How Japan Keeps Its Sinking Airport Open

Japan built an airport on land that keeps sinking. So how does Kansai International Airport stay open—and what does it cost to keep it working? From the clay under Osaka Bay to the steel plates under the terminal, this episode explains why Kansai was built offshore, how engineers correct uneven settlement, and why Typhoon Jebi changed the airport’s defenses. The 13.72 m figure is average settlement on Island 1 since construction began, including 9.82 m before opening. It is not a claim that the runway dropped 13.72 m after 1994 or sits that far below sea level. The 5 cm and 20 cm rates refer to the two islands over the year measured to December 2025.