Archaeologists say climate change is destroying the historical record of the Arctic people. The artefacts being received by the University of Alaska Fairbanks’s Museum of the North are more deteriorated than those unearthed decades ago, curator and professor Josh Reuther told KUAC, and he attributes that to the changing climate.A wooden mask recovered from the Nunalleq archaeological site in western Alaska [Credit: University of Aberdeen]
The problem isn’t just being noticed by academics in museums — archaeologists have seen changes in the field.
“It’s kind of a whole series of problems coming together at the same time to sort of create a perfect storm,” said Max Friesen, a University of Toronto archaeologist working on a dig in Canada’s Northwest Territories.
From left, UA Museum of the North Archaeology Curator Josh Reuther and Kaktovik resident Marie Rexford examine ivory and bone artifacts in the Barter Island collection [Credit: Kelsey Gobroski/UA Museum of the North]
“You have the potential melting of the permafrost, you have sea level rise, you have in some cases changing weather patterns.”
Friesen said he’s alarmed by the rapid deterioration. Until recently, he said, organic artefacts made of materials like wood or animal hides, were abundant around the region because they were preserved by permafrost or silty soils.
“It’s a very rich data base that’s being lost all across the Arctic,” he said.
A revival of pre-Inca water technology in the mountains of the Andes is set to keep taps flowing in the drought-affected Peruvian capital, Lima. Grouting ancient canals, it turns out, is a far cheaper solution to the city's water crisis than building a new desalination plant.Remnants of a Wari-made canal [Credit: Condesan]
Lima is one of the world's largest desert cities and relies for water on rivers that flow out of the Andes. But those rivers diminish to a trickle during a long dry season, leaving the population of almost 9 million with intermittent water supplies.
Now the city's water utility company, Sedapal, has decided to invest in conservation projects in the Andes to keep the rivers flowing and taps running. And researchers have discovered that the most cost-effective way is to revive a system of ancient stone canals, known locally as amunas, that were built in the Andes by the Wari culture between AD 500 and 1000, centuries before the rise of the Incas.
Forgotten paths
The canals captured water from rivers in the mountains during the rainy season and took it to places where it could infiltrate rocks that fed year-round springs further down the mountains, so maintaining river flow during the dry season.
The amunas fell into disrepair long ago and had been largely forgotten. In most places, their water now quickly returns to the rivers. But hydrologists such as Bert De Bièvre of Condesan, a Lima-based non-governmental organisation behind the project, say re-grouting the lined stretches of the canals with cement would allow them to resume their original purpose.
Paying for water delivered by truck is part of the daily routine for many inhabitants in Peru [Credit: Matt McGrath/BBC]
"The idea is to build a timelag into the hydrological system, delaying water run-off for weeks or even months until it benefits water supply in the dry season," De Bièvre says.
SEDEPAL has now decided to fund the plan by taking 1 per cent from its water charges for the next five years. The costs are estimated to be $23 million.
Holding back the flood
Lima has water shortages for seven months of the year but during the other five months, the Rimac, Chillon and Lurin rivers, which pass through Lima on their way to the Pacific Ocean, regularly cause floods and landslips. Keeping floodwaters back for the dry season makes obvious sense.
Research into the hydrology of individual canals is still in progress. "We have been injecting ink into the canal water to see where it resurfaces," says De Bièvre. But he is confident that the project could revive 50 amunas, mostly in the Chillon catchment.
According to a study by De Bièvre and Gena Gammie, a water specialist at Forest Trends, an NGO based in Washington DC that is backing the project, that should be enough to increase water supplies to Lima by 26 million cubic metres, and reduce the city's current water deficit in the dry season by as much as 60 per cent.
According to the study, other green investment initiatives that could keep water on the mountainsides for longer include reviving forests, wetlands and ancient agricultural terraces, and restricting livestock grazing on upland pastures. But the study found that reviving amunas would be by far the cheapest option, costing less than a hundredth as much as water from the city's new desalination plant.
Author: Fred Pearce | Source: New Scientist [April 20, 2015]
Climate change is threatening archaeological sites in N.W.T.'s Mackenzie Delta, says University of Toronto professor Max Friesen.Pingos in N.W.T.'s Mackenzie Delta are unmistakeable evidence of permafrost activity in the soil. University of Toronto professor Max Friesen says thawing permafrost due to climate change is endangering archaeological sites in the area [Credit: Karen McColl]
He says thawing permafrost is endangering sites and artifacts dating back thousands of years.
"Instead of having the archaeological remains and the houses and whatnot being stable, they're actually eroding out of the cliff face," he said.
"As you walk along the beach, you can actually see all the artifacts, animal bones, and even pieces of houses that are slumping down the slope and will eventually wash out into the ocean."
Friesen says researchers need to act quickly and prioritize which sites should be excavated before their contents are destroyed.
