High temperatures in the Late Cretaceous Arctic Ocean Export

@article{citeulike:3905, abstract = {To understand the climate dynamics of the warm, equable greenhouse world of the Late Cretaceous period, it is important to determine polar palaeotemperatures. The early palaeoceanographic history of the Arctic Ocean has, however, remained largely unknown, because the sea floor and underlying deposits are usually inaccessible beneath a cover of floating ice. A shallow piston core taken from a drifting ice island in 1970 fortuitously retrieved unconsolidated Upper Cretaceous organic-rich sediment from Alpha ridge1, 2, 3, 4, a submarine elevated feature of probable oceanic origin5. A lack of carbonate in the sediments from this core has prevented the use of traditional oxygen-isotope palaeothermometry. Here we determine Arctic palaeotemperatures from these Upper Cretaceous deposits using TEX86, a new palaeothermometer that is based on the composition of membrane lipids derived from a ubiquitous component of marine plankton, Crenarchaeota6. From these analyses we infer an average sea surface temperature of 15 °C for the Arctic Ocean about 70 million years ago7. This calibration point implies an Equator-to-pole gradient in sea surface temperatures of 15 °C during this interval and, by extrapolation, we suggest that polar waters were generally warmer than 20 °C during the middle Cretaceous ( 90 million years ago).}, author = {Jenkyns, Hugh C. and Forster, Astrid and Schouten, Stefan and Sinninghe Damste, Jaap S.}, citeulike-article-id = {3905}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/nature03143}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/nature03143}, day = {16}, doi = {10.1038/nature03143}, issn = {0028-0836}, journal = {Nature}, keywords = {arctic, climate, cretaceous, gradient, meridional, ocean, paleoclimate, temperature}, month = {December}, number = {7019}, pages = {888--892}, posted-at = {2009-10-05 22:58:52}, priority = {2}, publisher = {Nature Publishing Group}, title = {High temperatures in the Late Cretaceous Arctic Ocean}, url = {http://dx.doi.org/10.1038/nature03143}, volume = {432}, year = {2004} }

TY - JOUR ID - citeulike:3905 L3 - citeulike-article-id:3905 N2 - To understand the climate dynamics of the warm, equable greenhouse world of the Late Cretaceous period, it is important to determine polar palaeotemperatures. The early palaeoceanographic history of the Arctic Ocean has, however, remained largely unknown, because the sea floor and underlying deposits are usually inaccessible beneath a cover of floating ice. A shallow piston core taken from a drifting ice island in 1970 fortuitously retrieved unconsolidated Upper Cretaceous organic-rich sediment from Alpha ridge1, 2, 3, 4, a submarine elevated feature of probable oceanic origin5. A lack of carbonate in the sediments from this core has prevented the use of traditional oxygen-isotope palaeothermometry. Here we determine Arctic palaeotemperatures from these Upper Cretaceous deposits using TEX86, a new palaeothermometer that is based on the composition of membrane lipids derived from a ubiquitous component of marine plankton, Crenarchaeota6. From these analyses we infer an average sea surface temperature of 15 °C for the Arctic Ocean about 70 million years ago7. This calibration point implies an Equator-to-pole gradient in sea surface temperatures of 15 °C during this interval and, by extrapolation, we suggest that polar waters were generally warmer than 20 °C during the middle Cretaceous ( 90 million years ago). IS - 7019 JF - Nature SN - 0028-0836 EP - 892 TI - High temperatures in the Late Cretaceous Arctic Ocean PB - Nature Publishing Group VL - 432 SP - 888 KW - arctic KW - climate KW - cretaceous KW - gradient KW - meridional KW - ocean KW - paleoclimate KW - temperature AU - Jenkyns, Hugh AU - Forster, Astrid AU - Schouten, Stefan AU - Sinninghe Damste, Jaap PY - 2004/12/16/ UR - http://dx.doi.org/10.1038/nature03143 ER -