In what is a profound visual display of the earth’s increasingly warmer temperatures, glacial ice in the Andes that took a minimum of 1600 years to form have melted drastically in a mere 25 years, leaving behind a large pool of water framed by exposed rock and dimished beds of ice. As the ice melts, plants from thousands of years ago are being freed.
As the ice melts, plants that were trapped within it are exposed, and it is those very materials that are being used to analyze the glacial area’s history. Such a project has been undertaken by Ohio State University’s glaciologist Lonnie G. Thompson, who – along with his team – has published the results of their work on the Peruvian ice sheets known as the Quelccaya ice cap.
The timespan for the formation of the ice was determined by carbon dating the plants that have been exposed as the ice melts. The carbon being dated has a known decay rate and provides fairly exact data in return. In addition to the carbon dating, Thompson and team have published information on chemical tracers from ice pulled from the depths of the ice cap via drills.
These chemical tracers are significant to scientists because they provide information that reveals climate changes that have happened in the past. According to Thompson, in the late 1700s there was, in all likelihood, a period of weather variations that deviated from normal. This could have been responsible for famines during the French Revolution. While the ice cap has melted to varying degrees over its lifetime, evidence points to the recent melting as equal to or faster than melting seen when the ice age came to an end.
You can check out an interactive before-and-after image of the melting ice at the link below.
[via New York Times]