The eastern terminations of the Himalayan orogeny, named Namche Barwa, are considered a vital natural laboratory in the Tibetan plateau for geodynamics due to its distinctive geological and geomorphological characteristics. Magnetotelluric (MT) data measured at 83 sites around the Namche Barwa are imaged by three‐dimensional (3‐D) inversion to better reveal the crustal structure of the eastern Himalaya. The results show a complex and heterogeneous electrical structure beneath the Namche Barwa. The electrical conductors distributed in the middle and lower crust around the Namche Barwa provide additional evidence for the “crustal flow” model if they are considered as some parts of the flow in a relatively large‐scale region. The near‐surface resistivity model beneath the inner part of Namche Barwa conforms with the locations of hot spring and fluid inclusions, the brittle‐ductile transition, and the 300°C–400°C isotherm from previous hydrothermal studies. Relatively resistive upper crust (>800 Ωm) is underlain by a more conductive middle to lower crust (<80 Ωm). The electrical characteristics of the thermal structure at shallow depth indicate an accumulation of hydrous melting, a localized conductive steep dipping zone for decompression melting consistent with the “tectonic aneurysm” model for explaining the exhumation mechanism of metamorphic rocks at Namche Barwa. The results also imply that both surface processes and local tectonic responses play a vital role in the evolution of Namche Barwa. An alternative hypothesis that the primary sustained heat source accounts for the local thermal‐rheological structure beneath Namche Barwa is also discussed.

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SUMMARY The integrating technique of multi-geophysical datasets has been treated as a feasible way to improve the imaging resolution of the subsurface structure. Based on the limited memory quasi-Newton approach, we obtain the electrical and velocity structure through the individual inversions of magnetotelluric and ambient noise dispersion data, and propose an alternating joint inversion strategy for integrating the magnetotelluric and dispersion data with the cross-gradient structure constraints. A synthetic model has been applied to test the reliability and effectiveness of the joint inversion scheme. Some significant improvements have been achieved and shown in the joint inversion maps: the resolution of deep electric features is improved, especially that of the structure beneath the conductive layer; a finer velocity model is obtained than that of the ambient noise tomography. Based on the complementary advantages of the two geophysical methods, resistivity and velocity models with higher geometrical resemblance can be obtained. We also apply the method to the field data from the Tanlu fault zone, Eastern China. Structure similarities have been observed in the main features of the joint inversion models, which further validates the effectiveness and practicality of the proposed joint inversion strategy.