The effect of low-velocity sediments on the mislocation vectors of the GRF array
The effect of low-velocity sediments on the mislocation vectors of the GRF array
复制标题
低速沉积物对GRF阵列错位矢量的影响
DOI：
10.1111/j.1365-246x.1992.tb00866.x
复制
发表时间：
1992
影响因子：
2.8
通讯作者：
M. Weber
中科院分区：
文献类型：
--
作者：
F. Krüger;M. Weber
GRF阵列位于德国东南部Franconian Alb的侏罗纪石灰岩上。错位矢量在其慢度和方位分量上显示对称轴。对于慢度而言，隔离线相对于北面约为95“。方位方向图显示出与慢度方向图中的轴线几乎垂直的对称轴。来自NE的波的慢度较小，而来自西南的波的慢度较大。最大的方位异常出现在慢度分量改变方向的方向上。这些效应在很大程度上可以由一个低速沉积层以约0.8”的倾角倾斜到NNE来模拟。这种沉积楔体与地质数据有很好的相关性，能够再现观测到的错位矢量模式，并解释了观测到的旅行时残差的大部分。它进一步表明，在应用反演过程和层析方法之前，应消除局部效应，如沉积盖层的影响。
SUMMARY The GRF array is situated on Jurassic limestone of the Franconian Alb in SE Germany. The mislocation vectors show symmetry axes in their slowness and azimuth components. For the slowness the line of separation is at about 95" against north. The azimuth pattern shows a symmetry axis nearly perpendicular to the axis in the slowness pattern. Waves arriving from NE have a reduced slowness, whereas waves from SW have a larger slowness. The largest azimuth anomalies are found in the directions where the slowness components change direction. These effects can to a large extent be modellFd by a low-velocity sedimentary layer dipping to NNE with about 0.8" dip. Such a sedimentary wedge correlates well with the geological data, is able to reproduce the observed mislocation vector pattern and explains a major part of the observed traveltime residuals. It furthermore demonstrates that local effects, like the influence of sedimentary covers, should be removed before inversion procedures and tomographic methods are applied.