P135 THE SUBSURFACE REVEALED – THE “SEISMIC MICROSCOPE” Abstract 1 High- and ultra-high resolution water-born seismic techniques have been successfully applied to engineering and environmental problems. Key to the success is the unparalleled resolution one can achieve on water with advanced seismic profiling systems. This paper first demonstrates the resolving power comparing high- and ultra-high resolution seismic profiles measured above the same location. This is followed by case studies focusing on some specific problems successfully solved by the technique. Case studies include seismic surveys carried out on river Danube next to the Hungarian Nuclear Power Plant (TÓTH & HORVÁTH 1999)