Seasonal resolution of Eastern Mediterranean climate change since 34 ka from a Soreq Cave speleothem
Seasonal resolution of Eastern Mediterranean climate change since 34 ka from a Soreq Cave speleothem
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DOI：
10.1016/j.gca.2012.04.035
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发表时间：
2012-07-15
影响因子：
5
通讯作者：
Valley, John W.
中科院分区：
文献类型：
--
作者：
Orland, Ian J.;Bar-Matthews, Miryam;Valley, John W.
结合离子微探针分析三角洲O-18和共聚焦激光荧光显微镜成像的年度增长带在Soreq洞穴洞穴提供了34和4万年之间的次年度尺度的气候信息。这种高分辨率的方法非常适合在较宽的时间窗口内比较季节性气候模式，并详细研究快速气候事件，如新仙女木事件的终止。我们报告的次年度三角洲O-18梯度代表了降雨量和气温的季节性变化。一个显着的变化，荧光带的图案和梯度的三角洲O-18在现场测量跨单一的，每年的增长带表明在季节性气候模式的变化，东地中海地区的海因里希事件1后，再次新仙女木事件。在整个全新世，潮湿的冬季和干燥的夏季是区域气候的特征。在新仙女木期，我们发现区域气候可能比全新世更加干旱，但荧光带型表明洞穴的滴水供应全年更加一致。我们认为，减少梯度的季节性降水，偶尔降雪，植被的差异可能都有助于同位素和荧光带型观察海因里希事件1和末次冰期stadial。对新仙女木终止的详细调查揭示了区域环境变化的迅速开始。荧光带计数表明，新仙女木终止，记录在东地中海的降雨量，跨越了至少12年。(C)2012爱思唯尔有限公司保留所有权利。
The combination of ion microprobe analysis of delta O-18 and confocal laser fluorescent microscope imaging of annual growth bands in a Soreq Cave speleothem provides sub-annual-scale climate information between 34 and 4 ka. This high-resolution methodology is ideal both for comparing seasonal climate patterns across broad windows of time and examining rapid climate events, such as the Younger Dryas termination, in detail. The sub-annual delta O-18 gradients we report represent a combination of seasonal variability in rainfall amount and air temperature. A distinct change in both the pattern of fluorescent banding and the gradient of delta O-18 measured in situ across single, annual growth bands indicates a change in seasonal climate patterns of the Eastern Mediterranean region following Heinrich event 1 and again after the Younger Dryas. Throughout the Holocene, wet winters and dry summers characterized regional climate. During the Younger Dryas, we find that regional climate may have been more arid than in the Holocene, but the fluorescent banding pattern indicates that the supply of dripwater to the cave was more consistent year-round. We suggest that a reduced gradient of seasonal precipitation, occasional snowfall, and vegetation differences may have all contributed to the isotope and fluorescent banding patterns observed during Heinrich event 1 and the last glacial stadial. Detailed investigation of the Younger Dryas termination reveals a rapid onset of regional environmental change. Fluorescent band counting indicates that the Younger Dryas termination, as recorded by rainfall in the Eastern Mediterranean, spanned a minimum of 12 years. (C) 2012 Elsevier Ltd. All rights reserved.