World's Largest Tropical Glacier Shrinks
Earth is fast becoming a planet where tropical glaciers will be myths. Here are a couple of recently released satellite images from 1988 and 2010 showing the shrinkage of the world’s biggest tropical glacier, the Quelccaya Ice Cap in Peru.
High mountain tropical glaciers have long been the alarm bells of global warming, but this ice cap, with its many glacial arms, is especially important since its ice contains an archive of data about El Niño and La Niña episodes for the past 1,800 years. The receding glaciers have also exposed frozen plants that were locked beneath the glacier for thousands of years — giving clues to the age of the glacier advances through the last several millenniums.
“Quelccaya is now smaller than it was 6,000 years ago,” said pioneer tropical glacier researcher Lonnie Thompson of Ohio State University. “Moreover, the plant ages confirm that the advance of the Quelccaya Ice Cap about 6,000 years ago was much slower—about 300 meters over 1,600 years—than its current rate of retreat of about 300 meters in 25 years.”