Analysis on Marine Science and Technology Strategy and Key Layout of Japan and the Inspirations to China

The Basic Ocean Law (BOL) and Basic Ocean Plan (BLP) are important guarantee for the maritime strategy of Japan, which has established a complete policy system for the development of marine science and technology. On the other hand, the Japanese Government has started some major marine strategies and plans to promote the BLP. In this paper, the marine science and technology plans launched by the Japanese Government and its participation in the international cooperative research projects were introduced. The research of Japan Marine Science and Technology Center and the University of Tokyo Institute of Oceanography in the long-term planning and focus on the layout features, deep sea research technology layout, contents and advanced equipment were analyzed. At last, some recommendations for China’s development on marine science and technology were proposed, such as strengthening the legislation work and process, carrying out research and development of marine infrastructure with independent intellectual property rights, actively participating in international large-scale ocean plan, improving the discourse right and enhancing national maritime awareness and suggestions and so on.     

Characteristic and Geological Significance of Microbially Induced Sedimentary Structures(MISS) in Terrestrial P-T Boundary in Xingyang,Western He’nan Province

Microbially Induced Sedimentary Structures (MISS) are primary sedimentary structures that arise syndepositionally from microbial community activity. Especially valuable are MISS for the analysis of early Archean (and extraterrestrial) deposits. However, most reports of MISS have focused on the Precambrian and Phanerozoic mass extinction marine sediments, and only a few and terrestrial MISS have been studied. The MISS presented in this paper, which mainly consists of mat growth feature, mat destruction feature and mat decay feature, are well preserved in terrestrial clastic rocks around the P-T boundary in Xiyang area, western Henan. Large U ridges, oriented sand quartz, mica grains and thin clayey laminae arranged parallel to bedding plane are the main features visible under the microscope. Several lines of evidence indicate that the Xingyang MISS are of biogenic origin. Abundant MISS in Xingyang may indicate the degradation of terrestrial ecosystems and proliferation of microbial mats immediately after the severe Permian-Triassic mass extinction. Study aiming at MISS helps to analyze their space distribution in the globe and to probe into links between microbial proliferation and environmental stresses following the end-Permian mass extinction in terrestrial ecosystems.     

Using Geomechanical Method to Predict Tectonic Fractures in Low-Permeability Sandstone Reservoirs

Understanding and interpreting the timing, location, orientation, and intensity of natural fractures within a geological structure are commonly important to both exploration and production planning activities of low-porosity and low-permeability carbonate reservoirs. In this study, we explore the application of comprehensive geomechanical methods to quantitatively characterize the fracture parameters based on Strain Energy Density Theory, such as linear fracture density and volume fracture density. This study approach is based on the idea that energy generated by tectonic stress on brittle sandstone,which can be distinguished fracture surface energy, friction energy dissipation and residual strain energy and natural fractures can be interpreted or inferred from geomechanical-model-derived strains. For this analysis, we model an extension and compression compound fault block developed in a mechanically stratified sandstone and shale sequence because mechanics experimental data and drilling data exist that can be directly compared with model results.However, the results show that the approach and our study conclusion are independent of the specified structural geometry, which can correlate fracture parameters in different stages with different tectonic activities, and finally build and visualize fracture networks in sandstone. The presence or absence of filling minerals in fractures is shown to strongly control the destruction and transformation of low-permeability sandstone, and this control possesses crucial implications for interpreting fracture aperture and reservoir flow simulation.     

WFSD-4S孔流体地球化学特征

本文开展汶川地震断裂带科学钻探现场流体研究,探讨了泥浆添加剂产生的化学反应以及钻孔中岩性变化引起的流体异常特征,并在排除这些影响因素的情况下,讨论地震期间流体的异常。研究表明在WFSD-4S钻进期间发生的两次较大地震前均伴有Rn、Ar、N2和O2等气体异常现象,其中氡的日均值均超出背景值的2.5倍。根据岩心观察得到WFSD-4S钻井地区主断层约在1084 m,而在断层之上931 m处开始出现了大量气体的高值异常,该异常可能是由于地震孕育过程中地下气体的运移通道被打开造成气体向上迁移,使断层气体的响应特征提前发生。     

长江南京潮水位站近百年高潮位变化特征及成因分析

为研究南京站多年来年最高潮位的变化特征,根据水文变异综合诊断方法,分析检验了长江南京站近百年高潮潮位变化的整体趋势;利用db N系列小波变换分析了年高潮潮位变化的局部趋势;利用复数Morlet小波分析了年最高潮位的周期变化规律。分析结果表明,南京站年最高潮位序列总体上无明显趋势变化,局部变化趋势明显;年最高潮位存在5a、11a、42a和63a时间尺度四个主要变化周期。分析结果为认识南京站年最高潮位变化、做好水安全工作以及水资源的开发利用提供相关依据。     

汶川地震断裂带多次地震活动新证据

虹口乡八角庙出露完整的映秀—北川断裂带剖面断层岩,高分辨率磁化率测试揭示出多个具有高磁化率特征的断层岩带。系统的岩石磁学分析证明一层褐色断层岩相对围岩具有最大的磁化率值,存在新生成的磁铁矿和拥有相似的天然剩磁(NRM)和非磁滞剩磁(ARM)强度衰减过程。高磁化率特征是含铁顺磁性矿物受到断层滑移过程产生摩擦生热作用生成磁铁矿所致。同时断层岩还获得了热剩磁,记录了地震活动磁学信息。结合汶川地震科学钻探项目1号孔(WFSD-1)磁化率和岩石磁学研究结果,说明映秀—北川断裂带包含多层具有高磁化率特征的断层岩,暗示了多次强震的发生。具有高磁化率特征的断层岩可以作为判定地震活动的标志之一。     

Rainfall over Oman and its teleconnection with El Niño Southern Oscillation

The Sultanate of Oman is located in the south-eastern part of the Arabian Peninsula and covers the larger part of the southern coasts of the Arabian Peninsula in both arid and semi-arid environments except for the southern part which is swept by the monsoon affecting the Arabian Sea during the period from June to September. The summer rainfall over Oman shows year-to-year variability, and this is caused by oceanic and atmospheric influences. In the present study, we tried to explore the influence of El Niño on the rainfall over Oman using different data sets. The empirical orthogonal function (EOF) technique employed to the zonal wind at 850 hPa for the 30-year period shows that the second and third modes of EOF are showing high variability over the Oman regions. The corresponding PCs were subjected to FFT analysis, and it showed a peak about 5–6 years. In addition to this, the zonal wind over the Oman regions is correlated with the global zonal wind and found a significant correlation (1 % significant level). It has already been proved that the wind and rainfall during summer monsoon is in phase. Moreover, the spectral analysis of rainfall at Masirah station and the Niño3.4 index show the similar mode of variability indicating a direct relationship. The correlation between rainfall and the Niño3.4 index is also showing a positive significant value, and therefore, it can be concluded that the El Niño in the Pacific favours rainfall over the Oman region.     

Multichannel analysis of surface waves (MASW) for seismic site characterization using 2D genetic algorithm at Bahrah area,Wadi Fatima,Saudi Arabia

The present study deals with the seismic site classification of Bahrah area, Wadi Fatima, to characterize the local site conditions. The dynamic behavior of sediments was studied by the application of surface wave inversion. The multichannel analysis of surface waves (MASW) shallow geophysical technique was utilized for site classification. MASW survey was carried out at 66 sites along with 13 seismic refraction profiles at suitable localities. MASW and seismic refraction profiles were processed and compared with the available borehole data. The integration of MASW techniques with seismic refraction and borehole data progressively enhanced the subsurface visualization and reliability of the shear wave velocity estimation in the subsurface in the study area. The subsurface shear-wave velocity model was achieved by the solution of an inverse problem-based dispersion of surface waves and propagation in a vertically heterogeneous medium. The 2D genetic algorithm was employed for the inversion of dispersion curves to obtain velocity and thickness of subsurface layers. The depth to engineering bedrock and velocity of shear waves in the first 30 m was deciphered and mapped. The depth of bedrock in study area varies from 4 to 30 m, and V _{S 30} ranges from 320 to 800 m/s. The most of study area falls in B and C class categories in addition to few sites of D class according to the NEHRP guidelines.     

Assessing groundwater storage changes in the Nubian aquifer using GRACE data

Gravity Recovery and Climate Experiment (GRACE) level two (L2) data is used in estimating the groundwater storage changes (GWSC) in the Nubian Sandstone Aquifer System (NSAS). This set of data consists of spherical harmonics coefficients with specific degree and order. The GRACE data is de-correlated using a sixth degree polynomial in order to reduce the effect of the noise error resulting from the correlation between the spherical harmonics coefficients with the same degree parity. The GRACE estimates of GWSC are smoothed using Gaussian filter with half width of 1000 km. This half width is chosen in order to maximize the correlation between the GRACE estimates of GWSC and previous modeling results of the NSAS. The loss in groundwater storage occurring in each of the four countries sharing the NSAS is calculated to assess the sustainability of using the NSAS as a water resource in each country. The overarching finding in this study is that NSAS is losing its groundwater storage at a very high rate. Also, it is found that Egypt is the fastest in losing its groundwater storage from the NSAS. This loss of groundwater storage in Egypt may not necessarily be resulting from in-country extractions because of the trans-boundary nature of this aquifer. The GRACE-based estimates are found to be close to available data and previous modeling results of the NSAS.     

Detachment folding in a Lower Cambrian–Upper Permian karst reservoir: 3D model of the Yubei 3D area (eastern Markit Slope,Tarim Basin,Northwest China)

A three-dimensional (3D) structural modeling of the Lower Cambrian–Upper Permian Yubei 3D area was performed to understand its structural evolution. This model reproduces the present-day structure of the basin and comprises 11 horizons within Lower Cambrian to Upper Permian rocks. The analysis is based on 3D depth views and faults. The results image salt movements due to tectonics and/or burial. From these observations, this paper deduces that salt structures are correlated to the main faults and tectonic events. From the model analysis, we interpret the timing and geometry of Tarim Basin tectonics. The fault geometry can be resolved based on the strike of the fault, the morphology of hanging wall strata, and the stratigraphic distribution. Emphasis is placed on gypsum rock detachment, considering its movements during the Middle Caledonian event and decoupling effects during tectonic evolution. Moreover, we point to the structural control of the Paleozoic basement and the crustal architecture (Yubei 3D Zone) on the geometry of the Tarim Basin.