Computation of complete Bouguer anomalies from free-air anomalies in east sea

초록

This paper describes the results of complete Bouguer anomalies computed from the Free-air anomalies that derived from Sandwell and DNSC08 marine gravity models. Complete bouguer corrections consist of three parts: the bouguer correction (Bullard A), the curvature correction (Bullard B) and the terrain correction (Bullard C). These all corrections have been computed over the East Sea on a 1'×1' elevation data (topography and bathymetry) derived from ETOPO1 global relief model. In addition, a constant topographic (sea-water) density of 2,670kg/m3(1,030kg/m3) has been used for all correction terms. The distribution of complete bouguer anomalies computed from DNSC08 are -34.390 ∼ 267.925 mGal, and those from Sandwell are -32.446 ∼ 266.967 mGal in East Sea. The mean and RMSE value of the difference between DNSC08 and Sandwell is 0.036 ± 2.373 mGal. The highest value of complete bouguer anomaly are found around the region of 42 ∼ 43°N and 137 ∼ 139°E (has the lowest bathymetry) in both models. These values show that the gravity distribution of both models, DNSC08 and Sandwell, are very similar. They indicate that satellitebased marine gravity model can be effectively used to analyze the geophysical, geological and geodetic characteristics in East Sea.

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