On electro-acoustic characteristics of a marine broadband sparker for seismic exploration

• Published in: Journal of oceanology and limnology Vol. 42; no. 3; pp. 760 - 771
• Main Authors: Li, Jing, Liu, Kai, Zhang, Liancheng, Liu, Chenguang, Pei, Yanliang, Liu, Baohua
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.05.2024; Springer Nature B.V; Key Laboratory of Deep Sea Mineral Resources Development,Shandong(Preparatory),Qingdao 266061,China%Laboratory of Marine Geology,Laoshan Laboratory,Qingdao 266237,China; Key Laboratory of Marine Geology and Metallogency,First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China; Laboratory of Marine Geology,Laoshan Laboratory,Qingdao 266237,China; Laboratory of Marine Geology,Laoshan Laboratory,Qingdao 266237,China%Key Laboratory of Fluid Transmission Technology of Zhejiang Province,Zhejiang Sci-Tech University,Hangzhou 310018,China%Key Laboratory of Marine Geology and Metallogency,First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China; Key Laboratory of Submarine Acoustic Investigation and Application of Qingdao(Preparatory),Qingdao 266061,China
• Subjects: Acoustics; Broadband; Capacitance; Charging; Deep sea; Deep water; Earth and Environmental Science; Earth Sciences; Electric potential; electric potential difference; electric power; Electric sparks; Electrodes; Energy; Geological hazards; geophysics; Hazard assessment; infrastructure; Marine engineering; Mineral resources; Ocean floor; Oceanography; Research Paper; Seismic exploration; Seismic response; Shipbuilding; Sound sources; Statistical analysis; Statistical methods; Strata; Underwater exploration; Voltage; sparker seismic source; main frequency; high-resolution marine seismic exploration; sound source level; electro-acoustic characteristics
• ISSN: 2096-5508; 2523-3521
• DOI: 10.1007/s00343-023-3131-4

The construction of major marine infrastructure projects and the exploration and development of deep-sea mineral resources require fine imaging of seabed strata and structures. The high-resolution marine seismic exploration based on a high broadband sparker source is an important approach to reveal seabed stratum and reservoir structure, and identify geohazard. To optimize the performance of sparker seismic source, we investigated the electro-acoustic characteristics of spark discharge under conditions of different charging voltages and electrode numbers. Results show that the sound source level increased with the increase of the charging voltage, whereas the main frequency decreased when the charging voltage increases. In addition, it was found that the charging capacitance had more obvious influence on the main frequency than the sound source level did. Although the load energy decreased with increasing electrode number, the sound source level still increased but the main frequency decreased. Meanwhile, the primary to bubble (P/B) ratio increased with the increase of the electrode number. To gain a deeper insight into the electro-acoustic characteristics, we investigate the relationship between sound source level and power peak, from which a good correlation was observed. A more practical statistical analysis on the rise rate of current was processed, and a perfect logarithmic function was derived. Furthermore, we found that the main frequency was most possibly subjected to the electrical energy, especially the charging energy per electrode. The results indicate that the charging energy per electrode less than 10 J could increase the main frequency to above 300 Hz. At last, the main frequency could be reduced to 20 Hz when the charging energy of a single-electrode discharge was enhanced to over 4 kJ. This study shall be helpful in developing a sparker seismic source and improving the performance for marine engineering exploration and geohazard assessment.