Abstract:
We present a 3D crustal model of density and susceptibility distribution in the Wilkes Subglacial Basin and the Transantarctic Mountains (TAM) based on joint inversion of airborne gravity and magnetic data. The applied 'variation of information' technique enforces a coupling between gravity and magnetic sources to give an enhanced inversion result. Our model reveals a large-scale body located in the interior of the Wilkes Subglacial Basin interpreted as a batholithic intrusive structure, as well as a linear dense body at the margin of the Terre Adelie Craton. We provide six netCDF files, which include the input gravity and magnetic data, the inverted gravity and magnetic data, and inverted crustal density and susceptibility distribution. Additionally, a simple jupyter notebook that loads and plots the provided data can be found here: https://doi.org/10.5281/zenodo.8304170
Funding for this research was provided by NERC through a SENSE CDT studentship (NE/T00939X/1)
Keywords:
Density and susceptibility distribution, Gravity and magnetics, Joint inversion, Transantarctic Mountains, Wilks Subglacial Basin
Lowe, M., Jordan, T., Moorkamp, M., Ebbing, J., Green, C., Losing, M., & Larter, R. (2023). 3D density and susceptibility distribution of the Wilkes Subglacial Basin and Transantarctic Mountains in East Antarctica. (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/5e1424e7-124d-4cc3-ba06-b2285c0b458c
| Access Constraints: | No restrictions apply. |
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| Use Constraints: | This data is covered by a UK Open Government Licence (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) |
| Creation Date: | 2023-07-17 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | Mr Maximilian Lowe |
| Role(s) | Metadata Author, Investigator |
| Organisation | British Antarctic Survey |
| Name | Tom Jordan |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Name | Max Moorkamp |
| Role(s) | Investigator |
| Organisation | Ludwig Maximilian University of Munich |
| Name | Dr Jorg Ebbing |
| Role(s) | Investigator |
| Organisation | Christian-Albrechts-Universitat zu Kiel |
| Name | Dr Chris Green |
| Role(s) | Investigator |
| Organisation | University of Leeds |
| Name | Mareen Losing |
| Role(s) | Investigator |
| Organisation | University of Western Australia |
| Name | Dr Robert D Larter |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Reference: | Associated publication: Related research article to this data publication is submitted to JGR Solid Earth. The preprint is accessible at: https://essopenarchive.org/doi/full/10.22541/essoar.168987130.08453761/v1 * Related datasets: The gravity input data consist of airborne gravity data from AntGG [Scheinert et al., 2016] https://doi.org/10.1002/2015GL067439 and ground station from [Reitmayr et al., 2003] (Reitmayr, G., W. Korth, G. Caneva, and F. Ferraccioli (2003), Gravity Survey at the Oates Coast Area, East Antarctica, during the Joint German-Italian Expedition 1999/2000, TERRA ANTARTICA, 10, 97-104.) and [Zanutta et al., 2018] https://doi.org/10.3390/rs10101608 The magnetic data consist of airborne magnetic measurements from the ADMAP-2 [Golynsky et al., 2018] https://doi.pangaea.de/10.1594/PANGAEA.892724 |
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| Quality: | The RMS error between observed and inverted gravity field is 1.5 mGal and 0.7 nT for the magnetic field. The end members of the residual between observed and inverted values are + 37 and -18 mGal with a standard deviation of 3 mGal for the gravity inversion and for the magnetic inversion +341 and -65 nT with a standard deviation of 13 nT. | |
| Lineage: | Crustal density and susceptibility distribution are inferred from joint inversion of gravity and magnetic data using the 'variation of information' approach. The inversion is carried out with the academic software JIF3D (https://sourceforge.net/projects/jif3d/) developed by Max Moorkamp. The density and susceptibility inversion models are discretised into meshes with equal horizontal cell sizes of 7.5 km. The vertical cell size is 1 km at the surface and increases with depth by a factor 1.1 for each cell. Increasing vertical cell size with depth is introduced to account for decreasing resolution with increasing distance to the source in potential field applications. A horizontal cell size of 7.5 km is chosen because the input gravity and magnetic data have a resolution of 10 km. Additionally, a padding area of 20% around the study area is added to avoid edge effects. The resulting inversion mesh contains 244 cells east-west direction, 140 cells in north-south direction and 21 cells in the z direction (60 km below sea level). To constrain the model geometry, the bedrock topography Curie point depths and Moho depths are used as model boundaries. All cells are set to a starting value of 0 kg/m3 for the density anomaly model and 0 SI for the magnetic model and are iteratively updated during the VI inversion process. Note that all the elevation information are provided with positive values down. |
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| Spatial Coverage: | |
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| Latitude | |
| Southernmost | -76.8 |
| Northernmost | -66.5 |
| Longitude | |
| Westernmost | 131 |
| Easternmost | 172 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | 7.5 km |
| Longitude Resolution | 7.5 km |
| Horizontal Resolution Range | N/A |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | N/A |
| Detailed Location | Transantarctic Mountains and Wilkes Subglacial Basin |
| Data Collection: | The data preparation and the inversion set up is performed in python (version 3.10.11). The inversion itself is carried out in the JIF3D software using a Linux terminal. The gravity and magnetic data were upwardly continued at a constant station height using the Compudrape plug-in for Geosoft Oasis Montaj version 2021.2. |
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| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 12.2MB |
| Distribution Format | netCDF |
| Fees | N/A |
| Data Storage: | Data format is NetCDF4. Each physical parameter has his own NetCDF file. * Input_grav.nc contains the input gravity field. The variables in NetCDF file are projection_x_coordinate (polar stereographic), projection_y_coordinate (polar stereographic), projection_z_coordinate (station height in meter), crs (map projection information), scalar_gravity (inverted gravity field in m/s2), dGz (Error in m/s2) * Input_mag.nc contains the input magnetic field. The variables in NetCDF file are projection_x_coordinate (polar stereographic), projection_y_coordinate (polar stereographic), projection_z_coordinate (station height in meter), crs (map projection information), magnetic_field (magnetic field in nT), dT (Error in nT) * Inv_grav.nc contains the inverted gravity field. The variables in NetCDF file are projection_x_coordinate (polar stereographic), projection_y_coordinate (polar stereographic), projection_z_coordinate (station height in meter), crs (map projection information), inverted_Scalar_gravity (inverted gravity field in m/s2), dGz (Error in m/s2) * Inv_mag.nc contains the inverted magnetic field. The variables in NetCDF file are projection_x_coordinate (polar stereographic), projection_y_coordinate (polar stereographic), projection_z_coordinate (station height in meter), crs (map projection information), inverted_magnetic_field (magnetic field in nT), dT (Error in nT) * inv_density.nc contains the inverted crustal density distribution. The variables in NetCDF file are projection_x_coordinate (polar stereographic), x_cell_bnds (cell boundaries in x direction in polar stereographic coordinates), x_origin (model origin in x direction polar stereographic), projection_y_coordinate (polar stereographic), y_cell_bnds (cell boundaries in y direction in polar stereographic coordinates), y_origin (model origin in y direction polar stereographic), projection_z_coordinate (Model depth in meter), z_cell_bnds (cell boundaries in z direction in m), z_origin (model origin in depth in meter), crs (map projection information), density (Crustal density distribution in kg/m3), bg_densities (model background densities in kg/m3), bg_thicknesses (thickness of background model in meter) * inv_susceptibility.nc contains the inverted crustal susceptibility distribution. The variables in NetCDF file are projection_x_coordinate (polar stereographic), x_cell_bnds (cell boundaries in x direction in polar stereographic coordinates), x_origin (model origin in x direction polar stereographic), projection_y_coordinate (polar stereographic), y_cell_bnds (cell boundaries in y direction in polar stereographic coordinates), y_origin (model origin in y direction polar stereographic), projection_z_coordinate (Model depth in meter), z_cell_bnds (cell boundaries in z direction in m), z_origin (model origin in depth in meter), crs (map projection information), susceptibility (Crustal susceptibility distribution in SI). |