Summary
Aus22 is an azimuthally anisotropic S-wave tomographic model of the Australian Plate and its boundaries, calculated using waveform tomography. It is computed from a dataset of waveform fits of 0.9 million vertical component seismograms and includes the lithosphere and underlying upper mantle, including the mantle transition zone (De Laat et al., 2023).
Quicklinks
Description
| Name | Aus22 |
| Title | 3-D shear-wave model for the upper mantle of the Australian Plate from waveform inversion of a massive dataset. |
| Type | Tomographic Earth model |
| Sub Type | Shear-wave velocity model |
| Year | 2023 |
| Data Revision | r0.0 (revision history) |
| Short Description | Aus22 is an azimuthally anisotropic S-wave tomographic model of the Australian Plate and its boundaries, calculated using waveform tomography. It is computed from a dataset of waveform fits of 0.9 million vertical component seismograms and includes the lithosphere and underlying upper mantle, including the mantle transition zone (De Laat et al., 2023). |
| Authors: | Janneke I. de Laat – University of Cambridge, Cambridge, United Kingdom Sergei Lebedev – University of Cambridge, Cambridge, United Kingdom Nicolas Luca Celli – Dublin Institute for Advanced Studies, Dublin, Ireland Raffaele Bonadio – University of Cambridge, Cambridge, United Kingdom Bruna Chagas de Melo – Dublin Institute for Advanced Studies, Dublin, Ireland Nicholas Rawlinson – University of Cambridge, Cambridge, United Kingdom |
| Reference Model | The 3D reference model comprises modified CRUST2 (Bassin et al., 2000) for the crust (with added topography and bathymetry, smoothing at cell boundaries, and a 1D correction that brings the average at every depth close to global average) and our own 1D average for the upper mantle (Lebedev & Van der Hilst, 2008). The model distribution netCDF is truncated to depths >56 km because of the irregular gridding of the crustal depths. To plot cross-sections at the crustal depths, please use the dedicated tool in the distributed model bundle under the Model Download section below (see the readme in it for instructions). |
| Prior Model | None |
| Model Download | Aus22-DeLaat-2023.r0.0-n4.nc (see metadata) is the model in netCDF 4 Classic format. Aus22_DeLaat_etal_2023_mod.zip is the distribution model bundle (see the Reference Model section above). |
| Model Home Page | None |
| Depth Coverage | The model samples depths from the crust to the bottom of the mantle transition zone (7/660 km). |
| Area | The model spans between longitude 74° to 180°, -179° to -167° and latitude: -68° to 20°. |
| Data Set Description | The model is constrained by over 0.9 million vertical-component seismograms. The waveform dataset is global, with data sampling maximised in the Australia-centred hemisphere and is obtained from recordings of 26 thousand earthquakes at around 9100 seismic stations, in total. |
| Model resolution | The model is focussed on the Australian Plate, with the data coverage in this region maximized (all freely available broadband data were included in the hemisphere around Australia) and the regularisation tuned to optimize the resolution in the region. Every model-grid node of the model is sampled by at least 7973 paths. The model is parametrized using a triangular grid with an average 327 km inter-knot spacing and with a depth parametrization over 18 and 10 triangular basis functions for S- and P-wave velocities, respectively (S- wave velocities: 7, 20, 36, 56, 80, 110, 150, 200, 260, 330, 410−, 410+, 485, 585, 660−, 660+, 809 and 1007 km; P-wave velocities: 7, 20, 36, 60, 90, 150, 240, 350, 485 and 585 km). |
Citations and DOIs
To cite the original work behind this Earth model:
- De Laat, J.I., S. Lebedev, N.L. Celli, R. Bonadio, B. Chagas de Melo, N. Rawlinson. Structure and evolution of the Australian Plate and underlying upper mantle from waveform tomography with massive datasets, Geophys. J. Int., 234, 153-189, https://doi.org/
https://doi.org/10.1093/gji/ggad062 , 2023.
To cite IRIS DMC Data Products effort:
- Trabant, C., A. R. Hutko, M. Bahavar, R. Karstens, T. Ahern, and R. Aster (2012), Data Products at the IRIS DMC: Stepping Stones for Research and Other Applications, Seismological Research Letters, 83(5), 846–854, https://doi.org/10.1785/0220120032.
DOI for this EMC webpage: https://doi.org/10.17611/dp/emc.2024.aus22delaat23.1
References
- Bassin, C., Laske, G. & Masters, G. The Current Limits of Resolution for Surface Wave Tomography in North America. EOS Trans AGU 81, F897 (2000).
- Lebedev, S. & van der Hilst, R. D. Global upper-mantle tomography with the automated multimode inversion of surface and S-wave forms. Geophys. J. Int. 173, 505–518 (2008).
Credits
- r0.0 model provided by Jean-Joel Legre.
Revision History
revision r0.0: uploaded July 23, 2024.
Timeline
- 2024-08-07
- r0.0 online
