The Blue Lake Mt Gambier when it is still grey and just ready to turn brilliant blue. : 無料・フリー素材/写真
The Blue Lake Mt Gambier when it is still grey and just ready to turn brilliant blue. / denisbin
| ライセンス | クリエイティブ・コモンズ 表示-改変禁止 2.1 |
|---|---|
| 説明 | The Blue Lake, Mt Schank and Volcanoes. The jewel in the crown of Mt Gambier is undoubtedly the volcanic cone, the crater lakes especially the Blue Lake and the surrounding Botanic Gardens and parklands. The Botanic Garden on the north side was approved in 1872 but nothing happened about plantings and care until 1882. The first pleasure road through the saddle between the Blue Lake and the Valley Lake was created in the 1861 as a more direct road to the then newly created international port named Port MacDonnell. That is why the road is called the Bay road. Surveyor General George Goyder explored the lake surrounds himself in 1876 when he selected the site for the government tree nursery. Later the government established the first sawmill on the edge of the crater reserve near Moorak homestead in the early 1920s. The Centenary Tower was initiated in 1900 to celebrate the centenary of Captain Grant sighting Mt Gambier. It took several years to complete and was opened by the Chief Justice of SA Sir Samuel Way in 1907 but it was completed in 1904. The whole complex is a maar geomorphological formation which originated during a volcanic era about 28,000 years ago but in a second phase of volcanic activity 4,000 to 6,000 years ago the cones and lakes of Mt Gambier were created along with the cones of Mt Schank and Mt Burr near Millicent. Mt Gambier was the most recent volcanic explosion in Australia. The crater lakes are: Blue Lake, Valley Lake, Leg of Mutton Lake and Browne’s Lake (dry). The Blue Lake is linked to the aquifers beneath the deep layers of limestone which underlay the entire South East. Blue Lake is about 72 metres deep and some of the water in it is estimated to be about 500 years old but it is mixed with rain runoff each year as well. The Lake provides the water supply for Mt Gambier. Deep in the lake are examples of the oldest living organisms on earth- stromatalites. The lake changes colour from grey to vivid blue each November and reverts in the following April. The change in colour is related to the position of the sun and reflected light from suspended particles in the lake which reflect blue green light rather than brown grey light. Secondly the suspended matter only occurs because the water near the surface rises in temperature in the spring and it is this which causes the particles to precipitate out of the water. The precipitated matter settles on the bottom of the lake ready for a new cycle the following spring. Like the Blue Lake various sink holes in the district have linkages to the underlying aquifer through the layers of limestone too and they include Cave Gardens, Umpherstone, Piccaninni Ponds, etc. |
| 撮影日 | 2011-11-20 18:43:29 |
| 撮影者 | denisbin |
| タグ | |
| 撮影地 | |
| カメラ | DSC-S950 , SONY |
| 露出 | 0.004 sec (1/250) |
| 開放F値 | f/6.2 |