San Francisco Bay is located off the coast of the United States and is part of the Pacific Ocean. It connects with the Golden Gate Strait, which is world famous for its suspension bridge. This unique natural water area is gradually decreasing due to human activities. The San Francisco Bay, its features and its unusual facts will be described in more detail in the article.
general description
San Francisco Bay is one of the many bays of the vast Pacific Ocean. As stated earlier, this bay connects to the ocean through the Golden Gate Strait. Basically, the water area is shallow - on an area of more than 100 km 2 its depth does not exceed 10 meters, which is considered an extremely small value.
It should be noted that more than half of all river water falling into the bay originates in the Sierra Nevada, Hamilton and Santa Cruz mountains. The largest river carrying its waters into this area is the San Joaquin. Most of the other rivers first flow into the San Pablo and Saisan Bays, which are part of the San Francisco Bay. Currently, almost the entire water area near the coast, especially where migratory birds nest, is under the protection of the Ramsar Convention.
History
When asked what the San Francisco Bay is, you should turn to history. Natural conditions (river spills and soil erosion), as well as human activities, have largely affected the formation of the water area. Until 1850, the entire bay was navigable until it was discovered that sand that is carried by rivers accumulates in places where the underwater current of the bay is very weak. Because of this, its depth began to decline quite sharply.
Almost immediately after that, the earth extracted from the pits, as well as the soil from the constructed tunnels, began to be poured along the bay. At that time, shallow bays, sand dunes, tidal pools and marshy soils did not have an owner, that is, they were considered "no man's land".
Formation
Gradually, the coastline began to expand, and the bay began to decline. So, over 150 years, its water area has decreased by almost one third. Today, significant areas of lowlands and marshes have been restored. Despite this, it is very difficult to establish the exact area of the San Francisco Bay.
Most of the water that people destroyed as a result of their activities was built up. However, the soil structure here is such that it undergoes deformation. Due to the fact that this area is seismically unstable and dangerous after passing even minor earthquakes, the soil begins to "liquefy."
The islands
There are five large islands in the San Francisco Bay Area. Each of them has its own bright and interesting history. On the island of Alamida, there is a city with the same name, in which about 80 thousand people live. Scientists have found that in ancient times it was a peninsula, however, due to the increase in water level in the bay and erosion of the soil, Alamida gradually turned into an island. Currently, bridges and two underwater tunnels connect it to the mainland, one of which was built in 1928.
Angel Island (Angel) is a historic landmark in California. In 1863, forts were built here to defend against the Confederates during the Civil War. The island can be reached by ferry, there is no other connection with it.
Yerba Buena is an island on which a military base was located for 120 years, until 1990. After the closure, a program was adopted to restore and conserve flora and fauna. Currently, there are 3 natural parks.
Other islands
Treasure Island is located on the east side of San Francisco Bay. It is also known as the “treasure island”. This is an artificial island, which was created in the period from 1936 to 1937. He was “poured” at the opening of the Golden Gate exhibition, which had an international level. It got its name from the book Treasure Island by R. L. Stevenson.
In the center of the bay is one of the most famous islands in the world - Alcatraz, also called Rock, which translates from English as “rock”. In 1850, a fort was erected here, in which more than a hundred long-range guns were installed. He had practical protective functions. However, in 1909, all the buildings were demolished as unnecessary, and a military prison building was erected on their foundation, which in 1912 began to receive the first prisoners.
In 1934, Alcatraz became a federal prison intended for especially dangerous and main enemies of the state. Also here were placed those who had previously escaped from other prisons. Due to the temperature of the water in the San Francisco Bay, which does not rise above 18 ° C even in summer, as well as the remoteness of the island from the mainland, escape becomes impossible.
In 1963, the prison was closed, and a museum was opened on its territory, which is very popular among tourists. And the island of Alcatraz itself was recognized as a historical national monument.
Bridge
The most famous and recognizable part of the California Sea and San Francisco Bay is the Golden Gate Bridge. Built in the period from 1933 to 1937, this building became the largest with a similar structure. It creates a visual sensation as if the bridge were hanging. This is due to the nature of its type of construction. Its total length is 2737 m, and the height of the supports reaches 227 m, and this is only above the water. The mass of the structure has a volume of almost 900 thousand tons. At high tide, the distance from the surface of the water to the bridge reaches about 70 m.
The Golden Gate Bridge connected the main part of the city with the Marin County and the suburb of Sausalito. Almost immediately it became popular not only among local residents, but also tourists. Everyone wanted to be photographed against his background. Over time, this building became a kind of hallmark of the city, by which almost everyone can recognize San Francisco.
Wadden Sea
The water area of the San Francisco Bay belongs to the Wadden Sea. Watts are a series of shallow marine areas that are interrupted by shallow depths. Similar seas are located off the coast of Denmark, Germany and the Netherlands.
Its length is about 100 km 2 from east to west and from 5 to 19 km from south to north. As mentioned earlier, the sea is shallow, its average depth reaches 10 meters. The inhabitants are striking in their diversity. Here you can find beluga whales, swordfish, manta rays, sailfish and several species of sharks. Sperm whales, blue and gray whales often swim on plankton fields located in the bay during migration.
At the bottom of the California Sea live various mollusks, echinoderms and crustaceans. Along the coast you can often find sea turtles, which at some time lay eggs. There are also numerous nests of waterfowl and common birds. Since 2005, the California Sea and San Francisco Bay has been protected by UNESCO and is a World Heritage Site. This amazing place impresses with its beautiful landscapes, attracting numerous tourists here all year round.