Shorelines change rapidly, and the natural disasters such as earthquakes may destroy their morphologies. Therefore, shoreline monitoring is vital for preservation. Traditional methods, such as field surveys, are inefficient for monitoring coastal regions in terms of both time and cost. Alternatively, remote sensing technologies and image processing techniques can be used to derive such information effectively. The objective of this study is to investigate shoreline changes before and after an earthquake in Christchurch city from Canterbury region of New Zealand by non-parametrically processing of SAR imagery. The segmentation parameters were determined using optical SENTINEL 2A images and changes in the shoreline were determined using SAR data. The main motivation of the study is to use Optic SAR as a replacement for LiDAR data to analyze the shoreline changes. Experiments were performed to evaluate the proposed method by comparing the obtained results with the reference data. It was observed that the proposed method was effective in determining the changes in the shoreline with high accuracy.