The White Sea is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, the whole of the White Sea is under Russian sovereignty and considered to be part of the internal waters of Russia. Administratively, it is divided between Arkhangelsk and Murmansk Oblasts and the Republic of Karelia, the major port of Arkhangelsk is located on the White Sea. For much of Russias history this was Russias main centre of maritime trade. In the modern era it became an important Soviet naval and submarine base, the White Sea-Baltic Canal connects the White Sea with the Baltic Sea. The White Sea is one of four seas named in English after common colour terms — the others being the Black Sea, the Red Sea, the International Hydrographic Organization defines the northern limit of the White Sea as A line joining Svyatoi Nos and Cape Kanin. There are four main bays or gulfs on the White Sea and these bays connect with the funnel-shaped opening to the Barents Sea via a narrow strait called gorlo.
Kandalaksha Gulf lies in the part of the White Sea, it is the deepest part of the sea. On the south, Onega Bay receives the Onega River, to the southeast, the Dvina Bay receives the Northern Dvina River at the major port of Arkhangelsk. On the east side of the gorlo, opposite the Kola peninsula, is Mezen Bay and it receives the Mezen River and the Kuloy River. Other major rivers flowing into the sea are the Vyg, Umba and Ponoy. The seabed of the part and Dvina Bay is covered in silt and sand, whereas the bottom of the northern part. Ice age deposits often emerge near the sea shores, northwestern coasts are tall and rocky but the slope is much weaker at the southeastern side. The White Sea contains a number of islands, but most of them are small. The main island group is the Solovetsky Islands, located almost in the middle of the sea, kiy Island in Onega Bay is significant due to a historic monastery. Velikiy Island, located close to the shore, is the largest island in the Kandalaksha Gulf, the White Sea is a water-filled depression in the block of a continental shelf known as the Baltic Shield.
Its bottom is very uneven and contains the Kandalaksha Hollow in the northwest, the Onega Bay has many small underwater elevations. The opening and the gorlo of the sea are rather shallow, in addition, there is an underwater ridge in the northern part of the gorlo, resulting in maximum depths of 40 metres in that part
Rauma is a town and municipality of ca.39,700 inhabitants on the west coast of Finland,92 kilometres north of Turku, and 50 kilometres south of Pori. Granted town privileges on 17 April 1442, Rauma is known for its paper and maritime industry, high quality lace and the old architecture of its centre. In the 14th century, before being declared as a town, Rauma had a Franciscan monastery, in 1550, the townsmen of Rauma were ordered to relocate to Helsinki, but this was successfully countered and Rauma could continue its growth. Practically the whole town of Rauma was devastated in the fires of 1640 and 1682. The wooden city centre, which is how large the town was until 1809, has approximately 600 wooden buildings, the neo-renaissance style of many of the houses is a result of prosperity brought on by seafaring. In 1897 Rauma had the largest fleet of sailing boats in Finland, goods were mainly exported to Germany and the Baltic states. In the 1890s, Rauma got a college, which was annexed to the University of Turku.
A part of the department of education still exists in Rauma, the name Rauma comes from the Germanic word strauma, meaning stream. After World War II, Rauma developed into a city, the main industries being shipbuilding and pulp mills. Rauma is the fifth largest port in Finland with almost six million tonnes of shipping per year, olkiluoto Nuclear Power Plant is located next to Rauma, in Eurajoki. Near Rauma, there is the plant of Fenno-Skan. Rauma is located between Turku and Pori by the national road 8, Finnish national road 12 starts from Rauma and it was extended to the port of Rauma in 2008. A railway connection from Kokemäki is in active use, as there is a straight connection to the heavy industry areas. The rail passenger traffic ended in 1988, satakunnan Liikenne Oy runs the local bus traffic and it has 3 lines in Rauma. The hub for the buses is located in Savila while the Long distance buses operate from Rauma bus station. The long distance buses take passengers directly to Pori and Turku and to Tampere, the nearest airport is located in Pori.
The port of Rauma serves only freight ships on frequent basis, Rauma has its own dialect of Finnish, Rauman giäl. The dialect inherits words from languages such as Swedish, the dialect has been diluted into mainstream Finnish in day-to-day use, but it is fairly well studied and practiced as a hobby
The Atlantic Ocean is the second largest of the worlds oceans with a total area of about 106,460,000 square kilometres. It covers approximately 20 percent of the Earths surface and about 29 percent of its surface area. It separates the Old World from the New World, the Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Eurasia and Africa to the east, and the Americas to the west. The Equatorial Counter Current subdivides it into the North Atlantic Ocean, in contrast, the term Atlantic originally referred specifically to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the North African coast. The Greek word thalassa has been reused by scientists for the huge Panthalassa ocean that surrounded the supercontinent Pangaea hundreds of years ago. The term Aethiopian Ocean, derived from Ancient Ethiopia, was applied to the Southern Atlantic as late as the mid-19th century, many Irish or British people refer to the United States and Canada as across the pond, and vice versa.
The Black Atlantic refers to the role of ocean in shaping black peoples history. Irish migration to the US is meant when the term The Green Atlantic is used, the term Red Atlantic has been used in reference to the Marxian concept of an Atlantic working class, as well as to the Atlantic experience of indigenous Americans. Correspondingly, the extent and number of oceans and seas varies, the Atlantic Ocean is bounded on the west by North and South America. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea, to the east, the boundaries of the ocean proper are Europe, the Strait of Gibraltar and Africa. In the southeast, the Atlantic merges into the Indian Ocean, the 20° East meridian, running south from Cape Agulhas to Antarctica defines its border. In the 1953 definition it extends south to Antarctica, while in maps it is bounded at the 60° parallel by the Southern Ocean, the Atlantic has irregular coasts indented by numerous bays and seas. Including these marginal seas the coast line of the Atlantic measures 111,866 km compared to 135,663 km for the Pacific.
Including its marginal seas, the Atlantic covers an area of 106,460,000 km2 or 23. 5% of the ocean and has a volume of 310,410,900 km3 or 23. 3%. Excluding its marginal seas, the Atlantic covers 81,760,000 km2 and has a volume of 305,811,900 km3, the North Atlantic covers 41,490,000 km2 and the South Atlantic 40,270,000 km2. The average depth is 3,646 m and the maximum depth, the bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge. It runs from 87°N or 300 km south of the North Pole to the subantarctic Bouvet Island at 42°S, the MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2000 m along most of its length, the MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the other
The Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canadas Arctic islands. The sea is named after hydrographer Sir Francis Beaufort, the major Mackenzie River empties into the Canadian part of the sea, west of Tuktoyaktuk, which is one of the few permanent settlements on the sea shores. The sea, characterized by climate, is frozen over most of the year. Historically, only a narrow pass up to 100 km opened in August–September near its shores, claims that the seacoast was populated about 30,000 years ago have been largely discredited, present population density is very low. The sea contains significant resources of petroleum and natural gas under its shelf and they were discovered in the period between the 1950s and 1980s, and their exploration became the major human activity in the area since the 1980s. The traditional occupations of fishery and whale and seal hunting are practiced only locally, as a result, the sea hosts one of the largest colonies of beluga whales, and there is no sign of overfishing.
To prevent overfishing in its waters, the US adopted precautionary commercial fisheries management plan in August 2009, in April 2011 the Canadian government signed a memorandum of understanding with the Inuvialuit as a first step in developing a larger ocean management plan. The Canadian government has set a new block of the Beaufort Sea off the Parry Peninsula in the Amundsen as a Marine Protected Area, the protected area is set to protect species and habits for the Inuvialuit community. The International Hydrographic Organization defines the limits of the Beaufort Sea as follows, a line from Point Barrow, Alaska, to Lands End, Prince Patrick Island. There is a dispute involving a wedge-shaped slice on the International Boundary in the Beaufort Sea. Canada claims the maritime boundary to be along the 141st meridian west out to a distance of 200 nmi, following the Alaska–Yukon land border. The position of the United States is that the line is perpendicular to the coast out to a distance of 200 nmi.
This difference creates a wedge with an area of about 21,000 km2 that is claimed by both nations, Canadas position has its roots in the Treaty of Saint Petersburg between the United Kingdom and the Russian Empire that set the boundary between the two. They differ on what should be deemed equitable, Canada contends that an equidistance principle does not result in an equitable boundary, because distortion would occur. The coast of Yukon is concave, whereas the coast of Alaska is convex, because of this, Canada argues that special circumstances apply to this border, a position that the U. S. rejects. Before the end of 2004, the US leased eight plots of land below the water for oil exploration and exploitation, provoking a diplomatic protest from Canada. On 20 August 2009, United States Secretary of Commerce Gary Locke announced a moratorium on fishing of the Beaufort Sea north of Alaska. In July 2010, US–Canada negotiations have started in Ottawa with the meeting planned in 2011
The Arctic Ocean is the smallest and shallowest of the worlds five major oceans. Alternatively, the Arctic Ocean can be seen as the northernmost part of the all-encompassing World Ocean, located mostly in the Arctic north polar region in the middle of the Northern Hemisphere, the Arctic Ocean is almost completely surrounded by Eurasia and North America. It is partly covered by sea ice throughout the year and almost completely in winter, the summer shrinking of the ice has been quoted at 50%. The US National Snow and Ice Data Center uses satellite data to provide a record of Arctic sea ice cover. The Arctic may become ice free for the first time in human history within a few years or by 2040, for much of European history, the north polar regions remained largely unexplored and their geography conjectural. He was probably describing loose sea ice known today as growlers or bergy bits, his Thule was probably Norway, early cartographers were unsure whether to draw the region around the North Pole as land or water.
The makers of navigational charts, more conservative than some of the more fanciful cartographers, tended to leave the region blank and this lack of knowledge of what lay north of the shifting barrier of ice gave rise to a number of conjectures. In England and other European nations, the myth of an Open Polar Sea was persistent, john Barrow, longtime Second Secretary of the British Admiralty, promoted exploration of the region from 1818 to 1845 in search of this. In the United States in the 1850s and 1860s, the explorers Elisha Kane, even quite late in the century, the eminent authority Matthew Fontaine Maury included a description of the Open Polar Sea in his textbook The Physical Geography of the Sea. Nevertheless, as all the explorers who travelled closer and closer to the reported, the polar ice cap is quite thick. Fridtjof Nansen was the first to make a crossing of the Arctic Ocean. The first surface crossing of the ocean was led by Wally Herbert in 1969, in a dog sled expedition from Alaska to Svalbard, with air support.
The first nautical transit of the pole was made in 1958 by the submarine USS Nautilus. Since 1937, Soviet and Russian manned drifting ice stations have extensively monitored the Arctic Ocean, scientific settlements were established on the drift ice and carried thousands of kilometres by ice floes. In World War II, the European region of the Arctic Ocean was heavily contested, the Arctic Ocean occupies a roughly circular basin and covers an area of about 14,056,000 km2, almost the size of Antarctica. The coastline is 45,390 km long and it is surrounded by the land masses of Eurasia, North America, and by several islands. It is connected to the Pacific Ocean by the Bering Strait and to the Atlantic Ocean through the Greenland Sea, countries bordering the Arctic Ocean are, Norway, Greenland and the United States. There are several ports and harbours around the Arctic Ocean In Alaska, in Canada, ships may anchor at Churchill in Manitoba, Nanisivik in Nunavut, Tuktoyaktuk or Inuvik in the Northwest territories
Chukchi Sea is a marginal sea of the Arctic Ocean. It is bounded on the west by the Long Strait, off Wrangel Island, the Bering Strait forms its southernmost limit and connects it to the Bering Sea and the Pacific Ocean. The principal port on the Chukchi Sea is Uelen in Russia, the International Date Line crosses the Chukchi Sea from northwest to southeast. It is displaced eastwards to avoid Wrangel Island as well as the Chukotka Autonomous Okrug on the Russian mainland, the sea has an approximate area of 595,000 km2 and is only navigable about four months of the year. The main geological feature of the Chukchi Sea bottom is the 700-kilometre-long Hope Basin, depths less than 50 meters occupy 56% of the total area. The Chukchi Sea has very few compared to other seas of the Arctic. Wrangel Island lies at the limit of the sea, Herald Island is located near its northern limit. The sea is named after the Chukchi people, who reside on its shores, the coastal Chukchi traditionally engaged in fishing and the hunting of walrus in this cold sea.
In Alaska, the rivers flowing into the Chukchi Sea are the Kivalina, the Kobuk, the Kokolik, the Kukpowruk, the Kukpuk, the Noatak, the Utukok, the Pitmegea, and the Wulik, among others. Of rivers flowing in from its Siberian side, the Amguyema, the International Hydrographic Organization defines the limits of the Chuckchi Sea as follows, On the West. The Eastern limit of East Siberian Sea, a line from Point Barrow, Alaska to the Northernmost point of Wrangel Island. The Arctic Circle between Siberia and Alaska, common usage is that the southern extent is further south at the narrowest part of the Bering Strait which is on the 66th parallel north. The Chukchi Sea Shelf is the westernmost part of the shelf of the United States. Within this shelf, the 50-mile Chukchi Corridor acts as a passageway for one of the largest marine mammal migrations in the world, in 1728, Vitus Bering and in 1779, Captain James Cook entered the sea from the Pacific. Since further progress for that year was impossible, the ship was secured in winter quarters, even so, members of the expedition and the crew were aware only a few miles of ice-blocked sea lay between them and the open waters.
The following year, two days after Vega was released, she passed the Bering Strait and steamed towards the Pacific Ocean. In 1913, abandoned by expedition leader Vilhjalmur Stefansson, drifted in the ice along the northern expanses of the Chukchi Sea and sank, the survivors made it to Wrangel Island, where they found themselves in a hopeless situation. Then Captain Robert Bartlett walked hundreds of kilometers with Kataktovik, an Inuit man and they reached Cape Vankarem on the Chukotka coast, on April 15,1914
East Siberian Sea
The East Siberian Sea is a marginal sea in the Arctic Ocean. It is located between the Arctic Cape to the north, the coast of Siberia to the south, the New Siberian Islands to the west and Cape Billings, close to Chukotka and this sea borders on the Laptev Sea to the west and the Chukchi Sea to the east. This sea is one of the least studied in the Arctic area, the sea shores were inhabited for thousands of years by indigenous tribes of Yukaghirs and Evens and Evenks, which were engaged in fishing and reindeer husbandry. They were absorbed by Yakuts and by Russians, major industrial activities in the area are mining and navigation within the Northern Sea Route, commercial fishing is poorly developed. The largest city and port is Pevek, the northernmost city of mainland Russia, the present name was assigned to the sea on 27 June 1935 by Decree of the Soviet Government. Before that, the sea had no name was intermixedly called in Russia as Indigirskoe, Severnoe, Sibirskoe or Ledovitoe. The International Hydrographic Organization defines the limits of the East Siberian Sea as follows, the Eastern limit of Laptev Sea.
A line from the Northernmost point of Wrangel Island to the Northern sides of the De Long Islands and Bennett Island, from the Northernmost point of Wrangel Island through this island to Cape Blossom thence to Cape Yakan on the main land. Because it is open towards the Arctic Ocean in the north, the gulfs of the East Siberian Sea, like the Kolyma Bay, the Kolyma Gulf. There are no islands in the middle of the East Siberian Sea, but there are a few islands and island groups in its waters, like Ayon Island. The total area of the islands is only 80 km2, some islands mostly consist of sand and ice and gradually erode. The total catchment area is 1,342,000 km2, among the rivers flowing into the East Siberian Sea, the Indigirka, Uyandina, Kolyma, Rauchua and Pegtymel are the most important. Only a few rivers are navigable, the coastline of the sea is 3,016 km long. It makes large bends, sometimes stretching deep into the land, fine bends are rare and occur only in the river deltas. The coastal section between the New Siberian Islands and the mouth of the Kolyma River is uniform, with low and it extends landwards to the marshy tundra filled with numerous small lakes.
In contrast, the coast to the east of the Kolyma River is mountainous, about 70% of the sea is shallower than 50 m, with predominant depths of 20–25 m. North-east to the mouth of the Kolyma and Indigirka rivers, there are deep trenches on the seabed, the region of small depths in the western part forms the Novosibirsk shoal. The greatest depths of about 150 m are found in the part of the sea
Gulf of Finland
The Gulf of Finland is the easternmost arm of the Baltic Sea. It extends between Finland and Estonia all the way to Saint Petersburg in Russia, where the river Neva drains into it, other major cities around the gulf include Helsinki and Tallinn. The eastern parts of the Gulf of Finland belong to Russia, as the seaway to Saint Petersburg, the Gulf of Finland has been and continues to be of considerable strategic importance to Russia. Some of the problems affecting the Baltic Sea are at their most pronounced in the shallow gulf. The area of the gulf is 30,000 km2, the length is 400 km and the width varies from 70 km near the entrance to 130 km on the meridian of Moshchny Island, in the Neva Bay, it decreases to 12 km. The gulf is shallow with the depth decreasing from the entrance to the gulf to the continent. The sharpest change occurs near Narva-Jõesuu, which is why this place is called Narva wall, the average depth is 38 m with the maximum of 100 m. The depth of the Neva Bay is less than 6 metres, therefore, a channel was dug at the bottom for safe navigation.
Because of the influx of fresh water from rivers, especially from the Neva River. The average water temperature is close to 0 °C in winter, in summer, it is 15–17 °C at the surface, the gulf is usually frozen from late November to late April, the freezing starts in the east and gradually proceeds to the west. Complete freezing is usually reached by late January, and it not occur in mild winters. There are frequent strong winds causing waves, surges of water. The northern coast of the gulf is high and winding, with abundant small bays and skerries only a few large bays, the coast is mostly sloping, there are abundant sandy dunes, with occasional pine trees. The southern shores are smooth and shallow, but along the entire coast runs the Baltic Klint with the height up to 55 m, in the east, the gulf ends with Neva Bay and on the west merges with the Baltic Sea. The gulf contains numerous banks and islands, starting from 1700, nineteen artificial islands with fortresses were built in the gulf by Russia.
Their purpose was defense from attacks from water and their construction was urged by the Great Northern War of 1700–1721 and those include Fort Alexander, Krasnaya Gorka, Totleben and others. The largest rivers flowing into the gulf are Neva, keila, Pirita, Jägala, Luga and Kovashi flow into the gulf from the south. From the north flow Sestra River, Porvoo and several small rivers
The Adriatic Sea /ˌeɪdriˈætᵻk/ is a body of water separating the Italian Peninsula from the Balkan peninsula and the Apennine Mountains from the Dinaric Alps and adjacent ranges. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto to the northwest, the countries with coasts on the Adriatic are Albania and Herzegovina, Greece, Italy and Slovenia. The Adriatic contains over 1,300 islands, mostly located along its eastern, Croatian and it is divided into three basins, the northern being the shallowest and the southern being the deepest, with a maximum depth of 1,233 metres. The Otranto Sill, a ridge, is located at the border between the Adriatic and Ionian Seas. The prevailing currents flow counterclockwise from the Strait of Otranto, along the eastern coast, tidal movements in the Adriatic are slight, although larger amplitudes are known to occur occasionally. The Adriatics salinity is lower than the Mediterraneans because the Adriatic collects a third of the water flowing into the Mediterranean.
The surface water temperatures range from 30 °C in summer to 12 °C in winter. The Adriatic Sea sits on the Apulian or Adriatic Microplate, which separated from the African Plate in the Mesozoic era, the plates movement contributed to the formation of the surrounding mountain chains and Apennine tectonic uplift after its collision with the Eurasian plate. In the Late Oligocene, the Apennine Peninsula first formed, separating the Adriatic Basin from the rest of the Mediterranean, all types of sediment are found in the Adriatic, with the bulk of the material transported by the Po and other rivers on the western coast. The western coast is alluvial or terraced, while the eastern coast is indented with pronounced karstification. There are dozens of protected areas in the Adriatic, designed to protect the seas karst habitats. The sea is abundant in flora and fauna—more than 7,000 species are identified as native to the Adriatic, many of them endemic and threatened ones. The Adriatics shores are populated by more than 3.5 million people, the earliest settlements on the Adriatic shores were Etruscan and Greek.
By the 2nd century BC, the shores were under Romes control, following Italian unification, the Kingdom of Italy started an eastward expansion that lasted until the 20th century. Following World War I and the collapse of Austria-Hungary and the Ottoman Empire, the former disintegrated during the 1990s, resulting in four new states on the Adriatic coast. Italy and Albania agreed on their maritime boundary in 1992, Fisheries and tourism are significant sources of income all along the Adriatic coast. Adriatic Croatias tourism industry has grown faster economically than the rest of the Adriatic Basins, maritime transport is a significant branch of the areas economy—there are 19 seaports in the Adriatic that each handle more than a million tonnes of cargo per year. The largest Adriatic seaport by annual cargo turnover is the Port of Trieste, in the southeast, the Adriatic Sea connects to the Ionian Sea at the 72-kilometre wide Strait of Otranto
The Greenland Sea is often defined as part of the Arctic Ocean, sometimes as part of the Atlantic Ocean. However, definitions of the Arctic Ocean and its seas tend to be imprecise or arbitrary, in general usage the term Arctic Ocean would exclude the Greenland Sea. In oceanographic studies the Greenland Sea is considered part of the Nordic Seas, the Nordic Seas are the main connection between the Arctic and Atlantic oceans and, as such, could be of great significance in a possible shutdown of thermohaline circulation. In oceanography the Arctic Ocean and Nordic Seas are often referred to collectively as the Arctic Mediterranean Sea, the sea has Arctic climate with regular northern winds and temperatures rarely rising above 0 °C. The West Ice forms in winter in the Greenland Sea, north of Iceland and it is a major breeding ground of harp seal and hooded seal that has been used for seal hunting for more than 200 years. The International Hydrographic Organization defines the limits of the Greenland Sea as follows, a line joining the Northernmost point of Spitzbergen to the Northernmost point of Greenland.
The West coast of West Spitzbergen, a line joining Straumnes to Cape Nansen in Greenland. The East and Northeast coast of Greenland between Cape Nansen and the northernmost point, while the sea is known for millennia, its first scientific investigations were carried out in 1876–1878 within the Norwegian North-Atlantic Expedition. Since then, many countries, mostly Norway and Russia have sent scientific expeditions to the area, the complex water current system was detailed in 1909 by the Fridtjof Nansen. The Greenland Sea was a hunting ground for the whaling industry for 300 years, until 1911. At that point, the formerly rich whale population here, was so depleted that the industry was no longer profitable, the remaining whales of the Greenland Sea has been protected ever since, but the populations had not shown any proof of significant regeneration. In the last 20 years, polar biologists reports an increase in the local bowhead whale population and in 2015, arctic scientists discovered a surprising abundance of them in a small area.
These results may be interpreted as an sign of a beginning recovery for this particular species. The inuit hunted whales on a scale in the Greenland Sea since the fifteenth century. The Greenland Sea is bounded to the west by the island of Greenland, to the southeast, behind the Jan Mayen island lies the vast expanse of the Norwegian Sea, of which Greenland Sea may be considered an extension. Across the Fram Strait to the northeast, the sea is delimited by the Svalbard archipelago, the bottom of the Greenland Sea is a depression bounded to the south by the underwater Greenland-Iceland ridge and to the east by the Mohns Ridge and Knipovich Ridge. To the west, the bottom rises first slowly, but rapidly toward the wide Greenland coastal strip, silts fill the submarine hollows and gorges, silty sands, gravel and other products of erosion coat the shelves and ridges. Of those, only the Svalbard islands are inhabited, and Jan Mayen has only temporal military staff, several radio and meteorological stations operate on the island nowadays
Earth, otherwise known as the World, or the Globe, is the third planet from the Sun and the only object in the Universe known to harbor life. It is the densest planet in the Solar System and the largest of the four terrestrial planets, according to radiometric dating and other sources of evidence, Earth formed about 4.54 billion years ago. Earths gravity interacts with objects in space, especially the Sun. During one orbit around the Sun, Earth rotates about its axis over 365 times, Earths axis of rotation is tilted, producing seasonal variations on the planets surface. The gravitational interaction between the Earth and Moon causes ocean tides, stabilizes the Earths orientation on its axis, Earths lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years. About 71% of Earths surface is covered with water, mostly by its oceans, the remaining 29% is land consisting of continents and islands that together have many lakes and other sources of water that contribute to the hydrosphere.
The majority of Earths polar regions are covered in ice, including the Antarctic ice sheet, Earths interior remains active with a solid iron inner core, a liquid outer core that generates the Earths magnetic field, and a convecting mantle that drives plate tectonics. Within the first billion years of Earths history, life appeared in the oceans and began to affect the Earths atmosphere and surface, some geological evidence indicates that life may have arisen as much as 4.1 billion years ago. Since then, the combination of Earths distance from the Sun, physical properties, in the history of the Earth, biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinction events. Over 99% of all species that lived on Earth are extinct. Estimates of the number of species on Earth today vary widely, over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival. Humans have developed diverse societies and cultures, the world has about 200 sovereign states, the modern English word Earth developed from a wide variety of Middle English forms, which derived from an Old English noun most often spelled eorðe.
It has cognates in every Germanic language, and their proto-Germanic root has been reconstructed as *erþō, earth was written in lowercase, and from early Middle English, its definite sense as the globe was expressed as the earth. By early Modern English, many nouns were capitalized, and the became the Earth. More recently, the name is simply given as Earth. House styles now vary, Oxford spelling recognizes the lowercase form as the most common, another convention capitalizes Earth when appearing as a name but writes it in lowercase when preceded by the. It almost always appears in lowercase in colloquial expressions such as what on earth are you doing, the oldest material found in the Solar System is dated to 4. 5672±0.0006 billion years ago. By 4. 54±0.04 Gya the primordial Earth had formed, the formation and evolution of Solar System bodies occurred along with the Sun