For this post we thought we would pass on this fascinating article from the Columbus dispatch (an Ohio newspaper). The article discusses findings from a recent publication in the journal Proceedings of the National Academy of Sciences.
In the article they describe how looking at the layers of a glacier ice cap is like a snapshot of history. Based on their findings they were able to correlate certain chemical changes with events that occurred in the 16th century and during the time of the Spanish conquest.
Glaciers have a large significance in Inca culture. One glacier many of you are likely to see is the Chicon glacier, which overlooks and protects the town of Urubamba. Urubamba is an important town in the Sacred Valley that you pass by and can see on the trip from Cusco to Ollantaytambo. The province of Urubamba is crossed by the river Vincanota. When the river enters the Urubamba province it officially takes the name Urubamba river.
Urubamba was one of the main agricultural centers of the Empire of the Incas. In the city, adjacent to the monumental Church of San Francisco, are huge walls of Incan terraces that you can still admire. You can also see some pre-Hispanic walls, which served as Foundation and basis for the colonial buildings.
We visit the town of Urubamba as part of our Sacred Valley tour and the 2 day/1 night Sacred Valley with Machu Picchu tour. You will also have a chance to briefly stop and admire the Chicon glacier on your way to Kilometer 82 the start of the Inca trail.
The pictures attached to this post are of the Chicon glacier and the town of Urubamba!
“Ohio State researchers find earliest proof of man-made air pollution”
By Laura Arenschield
The Columbus Dispatch • Sunday February 15, 2015 9:11 AM
Climate researchers at Ohio State University have found the earliest evidence of human-produced air pollution in South America.
Tests of an ice core sample from Peru show that the Spanish empire sent thick clouds of lead dust into the atmosphere about 240 years before the Industrial Revolution.
The Spaniards forced Incas to refine silver extracted from the mountaintop mines of Potosi in what is now Bolivia. The dust was found in an ice core from the Quelccaya ice cap in Peru, the largest tropical glacier on Earth.
The researchers’ findings were published recently in the Proceedings of the National Academy of Sciences.
The Byrd Polar and Climate Research Center at Ohio State keeps hundreds of ice cores that are collected from glaciers and ice caps around the world and serve as frozen climate records.
Research teams collect core samples by drilling from the surface of the ice cap to the bedrock at its base. The layers tell the stories of how the climate changed over hundreds or thousands of years.
“The beauty of the Quelccaya record is we have very distinct annual layers,” said Lonnie Thompson, a climate-change scientist and glaciologist at the Byrd center.
“Every dry season, we have a dust layer, and we count those layers back in time, much like you would count tree rings.”
Thompson and his wife and colleague, Ellen Mosley-Thompson, a distinguished professor of geography and director of the Byrd Polar Research Center, removed the core from the Quelccaya ice cap in Peru in 2003.
The Thompsons realized that the Peruvian cores were similar to ice cores they had retrieved from Tibet and the Himalayas. When they found matches in ice cores taken from opposite sides of Earth, they knew they had “Rosetta stones” with which to compare other climate histories from tropical and subtropical regions.
The cores, which show unprecedented detail dating back 1,800 years, will help link past climate changes around the globe, they said.
Paolo Gabrielli, principle investigator and lecturer at the Byrd center, studied the Quelccaya sample, which contains ice layers from A.D. 793 to 1989. Gabrielli found low and stable levels of trace elements in the ice layers that would have formed from A.D. 794 to about 1450.
But around 1480, there was a spike in bismuth, a heavy metal that has similar properties to arsenic. And in the layers that would have formed around 1540, larger amounts of bismuth and other metals, including lead, began to appear.
Gabrielli started digging into historic records. The year 1480 coincides almost perfectly with the expansion of the Incan empire, which mined silver from the mountains in Bolivia and elsewhere in South America. And 1540 was less than a decade after the Spanish empire began colonizing South America and taking over the Incan silver mines.
By 1572, the Spanish had introduced a process that involved grinding silver ore, which contains more lead than silver, into a powder, then mixing it with mercury to refine the metal.
Atmospheric pollution in and around the area would have contained higher concentrations of bismuth and lead, something that Gabrielli’s research shows.
He analyzed the chemical composition of the metals in the ice sample and concluded that the bismuth and lead on Quelccaya probably came from Potosi, the largest silver mine in the area in the late 1500s.
“We know that they were mining and extracting silver ores, but we don’t know how much and when this process started to impact the environment,” Gabrielli said. “So this is all basically new information.”
The findings, he said, open the door for other researchers — anthropologists, historians — to tell the story of how the Spanish mines would have affected people throughout that part of South America. (The researchers point out however, that man-made air pollution in the 20th century far surpasses anything produced by the Spanish mines.)
Mr. Thompson said the next step in this research is another trip to Quelccaya to collect additional ice samples and conduct more tests to back up the findings.
That has to happen soon, though. Climate change and global warming have caused the Quelccaya ice cap to begin melting. The deeper, older layers are still preserved, Thompson said, but the record is getting muddled.
“In a way, I look at what we’re doing as kind of a salvage mission to get the histories before they disappear or they get altered to the degree where you can’t interpret them,” he said.
Thompson said it takes 20 to 30 years before the full effect of today’s climate change will be seen on the glaciers he studies.
“We already have a built-in warming going into the future,” he said. “A lot of these glaciers like Quelccaya, Kilimanjaro in Africa … are going to disappear.
“They will disappear, and the archive will disappear with them. Even if the world cools in the future, that archive of the past will be gone.”