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| Aoki, Kaori. |
| A tephra layer with normal grading in the sub‐bottom depth interval 119–122 cm in marine core SO202‐27‐6 was collected on Patton Seamount in the northeast North Pacific Ocean. Based on the geochemistry of volcanic glass shards determined by a wavelength dispersive electron probe micro‐analyser and an X‐ray fluorescence analyser, this layer is correlated to the Dawson tephra, a widespread late Pleistocene time marker tephra in Alaska and the Yukon. The age of the Dawson tephra in the core is 29.03 ± 0.178 ka (1 sigma) based on a published age model. The Dawson tephra is revealed to have been deposited in the transition from marine isotope stage 3 to 2, i.e. the last stage of Heinrich Stadial 3 derived from the ice‐rafted debris signal. According to the... |
| Tipo: Text |
Palavras-chave: Dawson tephra; Heinrich Stadial; Late Pleistocene; Marine sediment; MIS3; 2. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00598/71056/69371.pdf |
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| Bagniewski, Witold; Meissner, Katrin J.; Menviel, Laurie. |
| We present the first transient simulations of Marine Isotope Stage 3 (MIS 3) performed with an oxygen isotope-enabled climate model. Our simulations span several Dansgaard-Oeschger cycles and three Heinrich stadials and are directly compared with oxygen isotope records from 13 sediment and 2 ice cores. Our results are consistent with a 30-50% weakening of the Atlantic Meridional Overturning Circulation during Dansgaard-Oeschger stadials and a complete shutdown during Heinrich stadials. We find that the simulated delta O-18 anomalies differ significantly between Heinrich stadials and non-Heinrich stadials. This difference is mainly due to different responses in ocean circulation, and therefore climate, impacting oceanic delta O-18, while the volume of... |
| Tipo: Text |
Palavras-chave: MIS3; Model-data comparison; Heinrich events; Dansgaard-Oeschger cycles; Delta O-18; AMOC. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53180/55067.pdf |
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