Joint inversion of receiver functions, surface wave dispersion, and magnetotelluric data
Joint inversion of receiver functions, surface wave dispersion, and magnetotelluric data
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DOI：
10.1029/2009jb006369
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发表时间：
2010-04
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影响因子：
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通讯作者：
M. Moorkamp;Alan G. Jones;S. Fishwick
中科院分区：
文献类型：
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作者：
M. Moorkamp;Alan G. Jones;S. Fishwick
我们使用多目标遗传算法（GA）对一维地球的大地电磁、接收器函数和罗利波色散数据进行联合反演。所选择的遗传算法不仅产生一系列适合数据集的模型，而且还产生拟合不同数据集之间的权衡。通过对这种权衡的分析，可以深入了解地震数据集和大地电磁数据之间的兼容性，以及为地震数据假设的适当噪声水平。这些附加信息有助于评估联合模型的有效性，并且我们在现实条件下演示了我们的方法与合成数据的使用。我们将我们的方法应用于 Slave Craton 的一个站点和 Kaapvaal Craton 的一个站点。对于从克拉通，我们通过接收器函数和大地电磁数据的联合反演获得了与之前发布的模型类似的结果，但分辨率和绝对速度的控制得到了改进。我们在地壳底部发现了一个导电层，就在莫霍面之上；岩石圈地幔中的低速、低电阻率区域，以前称为中央从地幔导体；以及岩石圈-软流圈边界在地震速度和电阻率下降方面的迹象。对于卡普瓦尔克拉通，地震和大地电磁数据的质量都较低，这妨碍了详细而可靠的解释；尽管如此，我们发现地幔岩石圈中存在低速低电阻率区域的迹象。这两个例子展示了联合反演的潜力，特别是与非线性优化方法相结合。
We present joint inversion of magnetotelluric, receiver function, and Raleigh wave dispersion data for a one‐dimensional Earth using a multiobjective genetic algorithm (GA). The chosen GA produces not only a family of models that fit the data sets but also the trade‐off between fitting the different data sets. The analysis of this trade‐off gives insight into the compatibility between the seismic data sets and the magnetotelluric data and also the appropriate noise level to assume for the seismic data. This additional information helps to assess the validity of the joint model, and we demonstrate the use of our approach with synthetic data under realistic conditions. We apply our method to one site from the Slave Craton and one site from the Kaapvaal Craton. For the Slave Craton we obtain similar results to our previously published models from joint inversion of receiver functions and magnetotelluric data but with improved resolution and control on absolute velocities. We find a conductive layer at the bottom of the crust, just above the Moho; a low‐velocity, low‐resistivity zone in the lithospheric mantle, previously termed the Central Slave Mantle Conductor; and indications of the lithosphere‐asthenosphere boundary in terms of a decrease in seismic velocity and resistivity. For the Kaapvaal Craton both the seismic and the MT data are of lesser quality, which prevents as detailed and robust an interpretation; nevertheless, we find an indication of a low‐velocity low‐resistivity zone in the mantle lithosphere. These two examples demonstrate the potential of joint inversion, particularly in combination with nonlinear optimization methods.