The definition of the ocean
Salt water, which accounts for about 70.9% of the earth's surface area, is called ocean, which is distributed in huge basins on the surface. The area is about 362,000,000 square kilometers (140,000,000 square miles). The ocean contains more than1350 million cubic kilometers of water, accounting for about 97.5% of the total water of the earth. The global ocean is generally divided into several oceans and smaller oceans. The four oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean and the Arctic Ocean (some scientists add the fifth ocean, the Antarctic Sea, that is, the waters near Antarctica), and most of them are bounded by land and seabed topographic lines. The four oceans are connected in a large area around the Antarctic continent, that is, the Antarctic Sea (also known as the "Southern Ocean"). Traditionally, the Antarctic Sea has also been divided into three parts, belonging to three oceans. Including the corresponding part of the Antarctic Sea, the Pacific Ocean, the Atlantic Ocean and the Indian Ocean account for 49.8%, 24% and 20% of the total sea area of the earth respectively. Most of the important marginal seas are distributed in the northern hemisphere, and some are surrounded by continents or islands. The largest are the Arctic Ocean and its offshore waters, the Mediterranean Sea in Asia (between Australia and Southeast Asia), the Caribbean Sea and its adjacent waters, the Mediterranean Sea (Europe), the Bering Sea, the Sea of Okhotsk, the Yellow Sea, the East China Sea and the Sea of Japan.
The vast ocean, from blue to green, is beautiful and wide. Ocean, ocean. People always say this, but many people don't know that the sea and the ocean are not the same thing, they are different from each other. So, what's the difference between them and what does it matter?
The ocean is the central part of the ocean and the main body of the ocean. The total ocean area in the world accounts for about 89% of the ocean area. The water depth of the ocean is generally above 3000 meters, and the deepest point can reach 1 10,000 meters. The ocean is far from the land and is not affected by the land. Its water temperature and salinity have not changed much. Every ocean has its own unique ocean current and tidal system. The water in the ocean is blue and transparent, and there are few impurities in the water. There are four oceans in the world, namely, the Pacific Ocean, the Indian Ocean, the Atlantic Ocean and the Arctic Ocean.
The ocean at the edge of the ocean is an accessory part of the ocean. The area of the sea accounts for about 1 1% of the ocean. The water depth of the sea is relatively shallow, with an average depth of several meters to two or three kilometers. The sea is close to the mainland and is influenced by the mainland, rivers, climate and seasons. The temperature, salinity, color and transparency of seawater are all affected by land and have obvious changes. In summer, the sea gets warmer and the water temperature drops in winter. In some sea areas, seawater will freeze. Where the river flows into the sea, or in the rainy season, the sea water will weaken. Due to the influence of land, rivers carry sediment into the sea, and the offshore seawater is turbid and the transparency of seawater is poor. The sea has no independent tides and currents. The ocean can be divided into marginal sea, inland sea and Mediterranean sea. The marginal sea is not only the edge of the ocean, but also close to the continental front; This kind of sea is widely connected with the ocean and is generally separated from the ocean by a group of islands. China's East China Sea and South China Sea are marginal seas of the Pacific Ocean. The inland sea is a sea located on the mainland, such as the Baltic Sea in Europe. The Mediterranean Sea is a sea between several continents, and its water depth is generally deeper than that of the inland sea. There are nearly 50 major oceans in the world. The Pacific Ocean is the largest, followed by the Atlantic Ocean, and the Indian Ocean is similar to the Arctic Ocean.
(3) the generation of ocean currents
The water in the sea always flows in a regular and clear form, which is called ocean current. One of the most famous is the Gulf Stream, which is 50 miles wide at its narrowest point and has a velocity of 4 miles per hour. It goes north along the North American coast, crosses the North Atlantic, and regulates the climate in northern Europe. The North Pacific Ocean current is a similar warm current, which flows from the tropics to the north, raising the temperature on the west coast of North America.
The prevailing wind is the main force to keep the water moving. The different density of seawater is also one of the reasons for ocean currents. The density of cold water is higher than that of warm water, so cold water sinks and warm water rises. Based on the same principle, the cold water near the poles will also sink and flow to the equator below the sea surface. When it reaches the equator, the current rises, replacing the warm water flowing to the poles with surface current.
The coast and mainland of the island also have an influence on the current, either turning the current or dividing it into tributaries. However, in general, the mainstream flows around various ocean basins. Due to the salinity of the earth's seawater (4)
The salt content of seawater varies from place to place, averaging around 3.5%. Among these inorganic salts dissolved in seawater, the most common one is sodium chloride, that is, daily salt.
Some salt comes from volcanoes under the sea, but most of it comes from rocks in the earth's crust. Rock is decomposed by weathering, releasing salt, which is carried to the sea by river water. In the circulation process of seawater evaporation and then condensation into water, after seawater evaporation, salt remains and gradually accumulates to the existing concentration.
The ocean contains a lot of salt, and a layer of salt with a thickness of about1500m (about 600ft) can be spread on the global land.
⑤ Wave
The waves keep rolling on the sea, sometimes as flat as a mirror, and sometimes the waves are huge. Except those caused by earthquakes or volcanic eruptions, waves are mostly caused by winds blowing through the ocean. Waves aroused by storms in the distance may travel hundreds of miles to the coast.
The height between the waves from the peak to the bottom of the trough is mostly less than 10 foot. But in a storm, the waves may be surprisingly high; 1933, the maximum wave recorded in the Pacific Ocean was as high as 1 12 feet.
A wave has a peak, which is the top of the wave. There is also a trough, where the waves are the lowest.
The point where waves cause the maximum positive displacement is represented as the high point on the wave curve. At any given moment, all the points reached by the wave are in different vibration States within a wavelength range, and the vibration reaches the position of maximum positive displacement. The position where the vibration reaches the maximum negative displacement is called "trough". Like water waves, the highest part of a protrusion is a wave crest, and the lowest part of a depression is a wave trough. Waves and tides can also generate electricity.
⑥ Continental shelf
Some land, such as volcanic islands, will fall steeply into the sea. But around the mainland, most of them are frame landmasses covered by shallow sea, which is an extension of the mainland and is called the continental shelf. The continental shelf usually dips down to about 650 feet below sea level, and then drops sharply to the bottom of the sea. The steep side of the continental shelf is called continental slope. Most continental shelves extend about 50 miles offshore; Some are much narrower; However, the continental shelf on the northern shore of Siberia is 800 miles wide and extends to the Arctic Ocean. Most of the world's catches come from the rich waters on the continental shelf; Countries even claim sovereignty over the continental shelf off their coast, taking oil, mineral deposits and other commodity sources as their own.
All landowners island
An old navigator once said, "The islands in the ocean are like the stars in the sky, and no one can count them." This sentence describes the number of islands in the world. So far, it is difficult to tell the exact number of islands in the world's oceans. Some people say that it is around 200,000, and some people say that it is around 65,438+10,000. Which statement is closer? It depends on what method and standard you use to calculate.
In the ocean, some places show a few square meters of rocks on the water; Coral reefs in some places are like strings of pearls, scattered on the sea. The tide receded, rows of rocks were exposed, the sea rose, and some of them were submerged. If these rocks and beaches exposed to the sea are counted as islands, it may be reasonable to say that there are more than 200 thousand islands in the world.
According to the statistics of the number of islands published in the atlas published by various countries in the world, there are about 654.38+million islands in the world, which is well-founded. However, the standards and methods of statistical calculation in the world are not exactly the same: some regard reefs with 10 square meter or 100 square meter as islands; Some regard a small piece of land in the ocean of 500 square meters or even 1 square kilometer as an island. Obviously, the number of statistics by different standard methods is different. Take Indonesia, which has the largest number of islands in the world, as an example. According to the statistics of relevant departments of the Indonesian government, it is more than13,000, and according to the statistics of the Indonesian navy, it is17,000. The number of islands counted by different departments in a country differs by about 4000.
The area of islands in the world is about 9.77 million square kilometers, accounting for115 of the total land area.
The exploration of the ocean.
The science that studies the ocean is oceanography.
As early as prehistoric times, human beings have been traveling on the ocean, fishing from the ocean, making a living from the ocean and exploring the ocean. Before the development of aviation, navigation was the main mode of intercontinental transportation and travel. It was not until the middle of the 10 century that the exploration of the deep seabed really began. Although people know little about diving balls and submarines in the deep sea today.
The ocean is not a special product of the earth;
The ocean is not a special product of the earth, and there are oceans on other planets or satellites, some of which are several times more than the earth, and some are several times less than the earth.
Pet-name ruby relationship between ocean and climate
The ocean is one of the main factors that determine the development of the earth's climate. The ocean itself is the largest heat storage body on the earth's surface. Ocean current is the largest heat energy conveyor belt on the earth's surface. The gas exchange between the ocean and the air (the most important of which is water vapor, carbon dioxide and methane) has great influence on climate change and development. Like typhoons and hurricanes, they are located above the ocean and formed by ocean steam. However, the ocean will be strong, and it is also very strong.
& lt novel of the same name >
Title: Ocean
Author: Black Ming Jie
Date of publication: June 2006
Press: Inner Mongolia People's Publishing House
Pricing: RMB 4.50.
Content:
God knows, she really didn't mean to peek,
Just trying to figure out why the fate of the same boss is so different.
She is very busy,
He wandered around leisurely.
I thought I was in the dark, but I was caught red-handed.
She just made friends with him openly.
Look at him. He is tall and burly.
You can call it a tough guy,
Nothing to buy a bunch of exquisite sexy underwear?
What?
Are those things for her? !
Oh, my god
Now she is really humiliated and thrown into the Pacific Ocean!