莺歌海盆地泥底辟发育演化与天然气及CO2运聚成藏规律   总被引：3，自引：0，他引：3  

何家雄  徐瑞松  刘全稳  孙东山  万志峰 《海洋地质与第四纪地质》2008,28(1):91-98

泥底辟是南海北部边缘西区莺歌海盆地颇具特色的地震地质异常体,具有低密、低速及高温高压特征,其发育演化及所伴生的热流体上侵活动与天然气及CO2运聚分布乃至富集成藏均密切相关。将莺歌海盆地泥底辟划分为"深埋型"(低幅度弱-中能量泥底辟)、"浅埋型"(高幅度中-强能量泥底辟)及"喷口型"(高幅度特强能量泥底辟)三大类进行研究。研究表明,晚期泥底辟及热流体活动不仅为浅层天然气及CO2运聚成藏提供了纵向的高速运移通道和运聚动力条件,促使深部天然气及CO2向浅层大量运移聚集,而且导致盆地具有烃源岩早熟、天然气运聚供大于散的晚期动平衡成藏,以及泥底辟热流体上侵活动控制天然气及CO2运聚规律之特点。  相似文献   

海平面变化的小波和自回归模型集成预测试验     

袁林旺  谢志仁  钟鹤翔 《海洋科学》2008,32(4):31-35

针对海面变化预测时间序列模型中趋势组份和周期(准周期)组份的提取和预测问题,基于吴淞站1955～2001年月平均潮位序列,采用小波分析(WA)与自回归(AR)模型相结合的方案,对小波分解的不同尺度分量序列,借助于时间序列模型进行分量预测,再对它们进行叠加建立预测模型,进行了月平均潮位预测试验.以1955～1996年数据为基础建立模型,1997～2001年数据作为验证,结果表明两种方法的结合使用显示了较好的效果,具有较高的精度.  相似文献   

平均海平面上升对东中国海台风风暴潮影响的数值模拟     

高志刚  韩树宗  刘克修  郑运霞  于华明 《海洋通报(英文版)》2008,10(2)

本文采用ECOMSED模式模拟了影响东中国海的3次台风过程,经与实测资料对比验证了模型的可靠性。在此基础上设计了敏感性试验以考察海平面上升对风暴潮造成的影响。结果表明,海平面上升对风暴潮的影响在空间分布上不是一致的,且因具体台风过程而异。整体而言,海平面上升对风暴潮造成的影响有限。海平面上升0．5m,大部分站位风暴增水极值基本不变,即使海平面上升5m大部分站位的风暴增水极值相对改变量都小于10％。  相似文献   

南四湖清障工程行洪分析     

张涛  刘继军  于宪营  张德锋  齐云婷 《海洋湖沼通报》2008,(4)

根据1999年竣工的南四湖清障工程实施前后的水文观测资料,从湖区水面比降、洪水落平时间等要素的变化,进行了湖区行洪分析。通过分析发现:工程的实施,降低了卡口段的水位,减小了工程位置以下的湖区水面比降,缩短了湖区行洪时间,加快了洪水宣泄,使入湖河道洪水尽快下泄,提高了湖区行洪能力,分析成果对南四湖防洪调度以及进一步做好湖内清障工程,具有重要的参考价值。  相似文献   

晚更新世南黄海西部陆架的古长江三角洲   总被引：4，自引：0，他引：4  

陶倩倩  刘保华  李西双  张维冈  李达 《海洋地质与第四纪地质》2009,(2)

晚更新世气候的冷暖交替引起全球海平面的下降与上升,在南黄海地层中,最直接的体现就是海陆交互式沉积层。利用最新的高分辨率浅地层剖面资料,对南黄海西部近海陆架晚更新世以来的地震地层进行了详细划分,探讨了晚更新世两个海进层序中古三角洲的划分及其地震相特征,认为晚更新世南黄海古三角洲可分为4个较大的期次。根据沉积物特征分析判断4期古三角洲均为古长江形成,各期三角洲相互叠置,范围、厚度及扩建方向均有不同,各期古长江三角洲与海平面变化有很好的对应关系。  相似文献   

中国的海滩岩研究与进展   总被引：2，自引：0，他引：2  

孙金龙  徐辉龙 《热带海洋学报》2009,28(2)

海滩岩作为海陆交互作用的直接产物之一,对于研究古海平面变化、海岸带演化以及古气候变化等海陆相互作用过程具有重要意义.对我国的海滩岩研究历史与现状进行了分析,对当前的海滩岩研究中存在的一些争议和问题如海滩岩的定义、海滩岩的胶结物及其形成机制、海滩岩的形成时代、研究方法等进行了讨论,并对今后我国海滩岩研究的发展进行了展望.  相似文献   

Dynamic response characterization and simplified analysis methods for viscoelastic dampers considering heat transfer     

Kazuhiko Kasai  Dave Montellano Osabel  Daiki Sato 《地震工程与结构动力学》2023,52(1):27-50

Viscoelastic (VE) dampers are sensitive to temperature, excitation frequency, and strain level. As they dissipate the kinetic energy from earthquake or wind-induced structural vibrations, their temperature increases from the heat generated, consequently softening their VE materials and lowering their dynamic mechanical properties. Temperature increase can be significant for long-duration loading, but can be limited by heat conduction and convection which depend on damper configuration. The writers analytically explored such effect on the six different dampers by using their previously proposed three-dimensional finite-element analysis method. Results provided better understanding of how heat is generated within the VE material, conducted and stored in different damper parts, and dispersed to the surrounding air. These results also led to characterization of both local (e.g., temperatures, properties, and strain energy density) and global (e.g., hysteresis loops, and stiffness) behavior of VE dampers, and provided a framework for a new simplified one-dimensional (1D) modeling approach for time-history analysis. This new proposed 1D method greatly improves the computation time of the previously proposed long-duration method coupling fractional time-derivatives VE constitutive rule with 1D heat transfer analysis. Unlike the previous method, it idealizes uniform shear strain and VE material property distributions for computational efficiency, but still simulating non-uniform temperature distribution along the thickness direction of the VE material. Despite the approximations, it accurately predicts VE damper global responses.  相似文献   

Paleoshoreline reconstruction: A proposed method to approach submerged prehistoric landscapes of Espiritu Santo Island,Baja California Sur,Mexico     

Mayra C. Robles-Montes  Guillermo Martínez-Flores  Michael K. Faught  Enrique H. Nava-Sánchez 《Geoarchaeology》2024,39(2):106-121

When the first Americans inhabited the area now known as Isla Espiritu Santo, around 12.5 and 6 ka, the sea level continuously rose. This resulted in the loss of the coastal territory and the retreat of the human population further inland. Part of the archaeological evidence of this period currently lies over the seafloor and under the seabed. Therefore, reconstructing paleoshorelines is a necessary first step toward submerged precontact archaeology and a broad understanding of the spatial context in which those human populations interacted and how the landscapes changed. Isla Espiritu Santo is of prehistoric importance as it contains numerous Paleocoastal tradition sites as early as ~12,400 Cal B.P. This research aims to reconstruct the changing shoreline positions as sea levels rose around Isla Espiritu Santo between 12.5 and 6.5 ka. We apply numerical modeling to map digital elevation models at 1 ka intervals by estimating the changes in the morphology of the seafloor according to the deposition rates and global sea-level curve. The results show the evolution of coastal morphology and paleoshoreline's position. Three primary geoforms are proposed: (1) coastal plains, (2) tombolo, and (3) a coastal lagoon–island barrier system. This also offers insights into the physical aspect of submerged prehistoric landscapes and the possible resource exploitation options of early societies. In this research, the reconstruction of submerged landscapes seeks to contribute to the long-term goal of locating submerged precontact sites.  相似文献