123 / 2025-07-15 08:41:21

Projected Increase in Wave-induced Liquefaction Risks under Climate Change-induced Severer Wave Conditions

liquefaction,climate change,wave,soil bed,offshore wind

This paper discusses the potential for increased liquefaction risk in seabed along the Japanese coast due to more severe wave conditions caused by climate change. A simple and practical assessment method for wave-induced liquefaction was applied, utilizing Ocean Wave Information near the Japanese coast (NOWPHAS). The results for the current climate, based on the observed wave heights from NOWPHAS between 2015 and 2021, indicate that liquefaction could occur in a sandy seabed at water depths of up to 50 meters, and in a silt bed at water depths of up to 70 meters.  With a 4% wave height increase as projected by the Japanese Ports and Harbours Bureau, the water depths at which liquefaction could occur may increase only slightly by 5m. In contrast, under a more extreme yet possible scenario with a 30% increase in wave height, the water depths of liquefaction risk increase significantly by approximately 15–20 m. Namely, liquefaction could occur in sand beds at water depths up to 65 meters and in silty beds at water depths up to nearly 100m. This suggests that liquefaction is likely to occur in the seabed of loose sands and silts around anchors for floating offshore wind turbines which are typically installed at water depths beyond 50 meters, potentially causing instability in the foundations of floating offshore wind and cables, as well as significant scour and erosion around them.