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Congreso; IAG 2009.Geodesy for Planet Earth. Sesión: Gravity of the Planet Earth. Sub-Sesión: Gravity and geoid modeling. Focus on global and regional gravity and geoid modeling.; 2009

Institución organizadora:

IAG

Resumen:

The isostatic study of the Cacheuta Sub-basin was carried out using geoid Nt undulations (Eigen, 2008). Wavelengths exceeding structures size were eliminated by filtering methods, thereby leaving the observed residual undulations. We have prepared a perfectly balanced reference model (dipolar crust: - +). Basin depths h were used as input data. Compensating antiroot DR was calculated using the expression DR = 6.675 h. Using rectangular parallelepipeds to model both sediments and antiriot, residual undulations were calculated from Nr = (-Vs + Var) /g; with Vs: sediments potential; Var: antiroots potential and g: gravity. Taking into account the negative sign of the difference Nor Nr, we have inferred that the basin is isostatically under-compensated and that in the future, it would subside. Traditional gravimetric methods were used for validation. Both gravimetric method and geoid undulation method agree in corroborating the existence of isostatic under-compensation. This study clearly shows that N calculations made by means of equivalent sources and plain Stokes confirm consistency of the observed results. A direct passage can be made from N to g and vice versa. This study also shows that geoid undulations method can replace traditional gravity methods to obtain geological structures and thereby analyzing compensation state without using gravity data.