VUME Upper Mantle of the Earth



Three-Dimensional Density Model of the Earth



A three-dimensional (3D) density model of the Earth's crust and the upper mantle constructs on the basis of geological, seismic and gravity data.
The gravitational influence of the upper mantle (whose density model constructs using the 3D gravity modeling) compensates for a considerable portion of the Earth's crust gravity effect that is strongly affected by the Moho topography.
A combination of different geophysical surveys employing seismics, gravity and geoelectrics, together with geological and petrological studies, can provide new insights into the structures and tectonic evolution of the lithosphere and natural deposits. Interdisciplinary interpretation is essential for any numerical modeling of these structures and the processes acting on them.


The three-dimensional density model that reproduces the gravity field is a continental-scale representation of density structure to 410 km depth that characterizes the mantle and crust of the plate, subducted slab and continental margin with a minimum number of bodies.
The density predefining of each body makes after studying the dependency of density on composition of crustal and mantle materials and pressure-temperature conditions appropriate for the each setting. A database of independent geophysical information constrains the geometry of the top of the subducted slab, locally the Moho of the oceanic and continental crusts and, indirectly, the lithosphere-asthenosphere boundary underneath the continental plate.
Other boundaries, notably the intracrustal density discontinuity separating upper from lower crust below the continents is the result of fitting the observed and calculated Bouguer anomaly during forward modeling.
High-quality data from digital seismic instruments emplaced this decade have renewed interest in the measurement of low-frequency Earth normal modes with the goal of extracting heterogeneous density structure.
The 3D density model of the main Earth crust structures is compiled and calculated, leaning on the seismic-geological and experimental petrophysical data. The model gives a visual explanation for the observed geophysical anomalies. The schematic map of the basement tectonics is one of the investigation results.