What is the strait connecting Britain and France?

English Channel (English: English Channel, Brittany: Mor Breizh, Wales: M? R Udd (French: La Manche) is a strait that separates Britain from the European continent. Its narrowest area is the Dover Strait, facing Calais across the sea. There have been many military conflicts and naval battles here in history.

Geographical survey

Between Britain and France, the Lamanche Channel is a part of the English Channel. It is 560km long and has an average width of 180km. It connects the Atlantic Ocean to the west and the North Sea to the northeast through the Dover Strait. It is an international shipping artery. With large tidal range and abundant tidal energy resources, it is also an important fishing ground, and there have been many military conflicts and naval battles in history.

Also known as La Manche (French for Strait), the Dover Strait in the northeast (French for Dover Strait) lies between the island of Great Britain and the European continent. The northeast is connected with the North Sea and the southwest is connected with the Atlantic Ocean. Covering an area of 89,900 square kilometers, it is northeast (narrow)-southwest (wide) and looks like a trumpet. The total length of the Dover Channel and the English Channel is about 600 kilometers, generally bounded by the estuary of the Seine River in France and Portsmouth on the south bank of England. The former is narrow in the east and wide in the west, with an average width of about 180 km and the widest point of 220km；; The narrowest part of the latter is from Dover, England, to Grey Nose Point, west of Calais, France, which is only 33 kilometers. The average depth of the English Channel is 60m, and the deepest point is172m. The average depth of the Dover Strait is 30 meters, and the shallowest point is only 24 meters.

The English Channel is a part of the Atlantic Ocean, which lies between Britain and France. The widest point in the southwest is 240 kilometers; The narrowest point in the northeast is 33.8 kilometers, that is, from Dover, England to Calais, France. This part of the strait from Dover to Calais is a crossing area recognized by the British Strait Association. Although the distance from Dover to Calais is less than 1/3 of the Bohai Strait, its difficulty is not simply measured by distance. The average water temperature in the English Channel is 13.6 degrees Celsius.

The English Channel and the Dover Strait are the busiest straits in the world and have important strategic positions. There is a large amount of international shipping. At present, there are as many as 6,543,800 ships passing through the Strait every year, ranking first in the world. Historically, because it played a great role in the economic development of capitalist countries in Western Europe and Northern Europe, people called the waterways of these two straits "Silver Waterways".

form

The English Channel (including the Dover Strait) is actually a narrow shallow sea, which separates the island of Great Britain from the European continent and is also the smallest shallow sea on the continental shelf in Europe. The island of Great Britain was originally connected with the European continent. Later, influenced by the alpine orogeny, the two sides of the Dover Strait began to fold and fracture, the strait area sank, and the sea water gradually rose, resulting in the current land-sea distribution profile. So far, the area where these two straits are located is still slowly sinking.

geologic feature

The sediments are mainly gravels and rocks falling from steep cliffs, and some areas are exposed Cretaceous and later dense rocks. The coasts on both sides of the Dover Strait are composed of Cretaceous strata, and the shore walls are steep and extremely steep. The rocks on both sides of the river were washed away by seawater, which led to the collapse of the bank wall and the retreat of the coast. According to statistics, the width of the strait increases by about 1 meter every 100 years.

climate

The climate in the Straits is warm in winter and cool in summer. The annual temperature is small, rainy and foggy, and there is little sunshine. The lowest temperature is 5438+ 10 in June, with an average of about 4 ~ 6℃. In July, the highest temperature is about 17℃ on the French coast of Dover Strait. There are more than 200 rainy days throughout the year, and the annual precipitation is about 800 mm; On the British coast, there is less precipitation all year round, and there are three rainy days every week. The strait area is foggy, often foggy and white waves surge, which seriously affects the navigation of ships.

Located in the westerlies, the Strait is the main channel for water exchange between the Atlantic Ocean and the North Sea. The mainstream is a tributary of the North Atlantic Warm Current. This tributary makes the Atlantic seawater flow into the North Sea from the southwest through the channel area; The northeast wind will cause southwest airflow, which will make part of the North Sea water flow into the Strait. The characteristics of temperature and salinity have obvious temporal and spatial changes. In late winter (February), the surface salinity is the highest and the water temperature is low, which is 35.3,9 ~10℃ on the west side of the Strait. In the east, the temperature is 35.0, 6 ~ 6.5℃. In summer (August), the surface salinity decreases by about 0. 1 ~ 0.3, while the water temperature rises to 15 ~ 17℃. In the sea area east of 2┦ west longitude, due to strong tidal mixing, the vertical distribution of temperature and salt is uniform throughout the year. In the west of longitude 3┦, there is an obvious thermocline, which makes the bottom water temperature here not exceed 10 ~ 1 1℃ in summer. In some years, strong winds in summer will cause the thermocline to disappear.

resources

Rich in resources, there are oil and natural gas, rich in herring, herring, cod and flounder. Ocean tidal energy is about 80 million kilowatts, accounting for 3 ~ 8% of the world's ocean tidal energy (1~ 3 billion kilowatts), and it is the region with the richest ocean tidal energy resources in the world. From 65438 to 0966, France built the world's largest tidal power station at the mouth of the Lance River, with a total capacity of 240,000 kilowatts and an annual power generation of 544 million kWh.

The tidal range is large and the tidal energy resources are abundant. Tides are mainly semidiurnal tides, but shallow water tides (mainly quarter diurnal tides) are also obvious. Tidal waves have the characteristics of forward waves; In the form of kelvin wave, from the Atlantic to the Strait. Due to the influence of the earth's rotation and topography, the tidal range on the south side of the Strait (the northwest coast of France) is greater than that on the north side (the south coast of Britain). The former is generally 5-6 meters, while the latter is only 2-3 meters. Among them, the Gulf of Saint Marlowe and the mouth of the Somme along the coast of France are famous for their large tidal range. During the spring tide, the tidal range is about 9 ~ 12m, and the maximum tidal range can reach13.5m. In Alderney Waterway, the tidal current speed at high tide reaches 5.0m/s..

other guide

Crossing rules:

The obstacles to crossing the English Channel are: long distance, low water temperature, uncertain weather and tidal waves rolling back and forth between the Atlantic Ocean and the North Sea every six hours or so. One of the biggest obstacles comes from the cold ocean. Among the losers, about 80% had to quit because of hypothermia.

There is a rule that when crossing the English Channel, there must be official supervisors such as referees, navigators and pilots, and no auxiliary equipment is allowed. Although you can penetrate the swimsuit and eat midway, you must not touch any floating objects.