Lake Bumbunga, aka the Pink Lake, is one of the many coloured lakes in South Australia. The lakes gain their colours from minerals suspended in solution in the water. Like the Blue Lake in the south-east of the state, Lake Bumbunga changes colour over the year, depending on the concentration of minerals in the water.
Lake Bumbunga is a 1500 hectare lake made up of three salt pans. A salt pan is formed when the rate of water evaporation exceeds the rate of water precipitation. If the water is unable to drain into the ground, it remains on the surface until it evaporates, leaving behind minerals precipitated from the salt ions dissolved in the water. These minerals reflect the Sun's rays, usually creating a white colour.
The pink colour of the water comes from a pigment secreted by microscopic algae. The intensity of the pink varies with the amount of water in the lake. When the lake is drier more light is reflected from the white crystallized salt reducing the impact of the pink.
Salt has been harvested from Lake Bumbunga since 1912. Salt is dissolved from the saline mud after the winter rains.
The listed coordinates will bring you a location where you can observe the lake from a distance. You can also get good views from Blyth Road.
To log this Earthcache you will need to answer the following:
Question 1: What colours can you see in the lake at the moment? (Be descriptive. One word answers will not be sufficient.) Why do you think these colours are there?
Now drive to one of the lookouts on the side of the lake. (WP2 is for the parking location.)
IMPORTANT:
Walk as far into the lake as is safe/practical. Don’t drive on the lake – you will join the long list of people who have been bogged. The locals will laugh at you and then call a very expensive tow truck to get you out!
This earthcache also does not require you to swim! If the lake is full, make your observations from the side of the lake.
Question 2: What are the colours in the dirt/mud? Are the colours different from what you expected?
Question 3: Why do you think the mud is this colour?
Note that from this location you will be able to see the ‘Loch Eil monster’. The position of the monster may give you a hint for question 1.
Please do not put your answers in your logs, but email them to Doctor Owl for approval. Logs that have not been accompanied by the correct answers or which appear to be the result of armchair caching will be discretely queried and (if necessary) deleted.