The velocity-depth ambiguity in seismic traveltime data
The velocity-depth ambiguity in seismic traveltime data
复制标题
地震走时数据中的速度-深度模糊度
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
W. Ross
中科院分区：
文献类型：
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作者：
W. Ross
观测到的反射体地震走时的扰动可能是由地表和反射体之间的异常速度带或反射体本身的结构变化引起的。该速度-深度模糊度根据线性估计理论来公式化。这样的公式可以整合各种已发表的速度-深度模糊度的结果，并提出了稳定深度转换问题的解决方案的改进方法。通过解决一个相对简单的问题，即上覆岩层下的单个反射层的速度变化，可以得出以下结论：1）速度-深度模糊性是由走时误差引起的，如果速度不横向变化（或变化非常缓慢），则可以通过闭合形式的表达式与这些误差定量相关。除其他事项外，这些表达式表明，对于小的扩展长度（短于一半的深度）的速度和深度的误差是成反比的平方…
An observed disturbance in seismic traveltimes to a reflector can be caused either by an anomalous velocity zone between the surface and the reflector or by a structural variation in the reflector itself. This velocity‐depth ambiguity is formulated in terms of linear estimation theory. Such a formulation allows integration of various published results on velocity‐depth ambiguity and suggests improved methods of stabilizing the solution of a depth‐conversion problem. By solving a relatively simple problem that is amenable to analysis—a single reflector beneath an overburden with a variable velocity—the following conclusions can be drawn: 1) The velocity‐depth ambiguity is caused by traveltime errors and can be quantitatively related to those errors by closed‐form expressions if the velocities do not vary laterally (or vary very slowly). Among other things, those expressions show that for small spread lengths (shorter than haft the depth) the errors in velocity and depth are inversely proportional to the sq...