attachments/Image/Macquarie-Island1(1).jpg
http://upload.wikimedia.org/wikipedia/commons/thumb/3/3f/MacquarieIsland7.JPG/300px-MacquarieIsland7.JPGhttp://whc.unesco.org/en/list/629/