We know that three quarters of our planet is covered by water. The masses of salt water that are home to a large number of animal and plant species that form the richest ecosystems are known as oceans. doWhat is an ocean Really? What characteristics and importance does it have?
In this article, we'll focus on explaining what an ocean is, its characteristics, and its importance to life on the planet.
What is an ocean
An ocean is a large body of salt water that separates two or more land continents. . These aquatic extensions cover most of the surface of our planet (71% of the earth's surface) and communicate with each other, covering thousands of square kilometers and containing more than a trillion cubic kilometers of water.
Given these dimensions, it's understandable that the ocean is a distinctive feature of our world. Life originated in them and they still maintain the highest percentage of known biodiversity, which also means they are a source of food for humans and many other economic and recreational activities. Furthermore, it's important to mention that the Arctic Ocean is currently facing serious threats.
For this reason, the oceans have particularly fascinated and terrified him throughout human history, since they constituted windows of opportunity and lines of demarcation that prevented him from moving alone from one corner of the earth to another. Also, because these huge bodies of water play a vital role in Earth's natural cycles, many weather accidents and natural disasters occur on their surface, often keeping human coastal populations at bay.
The oceans are really huge masses of water. It has an estimated area of ​​361.000.000 square kilometers, or three-quarters of the entire Earth.
Its average depth is 3.900 meters (with better known exceptions, such as the Mariana Trench at 11.034 meters), and its volume is about 1.300.000.000 square kilometers, or 94% of the Earth's water.
Classification and origin
There are three oceans in the world: the Pacific Ocean, the Atlantic Ocean, and the Indian Ocean, followed by two smaller oceans: the North Pole and the South Pole. The first two on the list are generally divided into the Pacific Ocean and the North or South Atlantic, respectively. Of these, the largest is the Pacific Ocean.
The Atlantic Ocean separates the continents of Europe and Africa from the Americas, while the Pacific Ocean separates the latter from Asia and Oceania. The Indian Ocean, meanwhile, separates the African continent from Asia and Oceania below India.
The Arctic and Antarctic oceans are located near their respective north and south poles.
While water appears to be a ubiquitous substance on our world, we are less certain of its origin on our planet because it does not exist on other planets as we know it.
It is estimated that small amounts of liquid water were produced when the Earth cooled enough for liquid water to emerge, which was then augmented by ice from outer space in the form of comets from the solar system's asteroid belt.
Sea water is salty because it contains a lot of solid sodium and chlorine., which are converted into table salt (sodium chloride). However, salinity levels are variable and in polar regions it is quite low. It is important to remember that the knowledge of oceanography is vital to understanding the oceans.
Sea water also contains magnesium, potassium, calcium, and other elements in much smaller proportions. It is estimated that, given its size, all known elements can be found in it. A curious fact about ocean water is that its blue color, contrary to what one might think, It is not only due to the blue reflection of the sky, but due to its considerable proportions, the water tends to be blue.
Sea temperature and tides
The temperature of sea water is variable, its warm surface temperature usually ranges between 12 and 30 degrees Celsius, and can be from the surface to 50 meters or even 100 meters deep.
Below these distances, the liquid remains between 5 and -1 °C. Obviously, these values ​​are higher in tropical waters and near the equator, and lower as we approach the poles. Also, ocean water is warmer in summer and colder in winter.
Water in the ocean is never static, but is in constant motion due to the different types of tides caused by the gravitational pull of the moon and the sun, so the surface of the planet exposed to the moon will show a significant increase in water volume, while that exposed to sunlight will significantly reduce.
This gives rise to two types of tides:
- Spring tides. They occur when the Moon is in a new or full phase, that is, the Earth, the Moon and the Sun are aligned and the gravitational forces of the two stars combine to achieve the maximum attraction towards the body of water.
- dead tides. They occur when the Moon and Sun are at opposite ends of the Earth, thus canceling their mutual attraction by going in opposite directions. They occur during the waxing and waning phases of the moon.
Another form of ocean movement is ocean currents, which are the product of the action of the wind on the water, which displaces and moves them by the Coriolis effect and the rotation of the Earth. 28 different ocean currents are known, each of which connects different parts of the Earth in a tangled way.
Disasters and pollution of the oceans
Water in the oceans can be the source of many natural disasters, all due to its impact on planetary climates, as temperatures within the oceans change causing pressure changes and the creation of moving air masses. It is likely that this results in storms, hurricanes, tornadoes or other weather hazards that particularly affect coastal populations.
Likewise, earthquakes and tides can alter the regularity of the waters and trigger tsunamis, which can sweep away everything in their path, as explained in studies on the origin of tsunamis.
The environmental impact of human industrial activities on ecosystems is not immune to the impact of the oceans. This is an environmental tragedy when we consider that 70% of the oxygen on Earth comes from plankton on the ocean surface, which means that the ocean absorbs a large amount of carbon dioxide and prevents the greenhouse effect.
However, overfishing and pollution are estimated to have reduced ocean life by 40 percent since 1950, as many industrial complexes dump toxic waste into the sea. The importance of celebration of World Oceans Day to highlight these problems is undeniable.
The ecological destruction of the ocean is said to be 20-30% complete, with the most alarmist voices declaring that if all continues, marine life could become extinct en masse within 25 years.
I hope that with this information you can learn more about what an ocean is and its characteristics.