Tibetan ice cap holds a 128,000-year climate record

Scientists have found that ice cores from the Guliya Plateau in northwestern Tibet may preserve a climate record older than 128,000 years. Beryllium and chlorine isotope dating revealed traces of the Laschamp geomagnetic excursion over 41,000 years ago, extending the region's known glacial record by 100,000 years.

• Cores drilled in 1992 and 2015 showed identical oxygen isotope profiles
• Dating relies on beryllium and chlorine isotopes and the Laschamp excursion
• The Guliya record was previously thought to reach only the Holocene
• It is the oldest mountain ice core outside the polar regions