Preserving their ‘submerged’ heritage!

Mexico City / DPA

Many people think of archaeologists as people who excavate dry earth at scorched sites, or dust off relics with small paintbrushes under piercing sunlight, perhaps donning hats in the style of Indiana Jones. This is not the case with Pilar Luna’s team.
Their gear consists of air tanks, wetsuits, diving fins and dive tables for decompression. Luna is deputy director of underwater archaeology at the Mexican National Anthropology and History Institute.
This 72-year-old heads a team that includes about 20 diver-archaeologists who dive into the sea or into flooded caves or into the lakes that have formed inside the crater of the Nevado de Toluca (Snow-Capped Toluca Mountain), a dormant volcano 4,000 metres above sea-level, to study archaeological remains covered by water.
Luna, a pioneer of underwater archaeology in Mexico, no longer deep sea dives as she did for decades. She first heard about underwater archaeology in a book written by US archaeologist George Bass and later worked with him in the Mediterranean sea off Turkey.
She is currently the top leader of INAH water projects, a task that permitted the discovery of the oldest intact female skeleton in the Americas (between 12,000 and 13,000 years) a 40,000-year old prehistoric Gomphotherium elephant, pre-Hispanic craniums and altars and 16th-century cannon.
“There is an interesting saying that goes like this: ‘It is far easier to turn an archaeologist into a diver than to make a diver become an archaeologist,'” Luna told dpa.
“Diving is fascinating in and of itself. It is a marvellous sport, but it is totally different when the aim of diving is scientific research.”
Just like all certified divers, archaeologists must comply with specific diving schedules that include stops for decompression on the way up according to the depths reached. They must plan their work carefully and perform it shifts.
“I went to work in Turkey at a depth of 40 metres and in the morning we had 29 minutes of diving with 30 minutes of decompression stops. Then one must spend at least five hours on the surface. In the afternoon it was 27 minutes of diving with the same 30 minutes of decompression.”
“In the end, you are at your work site for only one hour at those depths. That is a big difference from archaeological work on land, where you can be there all day, and even into the night if you want to, you set up lights and you keep working,” Luna explained.
One of the major discoveries Luna’s team made occurred in 2011 in Hoyo Negro (the Black Hole), a flooded cave in Tulum, on the Yucatan Peninsula. A group of explorers alerted the INAH about a finding that would later turn out to be extraordinary. The team has written a scientific article about their research that will include stunning revelations.
“They entered through a sinkhole that is called The Virgin and began to explore at a depth of 100 metres, 200 metres, mapping out the area. They travelled 1,200 metres horizontally under water and suddenly they found a cavern in which the light from their flashlights did not touch roofs or walls on either side, neither upwards nor downwards,” Luna recalled.
It was in that hole with a 60-metre diameter that they found the skeleton of a woman, between 15 and 16 years old, whom archaeologists called Naia. Research shows that the girl was of Asian-Beringian origin. (Beringia is an area that includes the Bering Strait and parts of Siberia and Alaska next to it.)
They also found the remains of 27 animals, among them the Gomphotherium (related to elephants), two bear craniums, the mandibles of a giant sloth and a cougar.
“These animals are going to result in marvellous information. We have a study, and it is about to be published, about bears that were not found in Central America or North America – it appears that they came from the south – and of a giant sloth that possibly may be the only one of its kind in the world,” Luna said.
Underwater archaeologists face major challenges as part of their mission to conserve cultural heritage. They recover some pieces to study them, but the change of medium from water to air threatens their conservation. This is why the underwater archaeologists prefer to leave other pieces where they found them.
“Things that are submerged under water very often are better preserved than on land. The grave problem is to remove them from that medium and change their context, because then deterioration is terrible and in some materials it can cause total destruction,” Luna said.
In addition to studying Hoyo Negro, Luna’s team, which also includes historians and other experts, is focussed on creating a digital data record of the Yucatan sinkholes and to research archives to find data on a Spanish galleon that shipwrecked in 1631.
The galleon in question is the Nuestra Senora del Juncal (Our Lady of Juncal), a ship in the New Spain fleet that sank off the coast of Campeche in the Gulf of Mexico transporting valuable cargo.
“It was one of the fleet’s two most important ships and more than 30 people out of a little over 300 on board were saved.
“Those are the people who have told the story of the sinking … These are difficult jigsaw puzzles to put together because no one person was able to say precisely where the ship sank,” she added.
Luna has also had to fight off treasure seekers over the years.
“One of our great battles has been to defend the New Spain fleet from treasure hunters who are interested in shipwrecks of ships with cargos of gold, silver and gems. Mexico has never given them permission.”