The largest bay in the world and its geographical location

The largest bay in the world is the Bay of Bengal, followed by the Gulf of Mexico and the Gulf of Guinea.

The Bay of Bengal is a bay in the northern Indian Ocean, located on the equator, bordering the Indian Peninsula in the west, the zhina Peninsula in the east, Myanmar and Bangladesh in the north, the Indian Ocean from Sri Lanka to Sumatra in the south, and the Siam Bay and the South China Sea through the Straits of Malacca. It is about 1600 km wide and covers an area of 2170,000 square kilometers. The water depth is 2000-4000 meters, which is deeper in the south; Salinity 30-34? . The coastal countries are India, Bangladesh, Myanmar, Thailand, Sri Lanka, Malaysia and Indonesia.

Geographical overview of the Bay of Bengal The Bay of Bengal belongs to a bay in the Indian Ocean. West embedded in Ceylon,

It is bordered by India in the north, Myanmar and Andaman-Nicobar Ridge in the east, and the connecting line connecting Cape drago at the southern end of Sri Lanka and Cape Houlle at the northwest end of Sumatra in the south. The southern boundary line is about 1609 km long. It is about 1.600 km wide and covers an area of 2 1.72 million square kilometers, with an average water depth of 2,586 meters and a maximum water depth of 5,258 meters. The total volume is 56 1.6 million cubic kilometers. It is the largest bay in the world. There are many plankton in the offshore. There are andaman islands and Nicobar Islands in the bay.

The part of the Andaman-Nicobar Ridge exposed from the sea, with andaman islands in the north and Nicobar Islands in the south, separates the Bay of Bengal from the Andaman Sea in the east. At the top of the bay are giant deltas of Ganges and Brahmaputra rivers. Other rivers flowing into the Gulf are Mohanadi River, Godavari River and Krishna River in India. It is an important passage between the Pacific Ocean and the Indian Ocean. The water temperature is 25-27℃. Salinity 30-34? . There are many warm-loving creatures along the coast, such as mangroves at the mouth of the Ganges River and pearls in the coastal shoals of Sri Lanka.

It is located between Indian Peninsula, Indochina Peninsula, andaman islands and Nicobar Islands, with a depth of 2,000-4,000 meters, and the southern half is deeper. Rivers such as Ganges River and Brahmaputra River flow into the northern continental shelf, which is 160 km wide and narrower in the south. Indonesia's North-South Trench near Nicobar-Sumatra Island is one of its main submarine features, with the deepest depth of nearly 45 10 meters. Others include bottomless canyon, Andhra canyon, Krishna canyon, Madras canyon and Bournel canyon. The water temperature in the offshore area is constant all the year round, and gradually decreases to the north. The current changes with the seasons, and the northeast monsoon makes the seawater return clockwise, but the southeast monsoon is the opposite.

Geographical features of the Bay of Bengal The deep-sea basin is roughly U-shaped with a depth of 4,500m. The basin floor has two characteristics: the east is a straight ridge of 90 degrees east longitude, which is 5,000 kilometers long, and the Ganges Delta is alluvial by shelf sediments. The crest of the ridge at 90 degrees east longitude is about 21.34m deep, and its northern end is covered with sediments from the Ganges Delta. There are dendritic ditches (fan valleys) in the delta.

Because of its topographic effect, various forces are concentrated in circumferential annular flow, so tidal range, static vibration and internal waves are obvious. Its coastal trade is developed, and its main ports are Kolkata, Madras, Bangui, Chittagong, Yangon, Mahlman, Phuket, Thailand, Penang, Banda Aceh, Indonesia, Jaffna and Sri Lanka.

continental shelf

The width of the bay of Bengal shelf is 16 1 km, especially in the north and east, and the average depth of the shelf near the sea is183m. The continental shelf is mostly composed of sand, mostly clay and ooze on the seaward side, and several places are cut by some submarine canyons. Among them, the Ganges River Basin is located outside the Ganges-Brahmaputra River Delta, with a depth of 732 meters; The valleys of Andhra Pradesh, Krishna and Mahad Van are distributed on the western edge of the bay.

Characteristics of basin bottom

The deep-sea disk in the Bay of Bengal is roughly U-shaped, with a depth of 4500 meters. The basin bottom has two characteristics: the north is straight, 5000 kilometers long, and the east longitude is 90 degrees. Ganges delta is alluvial by shelf sediments. 90 degrees east longitude. The peak of the ridge is about 2 134 meters deep, and its northern end is covered with sediments from the Ganges Delta. There are dendritic ditches (fan valleys) in the delta. In this way, sediments can be transported to distant deep-sea basins.

Sea surface circulation

The surface circulation in the Bay of Bengal is strongly influenced by the monsoon. In spring and summer, the humid southwest wind causes clockwise circulation. Autumn and winter are converted into counterclockwise circulation by northeast wind.

Hydrological characteristics of rivers injected into the Bay of Bengal

Some major rivers from India and Myanmar flow into it. The famous rivers are Ganges, Yarlung Zangbo, Irrawaddy, salween and Krishna. Its famous islands include Sri Lanka, andaman islands, Nicobar Islands and Phuket.

deposit

The equatorial belt is the most abundant in the Indian Ocean, with an annual precipitation of 2,000-3,000 mm, and the seasonal distribution of precipitation is relatively uniform: in the northern Indian Ocean, the annual average precipitation is about 2,000 mm, and two-thirds of the precipitation is concentrated in the summer when the southwest wind prevails, while in the winter when the northeast wind prevails, the precipitation is less, belonging to the tropical monsoon distribution area. There is little annual precipitation in the Red Sea and the West Arabian Sea, and the annual precipitation is about 100-200mm, which belongs to the tropical desert climate zone. In the vast sea area of the South Indian Ocean, the annual precipitation is generally around1000 mm.

temperature

The Indian Ocean climate has obvious tropical maritime and monsoon characteristics. Most of the Indian Ocean is located in tropical and subtropical regions with a latitude of 40? In the vast sea area in the north, the annual average temperature is15-28℃; The annual temperature in the equatorial zone is 28℃, and some sea areas are as high as 30℃. The temperature is higher than the Pacific Ocean and Atlantic Ocean at the same latitude, so it is called tropical ocean. The temperature distribution in the Indian Ocean varies with latitude. The average annual temperature in the equatorial region is about 28℃. In the northern Indian Ocean, the summer temperature is 25-27? C, the winter temperature is 22-23℃, and the annual average temperature is about 25℃. Among them, the temperature in the Persian Gulf and the Red Sea on the east and west sides of the Arabian Peninsula is often above 30℃ in summer, while the temperature in the hottest season along the Somali coast is generally less than 25℃. The former is related to the baking of the surrounding dry and hot land, while the latter is the result of southwest wind blowing away the surface seawater, flooding the deep cold water and lowering the temperature. In the South Indian Ocean, summer temperature: 20? 25-27℃ nearby, 30? 20-22℃ nearby, 40? It's around 15℃, 60? Near 0℃; Winter temperature: 20 south latitude? 22-23℃ nearby, 30 south latitude? 15- 17℃, 40? Near 12- 13℃, 60 south latitude? The temperature nearby is as low as MINUS 10℃.

pressure factor

The atmospheric pressure systems that have the greatest influence on the Indian Ocean climate are: Indian low, equatorial low, Mongolian high and South Indian Ocean subtropical high. In winter (65438+ 10), influenced by Mongolian high pressure, northeast monsoon blows in the northern Indian Ocean, and the wind direction is consistent with the northeast trade wind. At this time, the temperature in the northern Indian Ocean is low and there is little rain, while the southeast wind blows in the southern Indian Ocean, and the northeast monsoon and southeast wind meet near the equator, forming a strong and rainy intertropical convergence zone. In summer (July), the direct point of the sun moves northward, and the Mongolian high is replaced by the Indian low. The southeast trade wind from the subtropical high in the South Indian Ocean passes through the equatorial sea with high temperature and high humidity, and turns into the southwest monsoon when it enters the North Indian Ocean. As the temperature rises, the precipitation increases greatly.

tropical storm

The Bay of Bengal is the birthplace of tropical storms. It is generally believed that most of these storms occur in the tropical waters of 5 -25 degrees north and south latitude. Typhoon, produced in the western Pacific Ocean, often attacks the Philippines, China, Japanese and other countries; Hurricanes originate in the Atlantic Ocean and often attack the United States, Mexico and other countries. They are called hurricanes. Every year from April to June 10, that is, at the turn of summer and autumn, violent storms are often accompanied by tidal waves, which set off huge waves and roared to the mouth of the Ganges-Brahmaputra River, causing great disasters. 1 970165438+1October 12, a strong storm formed in the Bay of Bengal hit Bangladesh, killing 300,000 people and leaving more than110,000 homeless. On September 20th19th and 20th, 2005, heavy rains hit southern India, causing floods in the coastal state of Andhra Pradesh, leaving nearly 654.38+million people homeless and causing a large number of casualties among local residents. Due to heavy rain, two major rivers have no dikes, resulting in the flooding of railway tracks and main roads leading to the city, at least 23 trains connecting northern and southern India have been cancelled, and another 12 train has been diverted to other routes. In Andhra Pradesh, 100 towns and 1300 villages were cut off, thousands of trees and telephone poles were uprooted by strong winds, and railways, highways and traffic were seriously blocked. According to local media reports, most of the dead died of electric shock or house collapse. The airport runway in the port city of Visaka Putnam is still closed due to accumulated water.

More than 35,000 residents living in low-lying areas have been evacuated to temporary shelters in government buildings and schools. Reuters quoted the office of Bangladesh Disaster Response Center as saying that the gale caused by tropical depression in the Bay of Bengal caused huge waves as high as 1.3 meters along the coast of Bangladesh, causing 1.2 million people to flee their homes. The official of the office said: "Some rivers have burst their banks, and the soaring river has washed away the bridge. In addition, at least 65,438+0,000 families have moved from the worst-hit Noakali area to the highlands. " According to local meteorological officials, at least 40 fishing boats were missing when the storm landed on the southern coast last weekend, with about 300 fishermen on board. An official of the Ministry of Fisheries said: "This fishing fleet used the fishing season to enter the Bay of Bengal, apparently ignoring the warning of bad weather." The Coast Guard and fishermen's organizations then launched a search and rescue operation in Dubo Acali, a disaster-stricken city in the south. Officials of the Ministry of Fisheries said that these missing fishermen may still have hope of survival, because according to past experience, "some missing fishermen can still return safely after the storm". Bangladeshi government officials have not commented on this news. However, the local meteorological department said that storms and tornadoes formed in the Bay of Bengal in September and1October each year will hit the eastern coasts of Bangladesh and India. Just in time for the full moon, the gravity of the moon and a series of small earthquakes made the flood more fierce.