pink lake loses its pink shade

pink lake loses its pink color

At the moment’s story is the reply to the September 2022 puzzler.

Alongside the coast of Senegal in West Africa, only a kilometer of shoreline separates the brilliant pink waters of Lake Retba from the deep blue-green waters of the Atlantic Ocean. However the circumstances of the lake (additionally known as Lac Rose) are usually not at all times so lush.

Situated about 40 kilometers (25 miles) northeast of Dakar, Retba Lake attracts guests who wish to see its distinctive shade and swim in its salty, buoyant waters. Retba Lake can be essential to the native financial system, with concentrations of salt crossing the Lifeless Sea. Harvesters gather 1000’s of tons of salt annually from its waters, that are used domestically for cooking and preserving meals, and are additionally exported to surrounding international locations.

water turns pink Dunaliella SalinaA single-celled alga that may tolerate a salty setting. D. Salina Greens are a sort of algae, however underneath demanding circumstances, equivalent to excessive salinity or intense daylight, they produce protecting carotenoids, together with orange-red beta-carotene.

The lake is normally pinkest through the dry season (November to June), when there may be fixed daylight and excessive concentrations of salt. The left picture, acquired by the Operational Land Imager (OLI) on Landsat 8, reveals the lake on Might 19, 2022, when the water appeared pink.

The pink shade fades through the area’s moist season (July to October), when extra clouds imply much less daylight and the water turns into more energizing attributable to rain water. The second picture (proper), obtained with the Operational Land Imager-2 (OLI-2) on Landsat 9, reveals the lake on September 16, 2022, when its shade roughly matched that of the Atlantic Ocean.

The moist season in 2022 was notably moist. Torrential rains in early August and early September induced lethal flooding in Dakar and surrounding areas. Extreme rainfall affected extra than simply the colour of the lake; For instance, in September flood waters breached the lakebed and washed away the salt mounds that harvesters had collected there.

Lake Retba is the one pink lake in Africa, however this phenomenon happens elsewhere across the planet. For instance, Torrevieja Lagoon in Spain and Lonar Lake in India each take their pink shade from the identical single-celled algae.

NASA Earth Observatory picture by Lauren Dauphin, utilizing Landsat knowledge from the US Geological Survey. The Story of Katherine Hansen.

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