On September 8, 2020, Proceedings of the National Academy of Sciences published Timing and Structure of the Younger Dryas Event and Its Underlying Climate Dynamics by XJTU Professor Cheng Hai and his team.
Well-dated Speleothem and ice-core records were combined in this study to pinpoint the timing of the Younger Dryas (YD). The results proved that the North Greenland Ice Core constitutes an ideal reference for characterizing the timing of YD and helps narrow the quoted absolute error of YD chronology from ±100-140 years to ±20-40 years. The initial YD onset occurred at ∼12,870±30 B.P. and terminated at ∼11,700 ± 40 B.P.
The study also found that “A possible extraterrestrial impact event at ∼12,820 B.P. inferred by Pt-anomaly in the GISP2 ice core appears to lag the initial onset of the YD by ∼50 y without apparent disruption on the hydroclimate trend, suggesting that this event might not be the trigger for the YD onset.”
This study was led by XJTU Professor Cheng Hai, Associate Professor Zhang Haiwei from the Institute of Global Environmental Change of XJTU, Professor Christoph Spötl from the University of Innsbruck, Professor Ashish Sinha from California State University, and additional researchers are from Spain, the US, Brazil, and China.
Link to the article: https://www.pnas.org/content/117/38/23408