The submarine cable across the Korea/Tsushima Strait measures voltage induced by ocean currents flowing above it. Previous studies confirmed that the cable voltage exhibits a linear relationship with volume transport through the Korea/Tsushima Strait observed by bottom mounted Acoustic Doppler Current Profilers over one year. In this study, we process the voltage data for about 25 years from 1999 to 2023. The processed voltage shows a significant correlation (r = 0.44) with the sea level difference across the Strait (Hakata, Japan minus Busan, Korea), which is used as an index of volume transport through the Korea/Tsushima Strait. This result indicates that the cable voltage data reliably represents the inflow into the East/Japan Sea through the Korea/Tsushima Strait over about 25 years. In addition, we discuss prominent voltage peaks observed during the passage of Typhoons Hinnamnor and Nanmadol in September 2022, suggesting that the voltage data can be applied to the analysis of short-term events such as typhoons.

Submarine cable voltage,Korea/Tsushima Strait,Volume transport,Sea level difference,Typhoon-induced variability