Tidal Wave

is a film directed by Shiro Moritani in 1973. It is based on the 1973 novel Japan Sinks by Sakyo Komatsu. The film stars Keiju Kobayashi, Hiroshi Fujioka and Ayumi Ishida. Synopsis Thirty million years ago, the country of Japan was part of the continent of Asia, and has since split off into its own archipelago. Another landmass shift is about to occur. In the present day, geophysicist Dr. Tadokoro and Onodera Toshio take the submarine Wadatsumi-1 to the Ogasawara Islands, in order to investigate tremors in the seafloor. They discover that the land mass of the Japanese islands is collapsing into the Japan Trench. Afterward, Onodera is introduced to Abe Reiko, and the two become lovers. Relaxing on the beach, they witness an eruption of Mt. Amagi. A meeting of government officials, including Prime Minister Yamamoto, focuses on assessing the disaster. Dr. Tadokoro warns that more eruptions and earthquakes are imminent, but his claims are rejected as alarmist. He later meets with a mysterious wealthy man named Mr. Watari, who agrees to fund the doctor's research expeditions. With this funding, he develops a course of action to address a nationwide earthquake disaster. During a meeting to secure a research submarine from France, the volcano Kirishima erupts.