TOKYO >> A total of 502 tsunami safety towers were erected in Tokyo and 22 other prefectures through April 2021, an 11-fold increase in the number that existed prior to the catastrophic 2011 Tohoku earthquake, according to a Cabinet Office survey. The quake was the strongest in Japan’s recorded history.

The government subsidizes half the construction costs for the towers, which provide temporary refuge during a tsunami. But the burden on local governments still amounts to several hundred million yen.

In 2014 the subsidy was increased to two-thirds in areas where extensive damage from a major Nankai Trough earthquake is anticipated, helping to speed up construction. The trough runs beneath the Pacific Ocean in southeast Japan, from Shizuoka to Kyushu. Seventy percent of towers are west of the densely populated Kanto region, where Tokyo is located. Shizu­oka prefecture, one such area west, has the most towers, at 139.

In addition, more high-rise buildings are designated as tsunami refuges, bringing the total to 15,304 buildings in 37 prefectures.

Local governments outside the Nankai Trough zone are seeking a subsidy increase. A bill by the Liberal Democratic Party would boost the subsidy to two-thirds in areas expected to suffer damage from big earthquakes with epicenters in the Japan and Chishima trenches.