image-of-the-week-2017-02-01

Red Tide at Walker Bay Captured in Satellite Imagery

This Sentinel 2A image acquired 11 January 2017 shows extensive red tide (highlighted in a yellow box) in the Vermont area not very far from the town of Hermanus in the Western Cape Province of South Africa. Red tide is a colloquial term used to refer to one of a variety of natural phenomena known as harmful algal blooms, which occur when south-easterly winds bring nutrients up from the ocean bottom that under certain conditions cause a population increase in phytoplankton on the sea surface. Certain species of phytoplankton, contain photosynthetic pigments that vary in colour from green to brown to red. Red tide is not only harmful to marine and coastal species of fish, birds and marine mammals but also poses potential harm to human health. People can become seriously ill from eating oysters and other shellfish contaminated with red tide toxin.

Image credits:
Copernicus Sentinel data 2017.

Attachments:
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image-of-the-week-2016-12-13

Natural Wonders of South Africa Series – Table Mountain

SPOT6/7 imagery of Table Mountain, Cape Town. The imagery acquired between 25 March and 6 July, 2015 shows the level plateau approximately 3 kilometres from side to side, edged by impressive cliffs.

On 2 December, 2012 Table Mountain was officially inaugurated as one of the seven natural wonders of the world in a ceremony held at the foot of the Mountain in Cape Town. The flat-topped mountain forms a prominent landmark overlooking the city of Cape Town in South Africa and is significant tourist attraction, with many visitors using the cableway or hiking to the top. The mountain also forms part of a National Park and is home to an unusually rich biodiversity consisting predominantly of several different types of the unique and rich Cape fynbos.

Image credits: Produced at SANSA Earth Observation. SPOT6: Copyright © 2013 Airbus DS. All rights reserved. SPOT6: Copyright © 2014 Airbus DS. All rights reserved.

 

Attachments:
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image-of-the-week-2016-12-05

Natural Wonders of South Africa Series - The Richtersveld

Landsat 8 natural colour composite image showing the Richtersveld. Acquired on 19 September 2016, the 753 natural band combination shows 8,000 square kilometres of coastal plain and sandveld, and to the east of that, the true Richtersveld – 3 000 square kilometres of geologically complex desert mountainland.

Lying inland from the coast between the mouth of the Orange River and Port Nolloth, The Richtersveld is characterised by rugged kloofs and high mountains. Scant rainfall, no permanent water source, tiny stone plants found nowhere else, the unusual halfmens, and spring daisies that defy the barren rock and stone are the hallmarks of this barren beauty. Legend has it that the Richtersveld Halfmens (i.e. desert plant with the mystical name Halfmens or “Half Person”) derives its name from the ancestors of the Bushmen who were driven south by warlike tribes from the north. Some turned to look back across the Orange River and were turned into 'halfmens' (half people), forever gazing northwards.

Image credits:

Produced at SANSA Earth Observation. Landsat imagery courtesy of NASA Goddard Space Flight Center and U.S. Geological Survey.

 

Attachments:
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image-of-the-week-2016-11-29

Natural Wonders of South Africa Series - The Orange River

Landsat 8 false colour composite image showing a portion of the Orange rive. Acquired on 22 March 2016, the 564 band combination shows built-up features for Upington, Northern Cape in shades of pink, purple and grey, water in black, and healthy vegetation and irrigated fields as bright red. The heart shaped structure visible on the eastern bank is Khi One Solar, a 50 Megawatt solar power plant.

The Orange river is the longest river in South Africa. For millions of years diamonds have been carried to the Atlantic by the Orange River, making it one of the richest alluvial diamond fields in the world. As the collection point for the majority of South Africa's water, the Orange River plays a major role in supporting agriculture, industry and mining.

Image credits:

Produced at SANSA Earth Observation. Landsat imagery courtesy of NASA Goddard Space Flight Center and U.S. Geological Survey.

Attachments:
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image-of-the-week-2016-11-23

Natural Wonders of South Africa 7 – The Little Karoo

A 3D drape of SPOT6/7 mosaic imagery, acquired 2016 showing an oblique view of the Little Karoo. Oudtshoorn, the "ostrich capital of the world" can be seen in the distance, nestled in the foothills of the Swartberg mountains.

The Little Karoo lies sandwiched between two huge ranges of folded mountains that run west to east across the Western Cape. Nestled in the foothills of the Swartberg range near the town of Oudtshoorn is the Cango fault and world famous, Cango Caves. The caves were created by the same process which hollowed out the Sterkfontein cave system in Gauteng and possess some of the most extensive and beautiful dripstone collections in the world.

Image credits:

Produced at SANSA Earth Observation. SPOT6: Copyright © 2013 Airbus DS. All rights reserved. SPOT6: Copyright © 2014 Airbus DS. All rights reserved.

Attachments:
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