Chronology and petrology in MIS4-2 of DSDP Site 94-609 ...

• Main Authors: Obrochta, Stephen P, Miyahara, Hiroko, Yokoyama, Yusuke, Crowley, Thomas J
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2012
• Subjects: Deep Sea Drilling Project DSDP; ice core; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.834701; https://doi.pangaea.de/10.1594/PANGAEA.834701

Ice-rafting evidence for a '1500-year cycle' sparked considerable debate on millennial-scale climate change and the role of solar variability. Here, we reinterpret the last 70,000 years of the subpolar North Atlantic record, focusing on classic DSDP Site 609, in the context of newly available raw data, the latest radiocarbon calibration (Marine09) and ice core chronology (GICC05), and a wider range of statistical methodologies. A ~1500-year oscillation is primarily limited to the short glacial Stage 4, the age of which is derived solely from an ice flow model (ss09sea), subject to uncertainty, and offset most from the original chronology. Results from the most well-dated, younger interval suggest that the original 1500 ± 500 year cycle may actually be an admixture of the ~1000 and ~2000 cycles that are observed within the Holocene at multiple locations. In Holocene sections these variations are coherent with 14C and 10Be estimates of solar variability. Our new results suggest that the '1500-year cycle' may ... : Supplement to: Obrochta, Stephen P; Miyahara, Hiroko; Yokoyama, Yusuke; Crowley, Thomas J (2012): A re-examination of evidence for the North Atlantic “1500-year cycle” at Site 609. Quaternary Science Reviews, 55, 23-33 ...