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1.
袁林旺  陈晔 《冰川冻土》2000,22(4):327-332
采用柴达木盆地达参１井井自然伽玛（ＧＲ）曲线进行古气候反演,分析了ＧＲ曲线记录的末次间冰期以来的环境变迁过程,表明ＧＲ曲线忠实地记录了构造运动及气候变化的影响,与古里雅产,格陵兰冰芯所记录的气候事件均能均较好对应,表明柴达木盆地同时包含了高原隆升和全球性气候变化的信息,是反映古气候变化良好的信息载体之一,是反映内陆干旱盆地环境与气候变化良好的代用指标。  相似文献   

2.
黄土高原末次间冰期气候的不稳定性特征   总被引：3，自引：0，他引：3  
欧共体格陵兰冰芯计划(GRIP)中的冰芯资料揭示末次间冰期气候具有快速变化的不稳定性特征,而美国格陵兰冰盖计划(GISP2)却不曾发现其不稳定证据。本文通过黄土高原诸剖面的古气候代用指标综合分析认为,末次间冰期,特别是早期气候曾出现过较大幅度的气候波动,存在不稳定性特征,支持了GRIP结果,表明中国黄土含有极地北大西洋的气候信息,是全球变化研究的理想记录。   相似文献   

3.
ＴＲＩＡＳＳＩＣＦＬＹＳＣＨＴＲＡＣＥＦＯＳＳＩＬＳＡＮＤＴＨＥＩＧＥＯＬＯＧＩＣＡＬＳＩＧＮＩＦＩＣＡＮＣＥＦＲＯＭＫＡＲＡ－ＫＯＲＵＭＲＡＮＧＥＳＩＮＸＩＪＩＮＧ，ＣＨＩＮＡTXＴＲＩＡＳＳＩＣＦＬＹＳＣＨＴＲＡＣＥＦＯＳＳＩＬＳＡＮＤＴＨＥＩＲＧ...  相似文献   

4.
ＡＷＯＲＫＩＮＧＨＹＰＯＴＨＥＳＩＳＩＮＴＨＥＳＥＣＯＮＤ－ＲＯＵＮＤＳＵＤＹＯＮＵＬＴＲＡＨＩＧＨ－ＰＲＥＳＳＵＲＥＭＥＴＡＭＯＲＰＨＩＳＭＩＮＴＨＥＤＡＢＩＥ－ＳＵＬＵＲＥＧＩＯＮTXＡＷＯＲＫＩＮＧＨＹＰＯＴＨＥＳＩＳＩＮＴＨＥＳＥＣＯＮＤＲＯ...  相似文献   

5.
ＴＲＩＡＳＳＩＣＶＯＬＣＡＮＩＳＭＩＮＮＯＲＴＨＷＥＳＴＹＵＮ－ＮＡＮ：ＧＥＯＬＯＧＩＣＡＬＲＥＣＯＲＤＯＦＤＥＬＡＭＩ－ＮＡ－ＴＩＯＮ－ＲＥＬＡＴＥＤＲＩＦＴＩＮＧＩＮＣＯＬＬＩＳＩＯＮＡＬＯＲＯＧＥＮＹTXＴＲＩＡＳＳＩＣＶＯＬＣＡＮＩＳＭＩＮＮＯ...  相似文献   

6.
研究了４１０哌啶树脂对Ｃｄ的吸附行为，在２％～２０％ＨＣＩ介质中［ＣｄＣｌ＿３］￣－被树脂吸附，采用４％～３０／ＨＮＯ＿３溶液可以解脱Ｃｄ，回收率在９６％以上。测定了Ｃｄ在该树脂上的分配系数为５４９０，对含Ｃｄ０．０６７μｇ／ｇ的标样ＧＳＲ－３平行测定６次，相对标准偏差为９．５％。方法用于化探样品中０．０Ｘ×１０￣－６级Ｃｄ的测定，结果满意。  相似文献   

7.
ＭＩＣＲＯＳＴＲＵＣＴＵＲＡＬＦＥＡＴＵＲＥＳＯＦＤＵＣＴＩＬＥＳＨＥＡＺＯＮＥＯＮＴＨＥＮＯＲＴＨＥＲＮＭＡＲＧＩＮＯＦＨＯＨＸＩＬ，ＱＩＮＧ－ＨＡＩＰＲＯＶＩＮＣＥ，ＣＨＩＮＡTXＭＩＣＲＯＳＴＲＵＣＴＵＲＡＬＦＥＡＴＵＲＥＳＯＦＤＵＣＴＩＬＥＳＨ...  相似文献   

8.
末次冰消期转暖的过程和机制一直是古气候研究的热点,然而对于末次冰消期全球气候在时间、空间上的变化以及热带低纬度地区在其中发挥的作用仍不明确。文章根据我国中低纬度地区的湖光岩玛珥湖、渭南黄土剖面和东海DGKS9603孔沉积物中的植硅体等环境指标的分析,研究了末次冰消期在这些地区的变化特点,并结合古里雅冰芯和南京葫芦洞石笋氧同位素记录与南极BYRD冰芯、北极格陵兰GRIP冰芯氧同位素记录进行了对比。结果表明,各地区转暖的时间并不同步,明显受印度洋季风或东南季风影响的古里雅、湖光岩地区是气候转暖较早的地区,格陵兰地区的快速转暖滞后于我国中低纬度转暖1.5~2.0ka以上。如何理解高纬度和热带低纬度地区气候转暖的差异性问题及其原因和机制有待于更多高分辨率气候记录研究和模型的检验。  相似文献   

9.
ＦＵＣＨＳＩＴＥＱＵＡＲＴＺＩＴＥＩＮＡＲＣＨＥＡＮＣＡＯＺＨＵＡＮＧＧＲＯＵＰＯＦＥＡＳＴＥＲＮＨＥＢＥＩ，ＣＨＩＮＡＡＮＤＩＴＳＧＥＯＬＯＧＩＣＡＬＩＭＰＬＩＣ－ＡＴＩＯＮTXＦＵＣＨＳＩＴＥＱＵＡＲＴＺＩＴＥＩＮＡＲＣＨＥＡＮＣＡＯＺＨＵＡＮＧＧ...  相似文献   

10.
ＳＥＧＵＥＮＣＥＢＡＳＥＤＬＩＴＨＯＦＡＣＩＥＳＰＡＬＥＯＧＥＯＧＲＡＰＨＹＯＦＰＥＲＭＩＡＮＩＮＴＨＥＳＩＣＨＵＡＮＹＵＮＮＡＮＧＵＩＺＨＯＵＧＵＡＮＧＲＥＧＩＯＮＴｉａｎＪｉｎｇｃｈｕｎ，ＣｈｅｎＨｏｎｇｄｅ，ＱｉｎＪｉａｎｘｉｏｎｇａ...  相似文献   

11.
《Quaternary Science Reviews》2005,24(1-2):173-194
The climate history and dynamics of the Greenland Ice Sheet are studied using a coupled model of the depositional provenance and transport of glacier ice, allowing simultaneous prediction of the detailed isotopic stratigraphy of ice cores at all the major Greenland sites. Adopting a novel method for reconstructing the age–depth relationship, we greatly improve the accuracy of semi-Lagrangian tracer tracking schemes and can readily incorporate an age-dependent ice rheology. The larger aim of our study is to impose new constraints on the glacial history of the Greenland Ice Sheet. Leading sources of uncertainty in the climate and dynamic history are encapsulated in a small number of parameters: the temperature and elevation isotopic sensitivities, the glacial–interglacial precipitation contrast and the effective viscosity of ice in the flow law. Comparing predicted and observed ice layering at ice core sites, we establish plausible ranges for the key model parameters, identify climate and dynamic histories that are mutually consistent and recover the past depositional elevation of ice cores to ease interpretation of their climatic records. With the coupled three-dimensional model of ice dynamics and provenance transport we propose a method to place all the ice core records on a common time scale and use discrepancies to adjust the reconstructed climate history. Analysis of simulated GRIP ice layering and borehole temperature profiles confirms that the GRIP record is sensitive to the dynamic as well as to the climatic history, but not enough to strongly limit speculation on the state of the Greenland Ice Sheet during the Eemian. In contrast, our study indicates that the Dye 3 and Camp Century ice cores are extremely sensitive to ice dynamics and greatly constrain Eemian ice sheet reconstructions. We suggest that the maximum Eemian sea-level contribution of the ice sheet was in the range of 3.5–4.5 m.  相似文献   

12.
Understanding climate during the last interglacial is critical for understanding how modern climate change differs from purely naturally forced climate change. Here we present the first high-resolution ice core record of the last interglacial and transition to the subsequent glacial period from Antarctica and the first glaciochemical record for this period from West Antarctica. Samples were collected from a horizontal ice trench in the Mt. Moulton Blue Ice Area (BIA) in West Antarctica and analyzed for their soluble major anions (Cl?, NO3?, SO42-), major and trace elements (Na, Mg, Ca, Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Al, S, Ti, V, Cr, Mn, Fe, Co, Cu, Zn) and water hydrogen isotopes (δD). The last interglacial is characterized by warmer temperatures (δD), weakened atmospheric circulation (dust elements, seasalts aerosols), decreased sea ice extent (Na, nssSO42-) and decreased oceanic productivity (nssSO42-). A combined examination of Mt. Moulton seasalts, dust, nssSO42- and δD records indicates that the last interglacial was extremely stable compared to glacial age climate events and it ended through a long period of gradual cooling unlike that projected for future Holocene climate.  相似文献   

13.
The 18O/16O profile of a 554-m long ice core through Taylor Dome, Antarctica, shows the climate variability of the last glacial–interglacial cycle in detail and extends at least another full cycle. Taylor Dome shares the main features of the Vostok record, including the early climatic optimum with later cool phase of the last interglacial period in Antarctica. Taylor Dome δ18O fluctuations are more abrupt and larger than those at Vostok and Byrd Station, although still less pronounced than those of the Greenland GISP2 and GRIP records. The influence of the Atlantic thermohaline circulation on regional ocean heat transport explains the partly “North Atlantic” character of this Antarctic record. Under full glacial climate (marine isotope stage 4, late stage 3, and stage 2), this marine influence diminished and Taylor Dome became more like Vostok. Varying degrees of marine influence produce climate heterogeneity within Antarctica, which may account for conflicting evidence regarding the relative phasing of Northern and Southern Hemisphere climate change.  相似文献   

14.
Oxygen isotope variations spanning the last glacial cycle and the Holocene derived from ice‐core records for six sites in Greenland (Camp Century, Dye‐3, GRIP, GISP2, Renland and NorthGRIP) show strong similarities. This suggests that the dominant influence on oxygen isotope variations reflected in the ice‐sheet records was regional climatic change. Differences in detail between the records probably reflect the effects of basal deformation in the ice as well as geographical gradients in atmospheric isotope ratios. Palaeotemperature estimates have been obtained from the records using three approaches: (i) inferences based on the measured relationship between mean annual δ18O of snow and of mean annual surface temperature over Greenland; (ii) modelled inversion of the borehole temperature profile constrained either by the dated isotopic profile, or (iii) by using Monte Carlo simulation techniques. The third of these approaches was adopted to reconstruct Holocene temperature variations for the Dye 3 and GRIP temperature profiles, which yields remarkably compatible results. A new record of Holocene isotope variations obtained from the NorthGRIP ice‐core matches the GRIP short‐term isotope record, and also shows similar long‐term trends to the Dye‐3 and GRIP inverted temperature data. The NorthGRIP isotope record reflects: (i) a generally stronger isotopic signal than is found in the GRIP record; (ii) several short‐lived temperature fluctuations during the first 1500 yr of the Holocene; (iii) a marked cold event at ca. 8.2 ka (the ‘8.2 ka event’); (iv) optimum temperatures for the Holocene between ca. 8.6 and 4.3 ka, a signal that is 0.6‰ stronger than for the GRIP profile; (v) a clear signal for the Little Ice Age; and (vi) a clear signal of climate warming during the last century. These data suggest that the NorthGRIP stable isotope record responded in a sensitive manner to temperature fluctuations during the Holocene. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

15.
白令海北部陆坡100ka来的古海洋学记录及海冰的扩张历史   总被引：4，自引：0，他引：4  
白令海北部陆坡B2-9柱状样中生源组分的研究显示, 自MIS5.3期以来表层生产力指标的粗组分和蛋白石含量呈阶梯状增加, 反映表层生产力阶段式的增长.全新世表层生产力达到最高, 并且MIS3.2~2期高, 比MIS5.3~3.3期最低.高有机碳含量对应于高C/N比值, 显示有机碳混合来源, 不能作为表层生产力的指标.MIS5.1, 3.3~3.2期和全新世高的有机碳含量和C/N比值反映间冰期陆源有机物质输入量的增加.MIS5.3期至中全新世, 不断增加的陆源砂级和粉砂级颗粒组分说明随着气候的逐渐变冷, 陆架海冰在不断扩张.伐冰碎屑和碳屑颗粒冰期、间冰段和末次冰消期升高, 而间冰期降低, 反映冰期白令海陆架海冰扩张和间冰期海冰消融的过程.冰期海冰扩张与北美大陆气候的相互关联, 揭示了晚第四纪冰期旋回中白令海海冰扩张及其对全球气候变化的响应.   相似文献   

16.
A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon.  相似文献   

17.
This paper for the first time reveals high-resolution core records of Zabuye Salt Lake in the interior of the Qinghai-Tibet Plateau. According to 1346 samples taken continuously, relatively accurate 14^C, U-series disequilibrium and ESR ages have been obtained, thus revealing that the lake core ages from 0 to 83.63 m of hole SZK02 are -800 to over 128 ka. In the paper, the lake core sedimentary characteristics （including the lithologies and mineral assemblages） are analyzed in detail and correlated with ostracod assemblages I to XX and sporopollen zones A to I, and on the basis of an integrated analysis of the δ^18O values of authigenic calcium-magnesium carbonate and environmental proxies of minerals, sporopollen and microfossils in the lake core, a correlation has been made of oxygen isotope change between this lake core and the Greenland GISP2 and GRIP and Guliya ice cores, and the climate of Zabuye Salt Lake since 128 ka BP is divided into the last interglacial stage （including substages e, d, c, b and a） of oxygen isotope stage （OIS） 5, early glacial stadial of the last glacial stage of OIS 4, interglacial stadial of the last glacial stage of OIS 3, late glacial stadial of the last glacial stage or Last Glacial Maximum of OIS 2 and postglacial state of OIS 1; in addition, 6 Heinrich （H6-H1） events, Younger Dryas event and 8.2 ka BP cold event have been recognized.  相似文献   

18.
《Quaternary Science Reviews》1999,18(8-9):1127-1135
We present the results of high-resolution multi-proxy climate studies of the S1 palaeosol, corresponding to oxygen isotope stage (OIS) 5, from the northwestern margin of the Chinese Loess Plateau area. Here, S1 is much thicker (ca. 6–8 m) than in the central Loess Plateau areas (ca. 2 m), where most previous studies have been conducted. Hence, much higher-resolution stratigraphic studies are possible, yielding more insight into the temporal variations of the East Asian monsoon during MIS 5. The frequency-dependent magnetic susceptibility, as well as the concentration of secondary carbonate, is used as an indicator of the summer monsoon intensity, and the median particle size as an indicator of the winter monsoon intensity. The results suggest that the northwestern margin of the Chinese Loess Plateau experienced the strongest summer monsoon intensity in sub-stage (OISS) 5e and the weakest in OISS 5a, among the three warmer periods during stage 5. The summer monsoon was weaker in OISS 5b than in OISS 5d. A dusty interval interrupted the second warmer period (5c) and a soil-forming event interrupted the first colder period (5d). The results also suggest that the directions of changes in the intensities of summer and winter monsoons may not always have been proportionately opposite. For example, the weakest summer monsoon occurred in OISS 5a during which the winter monsoon was not the strongest. We further conclude that the winter monsoon during the last interglacial was probably driven by global ice volume fluctuations, while the summer monsoon was primarily controlled by the northern hemisphere solar insolation and was probably modified by a feedback mechanism. That is, the climatic buffering effect of low-latitudinal oceans may have distorted the response of the summer monsoon to insolation variations. Finally, our results do not show the degree of climatic instability comparable to that recorded in the GRIP ice core for the last interglacial (OISS 5e), even though the study area is situated in a region which has been sensitive to climatic changes.  相似文献   

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