"might possibly be exposed in the South Pole-Aitken basin and/or the Crisium basin. The lunar mantle contains a seismic discontinuity at ~500 km depth, most likely related to a change in composition. Titan and Triton each have a mantle made of ice or other solid volatile substances. Some of the largest asteroids have mantles; for example, Vesta has a silicate mantle similar in composition to diogenite meteorites. Mantle (geology) The mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest"
"about under the oceans to for the continents. The crust and the cold, rigid, top of the upper mantle are collectively known as the lithosphere, and it is of the lithosphere that the tectonic plates are composed. Beneath the lithosphere is the asthenosphere, a relatively low-viscosity layer on which the lithosphere rides. Important changes in crystal structure within the mantle occur at below the surface, spanning a transition zone that separates the upper and lower mantle. Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core. The Earth's inner core might rotate at a"
"increase in seismic velocity and are similar to light reflecting from a mirror. The Earth's crust ranges from in depth and is the outermost layer. The thin parts are the oceanic crust, which underlie the ocean basins (5–10 km) and are composed of dense (mafic) iron magnesium silicate igneous rocks, like basalt. The thicker crust is continental crust, which is less dense and composed of (felsic) sodium potassium aluminium silicate rocks, like granite. The rocks of the crust fall into two major categories – sial and sima (Suess,1831–1914). It is estimated that sima starts about 11 km below the Conrad"
"Sima (geology) In geology, sima is the name for the lower layer of the Earth's crust. This layer is made of rocks rich in magnesium silicate minerals. Typically when the sima comes to the surface it is basalt, so sometimes this layer is called the 'basalt layer' of the crust. The sima layer is also called the 'basal crust' or 'basal layer' because it is the lowest layer of the crust. Because the ocean floors are mainly sima, it is also sometimes called the 'oceanic crust'. The name 'sima' was taken from the first two letters of silica and of"
"is composed of the Earth's rocky crust and the deeper mostly solid outer layer of the mantle. On land the crust is known as the continental crust while under the sea it is known as the oceanic crust. The latter is composed of relatively dense basalt and is some five to ten kilometres (three to six miles) thick. The relatively thin lithosphere floats on the weaker and hotter mantle below and is fractured into a number of tectonic plates. In mid-ocean, magma is constantly being thrust through the seabed between adjoining plates to form mid-oceanic ridges and here convection currents"
"the crust, upper mantle, lower mantle, outer core, and inner core. The geologic component layers of Earth are at the following depths below the surface: The layering of Earth has been inferred indirectly using the time of travel of refracted and reflected seismic waves created by earthquakes. The core does not allow shear waves to pass through it, while the speed of travel (seismic velocity) is different in other layers. The changes in seismic velocity between different layers causes refraction owing to Snell's law, like light bending as it passes through a prism. Likewise, reflections are caused by a large"
"Crust (geology) In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Moon, Mercury, Venus, Mars, Io, and other planetary bodies formed via igneous processes, and were later modified by erosion, impact cratering, volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two"
"as rocks or river water), then they record their findings on charts and maps. The following fields of science are generally categorized within the Earth sciences: Plate tectonics, mountain ranges, volcanoes, and earthquakes are geological phenomena that can be explained in terms of physical and chemical processes in the Earth's crust. Beneath the Earth's crust lies the mantle which is heated by the radioactive decay of heavy elements. The mantle is not quite solid and consists of magma which is in a state of semi-perpetual convection. This convection process causes the lithospheric plates to move, albeit slowly. The resulting process"
"Pedosphere The pedosphere (from Greek πέδον ""pedon"" ""soil"" or ""earth"" and σφαῖρα ""sphaira"" ""sphere"") is the outermost layer of the Earth that is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The pedosphere is the skin of the Earth and only develops when there is a dynamic interaction between the atmosphere (air in and above the soil), biosphere (living organisms), lithosphere (unconsolidated regolith and consolidated bedrock) and the hydrosphere (water in, on and below the soil). The pedosphere is the foundation of terrestrial life on Earth. The"
"Lower oceanic crust The lower oceanic crust is the lower part of the oceanic crust and represents the major part of it (volumetrically biggest part). It is generally located 4–8 km below the ocean floor and the major lithologies are mafic (ultramafic and gabbroic rocks) which derive from melts rising from the earth's mantle. This part of the oceanic crust is an important zone for processes such as melt accumulation and melt modification (fractional crystallisation and crustal assimilation). And the recycling of this part of the oceanic crust, together with the upper mantle has been suggested as a significant source"
"depth), with felsic composition (rich in silica and predominately quartz plus potassium-rich feldspar plus sodium-rich plagioclase) and phaneritic, subeuhedral texture (minerals are visible to the unaided eye and commonly some of them retain original crystallographic shapes). The Earth's crust averages about 35 kilometers thick under the continents, but averages only some 7–10 kilometers beneath the oceans. The continental crust is composed primarily of sedimentary rocks resting on a crystalline ""basement"" formed of a great variety of metamorphic and igneous rocks, including granulite and granite. Oceanic crust is composed primarily of basalt and gabbro. Both continental and oceanic crust rest on"
"Subsoil Subsoil is the layer of soil under the topsoil on the surface of the ground. Like topsoil it is composed of a variable mixture of small particles such as sand, silt and/or clay, but with a much lower percentage of organic matter and humus. Below the subsoil is the substratum, which can be residual bedrock, sediments, or aeolian deposits. As it is lacking in dark humus, subsoil is usually paler in color than the overlying topsoil. It may contain the deeper roots of some plants,such as trees,but a majority of plant roots lie within the topsoil. Clay-based subsoil has"
"Underwater Underwater refers to the region below the surface of water where the water exists in a swimming pool or a natural feature (called a body of water) such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water. A majority of the planet's solid surface is abyssal plain, at depths between below the surface of the oceans. The solid surface location on the planet closest to the centre of the orb is the Challenger Deep, located in the Mariana Trench at a depth of . Although a number of human activities"
"suggested at a range of depths. Transition zone (Earth) The transition zone is part of the Earth’s mantle, and is located between the lower mantle and the upper mantle, between a depth of 410 and 660 km (250 to 400 mi). The Earth’s mantle, including the transition zone, consists primarily of peridotite, an ultramafic igneous rock. The mantle was divided into the upper mantle, transition zone, and lower mantle as a result of sudden seismic-velocity discontinuities at depths of 410 and 660 km (250 to 400 mi). This is thought to occur as a result of rearrangement of grains in"
"Bedrock In geology, bedrock is the lithified rock that lies under a loose softer material called regolith at the surface of the Earth or other terrestrial planets. The broken and weathered regolith includes soil and subsoil. The surface of the bedrock beneath the soil cover is known as rockhead in engineering geology, and its identification by digging, drilling or geophysical methods is an important task in most civil engineering projects. Superficial deposits (also known as drift) can be extremely thick, such that the bedrock lies hundreds of meters below the surface. Bedrock may also experience subsurface weathering at its upper"
"formed almost immediately after formation of the Moon. Magmatism continued after the period of intense meteorite impacts ended about 3.9 billion years ago, but igneous rocks younger than 3.9 billion years make up only a minor part of the crust. Crust (geology) In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Moon, Mercury, Venus, Mars,"
"cryosphere (corresponding to ice) as a distinct portion of the hydrosphere, as well as the pedosphere (corresponding to soil) as an active and intermixed sphere. Earth science (also known as geoscience, the geographical sciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. There are four major disciplines in earth sciences, namely geography, geology, geophysics and geodesy. These major disciplines use physics, chemistry, biology, chronology and mathematics to build a qualitative and quantitative understanding of the principal areas or ""spheres"" of Earth. The Earth's crust, or lithosphere, is the outermost solid surface of"
"Stratum In geology and related fields, a stratum (plural: strata) is a layer of sedimentary rock or soil, or igneous rock that were formed at the Earth's surface, with internally consistent characteristics that distinguish it from other layers. The ""stratum"" is the fundamental unit in a stratigraphic column and forms the basis of the study of stratigraphy. Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural processes. They may extend over hundreds of thousands of square kilometers of the Earth's surface. Strata are typically seen as bands of different"
"Subcontinental lithospheric mantle The subcontinental lithospheric mantle (SCLM) is the uppermost solid part of Earth's mantle associated with the continental lithosphere. The modern understanding of the Earth's upper mantle is that there are two distinct components - the lithospheric part and the asthenosphere. The lithosphere, which includes the continental plates, acts as a brittle solid whereas the asthenosphere is hotter and weaker due to mantle convection. The boundary between these two layers is rheologically based and is not necessarily a strict function of depth. Specifically, oceanic lithosphere (lithosphere underneath the oceanic plates) and subcontinental lithosphere, is defined as a mechanical"
"Outer core The outer core of the Earth is a fluid layer about thick and composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. Its outer boundary lies beneath Earth's surface. The transition between the inner core and outer core is located approximately beneath the Earth's surface. Unlike the inner core, the outer core is liquid. The inner core is also referred to as the solid core. Seismic inversions of body waves and normal modes constrain the radius of the outer core to be 3483 km with an uncertainty of 5 km,"
"Asthenosphere The asthenosphere (from Greek ἀσθενής ""asthenḗs"" 'weak' + ""sphere"") is the highly viscous, mechanically weak and ductilely deforming region of the upper mantle of the Earth. It lies below the lithosphere, at depths between approximately below the surface. The Lithosphere-Asthenosphere boundary is usually referred to as LAB. The asthenosphere is almost solid, although some of its regions could be molten (e.g., below mid-ocean ridges). The lower boundary of the asthenosphere is not well defined. The thickness of the asthenosphere depends mainly on the temperature. However, the rheology of the asthenosphere also depends on the rate of deformation, which suggests"
"for applications such as submillimetre astronomy. High-altitude balloons are often flown by students and by amateur groups to altitudes on the order of , for both scientific and educational purposes. Mesosphere The mesosphere (; from Greek ""mesos"" ""middle"" ) is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature decreases as the altitude increases. This characteristic is used to define its limits: it begins at the top of the stratosphere (sometimes called the stratopause), and ends at the mesopause, which is the coldest part of Earth's atmosphere with"
"a thickness of making up about 84% of Earth's volume. It is predominantly solid but in geological time it behaves as a viscous fluid. Partial melting of the mantle at mid-ocean ridges produces oceanic crust, and partial melting of the mantle at subduction zones produces continental crust. The Earth's mantle is divided into two major rheological layers: the rigid lithosphere comprising the uppermost mantle, and the less viscous asthenosphere, separated by the lithosphere-asthenosphere boundary. Lithosphere underlying ocean crust has a thickness of around 100 km, whereas lithosphere underlying continental crust generally has a thickness of 150-200 km. The lithosphere and"
"and petroleum geology in which the (typically Precambrian) crystalline basement is not of interest as it rarely contains petroleum or natural gas. Basement (geology) In geology, basement and crystalline basement are the rocks below a sedimentary platform or cover, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin. In the same way, the sediments or sedimentary rocks on top of the basement can be called a ""cover"" or ""sedimentary cover"". Basement rock is the thick foundation of ancient, and oldest metamorphic and igneous rock that forms the crust of continents, often"
"Transition zone (Earth) The transition zone is part of the Earth’s mantle, and is located between the lower mantle and the upper mantle, between a depth of 410 and 660 km (250 to 400 mi). The Earth’s mantle, including the transition zone, consists primarily of peridotite, an ultramafic igneous rock. The mantle was divided into the upper mantle, transition zone, and lower mantle as a result of sudden seismic-velocity discontinuities at depths of 410 and 660 km (250 to 400 mi). This is thought to occur as a result of rearrangement of grains in olivine (which constitutes a large portion"
"the movement of material between the deep Earth and the surface reservoirs. This occurs through two different processes: volcanism and subduction of tectonic plates. Subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate and sinks into the mantle as the plates converge. This leads to the sinking of one plate into the mantle which creates a broad range of geochemical transformations or cycling. Volcanism is the process that takes place at divergent boundaries by which one tectonic plate separates from another creating a rift in which molten rock (magma)"
"Mesosphere The mesosphere (; from Greek ""mesos"" ""middle"" ) is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature decreases as the altitude increases. This characteristic is used to define its limits: it begins at the top of the stratosphere (sometimes called the stratopause), and ends at the mesopause, which is the coldest part of Earth's atmosphere with temperatures below . The exact upper and lower boundaries of the mesosphere vary with latitude and with season (higher in winter and at the tropics, lower in summer and at"
"A slice of the Earth from the Pacific Ocean through the Pacific Northwest might look something like the adjacent image. Beneath the Cascades, a dense oceanic plate plunges beneath the North American Plate; a process known as subduction. As the oceanic slab sinks deep into the Earth's interior beneath the continental plate, high temperatures and pressures allow water molecules locked in the minerals of solid rock to escape. The water vapor rises into the pliable mantle above the subducting plate, causing some of the mantle to melt. This newly formed magma rises toward the Earth's surface to erupt, forming a"
"formed from magma that cools and solidifies within the crust of the planet. In contrast, an ""extrusion"" consists of extrusive rock; rock formed above the surface of the crust. Large bodies of magma that solidify underground before they reach the surface of the crust are called plutons. Plutonic rocks form 7% of the Earth's current land surface. Coarse-grained intrusive igneous rocks that form at depth within the earth are called ""abyssal"" while those that form near the surface are called subvolcanic or ""hypabyssal"". Intrusive structures are often classified according to whether or not they are parallel to the bedding planes"
"Basement (geology) In geology, basement and crystalline basement are the rocks below a sedimentary platform or cover, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin. In the same way, the sediments or sedimentary rocks on top of the basement can be called a ""cover"" or ""sedimentary cover"". Basement rock is the thick foundation of ancient, and oldest metamorphic and igneous rock that forms the crust of continents, often in the form of granite. Basement rock is contrasted to overlying sedimentary rocks which are laid down on top of the basement"
"Subcutaneous tissue The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, or superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the hypodermis are fibroblasts, adipose cells, and macrophages. The hypodermis is derived from the mesoderm, but unlike the dermis, it is not derived from the dermatome region of the mesoderm. In arthropods, the hypodermis is an epidermal layer of cells that secretes the chitinous cuticle. The term also refers to a layer of cells lying immediately below the epidermis of plants. The hypodermis is beneath dermis which is"
"xenoliths found within the crust in the region support the metamorphic phase change associated with the density inversion in the lower crust. It is possible that the Sierra Nevada is the only place on Earth where dense material is currently being removed from the crust. Delamination (geology) In geophysics, delamination refers to the loss and sinking (foundering) of the portion of the lowermost lithosphere from the tectonic plate to which it was attached. The outer portion of the Earth is divided into an upper, lithosphere layer and a lower, asthenosphere layer. The lithosphere layer is composed of two parts, an"
"Mesosphere (mantle) In geology, the mesosphere refers to the part of the Earth's mantle below the lithosphere and the asthenosphere, but above the outer core. The upper boundary is defined by the sharp increase in seismic wave velocities and density at a depth of . At a depth of 660 km, ringwoodite (gamma-(Mg,Fe)SiO) decomposes into Mg-Si perovskite and magnesiowüstite. This reaction marks the boundary between upper mantle and lower mantle. This measurement is estimated from seismic data and high-pressure laboratory experiments. The base of the mesosphere includes the D' zone which lies just above the mantle-core boundary at approximately ."