A Study on the Crustal Structure Between Pohang, Kongju and Manripo by Gravity Method

중력 탐사에 의한 포항-공주-만리포간의 지각구조 연구

  • 민경덕 (연세대학교 지구시스템과학과)
  • Published : 2000.04.01

Abstract

The gravity measurement has been carried out to study the deep geologic structure at 331 gravity stations with an interval of 1∼1.5 km along the national road which crosses the southern part of the Korean peninsula from Pohang to Manripo. The Bouguer gravity anomalies were obtained from the observed gravity values, and interpreted by means of upward continuation using FFT (Fast Fourier Transform), Fourier-series method and nonlinear 2-D inversion method to determine the depths of Conrad and Moho discontinuities. The linear regression relations between elevations and gravity anomalies were also obtained to test isostasy in the study area. The depth of Conrad discontinuty is 13km between Pohang and Daegu, 16.5 km between Kimchon and Okchon, 9.7 km between Okchon and Daejeon, and 16.3 km near Manripo. The depth of Moho discontinuty is 32km between Pohang and Daegu, 35 km between Kimchon and Okchon, 28.7 km between Okchon and Daejeon, 40.5 km between Daejeon and Kongju, and 34.5 km between Kongju and Manripo. The result of testing isotasy indicates that the crust of this area seems to be not in perfect isostatic equilibrium but in a little undercompensated sate.

Keywords

References

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