کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6431263 1634953 2006 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Entrainment of meltwaters in hyperpycnal flows during deglaciation superfloods in the Gulf of Mexico
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
Entrainment of meltwaters in hyperpycnal flows during deglaciation superfloods in the Gulf of Mexico
چکیده انگلیسی

Northern Gulf of Mexico is a key archival site of the Laurentide Ice Sheet melting history and the only margins containing evidence of meltwater outflows contemporaneous with global meltwater pulse mwp-1A. Inconsistencies between these meltwater floods and the absence of strong climate responses to large freshwater fluxes predicted by climate models raised questions concerning the validity of planktonic foraminiferal δ18O record in the Gulf of Mexico as a reliable index of freshwater fluxes. Isotope records of depth-stratified foraminifera document unusual trends compatible with entrainment of 18O-depleted freshwaters in hyperpycnal flows reaching the seafloor and rising to the surface as buoyant plumes. These exceptionally large outbursts of floodwaters, coeval with a prominent erosion intensity peak in continental paleohydrology, were catastrophically released in a rapid succession over a period of ca. 500 yr (14.7-14.2 kyr). Correspondence in time and magnitude between the torrential floods and the mwp-1A event supports the view that LIS was likely a substantial freshwater source. Drainage of meltwaters through torrential hyperpycnal flows that underwent substantial mixing with seawater may resolve the problem with ocean modeling results that predict a much stronger climate response to large freshwater hypopycnal fluxes into the ocean.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 241, Issues 1–2, 15 January 2006, Pages 260-270
نویسندگان
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