Using Migrated Dip-Angle Gathers for Boulder Detection in UHR Seismic Reflection Data

Boulders and other objects pose a serious risk for the installation of offshore infrastructure, including wind parks, offshore platforms and cable routes. Such objects are difficult to detect within marine sediments using conventional seismic methods. We present here a method using migrated dip-angle gathers of conventional UHR seismic reflection data to identify diffractions caused by buried objects. Dip-angle gathers allow the geometric separation of reflected and diffracted energy and a localization of a point diffractor along a seismic profile. Dip-angle gathers thus represent an efficient method to identify boulders in marine sediments. The large volume of data to be interpreted requires a large manual effort. Machine learning algorithms show good results in identifying possible point diffraction locations.