A Baseline Assessment of Coral Reef in Malacca Straits,Malaysia

Coral reefs along the Malacca Straits (MS) are poorly developed mainly due to turbidity and sedimentation. This study describes the health status and community structure of the corals in Cape Rachado, West Coast of Peninsular Malaysia (WCPM), utilizing the Coral Video Transect (CVT) technique. All the survey transects were categorized as ‘fair’ coral conditions (27.39 ± 5.41%–48.56 ± 18.96%) with the reef floor mainly covered by corals and sediment. Twelve families of coral comprised of 25 distinct genera were identified. Coral communities were differentiated into four clusters with each being predominated by Galaxea, Diploastrea, Fungia and Pectinia respectively. Among all, Pectinia is the most spectacular genera and dominated the survey area. Along the MS, Favia, Favites and Porites are commonly found while Porites and Pectinia dominated the reefs. Low coral cover and diversity was recorded in MS as compared to the reefs in the South China Sea (SCS). The most prominent results include changes in the dominant coral from Porites to Pectinia while some species such as Acropora were absent from the study area. Based on the presented data, the reef in the study area was predominantly occupied by sediment and the coral communities were formed by a species with a high tolerance to turbidity and sedimentation.     

陕西大旱与太阳活动的关系

本文分析了公元５８０～１９７９年的陕西大早与大阳活动的关系，得到大旱主要发生在太阳黑子的高值段和下降段以及低值段。第２２大阳周峰年已经过去，粗略估计１９９６年是第２３太阳周的谷年。我们预测１９９５Ａｓｌ９９７年大旱１次，１９９７～２０００年基本上无大旱，２０００～２００５年大旱２～３次。     

南海北部陆架和陆坡区小型底栖动物群落的比较研究

为了解南海北部陆架与陆坡区小型底栖动物的群落特征,以及影响群落特征的环境因素,2015年6月对南海北部海域(19.3°—21.4°N, 112.4°—115.1°E)7个站位的小型底栖动物及环境因子进行了采样,并对陆架和陆坡区小型底栖动物群落的丰度、生物量、类群组成和群落结构进行比较。结果表明,在陆架站位,小型底栖动物由13个类群组成,平均丰度为(132±130)ind./10cm2,平均生物量为(169±79)μgdwt/10cm2;在陆坡站位由8个类群组成,平均丰度为(33±14)ind./10cm2,平均生物量为(56±35)μgdwt/10cm2。单因素方差分析结果表明,陆坡区小型底栖动物的总丰度和总生物量以及线虫和多毛类的丰度均显著低于陆架区,但优势类群的相对丰度组成没有显著不同,海洋线虫占总丰度的83%,其次为多毛类和桡足类,分别占7%和3%。环境因子的主成分分析(Principal ComponentsAnalysis,PCA)将陆架和陆坡站位沿第一主分量轴分开,小型底栖生物丰度和生物量与沉积物叶绿素a和脱镁叶绿酸含量以及底层水温呈最大正相关,与水深呈负相关;聚类(Cluster)和排序(non-metric Multidimensional Scaling, MDS),以相似性系数65%将7个站位划分为2组,与按照水深划分的陆架和陆坡组基本吻合;单因素相似性分析(one-way ANOSIM)显示陆架和陆坡区小型底栖动物群落结构差异显著;生物-环境分析(Biota-Environment,BIOENV)表明影响群落结构的最佳环境因子组合为叶绿素a和底层水温。综上可知,随水深增加的食物减少和底层水温的下降是限制南海北部研究海域小型底栖动物丰度和生物量及影响群落组成和结构的主要因素。     

Rock Physics Modeling and Reservoir Characterization to Estimate Hydrocarbon Zone of Cretaceous and Paleocene Strata and Subsurface Stratigraphic Correlation of Sulaiman Fold Belt to Sulaiman Depression

Doklady Earth Sciences - The research work involves rock physics modeling and reservoir characterization of Suliman fold belt to sulamain fold depression. This area is a brighter zone for...     

Adsorption capacity and mineralogical and physico-chemical characteristics of Shuwaymiyah palygorskite (Oman)

In this paper, Shuwaymiyah palygorskite in the Sultanate of Oman has been characterized mineralogically by X-ray diffraction (XRD) and electron microscopy, chemically by oxide compositions, structural formulae, and cation exchange capacity (CEC), and physically by specific surface area and adsorption isotherms. Batch adsorption studies were performed to evaluate the adsorption performance of methylene blue (MB) basic dye on the local clay mineral. The quantitative XRD analysis indicates that the purity of some selected samples of palygorskite clay is very high (about 70% of the clay minerals are palygorskite and 30% kaolinite). The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images clearly support this conclusion. The adsorption equilibrium revealed that Shuwaymiyah palygorskite clay can uptake up to 51 mg of MB per 1 g mass of clay. MB adsorption is best fitted by Langmuir isotherm, and a pseudo-second-order kinetic model can be efficiently used to predict the kinetic of adsorption of MB by the palygorskite. The results obtained from these laboratory-scale adsorption tests indicate the promising adsorption capability of the Omani palygorskite.     

Reevaluation of the earthquakes of 10 March and 19 May 1951 in southern Spain

Damage and parameters of the earthquakes of 10 March and 19 May 1951 in southern Spain have been reevaluated. Data available do not allow accurate depth determinations and previous estimates of larger depths are not confirmed, so depths have been fixed at 30 km for both shocks. Magnitudes (Ms) have been determined as 5.4 and 5.6, respectively. Intensities estimated at 22 and 29 sites from contemporary documentary sources give maximum values of VI–VII and VI (EMS Scale), lower than previous estimates. The focal mechanism for the May shock is right-lateral strike-slip with a normal component of motion, with planes with strikes 273° and 169°; seismic moment 1.9 × 10¹⁶ Nm and dimension 6 km (radius of circular fault). Shocks are located near the boundary between the Iberian plateau and the Guadalquivir Basin and may be related to faults connected with this boundary.