Responses of the Okhotsk Sea environment and sedimentology to global climate changes at the orbital and millennial scale during the last 350 kyr
Responses of the Okhotsk Sea environment and sedimentology to global climate changes at the orbital and millennial scale during the last 350 kyr
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DOI：
10.1016/j.dsr2.2011.05.016
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发表时间：
2012-02-01
影响因子：
3
通讯作者：
Ignatiev, Aleksandr V.
中科院分区：
文献类型：
--
作者：
Gorbarenko, Sergey A.;Harada, Naomi;Ignatiev, Aleksandr V.
我们测量了生产力代理（二氢卟酚，碳酸盐和有机碳，蛋白石，生物钡含量）和岩石物理代理（磁化率，含水量，密度，粗沉积物分数）在鄂霍次克海中部核心PC-7 R的沉积物。年龄模型涵盖了过去350万年的核心构建相关的日期系列的相对paleointensity低确认地磁强度记录，海洋同位素阶段（MIS）的边界确定在广泛的变化的岩石物理和生产力代理，和火山灰年代学。岩石物理和生产力代理堆栈的轨道变化落后于北方半球夏季辐射约6.3和5.9 kyr，分别。这一滞后与米兰科维奇的气候控制模型一致，该模型认为太阳辐射通过北方冰盖体积、海面和周围陆地的反应来控制气候，与沉积学证据相比，这种反应是快速的。鄂霍次克海的生产力代理也表明52个突然的，明显的生产力极小值与区域气候变冷在过去的350 kyr，这在这个边缘海的千年尺度的气候变化提出了有用的指标。根据北方半球Dansgaard-Oeschger旋回的同步性假设，以及近77 kyr来11次鄂霍次克海变冷与格陵兰冰芯突发性强冷事件和北大西洋Heinrich事件的同步性，这些都可视为Heinrich等效事件异常。鄂霍次克海事件在北大西洋沉积物、格陵兰冰盖、东亚夏季风和南极冰盖的记录中都有对应的记录。北极涛动可能是决定包括鄂霍次克海在内的北方半球高纬度地区轨道和千年气候振荡的主要因素。(C)2011爱思唯尔有限公司版权所有。
We measured productivity proxies (chlorin, carbonate and organic carbon, opal, and biogenic Ba content) and lithophysical proxies (magnetic susceptibility, water content, density, and coarse sediment fraction) in sediment of central Okhotsk Sea core PC-7R. The age model covering the last 350 kyr of this core was constructed by correlating the dated series of relative paleointensity lows recognized in geomagnetic intensity records, marine isotope stage (MIS) boundaries determined in broad variations of the lithophysical and productivity proxies, and tephrochronology. The orbital changes of the lithophysical and productivity proxy stacks lag behind Northern Hemisphere summer radiation by approximately 6.3 and 5.9 kyr, respectively. This lag is consistent with a Milankovich model of climate control by solar radiation through the northern ice sheet volume and sea surface and surrounding land responses, which are fast compared with sedimentological evidence. Productivity proxies of the Okhotsk Sea also demonstrate 52 abrupt, pronounced productivity minima associated with regional climate coolings during the last 350 kyr, which present useful indicators of millennial-scale climate changes in this marginal sea. Based on the postulated synchronicity of Dansgaard-Oeschger cycles in the Northern Hemisphere and the established simultaneity of 11 Okhotsk Sea coolings in the last 77 kyr with abrupt severe cold events in the Greenland ice core and North Atlantic Heinrich events, all of these may be regarded as Heinrich-equivalent event anomalies. The Okhotsk Sea events have their counterparts in the records of North Atlantic sediments, the Greenland ice sheet, East Asia summer monsoon, and the Antarctic ice sheet. Probably the Arctic Oscillation was the main factor determining orbital and millennial climate oscillations in the high-latitude Northern Hemisphere, including the Okhotsk Sea region. (C) 2011 Elsevier Ltd. All rights reserved.