The results of ultrasonic measurements of compressional and shear wave velocities in poorly consolidated marine sediments of the White Sea

Assessment of the elastic properties of bottom sediments is necessary for studying the engineering-geological conditions of the investigated water area. One of the methods for obtaining the elastic properties of sediments is ultrasonic research. In June 2024, ultrasonic studies were conducted on samples of poorly consolidated bottom sediments, represented by silts and clays of various mineral compositions, in Rugozerskaya Bay of the Kandalaksha Gulf in the White Sea. Sampling was carried out using a gravity corer at 11 stations, preliminarily selected based on the analysis of seismic-acoustic profiles. A total of 25 samples (cores) were collected, with sampling depths ranging from 0.2 to 2 meters. Ultrasonic measurements of compressional and shear wave velocities were performed on 88 samples from the collected cores. The compressional wave velocity was determined based on the first arrival times at a fixed measurement base (length of the sample), while the shear wave velocity was determined using the travel-time curve of the direct shear wave on the seismogram obtained by varying the measurement base. Ultrasonic studies were conducted using piezoelectric ceramic transducers for compressional and shear waves with frequencies of 60 kHz and 100 kHz, respectively. The resulting shear wave velocities in the sediments, represented by clays and silts, ranged from 10 to 40 m/s, while compressional wave velocities ranged from 1000 to 1800 m/s.

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