Kurnosov et al. reply

In our Letter1, we reported elastic properties for single crystals of Earth’s most abundant mineral, (Al,Fe)-bearing bridgmanite, at pressures of the lower mantle, measured by simultaneous Brillouin spectroscopy and X-ray diffraction. We used our data together with previously published results to model seismic wave velocities for Earth’s lower mantle. Contradicting previous work2, we showed that seismic wave velocities derived for a pyrolitic mantle containing (Al,Fe)-bearing bridgmanite are consistent with the seismic record in the lower mantle up to a depth of about 1,200 km. In the accompanying Comment, Lin et al.3 claim that our measurements are problematic because we measured insufficient velocity data and used insensitive crystal orientations to constrain the full elastic tensor and hence conclude that the uncertainties given in ref. 1 are underestimated. Here, we address their concerns3 and show them to be unwarranted