Stochastic Modeling of Short Term Variations of Sea Level in Eastern Canada     

Karim Hilmi  Mohammed I. El-Sabh  Jean-Pierre Chanut  Tad Murty 《Marine Geodesy》2013,36(3):197-218

Hourly sea level records from three stations in eastern Canada (Québec-Lauzon, Harrington-Harbour and Halifax) are analyzed both in frequency domain from 1970 to 1979 and in time domain during 1973. At the three stations, the deterministic model explains 90 to 96% of the total variability of sea level. The semidiurnal and diurnal tides contribute largely to its variations. The residual series, less than 10% of the initial variations of sea level, contain irregular values including extreme values of seiches and storm surges. Such random variations are analyzed and modeled following the method described by Box and Jenkins (1976). The long period variations (2 to 30 days) can be attributed to meteorological forcing (atmospheric pressure and winds). The short period variations (some hours to one day) can be attributed to longitudinal seiches, semidiurnal and diurnal atmospheric tides, and inertial oscillations. The water discharge from the St. Lawrence River contributes 29% of the monthly residual sea level at Qué  相似文献   

Bathymetry Data Correction Using Global Optimization Method     

Atanu Basu  N. K. Saxena 《Marine Geodesy》2013,36(1-2):37-60

The bathymetry data of marine bodies have been collected over a century, and the collected data have a wide range of resolution and accuracy. Acquisition of bathymetry data is very costly and time-consuming. One can use the old, low-quality bathymetry data to fill the gap in high-quality, recently acquired bathymetry data after correcting the old data to improve its quality so that it is comparable to the high-quality data. The old data correction can be treated as a nonlinear inverse problem. Simulated annealing (SA) global optimization method was used here in solving this problem. The two sets of data that were used are project survey (PS) and Vietnamese Navy Chart (VNC) data. The PS data were collected in 2000 in an offshore survey from the Vietnam coast in the South China Sea (SCS). The VNC data were obtained by digitizing VNC that was published in 1981. Inverse distance weighted (IDW) interpolation method was used for forward modeling. Weperformed the SA algorithm run starting at a high "temperature," then lowering the "temperature" gradually up to the "critical temperature" and then staying there for the rest of the run. The best model chosen by the algorithm showed an improvement of 63% from the original model. We then constructed a digital bathymetry model (DBM) of the study area with the combined corrected VNC and the PS data.  相似文献   

小秦岭金矿田中生代构造演化与矿床形成   总被引：23，自引：4，他引：23  

张进江  郑亚东  刘树文 《地质科学》2003,38(1):74-84

作为中国金矿主产地之一,小秦岭变质核杂岩经历两期不同性质的伸展。第一期为沿周缘拆离断层发育、方向与造山带平行的同造山伸展,上盘向WNW运动,活动时代为距今135～123Ma,属燕山期陆内造山形成的地壳增厚和岩浆活动共同作用的结果。第二期为退化变质糜棱岩带和正断层组成的变质核杂岩内部伸展构造,代表造山后进一步隆升导致的垮塌,时代为距今120～106Ma。小秦岭变质核杂岩内部发育与垮塌伸展同期的挤压性逆冲断层,由造山后残余挤压作用和构造剥蚀导致的伸展驱动力降低所致。小秦岭中蚀变千糜岩型金矿受退化变质糜棱岩带控制,成因为典型的伸展控矿机制,石英脉型金矿产于内部逆冲断层,成矿机制与小秦岭变质核杂岩垮塌伸展过程中的构造反转相关。  相似文献   

南口前中生代花岗岩成因特征     

卢崇海 《国土资源》1988,(4)

抚顺南口前中生代花岗岩是重熔型花岗岩,成岩物质源自深部地壳。花岗质岩浆经过多次脉动和涌动形成具有套迭式构造特征的杂岩体。在花岗质岩浆形成和演化过程中,由于岩浆挥发组分的活动,使金元素发生活化、迁移和富集而形成金矿床。  相似文献   

Population biology of the portunid crab Callinectes arcuatus Ordway in the Gulf of Nicoya,Costa Rica,Central America     

Ana I. Dittel  C.E. Epifanio  Juan Bautista Chavarria 《Estuarine, Coastal and Shelf Science》1985,20(5):593-602

Tropical blue crabs Callinectes arcuatus were collected by trawling in the Gulf of Nicoya on the Pacific coast of Costa Rica, Central America. The gulf population was generally dominated by females. Adult females were common in the upper, more estuarine regions of the gulf during rainy season, but appeared to migrate to the lower gulf during dry season for spawning. Biomass varied with seasonal changes in abundance, but was generally similar to biomass of C. sapidus in Chesapeake Bay. Analysis of size frequency indicated that the population is numerically dominated by adults during January and February and that juveniles are common during the remainder of the year. Extrapolation of available data suggests that female crabs reach maturity in approximately one year after hatching.  相似文献   

Hydrocarbons in the sediments of Port Valdez,Alaska: Consequences of five years' permitted discharge     

David G. Shaw  Thomas E. Hogan  Douglas J. McIntosh 《Estuarine, Coastal and Shelf Science》1985,21(2):131-144

Hydrocarbons have been investigated in the sediments of Port Valdez, Alaska after three to five years of oil terminal operation with a routine daily discharge of 170 kg of petroleum residue in an otherwise undeveloped area. Surficial benthic sediments (0–5 cm) and core segments down to 30 cm have been analyzed. Information about total hydrocarbons, unresolved complex mixture, normal alkanes, pristane, phytane, hopanes and polycyclic aromatic hydrocarbons indicates that petroleum, biogenic hydrocarbons, and combustion-derived aromatic hydrocarbons are present in sediments around the terminal at concentrations up to 218 μg g^?1 dry sediment. The vertical, horizontal and temporal distributions of anthropogenic hydrocarbons indicate that most of the sedimentary hydrocarbon accumulation has occurred within 1 km of the terminal. A simple calculation suggests that less than 3% of the total oil discharged during routine operations of the terminal has entered the sediments of Port Valdez. For comparison sediment hydrocarbon accumulation associated with a nearby small boat harbor was also examined.  相似文献   

应用聚类和因子分析讨论猫岭金矿元素组合特征     

孔繁华 《国土资源》1989,(2)

猫岭金矿是一低品位、大型热液型金矿床。金矿体主要以脉状、似层状、透镜状产于下元古界辽河群盖县组二段的千枚岩中,受北北东向片理化带及低序次构造裂隙所控制。矿床原生晕样品的 R 型聚类分析和因子分析的结果表明,与金矿化关系最密切的元素为 Pb、Ag,其次为 As。即 Au、Pb、Ag 代表了主成矿阶段矿化元素组合特征,而 As 和 Co、Ni 元素组合分别反映了与 Au 矿化具成因联系的毒砂和磁黄铁矿化特点。(Au、Pb、Ag)因子与(As、Ag)因子紧密相关,与宏观上所见矿化阶段生成的矿物(自然金、方铅矿等)沿毒砂裂隙分布的特点相吻合,从而说明这两个因子的元素组合代表了最佳成矿地段的元素组合特征。  相似文献   

桂东金矿床的成因矿物学研究     

刘腾飞 《南方国土资源》1996,(3)

桂东金矿产于寒武系水口群浅变质砂页岩内，石英和黄铁矿是各类金矿中主要的载金矿物。成因矿物学标型特征表明，矿床可分为变质热液、岩浆热液和复合迭加型，以后者为主。据硫、铅、氢、氧同位素组成特征，结合石英的含金性、晶胞参数和热发光性及黄铁矿微量元素等成因信息，论证了成矿物质来源、成矿流体性质与成矿的关系。金的富集是处于造山带构造环境，经历加里东运动及其以后构造—岩浆活动多次迭加的长期演化结果。据矿物的标型特征和控矿条件，认为各矿区深部、外围及该区东南部应作为今后进一步找矿的远景地区  相似文献   

浑北太古宙南龙王庙金矿床的成矿物质来源     

戴仕炳  刘连登 《国土资源》1989,(3)

浑河断裂以北的南龙王庙太古宙绿岩带金矿床是我国已知的最古老的后生金矿床,形成于晚太古宙(约2.6Ga)。深构相的韧性剪切带严格控制了金矿体,金矿体为剪切带的一部分。浑北绿岩金含量较低,平均为2.2ppb,但绿岩和矿石的微量金与铜、银、锌的相关性一致;它们的 As、Sb 等15种元素的克拉克值标准化曲线和谐,稀土元素球粒陨石标准化图谱及 LREE/HREE 比值两者相近。上述特征反映金源自绿岩(不同深度相)。包(?)同位素接近于变生热液,包体成分以低盐度、富 CO_2为特征。硫、铅同位素证明矿质源自绿岩。南龙王庙金矿床属同韧性剪切带变生热液金矿床。南龙王庙金矿的研究对我国寻找太古宙绿岩带金矿床有重要的参考意义。  相似文献   

辽南隈子金矿矿床地质特征及其成因探讨     

申少华  裴喜 《国土资源》1994,(4)

隈子金矿产于似斑状黑云母花岗岩所包围的辽河群盖县组残留体中，矿脉明显受层间断裂控制。矿石特征，硫、氧同位素，包裹体及红外光谱综合研究表明：隈子金矿床属中－高温成矿，成矿流体呈重熔岩浆热液特征。因此，该矿床是重熔岩浆热液矿床。  相似文献