From 1 - 10 / 19
  • Input and output files from first-principles calculations to compute the lattice thermal conductivity, elastic properties, and phase stability of various lower mantle minerals. Spreadsheets of processing and final results. Article pre-prints.

  • Data files have .dat extension and can be opened with Notepad or any basic text editor software. Each file contains details of sample name, dimensions (length and diameter). All deformed samples were pre-prepared cylinders of synthetic neighbourite. Each file contains 11 data column as follows: Time (hours); Time (secs); CP (V); Vol (V); Force(V); Temp (V); Disp(V); Euro disp (mm); Furn T (mV); PoreP (mV); Furnace Power where V= Volts, mV= millivolts. The Calibration sheet (specific to the apparatus used) uploaded together with the data files is required to convert V and mV raw data into values of stress, strain, strain rate, confining pressure and temperature.

  • The three-component data are downloaded from CDSN and processed with instrument response removed. The data coverages include sampling in the East Asia, southwest and northwest Pacific.

  • Log file and GSAS data files for synchrotron study of NaMnF3. Diffraction patterns from synchrotron experiments on NaMnF3. NERC grant: Understanding the D' zone: novel fluoride analogues to MgSiO3 post perovskite NERC grant abstract: The thermal boundary layers of a convecting system control many aspects of its style of convection and thermo-chemical history. For the silicate Earth these boundary layers are the lithosphere, whose low temperature and high rigidity induces slab-style downwellings, and the D' region on the mantle side of the core-mantle-boundary (CMB). The D' region is the source of plume-style convection and regulates heat exchange from the core to the silicate Earth. The lower thermal boundary is made more complex by the existance of a phase transition in the most common mineral in the lower mantle (magnesium-silicate perovskite) which changes the properties of the D' region at the CMB. Unfortunately, most of these properties cannot be measured at the extreme pressures (120 GPa) of stabilisation of the post-perovskite phase. The best chance of constraining them is through a combination of measurements on low-pressure analogue materials (which have the same crystal structure but a different chemical composition) and ab initio simulations of both the analogue and natural systems. We have recently developed a set of ABF3 analogues whose properties are much more similar to MgSiO3 than are those of the CaBO3 analogues currently in use. We propose, therefore, to use these improved fluoride analogues to determine the properties of post-perovskite which control the dynamics of D' (phase diagram, pressure-temperature-volume relations, viscosity, slip systems and thermal diffusivity). These measurements will allow models to be developed which accurately predict the behaviour of the lower thermal boundary layer of the mantle. This will place coinstraints on (1) the heat budget, dynamo power and start of crystallisation of the inner core, (2)the vigour of plumes, (3) the ratio of underside heating to internal heating in the mantle and, (4) the radioactive element budget of the silicate Earth.

  • The two-phase modeling of water between liquid iron and silicate melt at 50 and 135 gigapascals (corresponding to 3500 and 4200 kelvin) was performed by using ab initio molecular dynamics implemented in the Vienna Ab Initio Simulation Package.

  • Broadband data collected at the equatorial Mid-Atlantic Ridge from March 2016 to March 2017. From the Grant abstract: We will systematically image the entire length of an oceanic plate, from its birth at the Mid Atlantic Ridge to its oldest formation on the African margin. This is a large-scale focused effort with multiple scales of resolution and sensitivity, from a metre to kilometre scale using seismic and electromagnetic methods. This scale, focus, and interdisciplinary approach will finally determine the processes and properties that make a plate strong and define it. The project will be accomplished through a large, focused international collaboration that involves EU partners (3.5 M euro) and industry (6.4M euro), both already funded.

  • Synthetic seismic waveforms computed using the spectral element method for 1-D and 3-D Earth models for a variety of scenarios of structures in the deep Earth's interior.

  • 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.

  • This dataset holds the output of all the simulations in the Open Access article - Garel, F., S. Goes, D. R. Davies, J. H. Davies, S. C. Kramer, and C. R. Wilson, Interaction of subducted slabs with the mantle transition-zone: A regime diagram from 2-D thermo-mechanical models with a mobile trench and an overriding plate, Geochem. Geophys. Geosyst., 15, 1739-1765, doi 10.1002/2014GC005257, 2014.

  • The dataset consists of a table of 64 isotope ratio measurements of the AMES Ce standard (Willbold, 2007). The data was collected at Imperial College, London between April 2013 and March 2014 using a ThermoScientific Triton thermal-ionisation mass spectrometer following the technique described in Willbold, Journal of Analytical Atomic Spectrometry, 2007. The data is used to assess the reproducibility and accuracy of the mass spectrometric setup available at the time. Reference: Willbold, M., 2007. Determination of Ce isotopes by TIMS and MC-ICPMS and initiation of a new, homogeneous Ce isotopic reference material. Journal of Analytical Atomic Spectrometry, 22: 1364-1372 https://doi.org/10.1039/B705306A