Experts work to save Easter Island statues
Experts from Germany are investigating the use of a chemical to stabilise the stone monoliths, which have become severely eroded.
The Moai stone heads with their famous long faces and large noses were carved out of rock that was originally volcanic ash by the island’s inhabitants between 1100 and 1650.
They are one of the main sources of income for the island, known as Rapa Nui, drawing in more than 20,000 tourists a year and an annual revenue of more than 1.5m.
The damage is being caused by acid rain, souvenir hunters and the effects of exposure over hundreds of years. The rate of decay is increasing faster than ever, and experts have warned that unless something is done soon they will disappear.
Francesco Di Castri, former deputy director of the United Nations Educational, Scientific and Cultural Organisation (Unesco), said: "Something must be done immediately. If the Moai are destroyed, the island will be destroyed, because without tourism this island is nothing."
It is hoped a team of scientists from Germany will prove to be the saviours of the island, which lies more than 2,000 miles from its nearest populated neighbour, Chile.
At the end of last year, Unesco awarded the site world heritage status, and a German company, Denkmalpflege Maar, has now been awarded a contract worth 6.3m to find a way to restore and maintain the sculptures.
Led by Dr Peter Friese, from the Research and Development Laboratory for the Restoration of Old Buildings and Care of Memorials in Berlin, experts have been working to find a ‘miracle cure’ for the stones.
"We must develop a tailor-made solution for the Moai," said Friese, who has flown out to Easter Island.
"Rock restoration can be compared to medicine. The disintegrating rock is ill. We need to find out which medicine it needs and how that medicine should best be applied."
Rock samples from the island have been shipped over to his laboratory in the German capital to be tested.
Friese said: "The rock of the Moai contains a large amount of clay that causes the stone to swell each time it rains. As the rock dries, it shrinks again.
"The years of constant fluctuation have worn the rock down and caused it to crumble. Using newly developed methods, we now want to solidify the rock again using special chemicals that are in harmony with the rock’s properties."
The main problem now for the scientists is how best to impregnate the rock with the chemicals meant to prevent the widening of large cracks that are forming rapidly.
Friese’s colleague Thomas Bolze, from Potsdam, said: "We have been successful in solidifying small pieces of rock in our laboratory, but the challenge now is to see if we can do the same thing on the huge statues on Easter Island.
"The project will take some time, though, as we will have to test our methods on larger pieces of rock taken from the quarry before trying it out on the ancient statues."
Once they have reinforced the statues, the team will consider whether to try to waterproof them from the rain. "The solidification of the rock is our main priority," said Bolze.
There are 887 Moai sculptures on Rapa Nui and they were all carved in a quarry of unique volcanic ‘tuff’ rock.
Almost 300 of the statues were moved from the quarry and were placed on platforms built along the island’s coastline, just 40 of which are still standing.
No one knows how or why the islanders moved the giant rock sculptures - the largest of which stands at more than 70ft tall and weighs around 150 tons - but there are several hundred that remain in the Rano Rarakun quarry and a number that are lying in ‘transit’ just outside it.
Ironically, it was the islanders themselves who first damaged the statues when they tore them down in tribal wars, says Francisco Torres, director of Easter Island’s archaeological museum.
In the 1900s the first tourists began to arrive, taking with them bits of the archaeological treasures as souvenirs.