Is the Tsugaru Strait the high seas? Tsugaru Strait location

It's the high seas. Tsugaru Strait (Tsugaru-kaikyo; tsugaru strait）

In the Pacific Northwest, between Honshu, Japan and the island of Hokkaido. It is bordered by the Sea of Japan to the west and the Pacific Ocean to the east, and is 24,40 kilometers (15,25 miles) wide. An undersea tunnel has been built to connect Aomori and Hakodate on both sides of the strait.

The strait runs east-west, is about 130 kilometers long, and 18.75 kilometers wide from north to south. The middle of the strait is open and narrow at both ends, the east end is about 20 kilometers wide, and the west end is only 18 kilometers wide. The terrain of the strait is rugged, deep in the east and shallow in the west, with the shallowest point in the west being 133 meters and the deepest point in the east being 449 meters.

**The water depth of the waterway is generally 200 meters, and the deepest depth is 521 meters.

The Tsugaru Strait, located between Honshu and Hokkaido, is one of Japan's most important straits. It is connected to the Sea of Japan to the west, the Pacific Ocean to the east, and the strait to the north, to the Sea of Okhotsk and the Aleutian Islands, and to the south to the Hawaiian Islands and the Pacific Ocean. In addition, the Tsugaru Strait is also a necessary transit point for sailing from the eastern coast of Japan to the west.

The Tsugaru Strait belongs partly to Japan and partly to the international high seas.

The Tsugaru Strait is located in the northwest Pacific Ocean, between Honshu and Hokkaido Island in Japan (30 minutes east longitude 140 degrees east longitude, 41 degrees 30 minutes north latitude).

It is bordered by the Sea of Japan to the west and the Pacific Ocean to the east, and is 24-40 kilometers wide. It is an important strait north of the so-called first island chain. An undersea tunnel connecting Aomori and Hakodate across the Taiwan Strait has been completed.

Located between Honshu and Hokkaido, it is one of Japan's most important straits. It is bordered by the Sea of Japan to the west, the Pacific Ocean to the east, the Sea of Okhotsk and the Aleutian Islands to the north, and the Hawaiian Islands and the Pacific Ocean to the south. Its transportation and strategic position are very important.

In addition, the Tsugaru Strait is also a necessary point for Japanese navigation from the east coast to the west. Therefore, the Tsugaru Strait is of great significance to Japan's coastal shipping.

Japan's Kyodo News Agency said on the 21st that the Tsugaru Strait between Honshu and Hokkaido in Japan and other five places in the Japanese Sea are not 12 nautical miles according to the international territorial sea standard of 12 nautical miles, but 3 nautical miles, which is based on the secret agreement signed by the United States and Japan to allow the passage of US nuclear aircraft carriers.

Because, if the "12 nautical mile" standard of territorial waters is applied, Japan's "three non-nuclear principles" will collide head-on with the passage of US nuclear aircraft carriers in Japan's inland sea. The three non-nuclear principles refer to: "do not possess, do not manufacture, and do not introduce nuclear weapons".

If the 12-nautical-mile territorial sea standard were to be applied, the principle of "no introduction" would be violated.

Kyodo News reported on the basis of the testimonies of a number of former vice ministers of foreign affairs that the United States and Japan signed a secret treaty when revising the security treaty in 1960, and Japan narrowed its territorial waters according to the secret treaty, intending to leave the main shipping lanes through which the nuclear aircraft carrier passes as the high seas.

In addition to the Tsugaru Strait, there are also the Soya Strait between Hokkaido and the Kuril Islands, the Osumi Strait in southern Kyushu, and the east and west coasts of Tsushima Island. When Japan enacted the Territorial Sea Law in 1977, the 3 nautical mile standard was still applied to the above five sites. Japan** has been explaining this issue before:

This is to facilitate free passage around the perimeter of the main straits. Kyodo News reported that after the collapse of the Cold War system, if the US military docked its nuclear aircraft carrier in a Japanese port, it would remove the tactical nuclear **, but the nuclear submarine seems to be carrying the strategic nuclear ** through this "high sea in the inland sea".

According to Japanese law, Japan only enjoys an economic zone of 12 nautical miles, not a territorial sea, in fact, according to international law, Japan can be divided into inland seas, but at that time, the law was changed for the convenience of the US military.

According to international law, the Kamatsu Strait is supposed to belong to Japan's inland sea. However, for the sake of the convenience of the US military, the United States has carried out specialization, and some waters of the Kamitsu Strait have become open seas.

The Seikan Tunnel is a strait tunnel built in the Tsugaru Strait that connects Aomori with Hakodate in Hokkaido. For a long time, Aomori in Honshu and Hakodate in Hokkaido have been separated by the Tsugaru Strait. Passengers and cargo between the two places can only be transported by sea ferry, except by airplane.

From Aomori to Hakodate across the strait, sea voyages are hourly, and during typhoon season, sea transportation is interrupted at least 80 times a year. As a result, people are desperately hoping that in addition to airplanes and ferries, there will be more economical and convenient transportation between the two sides of the Taiwan Strait. The idea of the Seikan Tunnel Project came into being.

In May 1964, the Seikan Tunnel began to be excavated. After seven years of scientific investigation of the seabed, the experts finally selected a safe location for the tunnel, and the excavation of the main tunnel officially began in April 1971. After 12 years of construction, on January 27, 1983, the pilot tunnel of the Seikan Tunnel, the world's longest undersea tunnel, was finally opened from Hamana, Imabetsu Town, Aomori Prefecture in the south to Yuri, Chinai-cho, Hokkaido in the north.

On March 13, 1988, the Seikan Tunnel was officially opened, ending the history of shipping between Honshu and Hokkaido by sea. In the early morning of March 13, the first electrified train departed from Aomori Station and Hakodate Station opposite each other. It takes only about 30 minutes for the train to pass through the Tsugaru Strait from the bottom of the sea.

The Seikan Tunnel consists of 3 tunnels. The total length of the main tunnel is 1 km, including 1 km on the seabed, 1 km on the Honshu side of the land part, and 17 km on the Hokkaido side. The main tunnel is 9 meters wide and 9 meters high, with a cross-section of 80 square meters.

In addition to the main tunnel, there are two auxiliary tunnels: one is a pilot tunnel for subsea geology; The second is the operation tunnel for transporting equipment and transporting sand and gravel. The two tunnels are 4 meters high and 5 meters wide.

Seawater leaking into the tunnel is diverted to a tank in the pilot tunnel and then discharged from the ground with a high-pressure pump. The work pit is used as a place for train repairs and track maintenance. The cost of building this super tunnel is extremely high.

When construction of the main tunnel began in 1971, the total cost of the project was estimated at US$830 million, but subsequent additional costs were increased several times, and it was estimated that the entire project would cost US$2.7 billion by the time the tunnel was completed, an average of more than US$50 million per kilometre.