松辽盆地西部斜坡英台地区姚二、三段辫状河三角洲沉积特征研究

松辽地区西部斜坡英台地区姚家组二、三段,是在干旱一半干旱、源近流短、东倾陡坡背景下,在洪积扇前,由辫状河入湖形成的辫状河三角洲沉积。可明显区分出狭窄的辫状河三角洲平原,河口坝不太发育的辫状河三角洲前缘和夹浊积砂的辫状河前三角洲三种沉积亚相。辫状河三角洲平原由灰色含砾砂岩,粗、中砂岩,少量细砂岩,粉砂岩夹紫红色泥岩组成。具有明显的正韵律为特征。辫状河三角洲前缘沉积为灰色-绿灰色中、粗砂岩、细砂岩、少量的含砾砂岩,成正韵律或反韵律夹在灰绿色、灰黑色泥质岩中。辫状河前三角洲沉积多为灰绿色、灰黑色泥质岩,可夹少量砂质浊积岩。上述沉积特征明显地区别于正常河流三角洲沉积和扇三角洲沉积。     

Magnetic properties as indicators of pedogenic and pyrogenic processes at the Upper Paleolithic site of Kostenki 14

In geoarchaeological studies, there is an issue with distinguishing between natural and anthropogenic signals in pedological paleoarchives. With the pedostratigraphy of the Upper Paleolithic site of Kostenki 14, this issue is reflected by problems with the determination of features of pedogenic and pyrogenic processes. This issue was addressed by means of a thorough analysis of the magnetic properties of paleosols accompanied by micromorphological observations. Most of the humic samples were shown to be a result of pedogenesis, but two samples (a Paleolithic hearth sample and a sample from paleosol IIc) had features of intensely burnt material. The difference in the typical intensity of large-scale (natural or human-induced) and local-scale anthropogenic fire allowed for suggesting that the magnetic properties of the burnt sample were the result of an anthropogenically controlled fire event, that is, a hearth. This study shows that the magnetic properties of paleosols can be used to differentiate anthropogenic activity, in particular—burning, from pedogenic processes. This indicator is especially helpful in finding disturbed combustion features when the hearth structure is lost. This methodology used to demonstrate the local human-induced pyrogenic effect at the Upper Paleolithic site can contribute to the discussion of the niche construction effect of human activities in the Pleistocene.     

1981-2008年中国陆地植被NPP对气候变化响应的敏感性试验

在验证CENTURY模型对中国陆地植被净初级生产力(Net Primary Productivity,NPP)模拟能力的基础上,利用该模型探讨了1981-2008年中国陆地植被NPP的年际变异和变化趋势对CO₂浓度、温度和降水变化的响应。结果表明,中国陆地植被NPP对不同气候因子的响应程度存在明显不同。其中,CO₂浓度变化对植被NPP年际变异的影响不显著,但能够引起中国大部分地区植被NPP趋势系数增大;温度对中国中高纬度地区植被NPP的年际变化影响显著,但就全国范围而言,植被NPP年际变异对温度变化的响应程度总体低于对降水变化的响应程度;降水变化是对中国植被NPP变化趋势起主导作用的气候因子。此外,综合考虑温度和降水变化的影响发现,植被NPP变化趋势的响应特征类似于降水单独变化时植被NPP变化趋势的响应特征。     

A 16 ka climate record deduced from δ^13C and C/N ratio in Qinghai Lake sediments, northeastern Tibetan Plateau

1 INTRODUCTION δ13C in organic matters from lacustrine sedi- ments varies with several factors including aquatic plants, vegetation type in the catchment, atmos- pheric CO2 concentration, climate (temperature and precipitation), and properties of water, …     

Living with limits: growth,resources, and climate change

Is it possible for all of humanity to enjoy the standards of living of today's high-income countries? What would happen if these limits were reached, perhaps because of climate change or a shortage of natural resources essential to production? How would society manage – or fail to manage – such limits? Notwithstanding the current financial and economic crises, these are perhaps the biggest questions confronting our species (and of a host of other species, who are the victims of our decisions). The article begins by considering the biggest economic event of our lifetimes – the ‘great convergence’ and its implications for the demand for resources. The discussion then turns to a specific limit on our development, climate change, which is different from most other limits, because it involves a global public good: the atmosphere. What such limits might mean for our civilization is discussed. One can persuade people to tackle climate change only if those concerned with the dangers persuade ordinary people that action will not come at the expense of their prosperity.     

A comparative study of geothermal and meteorological records of climate change in Kamchatka

To reconstruct the recent climate history in Kamchatka, a series of repeated precise temperature logs were performed in a number of boreholes located in a broad east-west strip (between 52 and 54°N) in the central part of Kamchatka west of Petropavlovsk-Kamchatski. Within three years more than 30 temperature logs were performed in 10 holes (one up to six logs per hole) to the depth of up to 400 metres. Measured temperature gradients varied in a broad interval 0 to 60 mK/m and in some holes a sizeable variation in the subsurface temperatures due to advective heat transport by underground water was observed. Measured data were compared with older temperature profiles obtained in the early eighties by Sugrobov and Yanovsky (1993). Even when older data are of poorer precision (accuracy of about 0.1 K), they presented valuable information of the subsurface temperature conditions existing 20–25 years ago. Borehole observations and the inverted ground surface temperature histories (GSTHs) used for the paleoclimate reconstruction were complemented with a detailed survey of meteorological data. Namely, the long-term surface air temperature (SAT) and precipitation records from Petropavlovsk station (in operation since 1890) were used together with similar data from a number of local subsidiary meteo-stations operating in Central Kamchatka since 1950. Regardless of extreme complexity of the local meteorological/climate conditions, diversity of borehole sites and calibration of measuring devices used during the whole campaign, the results of the climate reconstruction supported a general warming of about 1 K characteristic for the 20th century, which followed an inexpressive cooler period typical for the most of the 19th century. In the last three to four decades the warming rate has been locally increasing up to 0.02 K/year. It was also shown that the snow cover played a dominant role in the penetration of the climate “signal” to depth and could considerably smooth down the subsurface response to the changes occurred on the surface.     

高台测震新旧台基记录地震及震相特征差异性对比分析

使用相同带宽、同类型地震计BBVS-120观测记录数据,对高台地震台新旧观测山洞的台基环境噪声、地震监测能力及震相记录特征进行对比分析,结果表明,高台测震新山洞的地震监测水平优于旧山洞,部分地区新山洞对于核面反射波的记录更加清晰。     

浙江省年平均气温百年序列的构建

长时间气温序列是气候变化研究的基础,早期气温观测台站的缺乏在某种程度上限制了区域性气温长序列的建立。将局部台站的气温观测值向代表全区水平的气温观测值转化,亦是一种有效利用早期少数气温站点构建区域性气温长序列的重要途径。基于浙江省气温观测台站资料的统计分析,提出了局部台站观测值全局修正（GAoSV）的气温长序列建立方式,并利用该方式构建了浙江省年平均气温百年序列。研究结果表明：省级区域内气温局部台站观测与全区台站观测,两者的气温年值变化具有高度的趋同相关性,所提出的GAoSV气温序列构建方式可在少数气温观测台站的情况下,有效保证全区气温序列的构建可信度,且随着观测台站数量增多,其构建可信度会进一步增大,该方式尤其适合早期气温观测台站稀缺（仅有1～2个）的省市级气温长序列的建立。以GAoSV方式建立的浙江省年平均气温百年序列显示,1905-2012年浙江省年平均气温总体在逐渐升高,增温速率约为0．11℃／10a,1980-2012年期间气温的上升趋势更为明显,增温速率约为0．51℃／10a。     

塔里木河流域适应气候变化和人类活动的应对措施

自2001年开始实施塔里木河流域近期综合治理工程,提出了以强化流域水资源统一管理和调度为核心,以源流区节水改造和干流河道治理为重点进行综合治理,积极稳妥地进行经济结构调整,实施退耕封育保护,有效保护好现有天然林草植被.通过向塔里木河下游生态输水,干涸近30a的台特玛湖于2001年11月16日开始有水,使塔里木河下游绿色走廊得到初步复苏等,流域生态环境得到极大的恢复.然而,自2007年以来,塔里木河向下游输水已大为减少,仅能输水到中游,特别是2009年水文干旱,塔里木河干流断流达1 100km多,使下游绿色走廊再度陷入生态危机.为此,需要重新审视塔里木河流域的综合治理,从加强源流治理开始,来巩固干流治理成果.认真总结10a来治理经验与教训,针对人类活动和气候变化对源流与干流造成的影响程度,积极采取应对措施.     

内蒙古巴彦塔拉盆地砂岩型铀矿化的蚀变特征

巴彦塔拉盆地砂岩型铀矿床产于下白垩统赛汉塔拉组下段辫状河流相砂岩中。本文通过对含矿主岩沉积特征、矿化和矿床蚀变特征的分析研究 ,认为早期为潜水氧化蚀变成矿 ;晚期为层间氧化 油气还原蚀变成矿 ,即来自蚀源区和天窗补给的含铀、含氧地下水遇沿断裂 (F2 1)上升的含H2 S的油气还原叠加改造成矿