利用SAR图像计算内波深度和振幅的可行性研究

根据星载合成孔径雷达(SAR)内波成像机理,建立了包括KdV方程、作用量谱平衡方程和Bragg散射模型在内的内波深度和振幅探测模型,更为严谨地推导出用SAR图像计算内波深度的方法,并首次推导出内波振幅的计算方法.利用该方法对台湾东北部海域的两幅ERS-1 SAR内波图像进行了实例研究,结果表明,该方法是合理且可行的.     

Generalized Nonlinear Subcritical Symmetric Instability

Starting from nonlinear equations on the f-plane containing frictional dissipation under the Boussinesq approximation, a new kind of generalized energy is proposed as the Lyapunov function, and averages are taken as any functions of (x, z) instead of the commonly-used means of bilinear functions of (x, z), thereby resulting in a new criterion of generalized nonlinear symmetric stability. It shows that not only must the dissipative coefficient be greater than a certain critical value but the initial disturbance amplitude must be synchronously smaller than another marginal value as well. It follows that the latter imposes a crucial constraint on the former, thus leading to the fact that when the amplitude is bigger compared to another critical value, generalized nonlinear subcritical symmetrical instability may occur. The new criterion contributes greatly to the improvement of the previous results of its kind.     

利用逆散射理论改善迭前深度偏移的振幅保护

一张迭前逆时间偏移图像没随深度增加适当地按比例成图。没按比例成图的图像的主要原因是测量资料的反向传播期间和正演模型波场的产生期间生成的波场的几何扩散。通过按比例放大在高斯——牛顿最优化技术中出现的近似海赛矩阵的倒数，这种未按比例的图像可以得到增强。但是，由于近似海赛矩阵计算一般地质模型的费用太贵，所以它只能用于简单背景的速度模型。     

我国南海海面高异常时间序列分析

利用小波多分辨分析方法对1992年10月至2002年8月南海区域海面高异常时间序列进行了分析处理,提取了该区域海面高线性升高信息.结果表明,南海区域在9.86 a的时间里海面高平均升高了94.1 mm;并获取了从2 a至45 d的5种波动传播的振幅和相位,分析了波动传播的概貌.     

3类地倾斜仪地球固体潮的潮汐响应特征及其差异

选用宜昌地震台DSQ水管倾斜仪、VS型垂直摆倾斜仪、VP型垂直摆倾斜仪2018-01-01~10-14整点观测数据,采用Nakai逐日拟合计算结果中的潮汐振幅比A和非数字滤波调和分析计算结果中的M₂波潮汐因子A_M2,对比分析这3类仪器对地倾斜固体潮的振幅响应特征。结果表明,该台NS分量潮汐振幅比只相当于EW分量的90%;1~9月M2波潮汐因子的月结果中误差小于0.02;给出6个分量9个月的54个潮汐因子结果,它们的中误差小于等于0.02;同一分量9个月结果（潮汐因子）之间的极差小于等于8.3%,离散相对中误差小于2.8%。     

利用SH波和P波振幅比测定中小地震的震源机制

用SH波和P波振幅比测定地震震源机制具有诸多优点,但它对台站布局要求较高。通过适当处理资料,降低该方法对台站分布的依赖程度,用此方法测定了几个地震的震源机制解并与其它方法得出的震源机制解进行了分析对比,结果表明,这样处理是可行的,一般只要有5个以上台站(震中距<120 km)记录到的地震都可以反演出较合理的震源机制解。     

Effect of source parameters on forward-directivity velocity pulse for vertical strike slip fault in half space

It has been found that the large velocity pulse is one of the most important characteristics of near-fault strong ground motions. Some statistical relationships between pulse period and the moment magnitude for near-fault strong ground motions have been established by Somerville （1998）; Alavi and Krawinkler （2000）; and Mavroeidis and Papageorgiou （2003）, where no variety of rupture velocity, fault depth, and fault distance, etc. were considered. Since near-fault ground motions are significantly influenced by the rupture process and source parameters, the effects of some source parameters on the amplitude and the period ofa forward-directivity velocity pulse in a half space are analyzed by the finite difference method combined with the kinematic source model in this paper. The study shows that the rupture velocity, fault depth, position of the initial rupture point and distribution of asperities are the most important parameters to the velocity pulse. Generally, the pulse period decreases and the pulse amplitude increases as the rupture velocity increases for shallow crustal earthquakes. In a definite region besides the fault trace, the pulse period increases as the fault depth increases. For a uniform strike slip fault, rupture initiating from one end of a fault and propagating to the other always generates a higher pulse amplitude and longer pulse period than in other cases.     

相位参数的效果分析

本文叙述了实测相位曲线的形态、特征、并对其地质效果进行了分析。同时将相位曲线与振幅曲线的地质效果进行了对比;相对振幅曲线而言,相位参数具有更高的分辨力。     

潮汐调和分析方法的回顾与展望

潮汐作为海洋中最普遍的运动过程,与国民经济建设密切相关。潮汐调和分析作为使用最广泛的潮汐数据分析方法,从1921年至今,已历经100年的发展历程。本文对潮汐调和分析方法100年来的研究与发展进行总结与回顾,并对其未来进行了展望,致敬在潮汐调和分析方法发展及应用历程中有所建树的先贤和前辈。