Errors of Earth Gravity Models as Depending on Seafloor Morphology

Resumo

Abstract—The empirical results on estimating the resolution and high-frequency noise in the Earth’s gravity models are presented. The Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences participated in a marine gravity survey in the Indian Ocean. Based on the survey data, gravity maps were constructed for ten regions with a total of 611 986 gravimetric points. The root mean square measurement error is at most 0.27 mGal. The differences between measured gravity and predictions by the EGM2008 gravity model are calculated. The statistical processing of the differences shows that they vary from –25 to 44 mGal on the shelf and from –7.4 to 6.2 mGal on the abyssal plain with a root mean square value of 1.33 mGal. The results of the survey indicate that the anomalies in the ultra-high-degree model can only be used for constructing gravity maps on the scale of 1 : 500 000 or smaller.