Climate change threatens ancient drawings inside French cave

Experts are racing to save ancient drawings within the Cosquer underwater cave in south-east France from the effects of global warming and marine pollution, ahead of the opening of a new virtual exhibition of the complex.

The entrance to the cave is 37 metres underwater in the Calanque (water inlet) de Morgiou, near Marseille.

At around 30,000 years old, it is known as the “underwater Lascaux” – referring to the network of Dordogne caves made famous for their hundreds of ancient wall paintings – and contains some of the world’s most important cave drawings.

Access to the cave is underwater, via a 100-metre-long flooded passage into a huge cavern of 2,500m2, much of which is also underwater.

The still-above-water walls have some of the world’s only examples of engravings and drawings from the Upper Palaeolithic period, in particular of marine animals, seals and penguins. A total of 229 figures across 13 species are represented.

Red and black handprint stencils, including those of children, were also recorded, as well as several hundred geometric signs, and eight male and female sexual drawings.

The cave is considered to be “unique for its size in Europe”, said archaeologist Michel Olive, who is in charge of studying the cave at the regional archaeology service le Service régional de l'archéologie, to Actu Marseille

Similarly, Luc Vanrell, an archaeologist working on the project, told France 3: ”The density of the graphic representations places Cosquer on a par with the four largest Palaeolithic cave art sites in the world, along with Altamira in Spain, Lascaux and Chauvet in France.

“And as it is likely that the walls now underwater were originally also decorated, this makes Cosquer a unique site in Europe.”

It was discovered in 1985 by professional diver and diving school instructor Henri Cosquer, officially reported in 1992 – after three people died trying to find the mysterious cave – and classed as a historic monument in the same year.

However, climate change is now threatening the cave, after a sudden 12cm rise in the water levels within the cave in 2011.

Mr Olive said: “At the time [of the paintings], it was right in the middle of the ice age, the sea level was 135 metres lower and the coast was 10km further.”

French scientists now say they are on a “race against the clock” against the rising water and marine pollution (including microplastics), which are also threatening the drawings.

Geologist Stéphanie Touron, a specialist in cave drawings at the Laboratoire de recherche des monuments historiques in France, said: “The sea, which rises and falls in the cave according to climatic variations, washes away the walls and threatens the information-rich soil.”

As a result, archaeological divers are stepping up their exploration and virtual record of the cave, and continuing digital 3D mapping. So far, more than 600 “graphic entities” have been recorded.

One of the divers, Bertrand Chazaly, who is in charge of digitisation operations, said: “Once completed, our virtual Cosquer cave, at millimetre-precision, will be an indispensable research tool for curators and archaeologists who cannot physically access the site.”

Open to the public

It comes as technicians and artists in Marseille are putting the finishing touches on a €23million replica of the cave for an exhibition that is set to open to the general public on Saturday, June 4.

Provence-Alpes-Côte d’Azur contributed €10m to the budget, in partnership with the Klébert Rossillon company, at the Villa Méditerranée in the city.

The actual cave is off-limits even to experienced divers and can only be accessed via a locked gate for authorised divers on state work.

The exhibition creators used 3D models of the cave collected by a team of archaeologists and also called on the expertise of cave specialists who helped with the creation in 2015 of a replica of the nearby Chauvet cave, in Ardèche.

Artists have painstakingly copied original work from the caves, and used the same materials as much as possible, including charcoal.

The exhibition is hoping to attract 500,000 visitors per year.

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