Sea Levels and Western Boundary Flow Near a Tectonic Zone in the Northern Pacific

This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake.     

A Crustal Upheaval in a Coastal Zone After Ocean Water Loading

A crustal upheaval in a coastal zone is studied by introducing a simplified theoretical model of an equivalent elastic plate on which oceanic water is acting as a static loading. With a solution for the plate, the author notes what is seen as a crustal upheaval under the loading of static oceanic water in a qualitative scope. The solution requires some assumed parameters for the plate and the loading. Some other conditions should be also given to realize a possible dynamical understanding of a sea level rise seen after global climatological warming and glacial melting.     

安德拉水位计测量中水位值计算的误差分析和估算

在安德拉水位计的实际应用中,除由压力测量引起的水位测量误差外,在水位数据的计算中,也存在着误差因素。本文分析了这些因素的误差分量,并粗略地估算了它们的大小;由此提出了参与水位值计算的几个主要订正参数的选值方法。     

遥墙机场环境噪声影响预评价

采用有效感觉噪声级Ｌｅｐｎ作为单个事件的评价量，用计权等效连续感觉噪声级Ｌｗｅｃｐｎ作为一段时间内多个事件的评价量，介绍了机场环境噪声影响预测的完整程序和方法。给出了遥墙机场１９９５年度的预测结果。     

A harmonic approach to global ocean tide analysis based on TOPEX/Poseidon satellite

The constant and harmonic parts of the global ocean tide are modeled by up to nine major tidal constituents, namely, S2, M2, N2, K1, P1, O1, Mf, Mm, and Ssa. Our computations start with the Fourier sine and cosine series expansion for the tidal constituents, including the constant Mean Sea Level (MSL). Although the frequencies of the tidal constituents are considered known, the coefficients of the sine and cosine functions are assumed to be unknown. Subsequently, the coefficients of the sine and cosine functions, as well as the constant part of the Fourier expansion, were expanded into spherical harmonics up to degree and order n, where n corresponds to the number of linearly independent spherical harmonic base functions needed to model the tidal constituents, determined via independent columns of the Gram matrix. The unknown coefficients of the spherical harmonic expansions are computed using sea level observations within cycles #1–#350 of the TOPEX/Poseidon satellite altimetry over 11 years of its mission. A set of orthonormal base functions was generated for the marine areas covered by TOPEX/Poseidon observations from the spherical harmonics using a Gram-Schmidt orthogonalization process. These were used for modeling the dominant tidal constituents. The computed models based on orthonormal base functions for the nine tidal constituents and the constant part of the Fourier expansion, were tested numerically for their validity and accuracy, proving centimeter accuracy.     

Technical Issues and Recommendations Related to the Installation of Continuous GPS Stations at Tide Gauges

Geodesists around the world have begun installing continuous GPS (CGPS) stations at tide gauges in order to determine the exact position of these tide gauges and, in particular, the vertical velocity of the land or the seafloor underlying each tide gauge. The goal is to make these measurements in a well-defined global reference frame. The scientific applications of these measurements include the calibration of satellite altimeters and the removal of crustal motion signals from long time series of sea level change. In this article we focus on the technical issues associated with this agenda, including site selection, instrumentation, monumentation, ancillary measurements, and the tide gauge leveling program. There is no universally best approach to building CGPS stations at tide gauges. Therefore we emphasize the various trade-offs that typically occur, and give general recommendations and rules of thumb based on recent installations and experience. Additional information can be found at the CGPS@TG website.     

应用Level Set方法模拟三维气泡与液滴的运动

将Level Set方法与ICE数值格式相结合,建立了求解含有运动界面的不可压缩气液两相流动问题的三维模型及数值解法。应用所建立的模型和算法三维模拟了4种典型气泡和液滴的运动过程,包括气泡从单个喷嘴生成和上升的过程,两个大小不同的空气气泡在水中自由上升时的相互作用过程,水滴下落冲击水面的过程和水滴与颗粒正向等温碰撞过程。模拟结果表明,所建立的模型与算法能准确方便地捕捉到三维气泡和液滴界面的破碎与融合等拓扑结构的变化,说明Level Set方法是一种行之有效且大有前途的处理气液运动界面问题的方法。     

细胞自动机的多重分形特征和动力学根源

用大量弹簧滑块组成的模型可以模拟地震的复杂性，本文以细胞自动机（ＣＡ）为数学工具，结合地震学和岩石力学的结果，考虑了能量的输入和损耗，进行了地震事件的数字模拟。对模型中输出的“地震”事件进行了时间和空间的多分形分析，并对自组织临界（ＳＯＣ）状态进行了讨论，进而得到事件至少在时间域里的分布呈现出层次结构，符合自相似特征。本文的ＣＡ模型属于确定性的混沌系统，而对于处在ＳＯＣ状态下的大量事件的频度和大小的统计与Ｇ－Ｒ指数律很好地吻合。结果表明，虽然自组织（ＳＯ）可能是更准确的地震表征，但ＳＯＣ仍然是研究地震现象的很好的模式。     

共和地震前兆起伏加剧的层次性与大震的跟踪预报

基于大震前前兆起伏加剧具有普适性的特征，本文研究了１９９０年共和Ｍｓ７．０地震前地震频次、小震调制比、地下水中氧含量及泉水流量等异常起伏加剧的多层次性。结果表明，各台大多数前兆异常可分出３个层次。综合分析各台前兆异常的起伏加剧现象，可以发现，该次地震前异常群体的演变过程可分为４个层次，本文结合孕震过程对４个层次进行了分析。根据大震前兆起伏加剧的多层次性可以对大震进行跟踪预报。     

地震活动性层次结构分析及危险区预测方法

对地震活动性进行层次结构分析可划分出不同的地震区带,中国大陆的地震活动可分为9个地震区带,分析各个区带的地震活动性可作出某一活跃期强震发生主体地区的判别,对某一个地震区带的地震活动进行层次结构分析可作出地震危险区预测。用震源面投影图代替点投影的震中分布图可更合理地解释一个构造带上强震的发生过程,更清楚地勾画出未来强震的孕震范围。对强震破裂区闭锁段、背景空区、孕震空区的关系用实测震例进行了解释。