Summary
GlobalEM-2009-10×10 is a global 3D inverse model of electrical conductivity of the Earth’s mantle based on C-responses at ground geomagnetic observatories using the global electromagnetic inversion technique of Kelbert, Egbert and Schultz (2008). Uses a 10×10 degree grid and a degree and order 9 spherical harmonics parameterization at a discrete set of layers with layer boundaries (km) [100 250 410 520 670 900 1200 1600 2000 2400 2900 3500].
Quicklinks
Description
| Name | GlobalEM-2009-10×10 |
| Title | Global electromagnetic induction constraints on transition-zone water content variations |
| Type | 3-D Electrical Conductivity Model |
| Sub Type | Global |
| Units | Siemens/meter |
| Year | 2009 |
| Short Description | Kelbert, Schultz, & Egbert (2009) inverted C-responses with the global electromagnetic inversion technique of Kelbert, Egbert and Schultz (2008). Uses a 10×10 degree grid and a degree and order 9 parameterization at a discrete set of layers with layer boundaries (km)[100 250 410 520 670 900 1200 1600 2000 2400 2900 3500]. Prior model was discretized from Kuvshinov and Olsen (2006): in log(10) resistivity, [2.2 2.2 2.2 1.4 1.4 0.4 -0.3 0 -0.6 -0.6 -0.6 -5]. Fits 52 ground magnetic observatories from Fujii and Schultz (2002) data set + 6 obs from Schultz and Larsen (1987) data set, 59 observatories total. The C-responses were corrected for auroral sources using a 1D + thinsheet at a 1×1 degree resolution; P10 source was assumption was employed for the inversion. |
| Authors: | |
| A. Kelbert | |
| Geomagnetism Program | |
| U.S. Geological Survey | |
| Golden, CO 80401, USA | |
| A. Schultz | |
| College of Earth, Ocean and Atmospheric Sciences | |
| Oregon State University | |
| Corvallis, Oregon 97331, USA | |
| G. D. Egbert | |
| College of Earth, Ocean and Atmospheric Sciences | |
| Oregon State University | |
| Corvallis, Oregon 97331, USA | |
| Previous Model | |
| Reference Model | |
| Prior Model | |
| Inversion Software | inversion3d/earth3d by Anna Kelbert |
| Model Download | GlobalEM-2009-10×10.nc (see metadata ), is the netCDF file for the model |
| Model Homepage | |
| Depth Coverage | 0 to 3500 km (can be considered adequately well resolved 410 to 1200 km) |
| Area | latitude: -80° to 80°, longitude: 0° to 360° |
| Data Set Description | Obtained from Fujii+6-TSU_C_prior_by_1×1_28_g001_9.rho using global2netcdf.m |
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Citations and DOIs
To cite the original work behind this Earth model:
- Kelbert, A., Schultz, A. and Egbert, G., 2009. Global electromagnetic induction constraints on transition-zone water content variations. Nature, 460(7258), p.1003.
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/GLOBALEM200910X10
References:
- Fujii, I. and Schultz, A., 2002. The 3D electromagnetic response of the Earth to ring current and auroral oval excitation. Geophysical Journal International, 151(3), pp.689-709.
- Kelbert, A., Egbert, G.D. and Schultz, A., 2008. Non-linear conjugate gradient inversion for global EM induction: resolution studies. Geophysical Journal International, 173(2), pp.365-381.
- Kuvshinov, A. and Olsen, N., 2006. A global model of mantle conductivity derived from 5 years of CHAMP, Ørsted, and SAC‐C magnetic data. Geophysical Research Letters, 33(18).
- Schultz, A. and Larsen, J.C., 1987. On the electrical conductivity of the mid-mantle-I. Calculation of equivalent scalar magnetotelluric response functions. Geophysical Journal International, 88(3), pp.733-761.
Credits
- Anna Kelbert
Timeline
- 2019-05-14
- online
