{"thcode":2,"term":{"code":2298,"name":"inverse modeling","parent":713,"scope":"An iterative approach to estimate the form and characteristics of a physical system explained by observations or measurements. Frequently used to determine a subsurface geological structure from measurements of physical properties obtained at or near the earth's surface."},"uf":[{"name":"geophysical inversion","usewith":false},{"name":"inverse problem","usewith":false},{"name":"inversion modeling","usewith":false}],"bt":[{"code":713,"name":"mathematical modeling","parent":2285,"scope":"Operational representation of a system in which the characteristics and behaviors of the component processes, phenomena, or objects, understood using mathematical relationships, are represented by numerical values (measured or hypothetical), so that calculations carried out using them return numerical estimates of system parameters that were not measured directly."},{"code":2285,"name":"modeling","parent":734,"scope":"Human-constructed representation of processes, phenomena, or objects so that the behaviors, characteristics and relationships among things that are being studied can be understood without exhaustive data collection and analysis."},{"code":734,"name":"methods","parent":1,"scope":"Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":2086,"name":"continuous resistivity profiling","parent":326,"scope":"Ship-based method of analyzing apparent resistivity of the sub-bottom (for example, spatial variation in pore-water salinity) by measuring the induced electromagnetic response to a current generated by the instruments."},{"code":326,"name":"electromagnetic surveying","parent":375,"scope":"Method of determining the shape and constituency of near-surface earth structures by variations of responses of the materials to electrical and magnetic fields. Use for ground-based methods of imaging."},{"code":459,"name":"geologic structure","parent":287,"scope":"General position of rocks in an area, and geometrical relationships among rocks."},{"code":470,"name":"geophysics","parent":291,"scope":"Branch of geology studying the physical characteristics and phenomena of the earth and its atmosphere."},{"code":501,"name":"gravitational field (earth)","parent":287,"scope":"Region or space around earth's mass which exerts a force that mutually attracts other masses in proportion to the product of the two masses and the distance between them."},{"code":677,"name":"magnetic field (earth)","parent":287,"scope":"The magnetic region surrounding earth.  It is generated by the dipolar characteristic of earth's core whereby earth itself acts as a great spherical magnet with poles near, but not exactly at, the North and South poles."},{"code":2085,"name":"magnetotelluric surveying","parent":326,"scope":"Passive geophysical technique that uses the earth's natural electromagnetic field to investigate the spatial variation of electrical resistivity in the subsurface."}]}