After the 3D seeker+ process, a horizon was picked. But some parts contain gaps/no pick due to bad data quality. Then I interpolated the entire horizon to fill in the gaps. However, the interpolated horizon amplitude map shows lots of stripes (like the contour lines) in the area where should not have any change by the interpolation process. I even checked the amplitude values from the same locations between the non-interpolated horizon and the interpolated horizon, they are not same.