50 Cent albums discography and Earth science: Difference between pages
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'''Earth science''' (also known as '''geoscience''', '''the geosciences''' or '''the Earth Sciences'''), is an all-embracing term for the sciences related to the planet [[Earth (planet)|Earth]]. It is arguably a special case in [[planetary science]], being the only known [[life]]-bearing planet. There are both [[reductionist]] and [[holism|holistic]] approaches to Earth science. The major historic [[discipline]]s use [[physics]], [[geology]], [[geography]], [[meteorology]], [[mathematics]], [[chemistry]] and [[biology]] to build a quantitative understanding of the principal areas or ''[[Earth's spheres|spheres]]'' of the Earth system.
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== Earth's spheres ==
Earth science generally recognizes 4 spheres, the lithosphere, the hydrosphere, the atmosphere, and the biosphere. These correspond to rocks, water, air, and life. Some practitioners include the crysophere (ice) as a distinct portion of the hydrosphere and the pedosphere (soil) as an active, intermixed sphere as part of Earth's spheres.
[[Image:Limu o Pele.jpg|300px|right|thumb|Lava flows from the [[Kīlauea]] volcano into the ocean on the [[Hawaii (island)|Island of Hawaii]]]]
*[[Geology]] describes the [[Rock (geology)|rocky]] parts of the Earth's [[Crust (geology)|crust]] (or [[lithosphere]]) and its historic development. Major subdisciplines are [[mineralogy]] and [[petrology]], [[geochemistry]], [[geomorphology]], [[paleontology]], [[stratigraphy]], [[engineering geology]] and [[sedimentology]].
*[[Geophysics]] and [[Geodesy]] investigate the [[figure of the Earth]], its reaction to forces and its [[magnetic field|magnetic]] and [[gravity field]]s. Geophysicists explore the [[Earth's core]] and [[Earth's mantle|mantle]] as well as the [[Plate tectonics|tectonic]] and [[Seismology|seismic]] activity of the lithosphere.
*[[Soil science]] covers the outermost layer of the Earth's crust that is subject to soil formation processes (or [[pedosphere]]). Major subdisciplines include [[edaphology]] and [[Pedology (soil study)|pedology]].
*[[Oceanography]] and [[hydrology]] (incl. [[limnology]]) describe the marine and freshwater domains of the [[water]]y parts of the Earth (or [[hydrosphere]]). Major subdisciplines include [[hydrogeology]] and [[Physical oceanography|physical]], [[Chemical oceanography|chemical]], and [[Marine biology|biological]] oceanography.
*[[Glaciology]] covers the [[ice|icy]] parts of the Earth (or [[cryosphere]]).
*[[Atmospheric sciences]] cover the [[gas]]eous parts of the Earth (or [[Earth's atmosphere|atmosphere]]) between the surface and the [[exosphere]] (~1000 km). Major subdisciplines are [[meteorology]], [[climatology]], [[atmospheric chemistry]] and [[atmospheric physics]].
==Earth's energy==
In [[geology]], [[continental drift]]s, [[mountain|mountain range]]s, [[volcano]]s, and [[earthquake]]s are phenomena that can be explained in terms of [[energy transformation]]s in the Earth's crust<ref>http://okfirst.ocs.ou.edu/train/meteorology/EnergyBudget.html</ref>. Recent studies suggest that the Earth transforms about 6.18 x 10<sup>-12</sup> J/s (joules per second) per kilogram. Given the [[Earth#mass|Earth's mass]], the rate of energy transformations inside the Earth is about 37 x 10<sup>12</sup> J/s (37 terawatts). The heat escaping from inside the Earth is only about 0.02% of the amount of energy Earth receives from Sun in the form of sunlight, and radiates back into space in the form of Infra red blackbody radiation (~1.74 x 10<sup>17</sup> J/s = 174 petawatts).
From the study of [[neutrino]]s radiated from the Earth (see [[KamLAND]]), scientists have recently estimated that about 24 terawatts (65%) of this rate of [[energy transformation]] is due to [[radioactive decay]] (principally of [[potassium]] 40, [[thorium]] 232 and [[uranium]] 238), and the remaining 13 terawatts is from the continuous gravitational ''sorting'' of the [[Planetary core|core]] and [[mantle]] of the earth, energies left over from the [[History of Earth|formation of the Earth]], about 4.57 billion years ago (this sorting represents continuing [[gravitational collapse]] of the Earth into the maximally compact object which is consistent with its composition-- a process which releases gravitational potential energy), and finally - from [[tidal flexing]] of Earth interior and crust. The magnitude of all of these energy sources decline over time, and based on half-life alone, it has been estimated that the current [[radioactivity|radioactive energy]] of the planet represents less than 1% of that which was available at the time the planet was formed.
As a result, geological forces of [[accretion (geology)|continental accretion]], [[subduction]] and [[sea floor spreading]], account for 90% of the Earth's energy. The remaining 10% of geological tectonic energy comes through [[hotspots]] produced by [[mantle plumes]], resulting in [[shield volcanoes]] like [[Hawaii]], [[geyser]] activity like [[Yellowstone]] or [[flood basalt]]s like [[Iceland]].
[[Tectonic]] process are driven by heat from the Earth's interior. The process is a simple heat engine which works via the upward buoyancy-induced motion of hot, low density magma after expansion by heat. The processes metamorphose weathered rocks, and (more importantly from the energy view) during [[orogeny]] periods, lift them up into mountain ranges. The potential energy represented by the mountain range's weight and height thus represents heat from the core of the Earth which has been partly transformed into gravitational potential energy. This potential energy may be suddenly released in landslides or [[tsunami]]s. Similarly, the energy release which drives an earthquake represents stresses in rocks that are mechanical potential energy which has been similarly stored from tectonic processes. An earthquake thus ultimately represents kinetic energy which is being released from elastic potential energy in rocks, which in turn has been stored from heat energy released by radioactive decay and gravitational collapse in the Earth's interior.
The energy which is responsible for the geological processes of ''erosion and deposition'' is a result of the interaction of solar energy and gravity. An estimated 23% of the total insolation is used to drive the [[water cycle]]. When [[water vapour]] condenses to fall as [[rain]], it dissolves small amounts of [[carbon dioxide]], making a weak [[acid]]. This acid acting upon the metallic [[silicate]]s that form most rocks produces [[chemical weathering]], removing the metals, and leading to the production of rocks and sand, carried by wind and water downslope through gravity to be deposited at the edge of continents in the sea. [[weathering|Physical weathering]] of rocks is produced by the expansion of ice crystals, left by water in the joint planes of rocks. A geologic cycle is continued when these eroded rocks are later uplifted into mountains.
Similarly meteorological phenomena like [[wind]], [[rain]], [[hail]], [[snow]], [[lightning]], [[tornado]]es and [[hurricanes]], are all a result of energy transformations brought about by solar energy on the planet Earth. It has been estimated that the average total ''solar incoming radiation'' (or [[insolation]]) is about 1350 watts per square meter incident to the summit of the atmosphere, at the equator at midday, a figure known as the [[solar constant]]. Although this amount varies a little each year, as a result of [[solar flares]], [[Solar Prominence|prominences]] and the [[sunspot cycle]]. Some 34% of this is immediately reflected by the planetary [[albedo]], as a result of clouds, snowfields, and even reflected light from water, rock or vegetation. As more energy is received in the tropics than is re-radiated, while more energy is radiated at the poles than is received, climatic homeostasis is only maintained by a transfer of energy from the tropics to the poles. ).[[Image:Volcano q.jpg|right|thumb|250px|A [[volcano]] is the release of stored energy from below the surface of Earth originating in radioactive decay and gravitational sorting in the Earth's core and mantle of energies left over from its formation]]
This transfer of energy is what drives the winds and the ocean currents. Like biological processes, all meteorological processes involve transformation of energy from a concentrated form such as sunlight into a less concentrated form, such as far infrared radiation (i.e., heat radiation at the much smaller characteristic temperatures that occur on Earth, and thus is diffused into many photons. However, energy may be temporarily locally stored during this process, and the sudden release of such stored sources is responsible for the dramatic processes mentioned above. For example, the kinetic energy of a snow-avalanche or hurricane is due to the sudden release of energy previously captured from solar radiations.
==Methodology==
Like all other scientists, Earth scientists apply the [[scientific method]]: formulate hypotheses after observation of and gathering data about natural phenomena and then test those hypotheses. In Earth science, data usually plays a critical role in testing and formulating hypotheses.
== Partial list of the major Earth Science topics ==
===Atmosphere===
* [[Atmospheric chemistry]]
* [[Climatology]]
* [[Meteorology]]
** [[Hydrometeorology]]
* [[Paleoclimatology]]
===Biosphere===
* [[Biogeography]]
* [[Paleontology]]
** [[Palynology]]
** [[Micropaleontology]]
* [[Geomicrobiology]]
===Hydrosphere===
* [[Hydrology]]
** [[Glaciology]]
** [[Limnology]]
* [[Hydrogeology]]
* [[Oceanography]]
** [[Chemical oceanography]]
** [[Marine biology]]
** [[Marine geology]]
** [[Paleoceanography]]
** [[Physical oceanography]]
=== Lithosphere or geosphere===
* [[Geology]]
** [[Economic geology]]
** [[Engineering geology]]
** [[Environmental geology]]
** [[Historical geology]]
*** [[Glaciology]]
*** [[Quaternary geology]]
** [[Planetary geology]]
** [[Sedimentology]]
** [[Stratigraphy]]
** [[Structural geology]]
* [[Geochemistry]]
* [[Geography]]
** [[Physical geography]]
* [[Geomorphology]]
* [[Geophysics]]
** [[Geochronology]]
** [[Geodynamics]] (see also [[Tectonics]])
** [[Geomagnetic]]s
** [[Gravimetry]] (also part of [[Geodesy]])
** [[Seismology]]
* [[Hydrogeology]]
* [[Mineralogy]]
** [[Crystallography]]
** [[Gemology]]
* [[Petrology]]
* [[Volcanology]]
===Pedosphere===
* [[Soil science]]
** [[Edaphology]]
** [[Pedology (soil study)|Pedology]]
===Systems===
* [[Environmental science]]
* [[Geography]]
** [[Human geography]]
** [[Physical Geography]]
* [[Gaia theory (science)|Gaia theories]]
===Others===
* [[Cartography]]
* [[Geoinformatics]] ([[GIS]])
* [[Geostatistics]]
* [[Geodesy]] and [[Surveying]]
== Notes and references ==
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==See also==
* [[List of basic earth science topics]]
* [[List of geoscience organizations]]
{{Earth science}}
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