厄尔尼诺与太阳活动的50d振荡   总被引：8，自引：0，他引：8  

李志安  林巧 《天文学报》1996,37(4):443-448

本文分析研究了１９８１—１９９４年太阳辐射流量（２８００ＭＨｚ）、太阳黑子相对数、大气角动量和地球自转日长变化序列的５０ｄ振荡．振荡周期的变化范围从４０ｄ至６０ｄ，它们的变化规律极其相似。１９８１年－１９９４年期间发生的３次厄尔尼诺均出现在太阳活动的５０ｄ振荡周期的谷值时期．这说明太阳活动的５０ｄ振荡可能是引起厄尔尼诺事件的一种原因．  相似文献   

Development of Climate and Earth System Models in China: Past Achievements and New CMIP6 Results     

Tianjun Zhou  Ziming Chen  Liwei Zou  Xiaolong Chen  Yongqiang Yu  Bin Wang  Qing Bao  Ying Bao  Jian Cao  Bian He  Shuai Hu  Lijuan Li  Jian Li  Yanluan Lin  Libin Ma  Fangli Qiao  Xinyao Rong  Zhenya Song  Yanli Tang  Bo Wu  Tongwen Wu  Xiaoge Xin  He Zhang  Minghua Zhang 《Acta Meteorologica Sinica》2020,34(1):1-19

The Earth-Climate System Model (ECSM) is an important platform for multi-disciplinary and multi-sphere integration research, and its development is at the frontier of international geosciences, especially in the field of global change. The research and development (R&D) of ECSM in China began in the 1980s and have achieved great progress. In China, ECSMs are now mainly developed at the Chinese Academy of Sciences, ministries, and universities. Following a brief review of the development history of Chinese ECSMs, this paper summarized the technical characteristics of nine Chinese ECSMs participating in the Coupled Model Intercomparison Project Phase 6 and preliminarily assessed the basic performances of four Chinese models in simulating the global climate and the climate in East Asia. The projected changes of global precipitation and surface air temperature and the associated relationship with the equilibrium climate sensitivity under four shared socioeconomic path scenarios were also discussed. Finally, combined with the international situation, from the perspective of further improvement, eight directions were proposed for the future development of Chinese ECSMs.  相似文献   

崂山花岗岩大型气泡状晶洞的发现及意义   总被引：1，自引：0，他引：1  

宋召军  刘锡清  宫丽明  李海锋  陈桥  顾畛逵 《海洋地质前沿》2013,(12):1-5

近年来,在崂山A型花岗岩中发现了一些大型气泡状晶洞,最大的直径可达3.1m,远超过以往报道过的花岗岩晶洞。这一发现,不仅对研究崂山花岗岩形成的原生环境有重要意义,而且也揭示了崂山花岗岩"天然石臼"的真正成因。同时,从洞穴学角度也肯定了一种新的洞穴类型的存在。花岗岩大型气泡状晶洞是珍稀的地质遗迹,具有较高的观赏和旅游价值,应加以保护。  相似文献   

恩施断裂中段第四纪活动特征与位移速率     

蔡永建  雷东宁  李恒  乔岳强  吴建超  Wu Jianchao 《大地测量与地球动力学》2011,31(1):39-43

对恩施断裂中段构造地貌、断裂剖面与洪积扇变形的分析表明,断裂在第四纪活动明显,以正倾滑兼右旋走滑为特征.根据洪积扇位错的水平距离、垂直高差以及形成时代,估算出断裂在中更新世晚期至晚更新世早、中期的右旋运动速率为0.43～0.5 mm/a,垂直运动速率0.07～0.17 mm/a.  相似文献   

五百梯长兴生物礁气藏储层连通性分析     

郭镜  杨剑  王桥  曾琴琴 《四川地质学报》2013,(4):409-411,416

五百梯长兴生物礁气藏储层岩性以白云岩为主,储层渗透性差非均质性很强。因此对该气藏连通性的研究是必要的。本文通过分析气藏的气体性质和折算地层压力在静态上来判断气藏是否连通,再通过井间干扰测试在动态上描述气藏连通性的好坏。连通性问题的研究能够直接指导五百梯长兴生物礁气藏生产,对于类似气藏也具有很好的借鉴和指导意义。  相似文献   

渝东南地区隐伏铝土矿物探勘查技术试验研究—以车盘矿区试验结果为例     

李华  艾斯卡尔  吾守艾力  李富  焦彦杰  王桥  周一敏 《地质学报》2013,87(3):384-392

全国矿产资源潜力评价研究表明渝东南地区有着丰富的铝土矿资源,在此开展隐伏铝土矿的物探勘查技术试验研究对今后勘查工作的展开具有重要的指导意义。文中首先在充分了解渝东南地区铝土矿的成矿规律及矿体特征的基础上,总结了该地区铝土矿的储存模式;然后根据其成矿规律和储存模式,结合前人的经验及区域物性差异,提出了使用电磁测深法来确定该区唯一含矿层位—梁山组地层的空间分布形态,以达到间接寻找隐伏铝土矿的方案。选取重庆武隆车盘矿区作为试验场地,在同一剖面上同时展开了可控源(人工场源)音频大地电磁测深法(CSAMT)和高频大地电磁测深法（EH4）两种方法的试验工作,介绍了数据采集及数据质量评价等,对两种电磁测深数据分别进行了人机交互的二维连续介质反演,并结合钻孔资料对两个反演的频率—视电阻率剖面进行了对比分析,最后结合区域地质构造背景勾画出物探成果推断图。  相似文献   

Chronologies of sedimentary changes in the south Bohai Sea,China: constraints from luminescence and radiocarbon dating   总被引：1，自引：0，他引：1  

Liang Yi  Zhongping Lai  Hongjun Yu  Xingyong Xu  Qiao Su  Jing Yao  Xulong Wang  Xuefa Shi 《Boreas: An International Journal of Quaternary Research》2013,42(2):267-284

The alternation of terrestrial and marine deposits is an indicator of past environmental and sea‐level changes. The age of deposition is usually dated by means of radiocarbon. However, radiocarbon dates of molluscan shells from coastal areas may be complicated by various sources of carbon, and problematic for deposits of 40–50 ka or older. Herein, we apply the Optically Stimulated Luminescence (OSL) dating method to date samples from terrestrial and marine/coastal sediments extracted from three cores in the south Bohai Sea, China. Multiple‐ and single‐aliquot regenerative‐dose procedures using OSL signals from fine‐silt (4–11 μm), coarse‐silt (38–63 μm) and fine‐sand (63–90 or 90–125 μm) quartz were employed to determine the equivalent dose (D _e). The results showed that: (i) OSL ages from quartz of different grain sizes and different protocols are consistent with each other; (ii) for Holocene samples, most of the radiocarbon dates agree well with OSL ages; (iii) for pre‐Holocene samples, radiocarbon dates cluster at 40–50 ¹⁴ C ka BP, whereas OSL ages are in stratigraphic order from 11 ka to 176 ka. Because of the self‐consistency of the quartz OSL ages, the stratigraphic agreement in the three cores, and the clustering of the radiocarbon dates, we suggest that the quartz OSL ages are more reliable with respect to dating the samples from the south Bohai Sea. Finally, the four marine strata identified in the south Bohai Sea are likely to have formed during the Holocene, Marine Isotopic Stage (MIS) 3–5, MIS 6 and probably MIS 7, respectively.  相似文献   

贵州丹寨地区南华系地层地球化学特征及其对古气候、古环境的意义          下载免费PDF全文

谯文浪  汪建国  陈武 《地质科学》2013,48(3):847-859

南华系是地球历史上最重要的成冰时期,为了示踪冰期前后的气候与环境的变化,本文通过对南华系细屑岩的化学成分分析,重塑南华系古气候、古环境的演化过程。分析结果显示铁丝坳组具有明显低的CIA指数以及低Ti/Al比值,说明该时期主要以寒冷干燥气候为主,化学风化程度低,物源供应和沉积速率相对较低,为冰期特征,隆里组和大塘坡组具有高的CIA指数以及相对较高的Ti/Al比值,表明该时期主要以温暖湿润气候为主,化学风化程度相对较高,物源供应和沉积速率相对较高,为间冰期特征。南沱组的CIA指数以及Ti/Al比值具有交替变化特征,说明南沱组沉积时期气候存在冷暖交替变化,反映了冰期与间冰期的相互转换特征。另外,在铁丝坳组顶部和大塘坡组的下部以及南沱组中上部,具有一定程度的正Eu异常,说明在南华系沉积时期,存在热液活动,而这种热液活动可能与冰期的消亡存在着成因联系。  相似文献   

Fatigue Behavior of Granite Subjected to Cyclic Loading Under Triaxial Compression Condition     

Zhechao Wang  Shucai Li  Liping Qiao  Jiangang Zhao 《Rock Mechanics and Rock Engineering》2013,46(6):1603-1615

A series of laboratory tests were performed to examine the fatigue behavior of granite subjected to cyclic loading under triaxial compression condition. In these tests, the influences of volumetric change and residual strain on the deformation modulus of granite under triaxial cyclic compression were investigated. It is shown that the fatigue behavior of granite varies with the tendency for volumetric change in triaxial cyclic compression tests. In the stress–strain space, there are three domains for fatigue behavior of rock subjected to cyclic loading, namely the volumetric compaction, volumetric dilation with strain-hardening behavior, and volumetric dilation with strain-softening behavior domains. In the different domains, the microscopic mechanisms for rock deformation are different. It was also found that the stress level corresponding to the transition from volumetric compaction to volumetric dilation could be considered as the threshold for fatigue failure. The potential of fatigue deformation was compared with that of plastic deformation. The comparison shows that rocks exhibit higher resistances to volumetric deformation under cyclic loading than under plastic loading. The influence of residual strain on the fatigue behavior of rock was also investigated. It was found that the axial residual strain could be a better option to describe the fatigue behavior of rock than the loading cycle number. A constitutive model for the fatigue behavior of rock subjected to cyclic loading is proposed according to the test results and discussion. In the model, the axial residual strain is considered as an internal state variable. The influences of confining pressure and peak deviatoric stress on the deformation modulus are considered in a term named the equivalent stress. Comparison of test results with model predictions shows that the proposed model is capable of describing the prepeak fatigue behavior of rock subjected to cyclic loading.  相似文献   

GPS-derived crustal deformation in southwestern China     

X. Qiao  S. Yang  R. Du  Q. Wang  K. Tan  L. Guo 《Australian Journal of Earth Sciences》2013,60(4):521-529

The Sichuan – Yunnan region is divided into nine active secondary crustal blocks, based on several GPS repeat surveys at more than 200 GPS sites during the period 1999 – 2005. Velocities of the nine secondary blocks are calculated and analysed. The strain field within the area related to the 2004 Sumatra – Andaman earthquake event is also analysed. Results indicate that the crustal movement in the northern and western areas of the Sichuan – Yunnan region is stronger than that in the south and east. The horizontal velocities change from 19 – 20 mm/y in the northern and the central rhombic block to 11.7 mm/y in the southern rhombic block. The orientations of block motion vary from 99° in the north to 126 – 150° in the central area and 156 – 188° in the south, implying that the motion of the Sichuan – Yunnan rhombic block is dominated by a clockwise rotation. The velocity differences between blocks inside and outside the rhombic block are about 6.5 – 7.7 mm/y in the northern and central Sichuan – Yunnan region. The southeastward extrusion rate of the Tibetan Plateau shows a remarkable downtrend of up to 47% along the Xianshuihe Fault, suggesting an increase in strain accumulation and hence an area prone to strong earthquakes. The horizontal coseismic deformation caused by the Mw9.0 Sumatra – Andaman earthquake is <10 mm with a south-southeast orientation towards the earthquake epicentre. The dilatational strain rates from coseismic displacements reveal a possible interaction between the extrusion from the Tibet plateau interior and the underthrust effects from the Sumatra – Andaman earthquake.  相似文献