What name is given to the molten rock below the Earth's surface? | Reference.com What name is given to the molten rock below the Earth's surface? A: Quick Answer The molten rock below the Earth’s surface is known as magma. Magma is a combination of a molten and semi-molten rock mixture that is extremely hot. Magma is between 1,292 and 2,372 degrees Fahrenheit, or 700 and 1,300 degrees Celsius. Full Answer Magma is a dynamic and fluid substance that is capable of creating new landforms. This molten rock starts in the upper part of the mantle and the lower portion of the crust. When magma erupts from a volcano or other vent, the molten rock is referred to as lava. When lava cools on the Earth’s surface and forms a solid structure, it is called igneous rock. What is molten rock? | Reference.com What is molten rock? A: Quick Answer Molten rock is rock heated to a temperature that is sufficient to turn it into a thick liquid. Molten rock often is associated with lava from a volcano. Additionally, molten rock exists below the surface of the Earth.

Full Answer Magma spewed from a volcano includes molten and semi-molten rock. The temperature at which a rock melts and becomes molten depends on the mineral or minerals within the rock itself. Different minerals possess different melting points. Carbonatite minerals have lower melting points while komatite minerals melt at higher temperatures. Many rocks are comprised of different minerals, resulting in disparate melting points for an individual rock. What is molten rock that reaches the Earth's surface? - Quora Quora Written Jan 15, 2015 In addition to magma from the Earth's interior that is called lava when it reaches the surface, a meteorite may have molten rock which reaches the Earth's surface. Whether the rock in the meteoroid melts during its interaction with the Earth's atmosphere is a complicated question depending on speed, size, and composition of the meteoroid. Many meteoroids evaporate completely as meteors in the atmosphere leaving no meteorite to reach the ground. Once molten rock (magma) reaches the earth’s surface, we call it ‘lava’. Once the lava hardens, it is rock - which is named according to its composition and textural characteristics. 51 Views J.

Anthony Carter , Open Minded Free Thinker, Adventurer, Eagle and Explorer Scout and lover of ideas and conversation! I find it seriously difficult to know how to handle questions of this sort. I'm utterly amazed that Quora allows this kind of thing on their site. You've already made apparent your knowledge of the fact that the red, hot stuff exuded/expelled from the crust (land) of the Earth is molten rock so telling you it's molten rock is redundant and superfluous... you've already shown you actually know this. Next is to tell you it's called "lava" but the problem there is that you have the vocabulary to ask about "molten rock" and "Earth's surface" so the idea that you're unaware of the word "lava" is just too much to digest. Are you serious? Coming here to ask a question like this when every 3rd grader in the WORLD doesn't even think to use Google to find answers to questions of markedly superior difficulty! magma - National Geographic Society magma Magma exists as pockets and plumes beneath the surface of the Earth.

Photograph by Carsten Peter, National Geographic Hawaii's Molten Magma Hawaiian magma is different than magma in other parts of the Earth because it has more molten rock and less dissolved gases and rock fragments. The Hawaiian volcano Kilauea, on the "Big Island" of Hawaii, has erupted with enough molten lava to pave a road around the Earth three times. Tapping into Magma’s Potential In 2009, the Icelandic Deep Drilling Project created a well that uses magma to generate geothermal energy. Normally, geothermal energy is created by pumping water into hot volcanic bedrock, creating steam that is then harnessed to generate electricity. While normal geothermal sources average around 60° to 80° Celsius (140° to 176° Fahrenheit), the magma well’s steam reached a record-breaking temperature of 450° Celsius (842° Fahrenheit)! This huge increase in temperature allowed just one magma well to generate roughly 36 megawatts of electricity, powering 36,000 homes. In comparison, one single wind turbine generates between 1 to 3 megawatts. Mysterious Magma Magma is usually studied as lava or igneous rock.

But most magma remains molten or partly molten beneath Earth’s surface. In fact, magma has only been discovered three times in its “natural” habitat deep in Earth’s crust. Geothermal drilling projects discovered two magma sites on the “Big Island” of Hawaii, and one on Iceland. Magma is a molten and semi-molten rock mixture found under the surface of the Earth. This mixture is usually made up of four parts: a hot liquid base, called the melt ; mineral s crystal lized by the melt; solid rock s incorporate d into the melt from the surrounding confine s; and dissolve d gas es. When magma is eject ed by a volcano or other vent , the material is called lava . Magma that has cooled into a solid is called igneous rock . Magma is extremely hot—between 700° and 1,300° Celsius (1,292° and 2,372° Fahrenheit). This heat makes magma a very fluid and dynamic substance, able to create new landform s and engage physical and chemical transform ations in a variety of different environment s. How Magma Forms Earth is divided into three general layers.

The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. Magma originate s in the lower part of the Earth’s crust and in the upper portion of the mantle. Most of the mantle and crust are solid, so the presence of magma is crucial to understanding the geology and morphology of the mantle. Differences in temperature , pressure , and structural formations in the mantle and crust cause magma to form in different ways. Decompression Melting Decompression melting involves the upward movement of Earth's mostly-solid mantle. This hot material rises to an area of lower pressure through the process of convection . Areas of lower pressure always have a lower melting point than areas of high pressure. This reduction in overlying pressure, or decompression, enables the mantle rock to melt and form magma. Decompression melting often occurs at divergent boundaries, where tectonic plate s separate. The rift ing movement causes the buoyant magma below to rise and fill the space of lower pressure. The rock then cools into new crust. Decompression melting also occurs at mantle plumes, columns of hot rock that rise from Earth’s high-pressure core to its lower-pressure crust.

When located beneath the ocean, these plumes, also known as hot spot s, push magma onto the seafloor. These volcanic mounds can grow into volcanic island s over millions of years of activity. Transfer of Heat Magma can also be created when hot, liquid rock intrude s into Earth’s cold crust. As the liquid rock solidifies, it loses its heat to the surrounding crust. Much like hot fudge being poured over cold ice cream, this transfer of heat is able to melt the surrounding rock (the “ice cream”) into magma. Transfer of heat often happens at convergent boundaries, where tectonic plates are crashing together. As the dense r tectonic plate subduct s, or sinks below, or the less-dense tectonic plate, hot rock from below can intrude into the cooler plate above. This process transfers heat and creates magma. Over millions of years, the magma in this subduction zone can create a series of active volcanoes known as a volcanic arc . Flux Melting Flux melting occurs when water or carbon dioxide are added to rock. These compounds cause the rock to melt at lower temperatures. This creates magma in places where it originally maintained a solid structure.

Much like heat transfer, flux melting also occurs around subduction zones. In this case, water overlying the subducting seafloor would lower the melting temperature of the mantle, generating magma that rises to the surface. Magma Escape Routes Magma leaves the confines of the upper mantle and crust in two major ways: as an intrusion or as an extrusion. An intrusion can form features such as dikes and xenoliths. An extrusion could include lava and volcanic rock. Magma can intrude into a low-density area of another geologic formation, such as a sedimentary rock structure. When it cools to solid rock, this intrusion is often called a pluton . A pluton is an intrusion of magma that wells up from below the surface. Plutons can include dikes and xenoliths. A magmatic dike is simply a large slab of magmatic material that has intruded into another rock body. A xenolith is a piece of rock trapped in another type of rock. Many xenoliths are crystals torn from inside the Earth and embed ded in magma while the magma was cooling. The most familiar way for magma to escape, or extrude , to Earth’s surface is through lava.

Lava eruptions can be “fire fountains” of liquid rock or thick, slow-moving rivers of molten material. Lava cools to form volcanic rock as well as volcanic glass . Magma can also extrude into Earth’s atmosphere as part of a violent volcanic explosion . This magma solidifies in the air to form volcanic rock called tephra . In the atmosphere, tephra is more often called volcanic ash . As it falls to Earth, tephra includes rocks such as pumice . Magma Chamber In areas where temperature, pressure, and structural formation allow, magma can collect in magma chamber s. Most magma chambers sit far beneath the surface of the Earth. The pool of magma in a magma chamber is layered. The least-dense magma rises to the top. The densest magma sinks near the bottom of the chamber. Over millions of years, many magma chambers simply cool to form a pluton or large igneous intrusion. If a magma chamber encounter s an enormous amount of pressure, however, it may fracture the rock around it. The cracks, called fissure s or vents, are tell-tale signs of a volcano. Many volcanoes sit over magma chambers.

As a volcano’s magma chamber experiences greater pressure, often due to more magma seeping into the chamber, the volcano may undergo an eruption . An eruption reduce s the pressure inside the magma chamber. As long as more magma pools into a volcano’s magma chamber, there is the possibility of an eruption and the volcano will remain active. Large eruptions can nearly empty the magma chamber. The layers of magma may be document ed by the type of eruption material the volcano emits. Gases, ash, and light-colored rock are emitted first, from the least-dense, top layer of the magma chamber. Dark, dense volcanic rock from the lower part of the magma chamber may be released later. In violent eruptions, the volume of magma shrinks so much that the entire magma chamber collapses and forms a caldera . Types of Magma All magma contains gases and a mixture of simple element s. Being that oxygen and silicon are the most abundant elements in magma, geologists define magma types in terms of their silica content, expressed as SiO2. These differences in chemical composition are directly related to differences in gas content, temperature, and viscosity .

Mafic Magma Mafic magma has relatively low silica content, roughly 50%, and higher contents in iron and magnesium. This type of magma has a low gas content and low viscosity, or resistance to flow. Mafic magma also has high mean temperatures, between 1000o and 2000o Celsius (1832o and 3632o Fahrenheit), which contributes to its lower viscosity. Low viscosity means that mafic magma is the most fluid of magma types. It erupts non-explosively and moves very quickly when it reaches Earth’s surface as lava. This lava cools into basalt , a rock that is heavy and dark in color due to its higher iron and magnesium levels. Basalt is one of the most common rocks in Earth’s crust as well as the volcanic islands created by hot spots. The Hawaiian Islands are a direct result of mafic magma eruptions. Steady and relatively calm “ lava fountain s” continue to change and expand the “Big Island” of Hawaii. Intermediate Magma Intermediate magma has higher silica content (roughly 60%) than mafic magma. This results in a higher gas content and viscosity.

Its mean temperature ranges from 800o to 1000o Celsius (1472o to 1832o Fahrenheit). As a result of its higher viscosity and gas content, intermediate magma builds up pressure below the Earth’s surface before it can be released as lava. This more gaseous and sticky lava tends to explode violently and cools as andesite rock. Intermediate magma most commonly transforms into andesite due to the transfer of heat at convergent plate boundaries. Andesitic rocks are often found at continent al volcanic arcs, such as the Andes Mountains in South America, after which they are named. Felsic Magma Felsic magma has the highest silica content of all magma types, between 65-70%. As a result, felsic magma also has the highest gas content and viscosity, and lowest mean temperatures, between 650o and 800o Celsius (1202o and 1472o Fahrenheit). Thick, viscous felsic magma can trap gas bubbles in a volcano’s magma chamber. These trapped bubbles can cause explosive and destructive eruptions.

These eruptions eject lava violently into the air, which cools into dacite and rhyolite rock. Much like intermediate magma, felsic magma may be most commonly found at convergent plate boundaries where transfer of heat and flux melting create large stratovolcano es. Term type of dark volcanic rock. buoyant transfer of heat by the movement of the heated parts of a liquid or gas. convergent plate boundary Noun area where two or more tectonic plates bump into each other. Also called a collision zone. core crystal Noun type of mineral that is clear and, when viewed under a microscope, has a repeating pattern of atoms and molecules. dacite Noun upward movement of Earth's mantle to an area of lower pressure, allowing mantle rock to melt, leading to magma formation. dense having parts or molecules that are packed closely together. destructive to break up or disintegrate. divergent boundary Noun area where two or more tectonic plates are moving away from each other. Also called an extensional boundary. document always changing or in motion. eject to get rid of or throw out. element chemical that cannot be separated into simpler substances. embed to attach firmly to a surrounding substance.

emit to give off or send out. encounter conditions that surround and influence an organism or community. eruption release of material from an opening in the Earth's crust. explosion violent outburst; rejection, usually of gases or fuel extrude to force or push out. felsic having to do with igneous rocks that contain mostly feldspars and quartz. fissure material that is able to flow and change shape. flux melting Noun process that occurs when water is added to hot, solid rock, lowering its melting point and allowing the creation of magma. fracture gas Noun state of matter with no fixed shape that will fill any container uniformly. Gas molecules are in constant, random motion. geology Noun study of the physical history of the Earth, its composition, its structure, and the processes that form and change it. hot spot Noun intensely hot region deep within the Earth that rises to just underneath the surface. Some hot spots produce volcanoes. rock formed by the cooling of magma or lava. incorporate to blend or bring together. intrude to thrust or bring into. landform molten rock, or magma, that erupts from volcanoes or fissures in the Earth's surface.

lava fountain Noun phenomenon where lava is forcefully but not violently ejected from a volcano through a fissure or vent. liquid Noun state of matter with no fixed shape and molecules that remain loosely bound with each other. mafic having to do with igneous rocks that contain large amounts of iron and magnesium. magma underground reservoir that holds molten rock. mantle mathematical value between the two extremes of a set of numbers. Also called the average. melt temperature at which a solid turns to liquid. mineral inorganic material that has a characteristic chemical composition and specific crystal structure. molten solid material turned to liquid by heat. morphology study of the form and structure of organisms or materials. originate igneous rock that has solidified beneath the Earth's surface. pressure force pressed on an object by another object or condition, such as gravity. pumice type of igneous rock with many pores. reduce fine-grained igneous rock containing large amounts of silica. rift break in the Earth's crust created by it spreading or splitting apart. rock natural substance composed of solid mineral matter. seafloor surface layer of the bottom of the ocean. sedimentary rock rock formed from fragments of other rocks or the remains of plants or animals.

silica chemical compound (SiO2) that makes up most of the Earth's rocks. stratovolcano steep volcano made of hardened lava, rock, and ash. Also known as a composite volcano. subduct to pull downward or beneath something. subduction zone area where one tectonic plate slides under another. tectonic plate Noun massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate. temperature solid material ejected from a volcano during an eruption. transform to change from one form into another. vent crack in the Earth's crust that spews hot gases and mineral-rich water. viscosity measure of the resistance of a fluid to a force or disturbance. viscous liquid that is thick and sticky. volcanic arc chain of volcanoes formed at a subduction zone. volcanic ash hard, brittle substance produced by lava cooling very quickly. volcanic island land formed by a volcano rising from the ocean floor. volcano Noun an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.

mantle - National Geographic Society mantle The mantle, between the brittle crust and super-dense core, makes up a whopping 84% of Earth’s total volume. Illustration by Ewalde1, courtesy Wikimedia. CC-BY-SA-3.0 Earth’s Active Mantle Earth is the only planet in our solar system with a continually active mantle. Mercury and Mars have solid, unmoving interior structures. Venus has an active mantle, but the structure of its crust and atmosphere prevent it from changing the Venusian landscape very often. Explosive Study Explosions, just like earthquakes, trigger seismic waves. Body waves from powerful nuclear explosions may have revealed clues about Earth’s interior—but such seismic study is prohibited as part of the Comprehensive Nuclear Test Ban Treaty. Mantling Conductivity Some mantle maps display electrical conductivity, not seismic waves. By mapping disturbances in electrical patterns, scientists have helped identify hidden “reservoirs” of water in the mantle. The mantle is the mostly-solid bulk of Earth’s interior. The mantle lies between Earth’s dense , super-heated core and its thin outer layer, the crust .

The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up a whopping 84% of Earth’s total volume . As Earth began to take shape about 4.5 billion years ago, iron and nickel quickly separated from other rock s and mineral s to form the core of the new planet. The molten material that surrounded the core was the early mantle. Over millions of years, the mantle cooled. Water trapped inside minerals erupt ed with lava, a process called “ outgas sing.” As more water was outgassed, the mantle solidified. The rocks that make up Earth’s mantle are mostly silicate s—a wide variety of compound s that share a silicon and oxygen structure. Common silicates found in the mantle include olivine, garnet, and pyroxene. The other major type of rock found in the mantle is magnesium oxide. Other mantle elements include iron, aluminum, calcium, sodium, and potassium. The temperature of the mantle varies greatly, from 1000° Celsius (1832° Fahrenheit) near its boundary with the crust, to 3700° Celsius (6692° Fahrenheit) near its boundary with the core.

In the mantle, heat and pressure generally increase with depth. The geothermal gradient is a measurement of this increase. In most places, the geothermal gradient is about 25° Celsius per kilometer of depth (1° Fahrenheit per 70 feet of depth). The viscosity of the mantle also varies greatly. It is mostly solid rock, but more viscous at tectonic plate boundaries and mantle plumes. Mantle rocks there are soft and able to move plastically (over the course of millions of years) at great depth and pressure. The transfer of heat and material in the mantle helps determine the landscape of Earth. Activity in the mantle drives plate tectonics , contributing to volcano es, seafloor spreading , earthquake s, and orogeny (mountain-building). The mantle is divided into several layers: the upper mantle, the transition zone, the lower mantle, and D” (D double-prime), the strange region where the mantle meets the outer core . Upper Mantle The upper mantle extends from the crust to a depth of about 410 kilometers (255 miles). The upper mantle is mostly solid, but its more malleable regions contribute to tectonic activity .

Two parts of the upper mantle are often recognized as distinct region s in Earth’s interior: the lithosphere and the asthenosphere. Lithosphere The lithosphere is the solid, outer part of the Earth, extending to a depth of about 100 kilometers (62 miles). The lithosphere includes both the crust and the brittle upper portion of the mantle. The lithosphere is both the coolest and the most rigid of Earth’s layers. The most well-known feature associated with Earth’s lithosphere is tectonic activity. Tectonic activity describes the interaction of the huge slab s of lithosphere called tectonic plate s. The lithosphere is divided into 15 major tectonic plates: the North American, Caribbean, South American, Scotia, Antarctic, Eurasian, Arabian, African, Indian, Philippine, Australian, Pacific, Juan de Fuca, Cocos, and Nazca. The division in the lithosphere between the crust and the mantle is called the Mohorovicic discontinuity , or simply the Moho. The Moho does not exist at a uniform depth, because not all regions of Earth are equally balanced in isostatic equilibrium.

Isostasy describes the physical, chemical, and mechanical differences that allow the crust to “float” on the sometimes more malleable mantle. The Moho is found at about 8 kilometers (5 miles) beneath the ocean and about 32 kilometers (20 miles) beneath continents. Different types of rocks distinguish lithospheric crust and mantle. Lithospheric crust is characterize d by gneiss ( continental crust ) and gabbro ( oceanic crust ). Below the Moho, the mantle is characterized by peridotite, a rock mostly made up of the minerals olivine and pyroxene. Asthenosphere The asthenosphere is the denser, weaker layer beneath the lithospheric mantle. It lies between about 100 kilometers (62 miles) and 410 kilometers (255 miles) beneath Earth’s surface. The temperature and pressure of the asthenosphere are so high that rocks soften and partly melt, becoming semi-molten. The asthenosphere is much more ductile than either the lithosphere or lower mantle. Ductility measures a solid material’s ability to deform or stretch under stress.

The asthenosphere is generally more viscous than the lithosphere, and the lithosphere-asthenosphere boundary (LAB) is the point where geologist s and rheologist s—scientists who study the flow of matter—mark the difference in ductility between the two layers of the upper mantle. The very slow motion of lithospheric plates “floating” on the asthenosphere is the cause of plate tectonics, a process associated with continental drift , earthquakes, the formation of mountains, and volcanoes. In fact, the lava that erupts from volcanic fissure s is actually the asthenosphere itself, melted into magma . Of course, tectonic plates are not really floating, because the asthenosphere is not liquid. Tectonic plates are only unstable at their boundaries and hot spots. Transition Zone From about 410 kilometers (255 miles) to 660 kilometers (410 miles) beneath Earth’s surface, rocks undergo radical transform ations. This is the mantle’s transition zone . In the transition zone, rocks do not melt or disintegrate . Instead, their crystal line structure changes in important ways. Rocks become much, much more dense.

The transition zone prevents large exchanges of material between the upper and lower mantle. Some geologists think that the increased density of rocks in the transition zone prevents subducted slabs from the lithosphere from falling further into the mantle. These huge pieces of tectonic plates stall in the transition zone for millions of years before mixing with other mantle rock and eventually returning to the upper mantle as part of the asthenosphere, erupting as lava, becoming part of the lithosphere, or emerging as new oceanic crust at sites of seafloor spreading. Some geologists and rheologists, however, think subducted slabs can slip beneath the transition zone to the lower mantle. Other evidence suggests that the transition layer is permeable , and the upper and lower mantle exchange some amount of material. Water Perhaps the most important aspect of the mantle’s transition zone is its abundance of water. Crystals in the transition zone hold as much water as all the oceans on Earth’s surface. Water in the transition zone is not “water” as we know it. It is not liquid, vapor , solid, or even plasma . Instead, water exists as hydroxide. Hydroxide is an ion of hydrogen and oxygen with a negative charge.

In the transition zone, hydroxide ions are trapped in the crystalline structure of rocks such as ringwoodite and wadsleyite. These minerals are formed from olivine at very high temperatures and pressure. Near the bottom of the transition zone, increasing temperature and pressure transform ringwoodite and wadsleyite. Their crystal structures are broken and hydroxide escapes as “ melt .” Melt particles flow upwards, toward minerals that can hold water. This allows the transition zone to maintain a consistent reservoir of water. Geologists and rheologists think that water entered the mantle from Earth’s surface during subduction. Subduction is the process in which a dense tectonic plate slips or melts beneath a more buoyant one. Most subduction happens as an oceanic plate slips beneath a less-dense plate. Along with the rocks and minerals of the lithosphere, tons of water and carbon are also transported to the mantle. Hydroxide and water are returned to the upper mantle, crust, and even atmosphere through mantle convection, volcanic eruptions, and seafloor spreading.

Lower Mantle The lower mantle extends from about 660 kilometers (410 miles) to about 2,700 kilometers (1,678 miles) beneath Earth’s surface. The lower mantle is hotter and denser than the upper mantle and transition zone. The lower mantle is much less ductile than the upper mantle and transition zone. Although heat usually correspond s to softening rocks, intense pressure keeps the lower mantle solid. Geologists do not agree about the structure of the lower mantle. Some geologists think that subducted slabs of lithosphere have settled there. Other geologists think that the lower mantle is entirely unmoving and does not even transfer heat by convection. D Double-Prime (D’’) Beneath the lower mantle is a shallow region called D'' , or “d double-prime.” In some areas, D’’ is a nearly razor-thin boundary with the outer core. In other areas, D’’ has thick accumulation s of iron and silicates. In still other areas, geologists and seismologist s have detected areas of huge melt. The unpredictable movement of materials in D’’ is influence d by the lower mantle and outer core.

The iron of the outer core influences the formation of a diapir , a dome -shaped geologic feature ( igneous intrusion ) where more fluid material is forced into brittle overlying rock. The iron diapir emits heat and may release a huge, bulging pulse of either material or energy—just like a Lava Lamp. This energy blooms upward, transferring heat to the lower mantle and transition zone, and maybe even erupting as a mantle plume. At the base of the mantle, about 2,900 kilometers (1,802 miles) below the surface, is the core-mantle boundary, or CMB. This point, called the Gutenberg discontinuity , marks the end of the mantle and the beginning of Earth’s liquid outer core. Mantle Convection Mantle convection describes the movement of the mantle as it transfers heat from the white-hot core to the brittle lithosphere. The mantle is heated from below, cooled from above, and its overall temperature decreases over long periods of time. All these elements contribute to mantle convection. Convection currents transfer hot, buoyant magma to the lithosphere at plate boundaries and hot spots.

Convection current s also transfer denser, cooler material from the crust to Earth’s interior through the process of subduction. Earth's heat budget , which measures the flow of thermal energy from the core to the atmosphere, is dominate d by mantle convection. Earth’s heat budget drives most geologic processes on Earth, although its energy output is dwarf ed by solar radiation at the surface. Geologists debate whether mantle convection is “whole” or “layered.” Whole-mantle convection describes a long, long recycling process involving the upper mantle, transition zone, lower mantle, and even D’’. In this model, the mantle convects in a single process. A subducted slab of lithosphere may slowly slip into the upper mantle and fall to the transition zone due to its relative density and coolness. Over millions of years, it may sink further into the lower mantle. Convection currents may then transport the hot, buoyant material in D’’ back through the other layers of the mantle. Some of that material may even emerge as lithosphere again, as it is spilled onto the crust through volcanic eruptions or seafloor spreading. Layered-mantle convection describes two processes.

Plumes of superheated mantle material may bubble up from the lower mantle and heat a region in the transition zone before falling back. Above the transition zone, convection may be influenced by heat transferred from the lower mantle as well as discrete convection currents in the upper mantle driven by subduction and seafloor spreading. Mantle plumes emanating from the upper mantle may gush up through the lithosphere as hot spots. Mantle Plumes A mantle plume is an upwell ing of superheated rock from the mantle. Mantle plumes are the likely cause of “ hot spot s,” volcanic regions not created by plate tectonics. As a mantle plume reaches the upper mantle, it melts into a diapir. This molten material heats the asthenosphere and lithosphere, triggering volcanic eruptions. These volcanic eruptions make a minor contribution to heat loss from Earth’s interior, although tectonic activity at plate boundaries is the leading cause of such heat loss. The Hawaiian hot spot, in the middle of the North Pacific Ocean, sits above a likely mantle plume. As the Pacific plate moves in a generally northwestern motion, the Hawaiian hot spot remains relatively fixed.

Geologists think this has allowed the Hawaiian hot spot to create a series of volcanoes, from the 85-million-year-old Meiji Seamount near Russia’s Kamchatka Peninsula, to the Loihi Seamount, a submarine volcano southeast of the “Big Island” of Hawaii. Loihi, a mere 400,000 years old, will eventually become the newest Hawaiian island. Geologists have identified two so-called “superplumes.” These superplumes, or large low shear velocity provinces ( LLSVP s), have their origins in the melt material of D’’. The Pacific LLSVP influences geology throughout most of the southern Pacific Ocean (including the Hawaiian hot spot). The African LLSVP influences the geology throughout most of southern and western Africa. Geologists think mantle plumes may be influenced by many different factors. Some may pulse, while others may be heated continually. Some may have a single diapir, while others may have multiple “stems.” Some mantle plumes may arise in the middle of a tectonic plate, while others may be “captured” by seafloor spreading zones. Some geologists have identified more than a thousand mantle plumes.

Some geologists think mantle plumes don’t exist at all. Until tools and technology allow geologists to more thoroughly explore the mantle, the debate will continue. Exploring the Mantle The mantle has never been directly explored. Even the most sophisticated drilling equipment has not reached beyond the crust. Drilling all the way down to the Moho (the division between the Earth's crust and mantle) is an important scientific milestone, but despite decades of effort, nobody has yet succeeded. In 2005, scientists with the Integrated Ocean Drilling Project drilled 1,416 meters (4,644 feet) below the North Atlantic seafloor and claimed to have come within just 305 meters (1,000 feet) of the Moho. Xenoliths Many geologists study the mantle by analyzing xenoliths. Xenolith s are a type of intrusion—a rock trapped inside another rock. The xenoliths that provide the most information about the mantle are diamonds. Diamonds form under very unique conditions: in the upper mantle, at least 150 kilometers (93 miles) beneath the surface. Above depth and pressure, the carbon crystallizes as graphite , not diamond.

Diamonds are brought to the surface in explosive volcanic eruptions, forming “diamond pipes” of rocks called kimberlites and lamprolites. The diamonds themselves are of less interest to geologists than the xenoliths some contain. These intrusions are minerals from the mantle, trapped inside the rock-hard diamond. Diamond intrusions have allowed scientists to glimpse as far as 700 kilometers (435 miles) beneath Earth’s surface—the lower mantle. Xenolith studies have revealed that rocks in the deep mantle are most likely 3-billion-year old slabs of subducted seafloor. The diamond intrusions include water, ocean sediment s, and even carbon. Seismic Waves Most mantle studies are conducted by measuring the spread of shock wave s from earthquakes, called seismic wave s. The seismic waves measured in mantle studies are called body wave s, because these waves travel through the body of the Earth. The velocity of body waves differs with density, temperature, and type of rock. There are two types of body waves: primary waves, or P-waves, and secondary waves, or S-waves. P-wave s, also called pressure waves, are formed by compression s.

Sound waves are P-waves—seismic P-waves are just far too low a frequency for people to hear. S-wave s, also called shear waves, measure motion perpendicular to the energy transfer. S-waves are unable to transmit through fluids or gases. Instruments placed around the world measure these waves as they arrive at different points on the Earth’s surface after an earthquake. P-waves (primary waves) usually arrive first, while s-waves arrive soon after. Both body waves “reflect” off different types of rocks in different ways. This allows seismologists to identify different rocks present in Earth’s crust and mantle far beneath the surface. Seismic reflections, for instance, are used to identify hidden oil deposits deep below the surface. Sudden, predictable changes in the velocities of body waves are called “seismic discontinuities.” The Moho is a discontinuity marking the boundary of the crust and upper mantle. The so-called “410-kilometer discontinuity” marks the boundary of the transition zone. The Gutenberg discontinuity is more popularly known as the core-mantle boundary (CMB).

At the CMB, S-waves, which can’t continue in liquid, suddenly disappear, and P-waves are strongly refract ed, or bent. This alerts seismologists that the solid and molten structure of the mantle has given way to the fiery liquid of the outer core. Mantle Maps Cutting-edge technology has allowed modern geologists and seismologists to produce mantle maps. Most mantle maps display seismic velocities, revealing patterns deep below Earth’s surface. Geoscientists hope that sophisticated mantle maps can plot the body waves of as many as 6,000 earthquakes with magnitude s of at least 5.5. These mantle maps may be able to identify ancient slabs of subducted material and the precise position and movement of tectonic plates. Many geologists think mantle maps may even provide evidence for mantle plumes and their structure. Term layer in Earth's mantle between the lithosphere (above) and the upper mantle (below). atmosphere name given to someone by their parents or leaders at their birth. body wave seismic wave that travels through the interior of the Earth. boundary to describe the characteristics of something. compound substance having at least two chemical elements held together with chemical bonds.

compression instance of being pressed together or forced into less space. consistent maintaining a steady, reliable quality. continent thick layer of Earth that sits beneath continents. continental drift movement of a fluid from a cool area to a warm area. core to match or be similar to. crust crystal Noun type of mineral that is clear and, when viewed under a microscope, has a repeating pattern of atoms and molecules. D'' deepest layer of Earth's mantle, about 2,700 kilometers (1,678 miles) beneath Earth’s surface. dense having parts or molecules that are packed closely together. diapir dome-shaped geologic feature (intrusion) where more fluid material is forced into brittle overlying rock. diapir dome-shaped geologic feature (intrusion) where more fluid material is forced into brittle overlying rock. discrete to fall apart and disappear. distinct to differentiate or recognize as different. dome capable of withstanding a certain amount of force by changing form before fracturing or breaking. dwarf to make something appear small by having it appear next to something much larger. earthquake Noun the sudden shaking of Earth's crust caused by the release of energy along fault lines or from volcanic activity.

Earth's heat budget Noun measurement of the flow of thermal energy from the core to the atmosphere, dominated by absorbed and reflected solar radiation. equipment tools and materials to perform a task or function. erupt to explode or suddenly eject material. fissure material that is able to flow and change shape. frequency Noun rate of occurrence, or the number of things happening in a specific area over specific time period. geologist person who studies the physical formations of the Earth. geothermal gradient Noun gradual change in temperature from the Earth's core (hot) to its crust (cool), about 25° Celsus per kilometer of depth (1° Fahrenheit per 70 feet of depth). glimpse graphite Noun soft, common allotrope of carbon that is the highest rank of coal. Also called black lead. Gutenberg discontinuity point between the Earth's mantle and the core below. hot spot Noun intensely hot region deep within the Earth that rises to just underneath the surface. Some hot spots produce volcanoes. chemical compound containing the OH‾ ion. igneous intrusion Noun rock formation created by magma as it is pushed from the Earth's mantle into cracks or holes in the crust.

influence force that effects the actions, behavior, or policies of others. ion Noun electrically charged atom or group of atoms, formed by the atom having gained or lost an electron. isostasy Noun equilibrium of Earth's crust, where the forces tending to elevate landmasses balance those tending to depress them. Also called isostatic equilibrium. layered-mantle convection process in which mantle convection is primarly carried out by activity in the upper mantle. lithosphere chemical and mechanical distinction between the cool, rigid lithosphere and the warmer, more ductile asthenosphere. LLSVP Noun (large low shear velocity province) seismically anomalous region at the deepest part of Earth's mantle. Also called a superplume or thermo-chemical pile. lower mantle bottom layer in Earth's mantle, closest to the core. magma intensity of an earthquake, represented by numbers on a scale. malleable flexible and capable of reforming itself without breaking when under stress. mantle mantle convection Noun slow movement of Earth's solid mantle caused by convection currents transferring heat from the interior of the Earth to the surface. mantle plume upwelling of magma within Earth's mantle.

melt inorganic material that has a characteristic chemical composition and specific crystal structure. Mohorovicic discontinuity point between Earth's crust and the mantle below. Also called the Moho. molten solid material turned to liquid by heat. oceanic crust thin layer of the Earth that sits beneath ocean basins. oil Noun fossil fuel formed from the remains of marine plants and animals. Also known as petroleum or crude oil. orogeny the way mountains are formed. outer core liquid, iron-nickel layer of the Earth between the solid inner core and lower mantle. outgas to release a gas that was dissolved, trapped, frozen or absorbed in another material. permeable allowing liquid and gases to pass through. perpendicular at a right angle to something. planet state of matter with no fixed shape and molecules separated into ions and electrons. plastically in a moldable, alterable manner. plate tectonics movement and interaction of the Earth's plates. precise force pressed on an object by another object or condition, such as gravity. P-wave seismic shock wave that represents longitudinal motion. Also called a primary wave or pressure wave. radical to bend or change the path of something.

region Noun any area on Earth with one or more common characteristics. Regions are the basic units of geography. large, concentrated supply or reserve. rheologist scientist who studies the flow and shape-changing (deformation) of matter. rigid natural substance composed of solid mineral matter. seafloor spreading shock wave of force or pressure that travels through the Earth. seismologist moving, measurable change in pressure and density of a material. silicate Noun most common group of minerals, all of which include the elements silicon (Si) and oxygen (O). slab flat, thick piece of material such as earth or stone. solar radiation light and heat from the sun. solar radiation light and heat from the sun. sophisticated to cause to slow or come to a stop. subduct to pull downward or beneath something. subduction process of one tectonic plate melting, sliding, or falling beneath another. S-wave seismic shock wave that represents perpendicular motion. Also called a secondary wave or shear wave. technology Noun the science of using tools and complex machines to make human life easier or more profitable. tectonic activity movement of tectonic plates resulting in geologic activity such as volcanic eruptions and earthquakes.

tectonic plate Noun massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate. temperature having to do with heat or temperature. transform to change from one form into another. transition zone Noun areas in the Earth's interior between the upper mantle, near the Earth's crust, and the lower mantle, near the Earth's core. upper mantle layer in Earth's mantle between the asthenosphere (above) and the lower mantle (below). upwell to rise, grow, or gush upward. vapor visible liquid suspended in the air, such as fog. velocity measurement of the rate and direction of change in the position of an object. viscosity measure of the resistance of a fluid to a force or disturbance. volcano Noun an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions. whole-mantle convection Noun process in which mantle convection is a result of activity in both the upper and lower mantle.

xenolith Reservoir of molten rock under Yellowstone is 2.5 times bigger than thought | Earth | EarthSky Reservoir of molten rock under Yellowstone is 2.5 times bigger than thought By Deanna Conners in Earth | July 22, 2014 If the Yellowstone supervolcano were to erupt today, it would have major, perhaps catastrophic, consequences. Yellowstone National Park and the surrounding area in North America is the site of some of the most powerful volcanic eruptions to have ever occurred on Earth. Scientists are trying to understand this supervolcano beneath Yellowstone. Thanks to new seismic sensors that have been installed in this area over the past decade, they now have better tools to visualize what lies beneath the surface. The latest string of research has found that the reservoir of magma – molten or semi-molten rock – under Yellowstone is about 2.5 times bigger than previously thought. This research was published in the journal Geophysical Research Letters on May 9, 2014. The Yellowstone supervolcano is thought to be relatively young, on a geologic timescale.

Scientists believe eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago. The last eruption sent ash across the entire continent we now know as North America and caused changes in the global climate. If the Yellowstone supervolcano were to erupt today, it would have serious consequences. Will the Yellowstone supervolcano erupt in your lifetime? Midway Geyser Basin, Yellowstone National Park. Image Credit: Neal Herbert, National Park Service . The magma reservoir in Yellowstone sits several kilometers above a hotspot in the mantle, and it captures much of the molten rock that rises to the surface. This molten rock is called “melt.” To visualize the size of the magma reservoir and estimate the amount of melt it contains, scientists used a technique called seismic tomography that measures how fast seismic waves from earthquakes travel through Earth’s crust. Areas where these waves slow down are indicative of warm, partially melted rock. The scientists analyzed seismic waves from 4,520 earthquakes that occurred in Yellowstone during 1984 to 2011. From these data, they were able to calculate the size of the magma reservoir.

It was found to be 90 kilometers (56 miles) long and about 5 to 17 kilometers (3 to 11 miles) deep , which is 2.5 times bigger than earlier estimates. The magma reservoir is believed to be the largest known magma reservoir in the world. Cross section of the Yellowstone hotspot and magma reservoir. Image appears courtesy of Jamie Farrell, University of Utah . They also found that magma reservoir contained about 5 to 15% melt, which is lower than an earlier estimate of 32% melt. Magma typically does not erupt unless it has high melt contents of 50% or more, according to the U.S. Geological Survey . The scientists are hoping to conduct future studies on the pore structure of the magma reservoir, which would help them to better understand the eruption potential. The Yellowstone volcanic field mostly developed during three enormous eruptions that occurred 2.1 million years ago, 1.3 million years ago, and 640,000 years ago. Yellowstone presently contains numerous geysers and hotsprings.

The new research at Yellowstone was conducted by Jamie Farrell and Robert Smith of the University of Utah, and Stephan Husen and Tobias Diehl of the Swiss Seismological Service. Funding for the research was provided by The Brinson Foundation, Carrico funds, and the University of Utah. Bottom line: New research published in the journal Geophysical Research Letters on May 9, 2014 has found that the magma reservoir beneath Yellowstone is about 2.5 times bigger than original estimates. It is believed to be the largest known magma reservoir in the world. BBC Earth - Magma wells up underground waiting to erupt Inside our planet Liz Bonnin uses a plum to explain what's happening inside the Earth. Reporting from Eyjafjallajokull volcano in Iceland, Liz Bonnin explains the Earth's inner structure using a plum to show the different layers inside our planet. She explains why hot bits of the mantle that are rising melt to form magma.

Magma Magma (from Ancient Greek μάγμα (mágma) meaning "thick unguent") is a mixture of molten or semi-molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals, dissolved gas and sometimes gas bubbles. Magma often collects in magma chambers that may feed a volcano or solidify underground to form an intrusion. Magma is capable of intruding into adjacent rocks (forming igneous dikes and sills), extrusion onto the surface as lava, and explosive ejection as tephra to form pyroclastic rock. Igneous Rock: Face of the Earth Home | Games | Glossary | Bulletin Board | Landforms | Rock Cycle | Processes | SKC Homepage Igneous Rock On the earth's surface, there are three types of rocks, metamorphic, sedimentary, and igneous. In northern Canada, much of the hard rock found is igneous rock. Igneous rock is rock formed by the hardening and crystallization of molten material that originates deep within the earth.

The word "igneous" comes from the Greek word for fire; some people call igneous rock a fire ball rock. Rocks that have hardened from magma, the hot liquid beneath the earth's crust, are called igneous rocks. The inside of the earth is very hot - hot enough to melt rocks. The deeper you get the hotter it gets. Below the surface, the molten rock is called magma; at the earth's surface it becomes lava, nothing has changed only the name of the liquid. Igneous rock is made by fire. Small wonder the magma from which igneous rock is formed can reach temperatures close to 1200 degrees Celsius. As the super hot magma cools, it solidifies to form a rock and that rock is called igneous rock. When most people think of igneous rock they vision a volcano erupting pumice and lava. Igneous rocks form directly by crystallization from materials from a magma melt. Igneous rocks crystalize after the magma reaches the earth's surface. Igneous rock is divided into 2 groups, extrusive and intrusive.

Extrusive rocks form when magma flows onto the surface of the earth or floor of the ocean through deep cracks or fissures and at volcanic vents, and then cools and hardens. Intrusive rock results when magma solidifies beneath the earth's surface in mines and tunnels or at the surface where it has been exposed by geological uplifting and by erosion. In general, extrusive rocks have a finer grained texture than intrusive rocks; intrusive rocks vary from thin sheets to huge, irregular masses. Since magma that forms intrusive rocks solidifies slowly, most intrusive rocks have larger crystals than extrusive rocks.

Question: What is the name given to the molten rock beneath the surface of the Earth?
Answer: Magma