$20 Billion Remote Airport Slowly Sinking Into The Sea

This engineering marvel sunk 38 feet in just three decades.

Damjan

• Published in Technology
• October 14, 2024

Kansai International Airport is one of Japan’s most remarkable feats of engineering, showcasing the country’s innovative approach to solving infrastructure challenges. Situated on a man-made island in Osaka Bay, this $20 billion airport was constructed to relieve overcrowding at Osaka International Airport.

Building an entire airport in the sea was ambitious, but it reflects Japan’s ability to push the boundaries of what is possible in modern architecture and civil engineering. The airport is on an artificial island named Kankūjima, around 300 miles west of Tokyo.

According to Google, Osaka Bay, where the island was built, is a significant body of water with an average depth of 27 meters. This bay flows into Wakayama Bay and, ultimately, the Pacific Ocean, providing a unique setting for this large-scale project.

Kansai International Airport is divided into terminals: Terminal 1, designed by the world-renowned architect Renzo Piano, and Terminal 2. Terminal 1 handles domestic and international flights and is the most extended airport terminal globally, spanning 1.7 kilometers. Terminal 2 is used for local flights, serving regional airlines and passengers.

Despite meticulous planning, Kansai International Airport has faced challenges since its opening in 1994, most notably due to the island’s gradual sinking. Although engineers took measures to reinforce the clay foundation beneath the airport, they underestimated the unpredictability of the sea floor.

The island has already sunk 38 feet since its construction and is expected to sink an additional 13 feet by 2056, raising concerns that it could be submerged by 2100.

The flooding of Kansai International Airport occurred in 2018 when Typhoon Jebi struck Japan’s west coast.

The unique design of the airport, which appears to float on water, has caught the attention of social media users worldwide. Enthusiastic posts describe it as a civil engineering marvel, with one user calling it "a wonderful site" and another praising it as "an airport floating in the middle of the ocean."

The airport, with its luxurious shops, including Chanel, Hermes, and Cartier, continues to draw admiration for its services and remarkable location and design. It sees approximately 20 million passengers annually, making it the third busiest airport in Japan.

According to the YouTube channel Design Nerd, Kansai International transports around one million tons of cargo yearly.

A picture of Kansai International Airport from before the addition of its second terminal.

One challenge occurred in 2018 when Typhoon Jebi hit Japan, causing severe damage to the airport. The storm breached the seawalls and flooded the terminal buildings.

The powerful winds were so intense that they pushed an oil tanker into the bridge connecting the airport to the mainland, leaving hundreds of passengers stranded. While the airport’s construction was hailed as groundbreaking, events like this typhoon demonstrate the vulnerabilities of building on an artificial island in the ocean.

Kansai International Airport is a testament to human ingenuity and Japan’s drive to solve urban infrastructure problems.

However, it also reminds us that even the most advanced engineering projects can encounter unforeseen challenges.

The island's ongoing sinking and the risks posed by natural disasters like typhoons continue to test the resilience of this incredible structure.

Damjan