• journal_title：Geology
• Contributor：Jim D. Marshall ; Barbara Lang ; Stephen F. Crowley ; Graham P. Weedon ; Peter van Calsteren ; Elizabeth H. Fisher ; Richard Holme ; Jonathan A. Holmes ; Richard T. Jones ; Alan Bedford ; Steven J. Brooks ; Jan Bloemendal ; Kostas Kiriakoulakis ; James D. Ball
• Publisher：Geological Society of America
• Date：2007-
• Format：text/html
• Language：en
• Identifier：10.1130/G23498A.1
• journal_abbrev：Geology
• issn：0091-7613
• volume：35
• issue：7
• firstpage：639

Abrupt cooling events are features of Holocene climate and may recur in the future. We use lake records from Hawes Water, NW England, to quantify the impact of two prominent early Holocene climatic events. Subdecadal oxygen isotope records from sedimentary carbonate (¹⁸δO_c), dated using thermal ionization mass spectrometry (TIMS) U-series analyses, provide evidence for abrupt cold events, lasting ∼50 and ∼150 yr at 9350 and 8380 yr ago, which correlate with the 9.3 ka and 8.2 ka events recognized in Greenland ice cores. At Hawes Water, mean July air temperatures, inferred from chirono-mid assemblages, decreased by ∼1.6 °C during each event. Calculations show that the isotopic excursions were dominantly caused by decreases in the isotopic composition of meteoric precipitation (¹⁸δO_p) by ∼1.3‰; this is interpreted as a direct downstream response to cooling and freshening of northeast Atlantic surface water by melting ice sheets. Intermediate in magnitude between events observed in Greenland and central Europe, the effects are consistent with a partial shutdown of the North Atlantic thermohaline circulation.