Description: High-resolution spherical harmonic representation of the Earth's topographic, isostatic, and topographic-isostatic gravitational potential based on a three-layer decomposition of the topography with variable density values and a modified Airy-Heiskanen concept incorporating seismic Moho depths. Main features: - Three-layer decomposition of the topography using information of the 5'x5'global topographic database DTM2006.0 - Rigorous separate modeling of rock, water, and ice masses with layer-specific density values (2670, 1000, 920 kg m-3) - Avoidance of geometry changes compared to classical condensation methods (e.g. rock-equivalent heights) - Ellipsoidal arrangement of the topography using the GRS80 ellipsoid as reference surface - Adapted and modified Airy-Heiskanen isostatic concept - Incorporation of seismic Moho depths derived from CRUST2.0 - Location-dependent estimation of the crust-mantle density contrast Processing: - Forward modelling in the space domain using tesseroid mass bodies - Transformation of global gridded values to the frequency domain by applying harmonic analysis up to degree and order 1800 Model versions: - Spherical harmonic coefficients of the RWI model are provided by three versions (GM = 3.986004415e+14 m3 s-2, a = 6378136.3 m): RWI_TOPO_2012 (topographic potential) RWI_ISOS_2012 (isosatic potential) RWI_TOIS_2012 (topographic-isostatic potential) - To allow the evaluation of the RWI model by synthesis software that by default subtracts the coefficients of a normal gravity field, three additional versions are available: RWI_TOPO_2012_plusGRS80 (topographic potential + GRS80) RWI_ISOS_2012_plusGRS80 (isosatic potential + GRS80) RWI_TOIS_2012_plusGRS80 (topogr.-isostatic potential + GRS80) where the following zonal harmonic coefficients of the GRS80 normal gravity field are added to the coefficients of the RWI model: C( 0,0) = 0.100000014676351e+01 C( 2,0) = -0.484167032228604e-03 C( 4,0) = 0.790304535833168e-06 C( 6,0) = -0.168725253450154e-08 C( 8,0) = 0.346053594536695e-11 C(10,0) = -0.265006548323563e-14 C(12,0) = -0.410788602320538e-16 C(14,0) = 0.447176931400485e-18 C(16,0) = -0.346362561442980e-20 Note that these coefficients are already rescaled to the above specified parameters GM and a of the RWI model. Details about the used DTM2006.0 topography model can be found in Pavlis et al. (2012, https://doi.org/10.1029/2011JB008916). Details about the used CRUST2.0 model is available from Laske et al. (2000, https://igppweb.ucsd.edu/~gabi/crust2.html).
Global identifier:
Doi(
"10.5880/ICGEM.2014.001",
)
Tags: Software ? Topographie ? Bewertungsverfahren ? Modellierung ? Datenbank ? EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TOPOGRAPHIC EFFECTS ? EARTH SCIENCE > SOLID EARTH > GRAVITY/GRAVITATIONAL FIELD ? Gravity forward modeling ? Isostatic potential ? Isostatic reduction ? Rock–Water–Ice (RWI) decomposition ? Spherical harmonic model ? Tesseroids ? Topographic gravity field model ? Topographic potential ? Topographic reduction ? Topographic-isostatic potential ? Topographic-isostatic reduction ?
License: Creative Commons Namensnennung 4.0
Language: Englisch/English
Issued: 2014-01-01
Accessed 2 times.