Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

To investigate the disturbed structure by mining, 3D high resolution seismic reflection survey has been conducted across a plot of land embracing subsided area. To guarantee the clear image at this site, closely spaced(0.5 m×1 m) CMP bin and high fold(≥ 40) array were implemented. For the 3-D survey, an area of 87 m×95 m was covered approximately with CMP bin size of 0.5 m×1 m. Common processing techniques such as deconvolution and band pass filtering were successfully applied to enhance the reflection signal and suppress the source-generated noise. Also, to determine the azimuth dependent stacking velocity, detailed semblance analyses were performed in which seismic CMP gather is divided into three parts with the azimuth range. Consequently, velocity functions for each of the three azimuth ranges have slight low deviations(<10%) from the velocity functions from the entire azimuth range. From this, it is turned out that azimuth independent velocity analysis was sufficient for NMO correction and stacking. Non-surface consistent statics caused by ground distrubance in 3D seismic data used in this study, careful residual statics correction was applied for successful shallow reflection imaging. About two and three reflection events were identified in both CMP gather and stack section. By correlating the ground subsidence data and 3D stack section, subsidence pattern and zone was interpreted.