気仙沼も襲った“黒い津波”の正体は“海底の土砂”　その恐ろしさを実験で学ぶ

Huge tsunamis struck various areas during the Great East Japan Earthquake. They surged over breakwaters into towns, swallowing cars and people and washing away homes. The tsunami that struck Kesennuma City, Miyagi Prefecture, was a murky black in color. The "black tsunami" is actually "silt," a type of soil that accumulates on the seabed and is finer than sand but larger than clay. "Black tsunami" samples were collected in Kesennuma City during the Great East Japan Earthquake. Experts analyzed the components and found that the samples contained silt that had accumulated on the seabed. Why is the "black tsunami" so terrifying? We investigated this in the laboratory of Professor Taro Arikawa of Chuo University's Faculty of Science and Engineering. From "Chant!" broadcast on March 11, 2021