Topic ID #24042 - posted 10/19/2012 1:34 AM

A New Radiocarbon Yardstick from Japan

Jennifer Palmer

A New Radiocarbon Yardstick from Japan
Andrew Alden    Post on Oct 18, 2012 by Andrew Alden from QUEST Northern California

Every historian knows about the Rosetta Stone, which had an ancient Egyptian text carved on it in three different scripts, two of which had long resisted translation. The ability to cross-correlate the scripts—to calibrate their alphabets—opened up a huge body of knowledge to scholars. Climate researchers, as well as archaeologists and geologists, look for similar natural records that allow us to calibrate different yardsticks of time. A paper published today in the journal Science unveils a superb "document" of conditions during the last 53,000 years in a single place: Japan's remarkable Lake Suigetsu.

In 2006, researchers drilled into the mud at the center of Lake Suigetsu and carefully extracted four long cores of sediment. They found that the top part of this sedimentary record consisted of thin annual layers—varves—representing about 60,000 years of time. Varves are close to the ideal time record, but the conditions that favor them are rare. And this record also contained abundant plant remains, allowing three different timekeeping "scripts" to be calibrated against each other: varves, tree rings, and radiocarbon. The first two are considered the most nearly perfect measure of absolute time, but radiocarbon is a much more important yardstick, although the stick is not quite straight.

Read more here.


Visit our Employment Network websites: - - For information on advertising on this website, contact