Humanity has always been attracted by secrets hidden from its sight. From the vast expanses of the Universe to the deepest points of the World Ocean… Modern technologies partially allow us to learn some of the secrets of the Earth, Water and Space. The more the veil of secrecy opens, the more a person wants to know, because new knowledge gives rise to questions. The largest, oldest and least explored Pacific Ocean is no exception. Its influence on the processes that take place on the planet is obvious: it is it that makes it possible for a deeper and more thorough study. The average depth of the Pacific Ocean, the topography of the bottom, the direction of currents, communication with the seas and other water bodies - everything matters for the optimal use by man of his unlimited resources.
World Ocean
All biological species on Earth depend on water, it is the basis of life, so the importance of studying the hydrosphere in all its manifestations becomes a priority for humanity. In the process of forming this knowledge, much attention is paid to both fresh sources and huge volumes of s alt resources. The world ocean is the main part of the hydrosphere, which occupies 94% of the earth's surface. Continents, islands andarchipelagos share water spaces, which makes it possible to designate them territorially on the face of the planet. Since 1953, the international hydrogeographic society has marked four oceans on the modern map of the world: the Atlantic, Indian, Arctic and Pacific. Each of them has the corresponding coordinates and boundaries, which are rather arbitrary for the movement of water flows. Relatively recently, the fifth ocean was singled out - the Southern Ocean. All of them differ significantly in area, water volumes, depths and composition. More than 96% of the entire hydrosphere is s alty ocean water, which moves in vertical and horizontal directions and has its own global mechanism for metabolism, creation and use of energy flows. The World Ocean plays a significant role in the life of a modern person: it forms the climatic conditions on the continents, provides an indispensable transport structure, gives people a lot of resources, including biological ones, and at the same time remains an ecosystem, the possibilities of which have not yet been fully explored.
Pacific Ocean
49, 5% of the area of the World Ocean and 53% of its water resources is occupied by the most ancient and mysterious part of it. The Pacific Ocean with incoming seas has the greatest extent of its water area: from north to south - 16 thousand km, from west to east - 19 thousand km. Most of it is located in the southern latitudes. The most significant are the numerical expressions of quantitative characteristics: the volume of the water mass is 710 million km3, the area occupiedalmost 180 million km3. The average depth of the Pacific Ocean, according to various estimates, varies from 3900 to 4200 meters. The only continent that is not washed by its waters is Africa. More than 50 states are located on its coast and islands, with all parts of the hydrosphere it has conditional boundaries and a constant exchange of flows. The number of islands located in the Pacific Ocean exceeds 10 thousand, they have different sizes and structure of formation. More than 30 seas are included in its water area (including internal ones), their area occupies 18% of the entire surface, the largest part is located on the western coast and washes Eurasia. The greatest depth of the Pacific Ocean, like the entire World Ocean, is in the Mariana Trench. Its research has been going on for more than 100 years, and the more information about the deep-sea quarry becomes available, the more it is of interest to scientists around the world. The shallowest depth of the Pacific Ocean is observed in its coastal zones. They have been studied quite well, but, given their constant use in human economic activity, the need for further scientific research is increasing.
History of development
The peoples who inhabited the Pacific coast on different continents knew a lot about its individual parts, but did not represent the full power and size of this body of water. The first European who saw a small coastal bay was the Spaniard - the conquistador Vasco de Balboa, who for this overcame the high mountain ranges of the Isthmus of Panama. He took what he sawsea and named it the South Sea. That is why the discovery of the Pacific Ocean and giving it its present name is the merit of Magellan, who was very lucky with the conditions in which he crossed its southern part. This name does not at all correspond to the true nature of this aquatic giant, but it has taken root more than all the others that have been proposed as it has been studied. Many expeditions followed in the footsteps of Magellan, the Pacific Ocean attracted new researchers with a large number of questions. The Dutch, the British, the Spaniards were looking for ways to communicate with known lands and in parallel opened new ones. Everything was of interest to researchers: what is the greatest depth of the Pacific Ocean, the speed and direction of movement of water masses, salinity, flora and fauna of waters, etc. Scientists managed to collect more accurate information in the 19th-20th centuries, this is the period of formation of oceanology as a science. But the first attempt to determine the depth of the Pacific Ocean was made by Magellan using a hemp line. He failed - the bottom could not be reached. A lot of time has passed since then, and today the results of ocean depth measurements can be seen on any map. Modern scientists use improved technology and can most likely indicate where the depth of the Pacific Ocean is maximum, where there are places with a lower level, and where there are shoals.
Bottom relief
More than 58% of the earth's surface is occupied by the ocean floor. It has a varied relief - these are large plains, high ridges anddeep depressions. In percentage terms, the ocean floor can be divided as follows:
- Mainland Shoal (depth from 0 to 200 meters) - 8%.
- Mainland slopes (from 200 to 2500 meters) - 12%.
- Ocean bed (from 2500 to 6000 meters) - 77%.
- Maximum depths (from 6000 to 11000 meters) - 3%.
The ratio is quite approximate, 2/3 of the ocean floor has been measured, and the data of various research expeditions may vary due to the constant movement of tectonic plates. The accuracy of measuring instruments increases every year, the information obtained earlier is corrected. In any case, the greatest depth of the Pacific Ocean, its minimum value and the average value depend on the topography of the ocean floor. The smallest depths, as a rule, are observed in the territory adjacent to the continents - this is the coastal part of the oceans. It can have a length from 0 to 500 meters, the average varies within 68 meters.
The continental shelf is characterized by a slight slope, that is, it is flat, with the exception of the coasts, on which the mountain ranges are located. In this case, the relief is quite diverse, depressions and bottom cracks can reach a depth of 400-500 meters. The minimum depth of the Pacific Ocean is less than 100 meters. The large reef and its lagoons with warm clear water provide a unique opportunity to see everything that happens on the bottom. Continental slopes also vary in slope and length -it depends on the location of the coastal region. Their typical structure has a smooth, gradually lowering relief or the presence of a deep canyon. They tried to explain this fact in two versions: tectonic and flooding of river valleys. The latter assumption is supported by soil samples from their bottom, which contains river pebbles and silt. These canyons are quite deep, due to their average depth of the Pacific Ocean is quite impressive. The bed is a flatter part of the relief with constant depth. Cracks, crevices and depressions at the bottom of the World Ocean are a frequent phenomenon, and the maximum value of their depths, as already mentioned, is observed in the Mariana Trench. The relief of the bottom of each area is individual, it is fashionable to compare it with land landscapes.
Peculiarities of the relief of the Pacific Ocean
The depth of the deeps in the Northern Hemisphere and a significant part of the Southern Hemisphere (and this is more than 50% of the total area of the ocean floor) varies within 5000 meters. In the northwestern part of the ocean, there are a large number of depressions and cracks that are located along the edge of the coastal zone, in the region of the continental slope. Almost all of them coincide with mountain ranges on land and have an oblong shape. This is typical for the coast of Chile, Mexico and Peru, and this group also includes the Aleutian northern basin, the Kuril and Kamchatka. In the Southern Hemisphere, a depression 300 meters long is located along the islands of Tonga, Kermadec. To find out how deep the Pacific Ocean is on average, people used various measuring instruments, the history of which is closely related toresearch work in the water spaces of the planet.
Depth Gauges
Lot is the most primitive means of measuring depth. It's a rope with a load on the end. This tool is not suitable for measuring sea and ocean depths, since the weight of the lowered cable will exceed the weight of the load. The results of the measurement with the help of the lot gave a distorted picture or did not bring any results at all. An interesting fact: Brook's lot was actually invented by Peter 1. His idea was that a load was attached to the cable, which floated when it hit the bottom. This stopped the process of lowering the lot and made it possible to determine the depth. A more advanced depth gauge worked on the same principle. Its feature was the possibility of capturing part of the soil for further research. All these measuring devices have a significant drawback - the measurement time. To fix the value of a large depth, the cable must be lowered in stages over several hours, while the research vessel must stand in one place. Over the past 25 years, soundings have been carried out with the help of an echo sounder, which works on the principle of signal reflection. The operating time has been reduced to a few seconds, while on the echogram you can view the types of bottom soils and detect sunken objects. To determine what the average depth of the Pacific Ocean is, it is necessary to take a large number of measurements, which are then summed up, as a result, the delta is calculated.
History of measurements
XIXthe century is "golden" for oceanography in general and the Pacific Ocean in particular. The first expeditions of Kruzenshtern and Lisyansky set as their goal not only the measurement of depths, but also the determination of temperatures, pressure, density and salinity of water. 1823-1826: taking part in the research work of O. E. Kotzebue, the physicist E. Lenz used the bathometer he created. The year 1820 was marked by the discovery of Antarctica, the expedition of navigators F. F. Bellingshausen and M. P. Lazarev studied the northern seas of the Pacific Ocean. At the end of the 20th century (1972-1976), the British vessel Challenger carried out a comprehensive oceanographic survey, which provided most of the information used to this day. Since 1873, the United States, with the help of the navy, measured the depths and fixed the relief of the bottom of the Pacific Ocean for laying a telephone cable. The 20th century was marked by a technological breakthrough for all mankind, which largely affected the work of Pacific Ocean researchers, who asked a lot of questions. Swedish, British and Danish expeditions set off on a round-the-world trip to explore the largest body of water on our planet. How deep is the Pacific Ocean at its maximum and minimum? Where are these points located? What underwater or surface currents influence them? What caused them to form? The study of the bottom was carried out for a long time. From 1949 to 1957, the crew of the Vityaz research ship mapped many relief elements on a map of the Pacific Ocean floor and tracked its currents. The watch was continued by othersships that constantly cruised in the water area to obtain the most accurate and timely information. In 1957, the scientists of the Vityaz vessel determined the point at which the greatest depth of the Pacific Ocean is observed - the Mariana Trench. Until today, its bowels are carefully studied not only by oceanologists, but also by biologists, for whom a lot of interesting things were also found.
Marian Trench
The trench stretches for 1500 meters along the islands of the same name in the western part of the Pacific coast. It looks like a wedge and has varying depths throughout. The history of occurrence is connected with the tectonic activity of this part of the Pacific Ocean. In this segment, the Pacific Plate is gradually moving under the Philippine Plate, moving 2-3 cm per year. At this point, the depth of the Pacific Ocean is maximum, and the depth of the World Ocean too. Measurements have been taken for hundreds of years, and each time their values are corrected. The 2011 study gives the most surprising result, which may not be conclusive. The deepest point of the Mariana Trench is the "Challenger Deep": the bottom is at a distance of 10,994 m below sea level. For its study, a bathyscaphe was used, equipped with cameras and devices for sampling soil.
How deep is the Pacific Ocean?
There is no unequivocal answer to this question: the bottom topography is so complex and not fully understood that each figure mentioned can be corrected in the near future. The average depth of the Pacific Ocean is 4000 meters, the smallest - less than 100 meters, the famous "Challenger Abyss"characterized by impressive figures - almost 11,000 meters! There are a number of depressions along the mainland, which also amaze with their depths, for example: the Vityaz 3 depression (Tonga trench, 10,882 meters); "Argo" (9165, Northern New Hebrides Trench); Cape Johnson (Philippine Trench, 10,497), etc. The Pacific Ocean contains the largest number of the deepest points of the World Ocean. A lot of interesting work and amazing discoveries await modern oceanologists.
Flora and fauna
Remarkable for researchers is the fact that even at a maximum depth of 11,000 meters, biological activity has been found: tiny microorganisms survive without light, while being subjected to the monstrous pressure of many tons of water. The vastness of the Pacific Ocean itself is an ideal habitat for many species of animals and plants. Which is confirmed by facts and concrete figures. More than 50% of the biomass of the World Ocean lives in the Pacific, the diversity of species is explained by the fact that vast expanses of water are located in all belts of the planet. Tropical and subtropical latitudes are more densely populated, but the northern borders are not empty either. A characteristic feature of the fauna of the Pacific Ocean is endemism. Here are the habitats of the most ancient animals of the planet, endangered species (sea lions, sea otters). Coral reefs are one of the wonders of nature, and the richness of flora and fauna attracts not only a lot of tourists, but also a large number of researchers. The Pacific Ocean is the largest and most powerful. The task of people is to study it andunderstanding of all the processes taking place in it, which will help reduce the degree of harm caused by humans to this unique ecosystem.
