Global Warming Behind Quelccaya Ice Cap Loss

Rising temperatures are linked with the rapid decline of Quelccaya Ice Cap, a new study has found.

Quelccaya Ice Cap, sitting at 18,000 feet above sea level in the Peruvian Andes, is the largest ice mass in the tropics. The ice cap was in the news in 2013 when researchers published a study saying that the glacier that took 1,600 years to form melted in less than 25 years. The Quelccaya Ice Cap has become a symbol of global warming.

However, there was considerable doubt over the cause for glacier retreat with some researchers saying that reduction in snowfall, rather than rising temperature, was behind the surface exposure in the glacier.

A latest study conducted by researchers at Dartmouth College and colleagues at the Ohio State University used ice cores from the region and beryllium-10 surface exposure dating method to find the reason behind the rapid decline of glacier size. Researchers wanted to understand how the glacier expanded and retreated in the past and what is driving the decline in the ice cover now.

Beryllium-10 surface exposure is a relatively new technique that looks at the levels of Beryllium in rocks.

Researchers found that the Quelccaya Ice Cap is sensitive to temperature fluctuations. The glacier expanded to its maximum size during the cooling event known as the Little Ice Age. Since then, the ice cover is shrinking due to changes in temperatures.

The current rapid decline of ice in Quelccaya is also a result of global warming, researchers said.

Ohio State University paleoclimatologist Lonnie Thompson has been studying the changes in the tropical ice cap since the 1960s.

"This is an important result since there has been debate about the causes of recent tropical glacial recession - for example, whether it is due to temperature, precipitation, humidity, solar irradiance or other factors," said Meredith Kelly, a co-author of the study, according to a news release. "This result agrees with Professor Thompson's earlier suggestions that these tropical glaciers are shrinking very rapidly today because of a warming climate."

The study is published in the journal Geology.