Triple diagram method for the prediction of wave height and period

Many formulations have been developed so far to predict the wave height and period from fetch length and wind blowing duration for a constant wind speed. This study aimed to predict wave parameters from fetch length and meteorological factors by using triple diagram methodology based on Kriging principles. Proposed model results were compared with Joint North Sea Wave Project (JONSWAP) model which is used so commonly in the ocean and coastal engineering studies. For the implementation of the methodology hourly wave and wind data were obtained from a buoy located in Lake Ontario. Numerical and graphical comparisons demonstrated that the proposed method outperforms the classical formulation.     

Structure and Quaternary tectonic history of the Woodlark triple junction region,Solomon Islands

The Woodlark triple junction region, a topographically and structurally complex triangular area of Quaternary age, lies east of Simbo Ridge and southwest of the New Georgia island group, Solomon Islands, at the junction of the Pacific, Australian and Solomon Sea plates. SeaMARC II side-scan imagery and bathymetry in conjunction with seismic reflection profiles, 3.5 kHz records, and petrologic, magnetic and gravity data show that the active Woodlark spreading centre does not extend into this region.South of the triple junction region, the Woodlark spreading centre reoriented at about 2 Ma into a series of short ESE-trending segments. These segments continued to spread until about 0.5 Ma, when the lithosphere on their northern sides was transferred from the Solomon Sea plate to the Australian plate. Simultaneously the Simbo transform propagated northwards along the western side of the transferred lithosphere, forming a trench-trench-transform triple junction located NNW of Simbo island and a new leaky plate boundary segment that built Simbo Ridge.As the Pacific plate approached, the area east of northern Simbo Ridge was tilted northwards, sheared by dominantly right-lateral faults, elevated, and intruded by arc-related magmas to form Ghizo Ridge. Calc-alkalic magmas sourced beneath the Pacific plate built three large strato-volcanic edifices on the subducting Australian plate: Simbo at the northern end of Simbo Ridge, and Kana Keoki and Coleman seamounts on an extensional fracture adjoining the SE end of Ghizo Ridge.A sediment drape, supplied in part from Simbo and Kana Keoki volcanoes, mantles the east-facing slopes of northern Simbo and Ghizo Ridges and passes distally into sediment ponded in the trench adjoining the Pacific plate. As a consequence of plate convergence, parts of the sediment drape and pond are presently being deformed, and faults are dismembering Kana Keoki and Coleman seamounts.The Woodlark system differs from other modern or Tertiary ridge subduction systems, which show wide variation in character and behaviour. Existing models describing the consequences of ridge subduction are likely to be predictive in only a general way, and deduced rules for the behaviour of oceanic lithosphere in ridge subduction systems may not be generally applicable.     

Propagation of the Southwest Indian Ridge at the Rodrigues Triple Junction

The analysis of multibeam bathymetric data of the Southwest Indian Ridge(SWIR) domain between the triple junction traces from 68° E to theRodrigues Triple Junction (RTJ; 70° E) reveals the evolution of thisridge since magnetic anomaly 4 (8 Ma). Image processing has been used toshow that the horizontal component of strain due to a network of normal stepfaults increases dramatically between 69°30 E and the RTJ. Thisarea close to the RTJ is characterized by a deep graben at the foot of thetriple junction trace on the African plate and by a narrow fault-boundedridge that joins an offset of the trace on the Antarctic plate. In thatarea, spreading is primarily amagmatic and dominated by tectonic extensionprocesses. To the west of 69°30 E, some lobate bathymetricfeatures atop of a large topographic high suggest volcanic constructions.Between 68°10 E and 69°25 E the southern flank of theSWIR domain is wider than the northern one and is characterized by a series of 7 en echelon bathymetric highs similar in size,shape and orientation to the one centred at 69°30E near the present-day triple junction. Their en echelon organization along the triple junction trace on the Antarctic plate and the typical lack of conjugated parts on the northern flank show that these bathymetric highs have been shifted to the south by successive northward relocalisations of the SWIR rifting zone. This evolution results in the asymmetric spreading of the SWIR in the survey area. The off-axis bathymetric highs connect to the offsets of the triple junction trace on the Antarctic plate when the Southeast Indian Ridges lightly lengthenstoward the northwest and the triple junction is relocated to the north. We propose that the SWIR lengthens toward the northeast with two propagation modes: 1) a continuous and progressive propagation with distributed deformation in preexisting crust of the Central Indian Ridge, 2) a discontinuous propagation with focusing of the deformation in a rift zone when the triple junction migrates rapidly to the north. The modes of propagation of the SWIR are related to different localisation and distribution of strain which are in turn controlled by changes of the triple junction configurations due to propagation, recession or a symmetric spreading on the Central and Southeast Indian Ridges.     

Estimation of Water Particle Velocities by Empirical Transfer Function

-In previous and this studies it appears that the linear and nonlinear wave theory can notaccurately and easily predict the water particle velocities.Therefore,different from the theoretical consider-ations,in this study we have attempted to determine the transfer function empirically.Laboratory experi-ments were performed under various wave conditions.The empirical formulas of the transfer function ofthe wave height,angular frequency and water particle velocity were obtained on the basis of these test databy dimensional analysis and regression analysis.In intermediate and deep water depth conditions,thetransfer function was only a function of a nondimensional parameter which is composed of the angular fre-quency,the depth of the velocity gauge under the still water level,water depth and the acceleration of grav-ity.Finally,the empirical formulas were compared with experimental data and observational data formpresent and Cavaleri's(1978)studies.The empirical formulas were found to be in sufficient correl     

GPS载波相位三差观测方程的改化

本文根据相关测量平差原理推导出改化ＧＰＳ载波相位三差观测方程的算法，使改化后的协因数呈分块对角体。这种改化算法不但顾及观测值的相关性，而且节省大量的存储单元。使采用严密平差法平差三差观测值成为一种最简单的数据处理方法之一。     

Seafloor spreading, obduction and triple junction tectonics of the Mineoka Ophiolite, Central Japan

The Tertiary Mineoka ophiolite occurs in a fault zone at the intersection of the Honshu and Izu forearcs in central Japan and displays structural evidence for three major phases of deformation: normal and oblique-slip faults and hydrothermal veins formed during the seafloor spreading evolution of the ophiolite at a ridge-transform fault intersection. These structures may represent repeated changes in differential stress and pore-fluid pressures during their formation. The second series of deformation is characterized by oblique thrust faults with Riedel shears and no significant mineral veining, and is interpreted to have resulted from transpressional dextral faulting during the obduction of the ophiolite through oblique convergence and tectonic accretion. This deformation occurred at the NW corner of a TTT-type (trench–trench–trench) triple junction in the NW Pacific rim before the middle Miocene. The third series of deformation of the ophiolite is marked by contractional and oblique shear zones, Riedel shears, and thrust faults that crosscut and offset earlier structures, and that give the Mineoka fault zone its lenticular (phacoidal) fabric at all scales. This deformation phase was associated with the establishment and the southward migration of the TTT Boso triple junction and with the kinematics of oblique subduction and forearc sliver fault development. The composite Mineoka ophiolite hence displays rocks and structures that evolved during its complex geodynamic history involving seafloor spreading, tectonic accretion, and triple junction evolution in the NW Pacific Rim.     

Recent advances in (soil moisture) triple collocation analysis

To date, triple collocation (TC) analysis is one of the most important methods for the global-scale evaluation of remotely sensed soil moisture data sets. In this study we review existing implementations of soil moisture TC analysis as well as investigations of the assumptions underlying the method. Different notations that are used to formulate the TC problem are shown to be mathematically identical. While many studies have investigated issues related to possible violations of the underlying assumptions, only few TC modifications have been proposed to mitigate the impact of these violations. Moreover, assumptions, which are often understood as a limitation that is unique to TC analysis are shown to be common also to other conventional performance metrics. Noteworthy advances in TC analysis have been made in the way error estimates are being presented by moving from the investigation of absolute error variance estimates to the investigation of signal-to-noise ratio (SNR) metrics. Here we review existing error presentations and propose the combined investigation of the SNR (expressed in logarithmic units), the unscaled error variances, and the soil moisture sensitivities of the data sets as an optimal strategy for the evaluation of remotely-sensed soil moisture data sets.     

Intraplate seismicity in the western Bohemian Massif (central Europe): A possible correlation with a paleoplate junction

Locations of the Eger Rift, Cheb Basin, Quaternary volcanoes, crustal earthquake swarms and exhalation centers of CO₂ and ³He of mantle origin correlate with the tectonic fabric of the mantle lithosphere modelled from seismic anisotropy. We suggest that positions of the seismic and volcanic phenomena, as well as of the Cenozoic sedimentary basins, correlate with a “triple junction” of three mantle lithospheres distinguished by different orientations of their tectonic fabric consistent within each unit. The three mantle domains most probably belong to the originally separated microcontinents – the Saxothuringian, Teplá-Barrandian and Moldanubian – assembled during the Variscan orogeny. Cenozoic extension reactivated the junction and locally thinned the crust and mantle lithosphere. The rigid part of the crust, characterized by the presence of earthquake foci, decoupled near the junction from the mantle probably during the Variscan. The boundaries (transitions) of three mantle domains provided open pathways for Quaternary volcanism and the ascent of ³He- and CO₂-rich fluids released from the asthenosphere. The deepest earthquakes, interpreted as an upper limit of the brittle–ductile transition in the crust, are shallower above the junction of the mantle blocks (at about 12 km) than above the more stable Saxothuringian mantle lithosphere (at about 20 km), probably due to a higher heat flow and presence of fluids.     

Hydraulic parameters and solute velocities in triple-porosity karstic-fissured-porous carbonate aquifers: case studies in southern Poland

 Rock and flow parameters of three karstic-fissured-porous aquifers in the Krakow-Silesian Triassic formations were measured using various methods and compared. Though cavern and fissure porosities are shown to be very low (cavern porosity below 0.5% and fracture porosity below 0.2%), they contribute dominantly to the hydraulic conductivity (from about 1.3×10^–6 to about 11×10^–6 m/s). Matrix porosity (2–11%) is shown to be the main water reservoir for solute transport and the main or significant contributor to the specific yield (<2%). Though the matrix porosity is shown to be much larger than the sum of the cavern and fissure porosities, its contribution to the total hydraulic conductivity is practically negligible (hydraulic conductivity of the matrix is from about 5×10^–11 m/s to about 2×10^–8 m/s). On the other hand, the matrix porosity (for neglected cavern and fissure porosities) when combined with tracer ages (or mean travel times) is shown to yield proper values of the hydraulic conductivity (K) by applying the following formula: K≅(matrix porosity×mean travel distance)/(mean hydraulic gradient×mean tracer age). Confirming earlier findings of the authors, this equation is shown to be of great practical importance because matrix porosity is easily measured in the laboratory on rock samples, whereas cavern and fracture porosities usually remain unmeasurable. Received: 21 February 1997 · Accepted: 13 May 1997     

中国及邻区重力特征与块体构造单元初划

以重力资料为基础,结合其分析结果和区域地质构造现象,以及前人研究成果,在总结中国海陆地质地球物理系列图编制项目组和前人对中国岩石圈三维结构宏观特征研究成果基础上,将块体构造理论应用于解释中国海陆宏观大地构造格架,并将其划分为3个构造域和20多个块体。对3个构造域及块体构造单元特征进行了分析,指出印支运动使中国岩石圈应力场发生了根本性变化,并为现今宏观大地构造格局的形成创造了条件。