[

Lake Natron is a salt lake located in northern Tanzania, close to the Kenyan border, in the eastern branch of the East African Rift. The lake is fed by the Southern Ewaso Ng'iro River and also by mineral-rich hot springs. It is quite shallow, less than three meters (10 feet) deep, and varies in width depending on its water level, which changes due to high levels of evaporation, leaving concentrations of salt and other minerals, notably sodium carbonate (natron).

With the humpback calving season drawing to a close, here’s a look at some of Rita Kluge’s distinctive marine photos from the south Pacific. The Sydney-based photographer fell in love with whales after witnessing southern rights from the New South Wales coastline as they travelled to and from their feeding grounds in the Antarctic. She has since been to Tonga, where humpbacks breed and calf in winter months, to photograph them in the water. (Photo by Rita Kluge/The Guardian)

Polar bears prepare to feast on the remains of a bowhead whale, harvested legally by whalers during their annual subsistence hunt, just outside the Inupiat village of Kaktovik, Alaska, USA, 10 September 2017. As climate change shrinks their natural habitat, polar bears are turning Kaktovik into their very own sanctuary city. (Photo by Jim Lo Scalzo/EPA/EFE)

Vogue Italia is hosting a series of shows in Milan exploring how the magazine seeks to engage with hot social and political issues and provoke debate through images by top photographers. The Photo Vogue festival in Milan is hosting three exhibitions. The first, Fashion and Politics in Vogue Italia, looks at the magazine’s ambition to be a catalyst for change – in subtle and playful ways. Here: David LaChapelle – October 2004. (Photo by David LaChapelle/The Guardian)

A French riot police officer is surrounded by flames, during a demonstration against the controversial labour reforms of the French government in Paris on September 15, 2016. Opponents of France's controversial labour reforms took to the streets on September 15, 2016 for the 14th time in six months in a last-ditch bid to quash the measures that lost the Socialist government crucial support on the left. Scores of flights in and out of France were cancelled as air traffic controllers went on strike to try to force the government to repeal the changes that became law in July. (Photo by Thomas Samson/AFP Photo)

The Viking longboat burns during the annual Up Helly Aa festival in Lerwick, Shetland Islands, on January 28, 2014. Up Helly Aa celebrates the influence of the Scandinavian Vikings in the Shetland Islands and culminates with up to 1,000 “guizers” (men in costume) throwing flaming torches into their Viking longboat and setting it alight later in the evening. (Photo by Andy Buchanan/AFP Photo via Getty Images)

Boozed up revellers dressed up in fluorescent colours during the opening day of the 2019 Notting Hill Carnival on August 25, 2019 in London, England. Up to a million people are expected to pack the streets of Notting Hill and surrounding areas over the course of the two day event. The annual celebration of Afro-Caribbean culture takes place each August bank holiday weekend. (Photo by London News Pictures)

Miss Bunni Lambada poses backstage during the Miss Pin Up NSW competition on October 23, 2010 in Sydney, Australia. Pinup girls from across New South Wales descended on The Entrance to compete in the state competition with hopes to represent NSW at the inaugural Miss Pin Up Australia national competition in January 2011. (Photo by Lisa Maree Williams/Getty Images)