The Sangar Strait, otherwise called Tsugaru, is located between the Japanese islands of Honshu and Hokkaido. It connects the Sea of Japan and the Pacific Ocean, while under it is Seikan - a railway tunnel stretching from Aomori Prefecture to the city of Hakodate.
Strait Information
The width of Tsugaru ranges from 18 to 110 km, depending on the place of measurement, the length is 96 km. The depth of the navigable part depends on the time of the ebb and flow, therefore it can vary from 110 to almost 500 meters.
The strait got its name in honor of the Tsugaru peninsula, located at the northern tip of Honshu. The same was named after the ethnonym of the tribe living in the area.
Until the middle of the twentieth century. The Sangarsky Channel was considered the official name, since the first map with its image was compiled by Admiral Kruzenshtern, giving him just such a toponym.
Despite the abundance of anchorage, Tsugaru is well blown by the winds due to the lack of closed spaces. Both banks adjacent to the strait have an uneven relief (mainly mountainous) covered with dense forest.
The cities closest to Zugar are Aomori, located on the south side, and Hakodate on the island of Hokkaido (Japan). Also in relative proximity are Sapporo and Yubari.
The main course to Tsugaru is directed east, however, it tends to branch and change its course of movement, reaching a speed of about 6 km / h, while the tidal wave travels at a speed of 2 m / s.
Sangar Strait regime
Until the Second World War, the passage of merchant and military vessels through the Sangarsky Strait was free. Since until that time not a single agreement had been concluded that regulated the Tsugaru regime, the Land of the Rising Sun actively used this omission against the USSR. So, with the onset of World War II, Japan closed access to the strait to all foreign vessels, declaring it a state’s defense zone.
For many years, Soviet ships lost the ability to pass the short cut to the Pacific Ocean. This was of great importance, since the Sea of Japan (it is easy to find it on the map) is closed and Tsugaru was the only strait connecting it with open waters.
Therefore, after the end of the war, along with the defeat of imperialism in the Land of the Rising Sun, the question of the mode of passage of ships was posed differently. As a result, at the 1951 conference in San Francisco on a peace treaty with Japan, the USSR put forward a proposal to demilitarize the strait and open it to merchant ships of all countries and military transport of coastal states. However, the initiative of the Soviet Union was rejected, despite its prudence in terms of ensuring freedom and security of navigation.
Today, the Sangarsky Strait is a free zone for the passage of any ships, however, its regime largely depends on the discretion of Japan and may change at any time.
Tsugaru and the Sea of Japan
On the map, this reservoir is located in the Pacific basin, separated from it by the islands of Japan and Sakhalin. Its area is 1.062 million square meters. km
In winter, the northern part of the water is icebound, and the only ice-free part of the sea on this side is the Tsugaru Strait. This makes it extremely popular for merchant ships in the coastal regions of Russia as the shortest way to the Pacific Ocean. In addition, Japan’s current military policy has severely reduced territorial waters - up to 3 nautical miles (instead of 20) from the coast so that the U.S. Navy can freely pass through the Strait of Sangar without violating the law banning the location of nuclear weapons in the Land of the Rising Sun.
The Sea of Japan, otherwise called the Vostochny Sea, washes the shores of Russia, Korea and Japan — the military ships of these states, according to the USSR’s plan, were to gain access to Tsugar.
Also, the Sangar Strait is used for fishing, catching crabs and algae.
Seikan
The Seikan railway tunnel with a length of 53.85 km with a fragment of 23.3 km that goes under water to a depth of 100 meters below sea level was considered the longest in the world before the construction of the Gotthard Base Tunnel. Due to the low cost of flights within Japan, it is not popular among local residents, since it is significantly inferior in terms of travel time.
This tunnel lies under the Sangarsky Strait, forming a railway link between the Honshu and Hokkaido Islands, being part of the Kaikyō (Kaikyo) line. Its name is derived from the abbreviation of the names of cities between which it has spread - Aomori and Hakodate Prefectures.
In addition, Seikan is the second most underwater tunnel after Kammon, connecting Honshu Island (Japan) and Kyushu.
Tunnel history
Seikan's design took 9 years. It was built 24 years from 1964 to 1988. The construction was attended by over 14 million people who paved the seamless path.
This is a special type of railway construction, in which welded rail lashes are used, the length of which significantly exceeds the standard. Due to this technology, the jointless path is more durable and reliable during operation, but it requires special attention and care, since the consequences of a malfunction are often fatal.
The impetus for the construction of the tunnel was the event of 1954: a large-scale marine disaster occurred in the Tsugaru Strait, which claimed more than 1000 lives. All these people were passengers of five ferries, cruising between Honshu and Hokkaido. The Japanese government reacted to the incident almost instantly - as early as next year, the survey work was completed, on the basis of which it was decided to build Seikan. The cost of its construction in the prices of that time amounted to about $ 4 billion.
On March 13, 1988, the tunnel was opened for freight and passenger traffic.
Modernity
On March 26 this year, the Shinkansen tunnel, a high-speed train running about 900 km between Tokyo and Hakodate (Hokkaido Islands) in 4 hours, was launched in the Seikan tunnel.
As mentioned above, now the tunnel continues to be relatively free, since even the replacement of the ferry crossing by the railway tunnel could not stop the decline in passenger flow in this direction. Over the eleven years since the beginning of the exploitation of Seikan, it has decreased by more than 1 million people. Previously, the flow amounted to more than 3 million passengers, but by 1999 it had fallen to less than 2 million.