Distribution Functions of Tsunami Wave Heights

The problem of describing the distribution functions of tsunami wave heights is discussed. Data on runup heights obtained in field surveys of several tsunamis for the last decade are used to calculate the empirical distribution functions. It is shown that the log-normal distribution describes the observed data well. This means that the irregular topography and coastline are major factors which influence the height distribution. The power distribution related with the geometric decay of the propagated wave is a good approximation for one event (Sulawesi, January 1, 1996) only. Results of a numerical simulation of the tsunami event in the Japan (East) Sea on July 12, 1993 are presented. It is shown that the computed wave height distribution, obtained by using the runup correction in the framework of nonlinear shallow-water theory, is in good agreement with the observed height distribution. Simulations are used to study the transformation of the distribution function on different distances from the source.     

An analysis of phytolith assemblages for the quantitativereconstruction of late Quaternary environments of the Lower Taieri Plain,Otago, South Island, New Zealand II. Paleoenvironmentalreconstruction

Fossil phytolith assemblages from a 154.5 m longdrillcore from the Lower Taieri Plain, Otago, New Zealand are presented. Transferfunctions, based on modern phytolith assemblages from sites within the sameregion, were applied to the fossil phytolith data set, and validated usingModern Analogue Technique (MAT) assemblage matching. Analogues for much of theHolocene and some of the Last Interglacial (provisionally Oxygen Isotope Stage5c) were obtained. Late Glacial/Holocene precipitation and pH estimates areconsistent with other paleoclimate records from the Otago region. Thephytolith-based precipitation and pH estimates may act as a combined proxy forsoil weathering. The precipitation estimates may also act as a useful index ofEffective Precipitation (EP). Temperature estimates derived have limited usefor paleoclimate interpretation. Estimates produced for the mid-Holoceneindicate a wetter environment than the present (50–100 mmgreater EP) with increased soil weathering (high precipitation/low pH). Soilconductivity estimates were below estuarine levels during a diatom inferredmarine transgression. This lack of phytolith response to conductivity changesis put down to a probable delayed development of suitable habitats forsaltmarsh plant species during the rapid transgression. The Last Interglacialestimates indicate conditions somewhat drier (200 mm less EP) thanthe Holocene. Consistently low log conductivity (below 0.7 µScm) estimates from the Last Interglacial contrast with the estuarineenvironments of the Holocene, indicating freshwater conditions in the Plainduring at least part of the Last Interglaciation.     

Li,K/Cl,SO_4-H_2O体系相平衡的热力学

介绍了根据自己研究测定的Ｌｉ，Ｋ／Ｃｌ，ＳＯ４－Ｈ２Ｏ体系２５℃的渗透系数等热力学性质获得的Ｐｉｔｚｅｒ混合参数，并用自由能最小化方法计算了２５℃ Ｌｉ，Ｋ／Ｃｌ．ＳＯ４－Ｈ２Ｏ体系的相图。结合测定得到的该体系５０℃、７５℃的相图和复盐ＬｉＫＳＯ４转变温度的研究，整个体系相平衡和热力学的研究结果可用于盐湖卤水中锂盐的分离提取。     

一种激光厚度测量方法的研究

阐述了利用激光器、图像传感器进行非接触厚度自动测量的原理。实验表明该方法具有实时性能好，测量重复精度较高等优点     

超定边值问题的样条解法

正在进行和即将进行的大量GPS＋Levelling测量使得大地水准面也成为直接观测量，因此经典的Molodensky天文重力准已经不能适应这一情况。为了从更广泛的意义上更好地利用各类观测值，本文使用样条函数作为基函数，讨论了局部地区超定边值问题的样条解法。     

Characteristic behavior and order relations for indicator variograms

Heuristic models for indicator variograms and their parameters (practical nugget effect and range) are proposed for a bivariate normal distribution with spherical correlogram. These models can be used conveniently as a preliminary check for bivariate normality. In the general non-Gaussian case, indicator variogram models for multiple threshold values must verify a certain number of order relations (inequalities) established directly from the properties of a general bivariate cumulative distribution function. An interesting, little-known maximum hole effect for indicator correlation is pointed out.     

Positive definiteness is not enough

Geostatisticians know that the mathematical functions chosen to represent spatial covariances and variograms must have the appropriate type of positive definiteness, but they may not realize that there are restrictions on the types of covariances and variograms that are compatible with particular distributions. This paper gives some examples showing that (1) the spherical model is not compatible with the multivariate lognormal distribution if the coefficient of variation is 2.0 or more (even in 1-D), and (2) the Gaussian covariance and several other models are not compatible with indicator random functions. As these examples concern quite different types of random functions, it is clear that there is a general problem of compatibility between spatial covariance models (or variograms) and a specified multivariate distribution. The problem arises with all distributions except the multivariate normal, and not just the two cited here. The need for a general theorem giving the necessary and sufficient conditions for a covariance or a variogram to be compatible with a particular distribution is stressed.     

Reflection and refraction of plane harmonic waves at an interface between elastic solid and porous solid saturated by viscous liquid

A general solution of Biot's field equations governing small motions of a porous solid saturated by viscous liquid is employed to study the reflection and refraction at the interface between an elastic solid and a liquid-saturated porous solid. The incident wave is assumed to be plane and homogeneous, propagating through the isotropic elastic solid. The poroelastic solid is considered to be a dissipative one. Amplitude and energy ratios are computed numerically for a particular model. With first-order corrections for the porosity of solid and viscosity of liquid, the limiting cases of low and high frequencies are computed.     

Simulation of geological surfaces using fractals

Methods suggested in the past for simulated ore concentration or pollution concentration over an area of interest, subject to the condition that the simulated surface is passing through specifying points, are based on the assumption of normality. A new method is introduced here which is a generalization of the subdivision method used in fractals. This method is based on the construction of a fractal plane-to-line functionf(x, y, R, e, u), where(x, y) is in[a, b]×[c, d], R is the autocorrelation function,e is the resolution limit, andu is a random real function on [–1, 1]. The simulation using fractals escapes from any distribution assumptions of the data. The given network of points is connected to form quadrilaterals; each one of the quadrilaterals is split based on ways which are extensions of the well-known subdivision method. The quadrilaterals continue to split and grow until resolution obtained in bothx andy directions is smaller than a prespecified resolution. If thex coordinate of theith quadrilateral is in[a _i ,b _i ] and they coordinate is in[c _i ,d _i ], the growth of this quadrilateral is a function of(b _i –a _i ) and(d _i –c _i ); the quadrilateral could grow toward the positive or negativez axis with equal probability forming four new quadrilaterals having a common vertex.This paper was presented at Emerging Concepts, MGUS-87 Conference, Redwood City, California, 13–15 April 1987.