Ice cores from the Peruvian Quelccaya Ice Cap -- dubbed the “Rosetta Stone” of glacier by Ohio State University researchers because some 1,800 years of the glacier’s history is shown with the ice – show similarities in chemical compositions at certain layers with those in the Himalayas.
In a study published last week in the online version of Science magazine, the researchers used the ice cores to compare the climate history from tropical and subtropical regions over the nearly 2,000 years.
“These ice cores provide the longest and highest-resolution tropical ice core record to date," said Lonnie Thompson, professor of earth sciences at Ohio State University and lead author of the study.
"In fact, having drilled ice cores throughout the tropics for more than 30 years, we now know that this is the highest-resolution tropical ice core record that is likely to be retrieved."
The researchers also looked at newly exposed plants due to melting of the glacier. The plants showed that the glacier is at its smallest size in more than 6,000 years.
This equates to a glacier that had lost 1,600 years of ice accumulation in only 25 years, the researchers said. They have stored the ice cores at the university in case it melts away completely, giving other researchers an opportunity in the future with improved technology to further study climate change and glacier melt.
The Quelccaya Ice Cap is the world’s largest tropical glacier. It is and is located about 5,500 meters above sea level in the Peruvian Andes. The region is a major source of freshwater for Peru, and the melting of the glacier is a big concern for water supplies.
"How much time do we have before 50 percent of Lima's or La Paz's water resources are gone?" The New York Times quoted researcher Douglas R. Hardy as saying.
The full text of the study is available at: http://www.sciencemag.org/content/early/2013/04/03/science.1234210 (subscription required).