Pesquisando por: "earth from " - Fotoarena - Agência de fotojornalismo

902_05_12528854highres Thousands of Hindus bathing in the sacred River Ganges, India. They are celebrating the avatarana or descent of the Ganges from heaven to earth, bathing in the Ganges on this day is said to rid the bather of ten sins. From The Wonders of the World, published c.1920.

902_05_12519046highres A magic lantern slide circa 1900. Religious slides. The 'Statutype' series of the life and work of Christ on Earth. This is a very fine and entirely new set of Slides, photographed from an original series of models sculptured by the French artist, Mestroianni. On the screen they appear almost stereoscopic, standing out well in relief owing to the shadows being real shadows, not merely painted. They are quite unique in appearance and very attractive, being printed, by a special process of our own, in a warm brown art tone. Great transparency is obtainable with this new process (Newtona), making these Slides very suitable for oil and acetylene lanterns. Messrs. Newton & Co. hold the sole right of making Slides of these copyright subjects in all English-speaking countries.Postcards of the above pictures can be obtained from Mr Noyer, 37, Boulevard de Strasbourg, Paris. Slide 6 The Flight into Egypt. Illustrator MASTROIANNI, Domenico

65197_rf_31_4327_025 Gardener harvesting potatoes from an allotment in England UK

71096_rf_28_roaring t_rex_196a1h A Carnivorous T.Rex Dinosaur From Earths Cretaceous Era Roaring.

71096_rf_28_creation of the moon_195a2h A 3D Conceptual Image, Showing The Creation Of The Moon, Many Millions Of Years Ago.

902_05_12321591HighRes Earth could not answer: nor the Seas that mourn In flowing Purple, of their Lord forlorn; Nor Heaven, with those eternal Signs reveal' And hidden by the sleeve of Night and Morn. Illustration by Edmund Dulac from the Rubaiyat of Omar Khayyam, published 1909.

902_05_12321590HighRes Earth could not answer: nor the Seas that mourn In flowing Purple, of their Lord forlorn; Nor Heaven, with those eternal Signs reveal' And hidden by the sleeve of Night and Morn. Illustration by Edmund Dulac from the Rubaiyat of Omar Khayyam, published 1909.

412-34965 Still life concept gardening supplies forming windmill tree

1019_13_KK-DSC_3400 Chicxulub comet. Colombian geologists found the first samples in south america of the Chicxulub Asteroid that triggered a mass extinction on earth, that included the the dinosaurs in Gorgona Island, 35 km. from the Pacific Colombian Coast..

1019_13_KK-DSC_3380 Chicxulub comet. Colombian geologists found the first samples in south america of the Chicxulub Asteroid that triggered a mass extinction on earth, that included the the dinosaurs in Gorgona Island, 35 km. from the Pacific Colombian Coast..

1019_13_KK-DSC_3368 Chicxulub comet. Colombian geologists found the first samples in south america of the Chicxulub Asteroid that triggered a mass extinction on earth, that included the the dinosaurs in Gorgona Island, 35 km. from the Pacific Colombian Coast..

975_08_TASS-D-83078 Russian cosmonauts vasily tsibliyev and alexander lazutkin landed on aug, 14th in the assigned area 168 kilomentes southneast of dzhezkazgan /kazakhstan/, the space expedition made by the cosmonauts on board the 'mir' space station continued for 185 days and went down in the history of world cosmonautics as the most difficult space flight with numerous mishaps, the picture showing the 'mir' station on near-earth orbit, made from tv screen.

925_02_MW017430 A group of men unloading soil from an engine boat, at Maowa Ferry Ghat, in Dhaka, Bangladesh

925_02_MW018637 The police came to tackle a disturbing situation among the people who came at the Chapi Kkollu Cemetery, in Oruro, Bolivia

925_02_MW018635 A view of the cemetery Iroko

925_02_MW018634 The celebration of the Day of the Dead, ritual tradition

925_02_MW018650 A store that sells tombs for the deceased

925_02_MW018643 The doors of the deceaseds homes are kept open for people for praying

925_02_MW018640 Children receive candy and pastries in exchange for praying at the altars of the houses

925_02_MW011640 Muslims from all walks of life come from different parts of the country by train, bus, boat and every possible way to attend Bishwa Ijtema the second largest Muslim pilgrimage on earth at the bank of Turag river in Tongi

917_03_WHA_119_0463 Melting Snows of Kilimanjaro. 2002, photographed from space orbit by the NASA Earth Observatory. Kilimanjaro's ice cap is particularly remarkable given its persistence through many previous shifts in climate.

908_06_lr2520019 The hanging-cloud bridge at Mount Gyédé near Ashikaga

925_04_MW003723 Some day I will walk again - Utpal always reminds himself

975_08_TASS-S-12310 Soviet spacecraft soyuz 31 docked to the salyut 6 space station, the picture was taken from soyuz 29, 1978.

917_36_WHA_113_0898 The Genesis creation narrative is the creation myth of both Judaism and Christianity. The Second Day of Creation: The earth and the waters are divided. From Physique sacree, ou Histoire-naturelle de la Bible, 1732-1737, by Johann Jakob Scheuchzer (1672 ? 1733), a Swiss scholar born at Zurich

948_05_00219974 The painter Correggio but the Holy Night has thought so in his dreams: all in heavenly light is the Divine Child, emanating from the all shine that resists shines on the faces of delighted Anwesenen. This is a picture of where we want to pray: "You dear holy, devout Christian, because today is your birthday, that's why on the earth far and wide, all the children happy time."

990_05_4-WWI-US-HF_7HR United States: May 17, 1918 A cartoon of the an American Boot about to crush the Kaiser and his Prussian junker satellites from the globe. The Kaiser is portrayed as a giant frog on top of the world. © Underwood Archives / The Image Works

990_05_1-Sci-Astro-HB_6HR Space: April 16, 1972 The view of earth from the Apollo 16 during the trans-lunar coast. North America's Lake Michigan and Lake Superior can be seen along with the Baja Peninsula on the far left. © Underwood Archives / The Image Works

925_07_MW023210 A woman reading holy prayers at the bank of the river Ganges at Haridwar, during Kumbh Mela, the biggest Hindu religious pilgrimage on earth

925_07_MW023208 A woman performing a religious ritual on the Kumbh Mela, in Haridwar, North India

925_07_MW023206 Naga sadhus (monks) walk with great fan fare and beating of drums in a procession to the ghats

925_01_MW020956 Cracked earth from dry desert conditions at Sossusvlei, Namib Desert in Namibia

925_01_MW003789 Using modern technology in irrigation is not new in Bangladesh

925_01_MW003788 Using modern technology in irrigation is not new in Bangladesh

925_07_MW023202 An elderly woman at the Kumbh Mela, the biggest Hindu religious pilgrimage on earth

925_02_MW023256 The residential space around Dhaka city is expanding rapidly

990_05_BO6-Eth-NA-CA_14HR California: c. 1930 Most villages had one or more sweat houses where the men gathered every day for the traditional custom of sweating. The earth covered house was built close to the river so the men could plunge into the water after sweating. A fire was built in the sweat house to make it hot, and the men scraped their bodies with a split deer rib to stimulate sweating. When they could endure the heat no longer, they ran from the sweat house and plunged into the nearby river.

948_05_00208524 This wave terrain will cause that Chorin, when it finally appears before our eyes, totally acts like a surprise. Only in the moment when we have passed the last ridge, rises the magnificent building, the wall covered the hills until then, from the earth, and is now free, visible to toe, in front of us. It is this architectural effect in good stead. You can probably make the assertion that this outperforms the picturesque. From the old buildings, if the same transformations were also subjected, is still much to receive and give the remains a full picture of what this rich monastery once was. Even the mass, the dimensions suggest.

948_05_01252781 A peaceful farmer ploughing the earth in the same way as they did thousands of years ago. The oxen walk in the yoke, as we already know from the Bible. Now, however, it should read: Ade pyramids, Cairo also ade, further into the wonderland of palm trees and temples we want to draw.

1016_03_51225 Magmatic (or igneous) rocks generally come from Earth?s upper mantle, where magma is partially melted. Depending on their rate of cooling, these rocks will be more or less fine- grained. Plutonic (or intrusive) rocks, which solidify slowly, are coarse-grained, while volcanic (or effusive) rocks, which solidify rapidly when they reach the surface, are fine-grained.

1016_03_62384 Landform built up as lava and ash are ejected from the upper mantle during successive eruptions, accumulating and solidifying on the surface.

1016_03_62315 As it is fed by more springs and meltwater from glaciers, it becomes a mountain stream, and then a young river. It continues flowing down the mountain, following steep slopes and forming waterfalls.

1016_03_59083 Archosaurs, or ?ruling reptiles,? first appeared during the Triassic, a period in Earth?s history that lasted from 251 to 200 million years BC. Some archosaurs would have gradually abandoned the ?crawling? stance, characterized by the belly hugging the ground and legs attached to the sides of the body (like modern crocodiles).

1016_03_58464 Even though the Moon is 378,000 km away from Earth, its gravitational force is strong enough to move the oceans. When Earth rotates so that a mass of water is facing the Moon, water rises in its direction: this bulge produces a high tide. At the same time, the Moon?s gravitational pull on water on the other side of Earth is much weaker. This water is affected by the centrifugal force created by the rotation of the Earth?Moon system and tends to bulge outward, creating another high tide. If Earth were made only of rigid materials, it would still be deformed by the action of these two forces and would be egg-shaped.

1016_03_58449 Saturn, with a yellowish tint, is the second-largest planet in the solar system. Like Jupiter, it is made almost entirely of hydrogen and helium. Its famous rings cover a distance of some 300,000 km in diameter ? almost the distance separating Earth from the Moon ? but their maximum thickness is only a few hundred meters.

1016_03_58326 Products containing recyclable materials are designated by a special symbol. A numerical code (from 1 to 7) in the center of the symbol distinguishes different plastic materials, and this facilitates manual sorting.

1016_03_58266 An image created from visible radiation shows the continents and oceans under partial cloud cover. The absence of cloud cover over the Sahara reveals the anticyclonic conditions above it.

1016_03_58221 Each wavelength has a different angle of refraction. White light from the Sun is thus dispersed by each raindrop into beams of colored light that cover the entire visible spectrum, from red to violet. We actually see only one color per raindrop, but the huge number of tiny prisms forms a range of colors in our perception: a rainbow.

1016_03_58144 At a very high altitude (between 6,000 m and 15,000 m), very strong winds blow from west to east around Earth. These are the jet streams, which are divided into polar systems (at about 60° latitude) and subtropical systems (above the tropics). The jet stream is shaped like a flattened tube several hundred kilometers wide.

1016_03_58141 From data obtained by weather satellites, computers produce maps simulating the general circulation of winds in Earth?s atmosphere. The.arrows indicate the direction of the winds, while the color zones indicate their speed. This image shows surface winds over the Pacific Ocean.

1016_03_57998 Contrary to popular belief, the cycle of the seasons?that is, the periodic change of climate over the months?is due not to Earth?s distance from the Sun, but to its inclination: our planet?s axis of rotation leans about 23.5° in relation to the ecliptic (the path of Earth?s orbit). This inclination is directly responsible for the variation in sunshine hours, and thus the succession of seasons, throughout the year.

1016_03_57992 The salinity of seawater is the amount of salt dissolved.in the water. On average, seawater contains 35 g of salt per liter. The more enclosed the sea, the higher its salinity. For example, salinity is lower than average in the North Pacific Ocean (32 g/l), but higher than average in the Red Sea (40 g/l). The Dead Sea is the saltiest body of water in the world, with a salinity of 330 g/l, and the Baltic Sea is one of the least salty, with a salinity of only 8 g/l. The balance between water evaporation from the oceans and precipitation is responsible for differences in salinity. Under subtropical anticyclones such as those in the Azores, evaporation is very high, and so the seawater is saltier. On the other hand, the equatorial region is subjected to strong and frequent rainfall, which results in a lower salinity level in seawater around the equator.

1016_03_57991 Water and the atmosphere are constantly exchanging energy in the form of heat. The surface temperature of.the seas and oceans thus plays a fundamental role in the regulation of atmospheric processes. Measurement of seawater temperature enables us to follow the evolution of climatic phenomena, such as El Nin?o, and ocean currents, such as the Gulf Stream, and to predict the formation of cyclones. Seawater temperature also provides information on the development of phytoplankton and shoals of fish. The distribution of surface temperatures is linked to hours of sunlight, which, in turn, depends on the latitude. The temperature of the oceans ranges from 28°C, near the equator, to ?2°C, in the high latitudes (north and south), closely following the distribution of solar radiation that reaches the surface of the water.

1016_03_57959 Like cyclones, tornadoes result from the circling of ascending winds around a low- pressure zone. Tornadoes are notable for their short duration (a few minutes) and the violence of the winds they generate.

1016_03_57954 TOPEX/Poseidon, a Franco-American satellite placed in an orbit of 1,330 km altitude in 1992, measures the height of the oceans around the planet. In June 1998, the large mass of cold water that began to migrate from west to east indicated the arrival of La Nin?a.

1016_03_57946 The equatorial zone of the Pacific Ocean is normally affected by the trade winds. Pushed by these constant winds, the surface water slowly moves from South America toward Southeast Asia, creating a mass of warm water that gradually swells through thermal expansion. Evaporation of warm surface water causes clouds to form, and the trade winds push these westward. Warm, humid air rises near Asia, while masses of cool, dry air descend near the South American coast. This atmospheric circulation, called the Walker cell, affects the climate of the entire Pacific zone: while the seasonal monsoon rains pour down on Asia, an anticyclone settles in over the South American coast.

1016_03_57945 The equatorial zone of the Pacific Ocean is normally affected by the trade winds. Pushed by these constant winds, the surface water slowly moves from South America toward Southeast Asia, creating a mass of warm water that gradually swells through thermal expansion. Evaporation of warm surface water causes clouds to form, and the trade winds push these westward. Warm, humid air rises near Asia, while masses of cool, dry air descend near the South American coast. This atmospheric circulation, called the Walker cell, affects the climate of the entire Pacific zone: while the seasonal monsoon rains pour down on Asia, an anticyclone settles in over the South American coast.

1016_03_57944 The equatorial zone of the Pacific Ocean is normally affected by the trade winds. Pushed by these constant winds, the surface water slowly moves from South America toward Southeast Asia, creating a mass of warm water that gradually swells through thermal expansion. Evaporation of warm surface water causes clouds to form, and the trade winds push these westward. Warm, humid air rises near Asia, while masses of cool, dry air descend near the South American coast. This atmospheric circulation, called the Walker cell, affects the climate of the entire Pacific zone: while the seasonal monsoon rains pour down on Asia, an anticyclone settles in over the South American coast.

1016_03_57942 The sterilization of its soil is the result of a half century of intensive agriculture. Traditionally, the periodic monsoon rains ensured wild vegetation in the region, and this protected the land from the Sun?s heat and returned humidity to the atmosphere, thus contributing to the water cycle. In cultivated fields, on the other hand, solar rays are absorbed directly by the soil, causing it to dry out.

1016_03_57923 Between 1970 and 2000, the Arctic pack ice lost more than 10% of its area, dropping from 13.5 to 12 million square kilometers. It has also become much thinner. Although the melting of ocean ice does not cause the sea level to rise, it does allow the water to absorb more solar rays, which intensifies global warming. Arctic regions should see a much greater increase in temperature than the rest of the planet.

1016_03_57801 A city located in a valley or basin, such as London, may be subjected to smog if its winters are humid. Clouds keep solar rays from warming the surface air, so it stays cold, humid, and polluted, which maintains and accentuates the phenomenon.

1016_03_57794 There are particular areas in the world where pockets of magma from Earth?s mantle rise very slowly to the surface. These places are called ?hot spots.? As magma pierces Earth?s crust, it collects and gradually begins to form small volcanic mountains in the middle of the tectonic plate. The positions of these volcanoes show the movement of the tectonic plates, which are floating on the mantle. As the plates slide, the rising magma creates a new volcano that slowly burns out. In the ocean, hot spots can be identified by the chains of volcanic islands they usually form. The islands of the Hawaiian Archipelago in the middle of the Pacific Ocean were created in this way.

1016_03_57793 Landform built up as lava and ash are ejected from the upper mantle during successive eruptions, accumulating and solidifying on the surface.

1016_03_57783 Strong and bendable, iron is the most widely used metal in the world. It can be turned into wrought iron or into steel, a very strong alloy used in the construction of bridges. Iron is often extracted from an ore called hematite.

1016_03_53562 Gently rounded or capped by tall peaks, mountains are the planet?s most striking showpieces. They are also Earth?s highest land features. Many of these massive, often steep formations are located along the edges of continents. They may form chains, or ranges, that extend for thousands of miles (or kilometers). The principal mountain ranges include the Rocky Mountains and the Andes, which run from North America all the way down through South America,.the Atlas Mountains in Africa, the Himalayas in Asia, and.the Alps in Europe. The longest mountain range in the world is at the bottom of the ocean! It measures more than 40,000 miles (65,000 km) long and reaches several miles (or kilometers) high.

1016_03_53480 The water flowing on Earth?s surface usually moves toward the sea. If an obstacle or hollow prevents the water from following its course, it may form a basin. As the water continues to collect, a lake is created. Most lakes are freshwater and contain only small amounts of mineral salts. There are, however, some saltwater lakes. Some contain large amounts of salt because nearby ocean water has managed to seep into them. Other lakes, such as those found in the middle of deserts, are extremely salty. This is because their waters are constantly evaporating under the Sun, leaving behind a high concentration of minerals in the remaining water. A lake may get its water from one or more rivers, which are called tributaries. Without tributaries, a lake may dry up quickly. The water in a lake may run out into one or more streams, called outlets, which follow a course toward the sea.

1016_03_53479 The water flowing on Earth?s surface usually moves toward the sea. If an obstacle or hollow prevents the water from following its course, it may form a basin. As the water continues to collect, a lake is created. Most lakes are freshwater and contain only small amounts of mineral salts. There are, however, some saltwater lakes. Some contain large amounts of salt because nearby ocean water has managed to seep into them. Other lakes, such as those found in the middle of deserts, are extremely salty. This is because their waters are constantly evaporating under the Sun, leaving behind a high concentration of minerals in the remaining water. A lake may get its water from one or more rivers, which are called tributaries. Without tributaries, a lake may dry up quickly. The water in a lake may run out into one or more streams, called outlets, which follow a course toward the sea.

1016_03_53240 Solid layer at the Earth's surface whose average thickness varies from 6 mi beneath the oceans to 35 mi beneath the mountains.

1016_03_52124 Water used in various human activities becomes loaded with many organic and chemical residues. This wastewater, which is often harmful to the environment, can have a disastrous effect if it is not properly treated before being released. It must undergo a complex purification process to keep it from polluting the natural environment.

1016_03_52108 Western end of the vast Eurasian supercontinent, separated from Asia, according to convention, by the Ural Mountains. It represents 7% of dry land on Earth.

1016_03_51412 The most accurate way to determine the altitude of a point in the geodetic network is a method called direct leveling. It consists of comparing two graduated level rods, one placed at the point to be measured (B), the other at a nearby point, the altitude of which is already known (A). An optical level placed at an equal distance between the two level rods determines the spot grade (difference in altitude) between the two points. This procedure is performed from point to point over the entire territory starting from base level (sea level).

1016_03_51411 The first step in making a map is to precisely determine a number of points in the region being portrayed: this is called a survey. Measurements of the terrain are taken using a procedure called triangulation. After precisely determining the distance between two points, the cartographer chooses a third point and then measures the angles it forms with the base of the triangle. Trigonometric calculation is used to determine the lengths of the two other sides of the triangle. From point to point, a basic network is built from which the entire territory can be surveyed.

1016_03_51404 An azimuthal (or planar) projection is produced on a plane so placed that it is tangential to one point on the planet?s surface. The map obtained is circular in shape and represents only one hemisphere. Because the distortion of shapes increases with distance from the tangent point, this type of projection is used mainly to portray polar regions.

1016_03_51403 An azimuthal (or planar) projection is produced on a plane so placed that it is tangential to one point on the planet?s surface. The map obtained is circular in shape and represents only one hemisphere. Because the distortion of shapes increases with distance from the tangent point, this type of projection is used mainly to portray polar regions.

1016_03_51388 Icebergs are named according to their shape above the waterline. The most common are tabular icebergs? large plates that detach from the Antarctic ice sheet in great numbers.

1016_03_51386 Icebergs are named according to their shape above the waterline. The most common are tabular icebergs? large plates that detach from the Antarctic ice sheet in great numbers.

1016_03_51384 Icebergs are named according to their shape above the waterline. The most common are tabular icebergs? large plates that detach from the Antarctic ice sheet in great numbers.

1016_03_51383 The Antarctic ice sheet, covering 14 million km2 and with a maximum thickness of 4.3 km, contains 91% of the volume of ice in the world. This considerable mass presses the continent down to several hundred meters below sea level. Each year, the ice sheet produces almost 100,000 icebergs, which are generally 10 times as large as those from the Arctic.

1016_03_51372 A mountain?s appearance depends greatly on its age. The youngest mountain chains on the planet (the Alps, Himalayas, Rockies, Andes, Caucasus), shaped by recent tectonic shocks have a very marked relief, with steep slopes and sharp peaks. Most of these mountains have not finished rising, as slow-moving lithospheric plates continue to deform the landscape. Old mountains (the Urals, Appalachians, Great Dividing Range in Australia, Drakensberg Mountains) are less rugged: they have been smoothed by erosion, which has taken material from the slopes and deposited it in the lowlands.

1016_03_51363 Loaded with carbon dioxide from the atmosphere, and sometimes with sulfur dioxide, rainwater chemically alters various minerals present in the ground, including limestone. The stone erodes on its surface and along the cracks.

1016_03_51360 River water scours materials from the banks and riverbed, rolling them against each other and fragmenting them. These particles have an abrasive effect that carves out riverbanks.

1016_03_51345 Even though the Moon is 378,000 km away from Earth, its gravitational force is strong enough to move the oceans. When Earth rotates so that a mass of water is facing the Moon, water rises in its direction: this bulge produces a high tide. At the same time, the Moon?s gravitational pull on water on the other side of Earth is much weaker. This water is affected by the centrifugal force created by the rotation of the Earth?Moon system and tends to bulge outward, creating another high tide. If Earth were made only of rigid materials, it would still be deformed by the action of these two forces and would be egg-shaped.

1016_03_51320 Far from the oceanic ridges, a layer of sediments (residues of marine organisms, sand, volcanic dust, and rubble) as thick as 500 m covers the seafloor.

1016_03_51314 The radial drainage pattern is characteristic of mountains, where watercourses diverge from a peak.

1016_03_51307 As it is fed by more springs and meltwater from glaciers, it becomes a mountain stream, and then a young river. It continues flowing down the mountain, following steep slopes and forming waterfalls.

1016_03_51305 The epicenter of an earthquake can be determined by analyzing data from three stations located at different places. For precise location, seismologists at each station draw a circle with a radius equivalent to the distance shown on the seismogram. The point where the three circles intersect is the epicenter.

1016_03_51302 P waves (primary waves).are transmitted through all materials and are the first to be recorded by seismographs. The differences in the mechanical properties of the mantle and the core keep them from reaching certain regions of the planet, which are called shadow zones.

1016_03_51291 Three conditions must be met for geysers to form. There must be: an underground circuit in which the water that percolates into the ground can circulate, then rise to the surface; a reservoir, where this water can accumulate; and a nearby pocket of magma (molten rock), which heats the trapped water. Water percolates into the ground and accumulates in reservoirs near a pocket of magma. As it is heated, the water slowly turns into steam. The pressure grows, propelling a powerful jet of water and steam toward the surface. The phenomenon can last from several minutes to several hours. The jet of water subsides when the reservoir contains no more water or steam.

1016_03_51277 Craters more than 1 km in diameter are called calderas. Formed when the top of a volcanic cone collapses, they may be up to 60 km in diameter. During an eruption, magma is ejected from the magma chamber via the central vent and secondary vents. The vents are gradually emptied. The central part of the volcano can no longer support the weight of the volcanic cone and the top collapses. The cone?s material covers the bottom of the caldera, which has very steep sides. Some calderas fill with water and form lakes.

1016_03_51275 Craters more than 1 km in diameter are called calderas. Formed when the top of a volcanic cone collapses, they may be up to 60 km in diameter. During an eruption, magma is ejected from the magma chamber via the central vent and secondary vents. The vents are gradually emptied. The central part of the volcano can no longer support the weight of the volcanic cone and the top collapses. The cone?s material covers the bottom of the caldera, which has very steep sides. Some calderas fill with water and form lakes.

1016_03_51263 Independent of interactions between the plates, hot spots occur in the middle of oceanic and continental plates. Pockets of magma rise from the lower mantle of Earth toward the surface, producing volcanic massifs such as Hawaii.

1016_03_51240 As it rises, Earth?s internal heat causes convection movements, or currents, that cause the tectonic plates to move. These currents form a sort of giant conveyor belt on which old crust gives way to new. Lava that flows from the ridges cools and forms new oceanic crust. Because Earth stays the same size, there are subduction zones where old crust is folded under and consumed by the down-going mantle.

1016_03_51236 When two oceanic plates move apart, a divergence zone is created, where volcanic mountains are formed from the rise of magma. The Mid-Atlantic Ridge is one of the submarine mountain belts known as oceanic ridges.

1016_03_51221 Quartzite results from the metamorphosis of siliceous sandstone. It is composed of aggregated quartz.

1016_03_51222 Granite gneiss is a foliated rock that results from the deformation of granite. It is composed of thin light- and dark- colored layers.

1016_03_51200 The crystal system refers to the internal structure of a mineral. Rhodonite takes its name from the Greek word rhodon, which means ?pink?.

1016_03_51191 The crystal system refers to the internal structure of a mineral. Cassiterite is an ore?a mineral from which tin is extracted.

1016_03_51183 The Mohs scale compares the hardness of minerals on a scale of 1 to 10, from the softest (1) to the hardest (10). Each mineral is classified according to how it scratches the others or is scratched by them. Diamond, the hardest mineral, cannot be scratched, and thus has the highest rating.

1016_03_51179 The Mohs scale compares the hardness of minerals on a scale of 1 to 10, from the softest (1) to the hardest (10). Each mineral is classified according to how it scratches the others or is scratched by them. Apatite has a hardness of 5.

1016_03_51176 The Mohs scale compares the hardness of minerals on a scale of 1 to 10, from the softest (1) to the hardest (10). Each mineral is classified according to how it scratches the others or is scratched by them. Talc, which can be scratched by a fingernail, has a hardness of 1.