Measurements of mantle wave velocities and inversion for lateral heterogeneity and anisotropy. II - Analysis by the single-station method
Measurements of mantle wave velocities and inversion for lateral heterogeneity and anisotropy. II - Analysis by the single-station method
复制标题
地幔波速度的测量和横向不均匀性和各向异性的反演。
DOI：
10.1111/j.1365-246x.1984.tb01964.x
复制
发表时间：
1984
影响因子：
2.8
通讯作者：
D. L. Anderson
中科院分区：
文献类型：
--
作者：
I. Nakanishi;D. L. Anderson
用单站法测量了G_2，G_3，R_2和R_3（100- 330秒）的相速度和群速度，并反演出速度横向变化的球谐函数。已经研究了大约200条路径。结果是为度和订单高达6。相速度表示的偶次谐波与从大圆相速度获得的偶次谐波一致（论文I）。奇次谐波受到较少的约束，并且通常具有比偶次谐波更大的标准偏差。为了抑制不确定的谐波的速度等值线图，我们构造了一个过滤器，这是来自反问题的制定。滤波器减小了区域变化的幅度，但不改变整体模式。其区域变化规律与大圆资料区域化反演结果基本一致。速度图显示了海洋和大陆之间的显著差异。分析了面波速度与热流和非静力大地水准面的关系。当l = 1-6时，慢度与热流密切相关。相关性在l = 2和5处达到峰值。在l = 2和3时，大地水准面与慢度之间存在一个正相关关系，
从l = 4到6正相关。
Phase and group velocities of G_2, G_3, R_2 and R_3 (100-330_s) are measured by the single-station method and are inverted to give a spherical harmonic representation of the velocity lateral variation. Approximately 200 paths have been studied. The results are presented for degrees and orders up to 6. The even harmonics of the phase velocity representation are consistent with those obtained from great circle phase velocities (Paper I). The odd harmonics are less constrained and generally have larger standard deviations than the even harmonics. To suppress the poorly determined harmonics in the velocity contour maps we construct a filter which is derived from an inverse problem formulation. The filter reduces the amplitudes of regional variations, but does not change the overall pattern. The patterns of the regional variations are generally consistent with those obtained by regionalized inversion of great circle data (Paper I). The velocity maps show significant differences within oceans and continents. An analysis is made of correlations of surface wave velocities with heat flow and the non-hydrostatic geoid. The slownesses correlate well with heat flow for l = 1-6. The correlation peaks at l = 2 and 5. The geoid has an anticorrelation with the slownesses at l = 2 and 3, and a
positive correlation from l = 4 to 6.