Bottom Sediment Investigations of Lake Onega Using Underwater Seismic and Electromagnetic Surveys

We present the results of very high-resolution seismic profiling (VHR) and underwater electrical resistivity tomography (ERT) measurements in the Petrozavodsk Bay of Lake Onega, which were carried out to research the structure of Quaternary sediments. According to the VHR, five seismic sequences were identified during the seismic stratigraphy analysis, and a three-layer geoelectric section was obtained using ERT. The next step was an accomplishment of 2D ERT inversion based on reflectors from the VHR data. The joint interpretation of geophysical data was completed on the basis of comparative and cluster analyses with reference to the well and known geological data. During the research new information was obtained about the physical properties of the bottom sediments. The results indicate the need to apply such an approach to the interpretation of geophysical data and the prospects for the joint application of VHR and ERT acquisitions.