Open source modeling code, with which all data were generated: https://github.com/kuangdai/AxiSEM-3D This code was primarily developed within the NERC-funded project, and used for a at least 10 publications over the past two years: [1] Wolf, Long, Leng, Nissen-Meyer. Sensitivity of SK(K)S and ScS phases to heterogeneous anisotropy in the lowermost mantle from global wavefield simulations, 2021. GJI, 228, 366–386, https://doi.org/10.1093/gji/ggab347 [2] Krier, Thorne, Leng, Nissen-Meyer: A compositional component to the Samoa ultralow-velocity zone revealed through 2- and 3-D waveform modeling of SKS and SKKS differential travel-times and amplitudes, Journal of Geophysical Research. doi:10.1029/2021JB021897 [3] Thorne, M. S., Leng, K., Pachhai, S., Rost, S., Wicks, J., & Nissen-Meyer, T. (2021). The most parsimonious ultralow-velocity zone distribution from highly anomalous SPdKS waveforms. Geochemistry, Geophysics, Geosystems, 22, e2020GC009467. https://doi.org/10.1029/2020GC009467 [4] Haindl, Leng, Nissen-Meyer, 2021. A 3D Complexity-Adaptive Approach to Explore Sparsity in Visco-Elastic Wave Propagation, Geophysics, doi.org/10.1190/geo2020-0490.1 [5] Tesoniero, Leng, Long, Nissen-Meyer. Full wave sensitivity of SK(K)S phases to arbitrary anisotropy in the upper and lower mantle, Geophysical Journal International, 222, 412–435, https://doi.org/10.1093/gji/ggaa171 [6] Thorne, M.S.; Pachhai, S.; Leng, K.; Wicks, J.K.; Nissen-Meyer, T, 2020. New Candidate Ultralow-Velocity Zone Locations from Highly Anomalous SPdKS Waveforms. Minerals 2020, 10, 211. [7] Fernando, Leng, Nissen-Meyer, 2020. Oceanic high-frequency global seismic wave propagation with realistic bathymetry, Geophysical Journal International, 222, 1178–1194, https://doi.org/10.1093/gji/ggaa248 [8] Leng, Korenaga, Nissen-Meyer, 2020. Three-dimensional scattering of elastic waves by small-scale heterogeneities in the Earth’s mantle, Geophysical Journal International, 223, 1, 502–525, https://doi.org/10.1093/gji/ggaa331 [9] Szenicer, Leng, Nissen-Meyer, 2020. A complexity-driven framework for waveform tomography with discrete adjoints, Geophysical Journal International, https://doi.org/10.1093/gji/ggaa349 [10] Leng, Nissen-Meyer, van Driel, Hosseini, Al-Attar, 2019. AxiSEM3D: broad-band seismic wavefields in 3-D global earth models with undulating discontinuities, Geophysical J Int., 217, 2125–2146 Each of publications is based on the code mentioned above, and metadata for running the simulations of the papers are given therein, in a reproducible manner.

Dataset contains 3D synthetic seismic waveforms for axisymmetric global Earth velocity models. The waveforms were calculated using the finite difference approach with the PSVAxi algorithm (Jahnke, G et al., 2008. doi:10.1111/j.1365-246X.2008.03744.x). The Earthmodels are 1D and use PREM parameters except close to the core-mantle boundary (CMB) where 3D ultra-low velocity zones (ULVZs) are added to the PREM background model. ULVZ are thin layers of strongly reduced seismic velocities located at the CMB that have been observed in several regions of the Earth. The dataset models interaction of the seismic wavefield with ULVZ structure with varying elastic parameters (P-wave, S-wave velocity, density), location (location at source or receiver side along the great circle path), ULVZ length, shape (box, Gaussian, trapezoid) and height. Detailed description of the approach and the model space are given in Vanacore et al, (2016). Data format is SAC (Seismic Analysis Code). Vanacore, E.A., Rost, S., Thorne, M.S., 2016. Ultralow-velocity zone geometries resolved by multidimensional waveform modelling. Geophys. J. Int. 206, 659–674. doi:10.1093/gji/ggw114