کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9522192 1634954 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mid-latitude Southern Indian Ocean response to Northern Hemisphere Heinrich events
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
Mid-latitude Southern Indian Ocean response to Northern Hemisphere Heinrich events
چکیده انگلیسی
The lack of temporal resolution and accurate chronology of Southern Ocean marine cores has hampered comparison of glacial millennial-scale oscillations between the Southern Ocean, Antarctic ice and other records from both hemispheres. In this study, glacial climate variability is investigated over the last 50 ka using a multi-proxy approach. A precise chrono-stratigraphy was developed on the high-sedimentation rate core MD94-103 (Indian Southern Ocean, 45°35′S 86°31′E, 3560 m water depth) by geomagnetic synchronization between the later core and NAPIS75, and 14C dates. High-resolution time-series of δ18O in planktonic foraminifera Globigerina bulloides and Neogloboquadrina pachyderma, and sea surface temperatures (SSTs) estimated from the alkenone UK′37 index and foraminifera assemblages have been generated. Temporal evolution of the two temperature proxy records is notably different during the last glacial period. While foraminifera data indicate a consistent cooling towards the last glacial maximum, anomalous warm glacial alkenone temperatures suggest a strong advection of 〈warm〉 “detrital” alkenones by surface waters of the Agulhas current. Superimposed to this general trend, during Heinrich events, foraminiferal SSTs point to warmer surface waters, while concurrent alkenone SSTs exhibit apparent coolings probably caused by enhanced local alkenone production. By analogy to modern observations, possible influence of ENSO-like conditions on the subantarctic Southern Ocean SSTs is discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 240, Issues 3–4, 15 December 2005, Pages 724-731
نویسندگان
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