Geophysical Exploration of Geological Hazards in the Eastern Gulf of Finland

Abstract

Summary The harbors infrastructure of the Eastern Gulf of Finland is being actively developed. In addition to the existing harbors of Vyborg, Vysotsk and the Big Port of St. Petersburg, the General Scheme of the Russian harbors complex in the Eastern Gulf of Finland includes several new ports such as Primorsk and Ust-Luga. Reconstruction of existing and construction of new harbor facilities require reliable site surveys results that will provide a comprehensive study of the engineering and geological conditions of the construction area. Nobody doubts the utility of seismoacoustic exploration during engineering geological offshore site investigations. Though, the quality of data obtained by different seismoacoustic techniques may be poor and have fail resolution and low penetration depth which depend on seismo-geological conditions. The article demonstrates the combine application of very high and ultra high resolution seismic which were useful for geophysical exploration of geological hazards in the seismo-geological conditions of the Eastern Gulf of Finland. There are widespread thixotropic muds and clays, dissected roof of the bedrock, landslide faults and shallow gas charged intervals. The main goal of this article is to present new high resolution geophysical data from that area of the Gulf of Finland which had previously lacked good data for understanding the marine geology and geological hazards mapping.