document_title: Earth

question_text: where does the original flow of energy on earth come from

question_tokens: where does the original flow of energy on earth come from

text: Earth

text: Name and etymology

text: The modern English word  Earth developed from a wide variety of Middle English forms,[n 6] which derived from an Old English noun most often spelled eorðe.[39] It has cognates in every Germanic language, and their proto-Germanic root has been reconstructed as *erþō. In its earliest appearances, eorðe was already being used to translate the many senses of Latin terra and Greek γῆ (gē): the ground,[n 7] its soil,[n 8] dry land,[n 9] the human world,[n 10] the surface of the world (including the sea),[n 11] and the globe itself.[n 12] As with Terra and Gaia, Earth was a personified goddess in Germanic paganism: the Angles were listed by Tacitus as among the devotees of Nerthus,[48] and later Norse mythology included Jörð, a giantess often given as the mother of Thor.[49]

text: Originally, earth was written in lowercase, and from early Middle English, its definite sense as "the globe" was expressed as the earth. By Early Modern English, many nouns were capitalized, and the earth became (and often remained) the Earth, particularly when referenced along with other heavenly bodies. More recently, the name is sometimes simply given as Earth, by analogy with the names of the other planets.[39] House styles now vary: Oxford spelling recognizes the lowercase form as the most common, with the capitalized form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name (e.g. "Earth's atmosphere") but writes it in lowercase when preceded by the (e.g. "the atmosphere of the earth"). It almost always appears in lowercase in colloquial expressions such as "what on earth are you doing?"[50]

text: Chronology

text: Formation

text: The oldest material found in the Solar System is dated to 7000456720000000000♠4.5672±0.0006 billion years ago (Bya).[51] By 7000454000000000000♠4.54±0.04 Bya[52] the primordial Earth had formed. The formation and evolution of Solar System bodies occurred along with the Sun. In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into a circumstellar disk, and then the planets grow out of that disk along with the Sun. A nebula contains gas, ice grains, and dust (including primordial nuclides). According to nebular theory, planetesimals formed by accretion, with the primordial Earth taking 10–7001200000000000000♠20 million years (Mys) to form.[53]

text: A subject of on-going research is the formation of the Moon, some 4.53 Bya.[54] A working hypothesis is that it was formed by accretion from material loosed from Earth after a Mars-sized object, named Theia, impacted Earth.[55] In this scenario, the mass of Theia was approximately 10% of that of Earth,[56] it impacted Earth with a glancing blow,[57] and some of its mass merged with Earth. Between approximately 4.1 and 7000380000000000000♠3.8 Bya, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of the Moon, and by inference, to that of Earth.

text: Geological history

text: Earth's atmosphere and oceans were formed by volcanic activity and outgassing that included water vapor. The origin of the world's oceans was condensation augmented by water and ice delivered by asteroids, protoplanets, and comets.[58] In this model, atmospheric "greenhouse gases" kept the oceans from freezing when the newly forming Sun had only 70% of its current luminosity.[59] By 7000350000000000000♠3.5 Bya, Earth's magnetic field was established, which helped prevent the atmosphere from being stripped away by the solar wind.[60]

text: A crust formed when the molten outer layer of Earth cooled to form a solid. The two models[61] that explain land mass propose either a steady growth to the present-day forms[62] or, more likely, a rapid growth[63] early in Earth history[64] followed by a long-term steady continental area.[65][66][67] Continents formed by plate tectonics, a process ultimately driven by the continuous loss of heat from Earth's interior. On time scales lasting hundreds of millions of years, the supercontinents have assembled and broken apart. Roughly 7002750000000000000♠750 million years ago (Mya), one of the earliest known supercontinents, Rodinia, began to break apart. The continents later recombined to form Pannotia, 600–7002540000000000000♠540 Mya, then finally Pangaea, which also broke apart 7002180000000000000♠180 Mya.[68]

text: The present pattern of ice ages began about 7001400000000000000♠40 Mya and then intensified during the Pleistocene about 7000300000000000000♠3 Mya. High-latitude regions have since undergone repeated cycles of glaciation and thaw, repeating about every 40,000–7012315576000000000♠100000 years. The last continental glaciation ended 10,000 years ago.[69]

text: Origin of life and evolution

text: Chemical reactions led to the first self-replicating molecules about four billion years ago. A half billion years later, the last common ancestor of all life arose.[70] The evolution of photosynthesis allowed the Sun's energy to be harvested directly by life forms. The resultant molecular oxygen (O2) accumulated in the atmosphere and due to interaction with ultraviolet solar radiation, formed a protective ozone layer (O3) in the upper atmosphere.[71] The incorporation of smaller cells within larger ones resulted in the development of complex cells called eukaryotes.[72] True multicellular organisms formed as cells within colonies became increasingly specialized. Aided by the absorption of harmful ultraviolet radiation by the ozone layer, life colonized Earth's surface.[73] Among the earliest fossil evidence for life is microbial mat fossils found in 3.48 billion-year-old sandstone in Western Australia,[74] biogenic graphite found in 3.7 billion-year-old metasedimentary rocks in Western Greenland,[75] remains of biotic material found in 4.1 billion-year-old rocks in Western Australia.[30][31] 3.45 billion-year-old Australian rocks once contained microorganisms, the earliest direct evidence of life on Earth.[76][77]

text: During the Neoproterozoic, 7002750000000000000♠750 to 580 Mya, much of Earth might have been covered in ice. This hypothesis has been termed "Snowball Earth", and it is of particular interest because it preceded the Cambrian explosion, when multicellular life forms significantly increased in complexity.[78] Following the Cambrian explosion, 7002535000000000000♠535 Mya, there have been five major mass extinctions.[79] The most recent such event was 7001660000000000000♠66 Mya, when an asteroid impact triggered the extinction of the non-avian dinosaurs and other large reptiles, but spared some small animals such as mammals, which then resembled shrews. Over the past 7001660000000000000♠66 Mys, mammalian life has diversified, and several million years ago an African ape-like animal such as Orrorin tugenensis gained the ability to stand upright.[80] This facilitated tool use and encouraged communication that provided the nutrition and stimulation needed for a larger brain, which allowed the evolution of humans. The development of agriculture, and then civilization, led to humans having an influence on Earth and the nature and quantity of other life forms that continues today.[81]

text: Future

text: Earth's expected long-term future is closely tied to that of the Sun. Over the next 7000110000000000000♠1.1 Bys, solar luminosity will increase by 10%, and over the next 7000350000000000000♠3.5 Bys by 40%.[82] The Earth's increasing surface temperature will accelerate the inorganic CO2 cycle, reducing its concentration to levels lethally low for plants (6995099999999999999♠10 ppm for C4 photosynthesis) in approximately 500–7002900000000000000♠900 Mys.[83] The lack of vegetation will result in the loss of oxygen in the atmosphere, and animal life will become extinct.[84] After another billion years all surface water will have disappeared[85] and the mean global temperature will reach 7002343150000000000♠70 °C[84] (7002343150000000000♠158 °F). From that point, the Earth is expected to be habitable for another 7016157788000000000♠500 Ma,[83] possibly up to 7016725824800000000♠2.3 Ga if nitrogen is removed from the atmosphere.[86] Even if the Sun were eternal and stable, 27% of the water in the modern oceans will descend to the mantle in one billion years, due to reduced steam venting from mid-ocean ridges.[87]

text: The Sun will evolve to become a red giant in about 7000500000000000000♠5 Bys. Models predict that the Sun will expand to roughly 1 AU (150 million km; 93 million mi), which is about 250 times its present radius.[82][88] Earth's fate is less clear. As a red giant, the Sun will lose roughly 30% of its mass, so, without tidal effects, Earth will move to an orbit 1.7 AU (250 million km; 160 million mi) from the Sun when the star reaches its maximum radius. Most, if not all, remaining life will be destroyed by the Sun's increased luminosity (peaking at about 5,000 times its present level).[82] A 2008 simulation indicates that Earth's orbit will eventually decay due to tidal effects and drag, causing it to enter the Sun's atmosphere and be vaporized.[88]

text: Physical characteristics

text: Shape

text: The shape of Earth is approximately oblate spheroidal. Due to rotation, the Earth is flattened along the geographic axis and bulging around the equator.[90] The diameter of the Earth at the equator is 43 kilometres (27 mi) larger than the pole-to-pole diameter.[91] Thus the point on the surface farthest from Earth's center of mass is the summit of the equatorial Chimborazo volcano in Ecuador.[92][93][94][95] The average diameter of the reference spheroid is 12,742 kilometres (7,918 mi). Local topography deviates from this idealized spheroid, although on a global scale these deviations are small compared to Earth's radius: The maximum deviation of only 0.17% is at the Mariana Trench (10,911 metres (35,797 ft) below local sea level), whereas Mount Everest (8,848 metres (29,029 ft) above local sea level) represents a deviation of 0.14%.[n 13]

text: In geodesy, the exact shape that Earth's oceans would adopt in the absence of land and perturbations such as tides and winds is called the geoid. More precisely, the geoid is the surface of gravitational equipotential at mean sea level.

text: Chemical composition

text:
Chemical composition of the crust[97]

Compound
Formula
Composition

Continental
Oceanic

silica
SiO2
60.2%
48.6%

alumina
Al2O3
15.2%
16.5%

lime
CaO
5.5%
12.3%

magnesia
MgO
3.1%
6.8%

iron(II) oxide
FeO
3.8%
6.2%

sodium oxide
Na2O
3.0%
2.6%

potassium oxide
K2O
2.8%
0.4%

iron(III) oxide
Fe2O3
2.5%
2.3%

water
H2O
1.4%
1.1%

carbon dioxide
CO2
1.2%
1.4%

titanium dioxide
TiO2
0.7%
1.4%

phosphorus pentoxide
P2O5
0.2%
0.3%

Total
99.6%
99.9%

text: Earth's mass is approximately 7024597000000000000♠5.97×1024 kg (5,970 Yg). It is composed mostly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%), with the remaining 1.2% consisting of trace amounts of other elements. Due to mass segregation, the core region is estimated to be primarily composed of iron (88.8%), with smaller amounts of nickel (5.8%), sulfur (4.5%), and less than 1% trace elements.[98]

text: The most common rock constituents of the crust are nearly all oxides: chlorine, sulfur, and fluorine are the important exceptions to this and their total amount in any rock is usually much less than 1%. Over 99% of the crust is composed of 11 oxides, principally silica, alumina, iron oxides, lime, magnesia, potash, and soda.[97][98][99]

text: Internal structure

text: Earth's interior, like that of the other terrestrial planets, is divided into layers by their chemical or physical (rheological) properties. The outer layer is a chemically distinct silicate solid crust, which is underlain by a highly viscous solid mantle. The crust is separated from the mantle by the Mohorovičić discontinuity. The thickness of the crust varies from about 7003600000000000000♠6 km (kilometers) under the oceans to 30–50 km 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 410 and 7005660000000000000♠660 km 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.[100] The Earth's inner core might rotate at a slightly higher angular velocity than the remainder of the planet, advancing by 0.1–0.5° per year.[101] The radius of the inner core is about one fifth of that of Earth.

text:
Geologic layers of Earth[102]

Earth cutaway from core to exosphere. Not to scale.
Depth[103]
km
Component layer
Density
g/cm3

0–60
Lithosphere[n 14]
—

0–35
Crust[n 15]
2.2–2.9

35–60
Upper mantle
3.4–4.4

  35–2890
Mantle
3.4–5.6

100–700
Asthenosphere
—

2890–5100
Outer core
9.9–12.2

5100–6378
Inner core
12.8–13.1

text: Heat

text: Earth's internal heat comes from a combination of residual heat from planetary accretion (about 20%) and heat produced through radioactive decay (80%).[104] The major heat-producing isotopes within Earth are potassium-40, uranium-238, and thorium-232.[105] At the center, the temperature may be up to 6,000 °C (10,830 °F),[106] and the pressure could reach 360 GPa.[107] Because much of the heat is provided by radioactive decay, scientists postulate that early in Earth's history, before isotopes with short half-lives were depleted, Earth's heat production was much higher. At approximately 7016946728000000000♠3 Ga, twice the present-day heat would have been produced, increasing the rates of mantle convection and plate tectonics, and allowing the production of uncommon igneous rocks such as komatiites that are rarely formed today.[104][108]

text:
Present-day major heat-producing isotopes[109]

Isotope
Heat release
W/kg isotope
Half-life
years
Mean mantle concentration
kg isotope/kg mantle
Heat release
W/kg mantle

238U
94.6 × 10−6
4.47 × 109
30.8 × 10−9
2.91 × 10−12

235U
569 × 10−6
0.704 × 109
0.22 × 10−9
0.125 × 10−12

232Th
26.4 × 10−6
14.0 × 109
124 × 10−9
3.27 × 10−12

40K
29.2 × 10−6
1.25 × 109
36.9 × 10−9
1.08 × 10−12

text: The mean heat loss from Earth is 87 mW m−2, for a global heat loss of 4.42 × 1013 W.[110] A portion of the core's thermal energy is transported toward the crust by mantle plumes, a form of convection consisting of upwellings of higher-temperature rock. These plumes can produce hotspots and flood basalts.[111] More of the heat in Earth is lost through plate tectonics, by mantle upwelling associated with mid-ocean ridges. The final major mode of heat loss is through conduction through the lithosphere, the majority of which occurs under the oceans because the crust there is much thinner than that of the continents.[112]

text: Tectonic plates

text:
Earth's major plates[113]

Plate name
Area
106 km2

  Pacific Plate

103.3

  African Plate[n 16]

78.0

  North American Plate

75.9

  Eurasian Plate

67.8

  Antarctic Plate

60.9

  Indo-Australian Plate

47.2

  South American Plate

43.6

text: The mechanically rigid outer layer of Earth, the lithosphere, is divided into pieces called tectonic plates. These plates are rigid segments that move in relation to one another at one of three types of plate boundaries: convergent boundaries, at which two plates come together, divergent boundaries, at which two plates are pulled apart, and transform boundaries, in which two plates slide past one another laterally. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation can occur along these plate boundaries.[114] The tectonic plates ride on top of the asthenosphere, the solid but less-viscous part of the upper mantle that can flow and move along with the plates.[115]

text: As the tectonic plates migrate, oceanic crust is subducted under the leading edges of the plates at convergent boundaries. At the same time, the upwelling of mantle material at divergent boundaries creates mid-ocean ridges. The combination of these processes recycles the oceanic crust back into the mantle. Due to this recycling, most of the ocean floor is less than 7015315576000000000♠100 Ma old in age. The oldest oceanic crust is located in the Western Pacific and has an estimated age of 7015631152000000000♠200 Ma.[116][117] By comparison, the oldest dated continental crust is 7017127177128000000♠4030 Ma.[118]

text: The seven major plates are the Pacific, North American, Eurasian, African, Antarctic, Indo-Australian, and South American. Other notable plates include the Arabian Plate, the Caribbean Plate, the Nazca Plate off the west coast of South America and the Scotia Plate in the southern Atlantic Ocean. The Australian Plate fused with the Indian Plate between 50 and 7001550000000000000♠55 Mya. The fastest-moving plates are the oceanic plates, with the Cocos Plate advancing at a rate of 75 mm/year[119] and the Pacific Plate moving 52–69 mm/year. At the other extreme, the slowest-moving plate is the Eurasian Plate, progressing at a typical rate of 21 mm/year.[120]

text: Surface

text: The total surface area of the Earth is about 510 million km2 (197 million sq mi).[13] Of this, 70.8%,[13] or 361.13 million km2 (139.43 million sq mi), is below sea level and covered by ocean water.[121] Below the ocean's surface are much of the continental shelf, mountains, volcanoes,[91] oceanic trenches, submarine canyons, oceanic plateaus, abyssal plains, and a globe-spanning mid-ocean ridge system. The remaining 29.2%, or 148.94 million km2 (57.51 million sq mi), not covered by water has terrain that varies greatly from place to place and consists of mountains, deserts, plains, plateaus, and other landforms. Tectonics and erosion, volcanic eruptions, flooding, weathering, glaciation, the growth of coral reefs, and meteorite impacts are among the processes that constantly reshape the Earth's surface over geological time.[122][123]

text: The continental crust consists of lower density material such as the igneous rocks granite and andesite. Less common is basalt, a denser volcanic rock that is the primary constituent of the ocean floors.[124] Sedimentary rock is formed from the accumulation of sediment that becomes buried and compacted together. Nearly 75% of the continental surfaces are covered by sedimentary rocks, although they form about 5% of the crust.[125] The third form of rock material found on Earth is metamorphic rock, which is created from the transformation of pre-existing rock types through high pressures, high temperatures, or both. The most abundant silicate minerals on Earth's surface include quartz, feldspars, amphibole, mica, pyroxene and olivine.[126] Common carbonate minerals include calcite (found in limestone) and dolomite.[127]

text: The elevation of the land surface varies from the low point of −418 m (−1,371 ft) at the Dead Sea, to a maximum altitude of 8,848 m (29,029 ft) at the top of Mount Everest. The mean height of land above sea level is about 797 m (2,615 ft).[128]

text: The pedosphere is the outermost layer of Earth's continental surface and is composed of soil and subject to soil formation processes. The total arable land is 10.9% of the land surface, with 1.3% being permanent cropland.[129][130] Close to 40% of Earth's land surface is used for agriculture, or an estimated 16.7 million km2 (6.4 million sq mi) of cropland and 33.5 million km2 (12.9 million sq mi) of pastureland.[131]

text: Hydrosphere

text: The abundance of water on Earth's surface is a unique feature that distinguishes the "Blue Planet" from other planets in the Solar System. Earth's hydrosphere consists chiefly of the oceans, but technically includes all water surfaces in the world, including inland seas, lakes, rivers, and underground waters down to a depth of 2,000 m (6,600 ft). The deepest underwater location is Challenger Deep of the Mariana Trench in the Pacific Ocean with a depth of 10,911.4 m (35,799 ft).[n 17][132]

text: The mass of the oceans is approximately 1.35×1018 metric tons or about 1/4400 of Earth's total mass. The oceans cover an area of 7014361800000000000♠3.618×108 km2 with a mean depth of 7003368200000000000♠3682 m, resulting in an estimated volume of 7018133200000000000♠1.332×109 km3.[133] If all of Earth's crustal surface were at the same elevation as a smooth sphere, the depth of the resulting world ocean would be 2.7 to 2.8 km.[134][135]

text: About 97.5% of the water is saline; the remaining 2.5% is fresh water. Most fresh water, about 68.7%, is present as ice in ice caps and glaciers.[136]

text: The average salinity of Earth's oceans is about 35 grams of salt per kilogram of sea water (3.5% salt).[137] Most of this salt was released from volcanic activity or extracted from cool igneous rocks.[138] The oceans are also a reservoir of dissolved atmospheric gases, which are essential for the survival of many aquatic life forms.[139] Sea water has an important influence on the world's climate, with the oceans acting as a large heat reservoir.[140] Shifts in the oceanic temperature distribution can cause significant weather shifts, such as the El Niño-Southern Oscillation.[141]

text: Atmosphere

text: The atmospheric pressure on Earth's surface averages 101.325 kPa, with a scale height of about 8.5 km.[3] It has a composition of 78% nitrogen and 21% oxygen, with trace amounts of water vapor, carbon dioxide, and other gaseous molecules. The height of the troposphere varies with latitude, ranging between 8 km at the poles to 17 km at the equator, with some variation resulting from weather and seasonal factors.[142]

text: Earth's biosphere has significantly altered its atmosphere. Oxygenic photosynthesis evolved 7000270000000000000♠2.7 Gya, forming the primarily nitrogen–oxygen atmosphere of today.[71] This change enabled the proliferation of aerobic organisms and, indirectly, the formation of the ozone layer due to the subsequent conversion of atmospheric O2 into O3. The ozone layer blocks ultraviolet solar radiation, permitting life on land.[143] Other atmospheric functions important to life include transporting water vapor, providing useful gases, causing small meteors to burn up before they strike the surface, and moderating temperature.[144] This last phenomenon is known as the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the ground, thereby raising the average temperature. Water vapor, carbon dioxide, methane, nitrous oxide, and ozone are the primary greenhouse gases in the atmosphere. Without this heat-retention effect, the average surface temperature would be −18 °C, in contrast to the current +15 °C,[145] and life on Earth probably would not exist in its current form.[146] In May 2017, glints of light, seen as twinkling from an orbiting satellite a million miles away, were found to be reflected light from ice crystals in the atmosphere.[147][148]

text: Weather and climate

text: Earth's atmosphere has no definite boundary, slowly becoming thinner and fading into outer space. Three-quarters of the atmosphere's mass is contained within the first 11 km (6.8 mi) of the surface. This lowest layer is called the troposphere. Energy from the Sun heats this layer, and the surface below, causing expansion of the air. This lower-density air then rises and is replaced by cooler, higher-density air. The result is atmospheric circulation that drives the weather and climate through redistribution of thermal energy.[149]

text: The primary atmospheric circulation bands consist of the trade winds in the equatorial region below 30° latitude and the westerlies in the mid-latitudes between 30° and 60°.[150] Ocean currents are also important factors in determining climate, particularly the thermohaline circulation that distributes thermal energy from the equatorial oceans to the polar regions.[151]

text: Water vapor generated through surface evaporation is transported by circulatory patterns in the atmosphere. When atmospheric conditions permit an uplift of warm, humid air, this water condenses and falls to the surface as precipitation.[149] Most of the water is then transported to lower elevations by river systems and usually returned to the oceans or deposited into lakes. This water cycle is a vital mechanism for supporting life on land and is a primary factor in the erosion of surface features over geological periods. Precipitation patterns vary widely, ranging from several meters of water per year to less than a millimeter. Atmospheric circulation, topographic features, and temperature differences determine the average precipitation that falls in each region.[152]

text: The amount of solar energy reaching Earth's surface decreases with increasing latitude. At higher latitudes, the sunlight reaches the surface at lower angles, and it must pass through thicker columns of the atmosphere. As a result, the mean annual air temperature at sea level decreases by about 0.4 °C (0.7 °F) per degree of latitude from the equator.[153] Earth's surface can be subdivided into specific latitudinal belts of approximately homogeneous climate. Ranging from the equator to the polar regions, these are the tropical (or equatorial), subtropical, temperate and polar climates.[154]

text: This latitudinal rule has several anomalies:

text:
Proximity to oceans moderates the climate. For example, the Scandinavian Peninsula has more moderate climate than similarly northern latitudes of northern Canada.
The wind enables this moderating effect. The windward side of a land mass experiences more moderation than the leeward side. In the Northern Hemisphere, the prevailing wind is west-to-east, and western coasts tend to be milder than eastern coasts. This is seen in Eastern North America and Western Europe, where rough continental climates appear on the east coast on parallels with mild climates on the other side of the ocean.[155] In the Southern Hemisphere, the prevailing wind is east-to-west, and the eastern coasts are milder.
The distance from the Earth to the Sun varies. The Earth is closest to the Sun (at perihelion) in January, which is summer in the Southern Hemisphere. It is furthest away (at aphelion) in July, which is summer in the Northern Hemisphere, and only 93.55% of the solar radiation from the Sun falls on a given square area of land than at perihelion. Despite this, there are larger land masses in the Northern Hemisphere, which are easier to heat than the seas. Consequently, summers are 2.3 °C (4 °F) warmer in the Northern Hemisphere than in the Southern Hemisphere under similar conditions.[156]
The climate is colder at high altitudes than at sea level because of the decreased air density.

text: The commonly used Köppen climate classification system has five broad groups (humid tropics, arid, humid middle latitudes, continental and cold polar), which are further divided into more specific subtypes.[150] The Köppen system rates regions of terrain based on observed temperature and precipitation.

text: The highest air temperature ever measured on Earth was 56.7 °C (134.1 °F) in Furnace Creek, California, in Death Valley, in 1913.[157] The lowest air temperature ever directly measured on Earth was −89.2 °C (−128.6 °F) at Vostok Station in 1983,[158] but satellites have used remote sensing to measure temperatures as low as −94.7 °C (−138.5 °F) in East Antarctica.[159] These temperature records are only measurements made with modern instruments from the 20th century onwards and likely do not reflect the full range of temperature on Earth.

text: Upper atmosphere

text: Above the troposphere, the atmosphere is usually divided into the stratosphere, mesosphere, and thermosphere.[144] Each layer has a different lapse rate, defining the rate of change in temperature with height. Beyond these, the exosphere thins out into the magnetosphere, where the geomagnetic fields interact with the solar wind.[160] Within the stratosphere is the ozone layer, a component that partially shields the surface from ultraviolet light and thus is important for life on Earth. The Kármán line, defined as 100 km above Earth's surface, is a working definition for the boundary between the atmosphere and outer space.[161]

text: Thermal energy causes some of the molecules at the outer edge of the atmosphere to increase their velocity to the point where they can escape from Earth's gravity. This causes a slow but steady loss of the atmosphere into space. Because unfixed hydrogen has a low molecular mass, it can achieve escape velocity more readily, and it leaks into outer space at a greater rate than other gases.[162] The leakage of hydrogen into space contributes to the shifting of Earth's atmosphere and surface from an initially reducing state to its current oxidizing one. Photosynthesis provided a source of free oxygen, but the loss of reducing agents such as hydrogen is thought to have been a necessary precondition for the widespread accumulation of oxygen in the atmosphere.[163] Hence the ability of hydrogen to escape from the atmosphere may have influenced the nature of life that developed on Earth.[164] In the current, oxygen-rich atmosphere most hydrogen is converted into water before it has an opportunity to escape. Instead, most of the hydrogen loss comes from the destruction of methane in the upper atmosphere.[165]

text: Gravitational field

text: The gravity of Earth is the acceleration that is imparted to objects due to the distribution of mass within the Earth. Near the Earth's surface, gravitational acceleration is approximately 9.8 m/s2 (32 ft/s2). Local differences in topography, geology, and deeper tectonic structure cause local and broad, regional differences in the Earth's gravitational field, known as gravitational anomalies.[166]

text: Magnetic field

text: The main part of Earth's magnetic field is generated in the core, the site of a dynamo process that converts the kinetic energy of thermally and compositionally driven convection into electrical and magnetic field energy. The field extends outwards from the core, through the mantle, and up to Earth's surface, where it is, approximately, a dipole. The poles of the dipole are located close to Earth's geographic poles. At the equator of the magnetic field, the magnetic-field strength at the surface is 3.05 × 10−5 T, with global magnetic dipole moment of 7.91 × 1015 T m3.[167] The convection movements in the core are chaotic; the magnetic poles drift and periodically change alignment. This causes secular variation of the main field and field reversals at irregular intervals averaging a few times every million years. The most recent reversal occurred approximately 700,000 years ago.[168][169]

text: Magnetosphere

text: The extent of Earth's magnetic field in space defines the magnetosphere. Ions and electrons of the solar wind are deflected by the magnetosphere; solar wind pressure compresses the dayside of the magnetosphere, to about 10 Earth radii, and extends the nightside magnetosphere into a long tail.[170] Because the velocity of the solar wind is greater than the speed at which waves propagate through the solar wind, a supersonic bowshock precedes the dayside magnetosphere within the solar wind.[171] Charged particles are contained within the magnetosphere; the plasmasphere is defined by low-energy particles that essentially follow magnetic field lines as Earth rotates;[172][173] the ring current is defined by medium-energy particles that drift relative to the geomagnetic field, but with paths that are still dominated by the magnetic field,[174] and the Van Allen radiation belt are formed by high-energy particles whose motion is essentially random, but otherwise contained by the magnetosphere.[170][175]

text: During magnetic storms and substorms, charged particles can be deflected from the outer magnetosphere and especially the magnetotail, directed along field lines into Earth's ionosphere, where atmospheric atoms can be excited and ionized, causing the aurora.[176]

text: Orbit and rotation

text: Rotation

text: Earth's rotation period relative to the Sun—its mean solar day—is 86,400 seconds of mean solar time (86,400.0025 SI seconds).[177] Because Earth's solar day is now slightly longer than it was during the 19th century due to tidal deceleration, each day varies between 0 and 2 SI ms longer.[178][179]

text: Earth's rotation period relative to the fixed stars, called its stellar day by the International Earth Rotation and Reference Systems Service (IERS), is 86,164.0989 seconds of mean solar time (UT1), or 23h 56m 4.0989s.[2][n 18] Earth's rotation period relative to the precessing or moving mean vernal equinox, misnamed its sidereal day, is 86,164.0905 seconds of mean solar time (UT1) (23h 56m 4.0905s).[2] Thus the sidereal day is shorter than the stellar day by about 8.4 ms.[180] The length of the mean solar day in SI seconds is available from the IERS for the periods 1623–2005[181] and 1962–2005.[182]

text: Apart from meteors within the atmosphere and low-orbiting satellites, the main apparent motion of celestial bodies in Earth's sky is to the west at a rate of 15°/h = 15'/min. For bodies near the celestial equator, this is equivalent to an apparent diameter of the Sun or the Moon every two minutes; from Earth's surface, the apparent sizes of the Sun and the Moon are approximately the same.[183][184]

text: Orbit

text: Earth orbits the Sun at an average distance of about 150 million km (93 million mi) every 365.2564 mean solar days, or one sidereal year. This gives an apparent movement of the Sun eastward with respect to the stars at a rate of about 1°/day, which is one apparent Sun or Moon diameter every 12 hours. Due to this motion, on average it takes 24 hours—a solar day—for Earth to complete a full rotation about its axis so that the Sun returns to the meridian. The orbital speed of Earth averages about 29.78 km/s (107,200 km/h; 66,600 mph), which is fast enough to travel a distance equal to Earth's diameter, about 12,742 km (7,918 mi), in seven minutes, and the distance to the Moon, 384,000 km (239,000 mi), in about 3.5 hours.[3]

text: The Moon and Earth orbit a common barycenter every 27.32 days relative to the background stars. When combined with the Earth–Moon system's common orbit around the Sun, the period of the synodic month, from new moon to new moon, is 29.53 days. Viewed from the celestial north pole, the motion of Earth, the Moon, and their axial rotations are all counterclockwise. Viewed from a vantage point above the north poles of both the Sun and Earth, Earth orbits in a counterclockwise direction about the Sun. The orbital and axial planes are not precisely aligned: Earth's axis is tilted some 23.44 degrees from the perpendicular to the Earth–Sun plane (the ecliptic), and the Earth–Moon plane is tilted up to ±5.1 degrees against the Earth–Sun plane. Without this tilt, there would be an eclipse every two weeks, alternating between lunar eclipses and solar eclipses.[3][185]

text: The Hill sphere, or the sphere of gravitational influence, of the Earth is about 1.5×10^6 km (930,000 mi) in radius.[186][n 19] This is the maximum distance at which the Earth's gravitational influence is stronger than the more distant Sun and planets. Objects must orbit the Earth within this radius, or they can become unbound by the gravitational perturbation of the Sun.

text: Earth, along with the Solar System, is situated in the Milky Way and orbits about 28,000 light-years from its center. It is about 20 light-years above the galactic plane in the Orion Arm.[187]

text: Axial tilt and seasons

text: The axial tilt of the Earth is approximately 23.439281°[2] with the axis of its orbit plane, always pointing towards the Celestial Poles. Due to Earth's axial tilt, the amount of sunlight reaching any given point on the surface varies over the course of the year. This causes the seasonal change in climate, with summer in the Northern Hemisphere occurring when the Tropic of Cancer is facing the Sun, and winter taking place when the Tropic of Capricorn in the Southern Hemisphere faces the Sun. During the summer, the day lasts longer, and the Sun climbs higher in the sky. In winter, the climate becomes cooler and the days shorter. In northern temperate latitudes, the Sun rises north of true east during the summer solstice, and sets north of true west, reversing in the winter. The Sun rises south of true east in the summer for the southern temperate zone and sets south of true west.

text: Above the Arctic Circle, an extreme case is reached where there is no daylight at all for part of the year, up to six months at the North Pole itself, a polar night. In the Southern Hemisphere, the situation is exactly reversed, with the South Pole oriented opposite the direction of the North Pole. Six months later, this pole will experience a midnight sun, a day of 24 hours, again reversing with the South Pole.

text: By astronomical convention, the four seasons can be determined by the solstices—the points in the orbit of maximum axial tilt toward or away from the Sun—and the equinoxes, when the direction of the tilt and the direction to the Sun are perpendicular. In the Northern Hemisphere, winter solstice currently occurs around 21 December; summer solstice is near 21 June, spring equinox is around 20 March and autumnal equinox is about 22 or 23 September. In the Southern Hemisphere, the situation is reversed, with the summer and winter solstices exchanged and the spring and autumnal equinox dates swapped.[188]

text: The angle of Earth's axial tilt is relatively stable over long periods of time. Its axial tilt does undergo nutation; a slight, irregular motion with a main period of 18.6 years.[189] The orientation (rather than the angle) of Earth's axis also changes over time, precessing around in a complete circle over each 25,800 year cycle; this precession is the reason for the difference between a sidereal year and a tropical year. Both of these motions are caused by the varying attraction of the Sun and the Moon on Earth's equatorial bulge. The poles also migrate a few meters across Earth's surface. This polar motion has multiple, cyclical components, which collectively are termed quasiperiodic motion. In addition to an annual component to this motion, there is a 14-month cycle called the Chandler wobble. Earth's rotational velocity also varies in a phenomenon known as length-of-day variation.[190]

text: In modern times, Earth's perihelion occurs around 3 January, and its aphelion around 4 July. These dates change over time due to precession and other orbital factors, which follow cyclical patterns known as Milankovitch cycles. The changing Earth–Sun distance causes an increase of about 6.9%[n 20] in solar energy reaching Earth at perihelion relative to aphelion. Because the Southern Hemisphere is tilted toward the Sun at about the same time that Earth reaches the closest approach to the Sun, the Southern Hemisphere receives slightly more energy from the Sun than does the northern over the course of a year. This effect is much less significant than the total energy change due to the axial tilt, and most of the excess energy is absorbed by the higher proportion of water in the Southern Hemisphere.[191]

text: A study from 2016 suggested that Planet Nine tilted all Solar System planets, including Earth's, by about six degrees.[192]

text: Habitability

text: A planet that can sustain life is termed habitable, even if life did not originate there. Earth provides liquid water—an environment where complex organic molecules can assemble and interact, and sufficient energy to sustain metabolism.[193] The distance of Earth from the Sun, as well as its orbital eccentricity, rate of rotation, axial tilt, geological history, sustaining atmosphere, and magnetic field all contribute to the current climatic conditions at the surface.[194]

text: Biosphere

text: A planet's life forms inhabit ecosystems, whose total is sometimes said to form a "biosphere". Earth's biosphere is thought to have begun evolving about 7000350000000000000♠3.5 Gya.[71] The biosphere is divided into a number of biomes, inhabited by broadly similar plants and animals. On land, biomes are separated primarily by differences in latitude, height above sea level and humidity. Terrestrial biomes lying within the Arctic or Antarctic Circles, at high altitudes or in extremely arid areas are relatively barren of plant and animal life; species diversity reaches a peak in humid lowlands at equatorial latitudes.[195]

text: In July 2016, scientists reported identifying a set of 355 genes from the last universal common ancestor (LUCA) of all organisms living on Earth.[196]

text: Natural resources and land use

text:
Estimated human land use, 2000[197]

Land use
Mha

Cropland
1,510–1,611

Pastures
2,500–3,410

Natural forests
3,143–3,871

Planted forests
126–215

Urban areas
66–351

Unused, productive land
356–445

text: Earth has resources that have been exploited by humans. Those termed non-renewable resources, such as fossil fuels, only renew over geological timescales.

text: Large deposits of fossil fuels are obtained from Earth's crust, consisting of coal, petroleum, and natural gas. These deposits are used by humans both for energy production and as feedstock for chemical production. Mineral ore bodies have also been formed within the crust through a process of ore genesis, resulting from actions of magmatism, erosion, and plate tectonics.[198] These bodies form concentrated sources for many metals and other useful elements.

text: Earth's biosphere produces many useful biological products for humans, including food, wood, pharmaceuticals, oxygen, and the recycling of many organic wastes. The land-based ecosystem depends upon topsoil and fresh water, and the oceanic ecosystem depends upon dissolved nutrients washed down from the land.[199] In 1980, 50.53 million km2 (19.51 million sq mi) of Earth's land surface consisted of forest and woodlands, 67.88 million km2 (26.21 million sq mi) was grasslands and pasture, and 15.01 million km2 (5.80 million sq mi) was cultivated as croplands.[200] The estimated amount of irrigated land in 1993 was 2,481,250 km2 (958,020 sq mi).[14] Humans also live on the land by using building materials to construct shelters.

text: Natural and environmental hazards

text: Large areas of Earth's surface are subject to extreme weather such as tropical cyclones, hurricanes, or typhoons that dominate life in those areas. From 1980 to 2000, these events caused an average of 11,800 human deaths per year.[201] Many places are subject to earthquakes, landslides, tsunamis, volcanic eruptions, tornadoes, sinkholes, blizzards, floods, droughts, wildfires, and other calamities and disasters.

text: Many localized areas are subject to human-made pollution of the air and water, acid rain and toxic substances, loss of vegetation (overgrazing, deforestation, desertification), loss of wildlife, species extinction, soil degradation, soil depletion and erosion.

text: There is a scientific consensus linking human activities to global warming due to industrial carbon dioxide emissions. This is predicted to produce changes such as the melting of glaciers and ice sheets, more extreme temperature ranges, significant changes in weather and a global rise in average sea levels.[202]

text: Human geography

text:
North America
  South America
  Antarctica

  Europe
  Africa

  Asia
  Australia

v
t
e

text: Cartography, the study and practice of map-making, and geography, the study of the lands, features, inhabitants and phenomena on Earth, have historically been the disciplines devoted to depicting Earth. Surveying, the determination of locations and distances, and to a lesser extent navigation, the determination of position and direction, have developed alongside cartography and geography, providing and suitably quantifying the requisite information.

text: Earth's human population reached approximately seven billion on 31 October 2011.[204] Projections indicate that the world's human population will reach 9.2 billion in 2050.[205] Most of the growth is expected to take place in developing nations. Human population density varies widely around the world, but a majority live in Asia. By 2020, 60% of the world's population is expected to be living in urban, rather than rural, areas.[206]

text: It is estimated that one-eighth of Earth's surface is suitable for humans to live on – three-quarters of Earth's surface is covered by oceans, leaving one-quarter as land. Half of that land area is desert (14%),[207] high mountains (27%),[208] or other unsuitable terrains. The northernmost permanent settlement in the world is Alert, on Ellesmere Island in Nunavut, Canada.[209] (82°28′N) The southernmost is the Amundsen–Scott South Pole Station, in Antarctica, almost exactly at the South Pole. (90°S)

text: Independent sovereign nations claim the planet's entire land surface, except for some parts of Antarctica, a few land parcels along the Danube river's western bank, and the unclaimed area of Bir Tawil between Egypt and Sudan. As of 2015[update], there are 193 sovereign states that are member states of the United Nations, plus two observer states and 72 dependent territories and states with limited recognition.[14] Earth has never had a sovereign government with authority over the entire globe, although some nation-states have striven for world domination and failed.[210]

text: The United Nations is a worldwide intergovernmental organization that was created with the goal of intervening in the disputes between nations, thereby avoiding armed conflict.[211] The U.N. serves primarily as a forum for international diplomacy and international law. When the consensus of the membership permits, it provides a mechanism for armed intervention.[212]

text: The first human to orbit Earth was Yuri Gagarin on 12 April 1961.[213] In total, about 487 people have visited outer space and reached orbit as of 30 July 2010[update], and, of these, twelve have walked on the Moon.[214][215][216] Normally, the only humans in space are those on the International Space Station. The station's crew, made up of six people, is usually replaced every six months.[217] The farthest that humans have traveled from Earth is 400,171 km, achieved during the Apollo 13 mission in 1970.[218]

text: Moon

text:
Characteristics

Diameter
3,474.8 km

Mass
7.349×1022 kg

Semi-major axis
384,400 km

Orbital period
27 d 7 h 43.7 m

text: The Moon is a relatively large, terrestrial, planet-like natural satellite, with a diameter about one-quarter of Earth's. It is the largest moon in the Solar System relative to the size of its planet, although Charon is larger relative to the dwarf planet Pluto. The natural satellites of other planets are also referred to as "moons", after Earth's.

text: The gravitational attraction between Earth and the Moon causes tides on Earth. The same effect on the Moon has led to its tidal locking: its rotation period is the same as the time it takes to orbit Earth. As a result, it always presents the same face to the planet. As the Moon orbits Earth, different parts of its face are illuminated by the Sun, leading to the lunar phases; the dark part of the face is separated from the light part by the solar terminator.

text: Due to their tidal interaction, the Moon recedes from Earth at the rate of approximately 38 mm/yr. Over millions of years, these tiny modifications—and the lengthening of Earth's day by about 23 µs/yr—add up to significant changes.[219] During the Devonian period, for example, (approximately 7002410000000000000♠410 Mya) there were 400 days in a year, with each day lasting 21.8 hours.[220]

text: The Moon may have dramatically affected the development of life by moderating the planet's climate. Paleontological evidence and computer simulations show that Earth's axial tilt is stabilized by tidal interactions with the Moon.[28] Some theorists think that without this stabilization against the torques applied by the Sun and planets to Earth's equatorial bulge, the rotational axis might be chaotically unstable, exhibiting chaotic changes over millions of years, as appears to be the case for Mars.[221]

text: Viewed from Earth, the Moon is just far enough away to have almost the same apparent-sized disk as the Sun. The angular size (or solid angle) of these two bodies match because, although the Sun's diameter is about 400 times as large as the Moon's, it is also 400 times more distant.[184] This allows total and annular solar eclipses to occur on Earth.

text: The most widely accepted theory of the Moon's origin, the giant-impact hypothesis, states that it formed from the collision of a Mars-size protoplanet called Theia with the early Earth. This hypothesis explains (among other things) the Moon's relative lack of iron and volatile elements and the fact that its composition is nearly identical to that of Earth's crust.[222]

text: Asteroids and artificial satellites

text: Earth has at least five co-orbital asteroids, including 3753 Cruithne and 2002 AA29.[223][224] A trojan asteroid companion, 2010 TK7, is librating around the leading Lagrange triangular point, L4, in the Earth's orbit around the Sun.[225][226]

text: The tiny near-Earth asteroid 2006 RH120 makes close approaches to the Earth–Moon system roughly every twenty years. During these approaches, it can orbit Earth for brief periods of time.[227]

text: As of June 2016[update], there were 1,419 operational, human-made satellites orbiting Earth.[5] There are also inoperative satellites, including Vanguard 1, the oldest satellite currently in orbit, and over 16,000 pieces of tracked space debris.[n 3] Earth's largest artificial satellite is the International Space Station.

text: Cultural and historical viewpoint

text: The standard astronomical symbol of Earth consists of a cross circumscribed by a circle, ,[228] representing the four corners of the world.

text: Human cultures have developed many views of the planet. Earth is sometimes personified as a deity. In many cultures it is a mother goddess that is also the primary fertility deity,[229] and by the mid-20th century, the Gaia Principle compared Earth's environments and life as a single self-regulating organism leading to broad stabilization of the conditions of habitability.[230][231][232] Creation myths in many religions involve the creation of Earth by a supernatural deity or deities.[229]

text: Scientific investigation has resulted in several culturally transformative shifts in people's view of the planet. In the West, belief in a flat Earth[233] was displaced by the idea of spherical Earth, credited to Pythagoras in the 6th century BC.[234] Earth was further believed to be the center of the universe until the 16th century when scientists first theorized that it was a moving object, comparable to the other planets in the Solar System.[235] Due to the efforts of influential Christian scholars and clerics such as James Ussher, who sought to determine the age of Earth through analysis of genealogies in Scripture, Westerners before the 19th century generally believed Earth to be a few thousand years old at most. It was only during the 19th century that geologists realized Earth's age was at least many millions of years.[236]

text: Lord Kelvin used thermodynamics to estimate the age of Earth to be between 20 million and 400 million years in 1864, sparking a vigorous debate on the subject; it was only when radioactivity and radioactive dating were discovered in the late 19th and early 20th centuries that a reliable mechanism for determining Earth's age was established, proving the planet to be billions of years old.[237][238] The perception of Earth shifted again in the 20th century when humans first viewed it from orbit, and especially with photographs of Earth returned by the Apollo program.[239]


document_title: Pac-12 Conference

question_text: when did pac 10 change to pac 12

question_tokens: when did pac 10 change to pac 12

root

text: Pac-12 Conference

text: Member schools[edit]

text: Full members[edit]

text: The Pac-12 has twelve full member institutions. Football is the only sport where the conference is split into two divisions, the North Division and the South Division.

tag: p

text: Unusual for a major conference, the Pac-12's members are spread evenly between 3 regions, with 4 schools each in California, the Pacific Northwest, and the Four Corners region.

text: † Total University of Colorado System Endowment

text:
Institution
Location
Founded
Joined
Type
Enrollment
Endowment[4]
Nickname
Colors

Arizona !University of Arizona
Tucson, Arizona
1885
1978
Public
43,625 [5]
7008843529000000000♠$843,529,000
Wildcats

Arizona State University
Tempe, Arizona
1885
1978
Public
71,946 [6]
7008661046000000000♠$661,046,000
Sun Devils

California, Berkeley !University of California, Berkeley
Berkeley, California
1868
1915
Public
41,910 [7]
7009179460200000000♠$1,794,602,000
Golden Bears

California, Los Angeles !University of California, Los Angeles
Los Angeles, California
1919
1928
Public
45,428 [8]
7009206257300000000♠$2,062,573,000
Bruins

Colorado !University of Colorado Boulder
Boulder, Colorado
1876
2011
Public
33,246 [9]
7009122020400000000♠$1,220,204,000 †
Buffaloes

Oregon !University of Oregon
Eugene, Oregon
1876
1915
Public
22,980 [10]
7008828459000000000♠$828,459,000
Ducks

Oregon State University
Corvallis, Oregon
1868
1915
Public
31,904 [11]
7008549448000000000♠$549,448,000
Beavers

Southern California !University of Southern California
Los Angeles, California
1880
1922
Private
45,500 [12]
7009512845900000000♠$5,128,459,000
Trojans

Stanford University
Stanford, California
1891
1918
Private
16,336 [13]
7010247849430000000♠$24,784,943,000
Cardinal

Utah !University of Utah
Salt Lake City, Utah
1850
2011
Public
32,780 [14]
7009112768600000000♠$1,127,686,000
Utes

Washington !University of Washington
Seattle, Washington
1861
1915
Public
56,819 [15]
7009252925000000000♠$2,529,250,000
Huskies

Washington State University
Pullman, Washington
1890
1917
Public
30,614 [16]
7008974029000000000♠$974,029,000
Cougars

tag: table

text: Affiliate members[edit]

text: The Pac-12 has three affiliate member institutions in California.

text:
Institution
Location
Founded
Joined
Type
Enrollment
Nickname
Colors
Primary Conference
Pac-12 Sports

California Polytechnic State University
San Luis Obispo, California
1901
1986–87
Public
19,777
Mustangs

Big West
Wrestling

California State University, Bakersfield
Bakersfield, California
1965
1987–88
Public
8,002
Roadrunners

WAC
Wrestling

San Diego State University
San Diego
1897
2005–06
Public
34,500
Aztecs

Mountain West
Men's soccer

text: Cal State Bakersfield initially announced it would become a men's soccer affiliate starting in 2013,[17] but never went through with those plans, accepting an invitation to become an all-sports member of the Western Athletic Conference, which sponsors men's soccer, also in 2013. The school will maintain its Pac-12 affiliation in wrestling, which the WAC does not sponsor.[18]

text: Former members[edit]

text: No school has left the Pac-12 since its founding as the AAWU in 1959. Two members of the PCC were not invited to join the AAWU or its successors.

text:
Institution
Location
Founded
Joined
Left
Type
Enrollment
Nickname
Colors
Current Conference

University of Idaho
Moscow, Idaho
1889
1922
1959
Public
11,957
Vandals

Big Sky

University of Montana
Missoula, Montana
1893
1924
1950
Public
14,921
Grizzlies

text: Former affiliate members[edit]

text:
Institution
Location
Founded
Type
Enrollment
Nickname
Primary Conference
Pac-12 Sports
Joined
Left

Boise State University
Boise, Idaho
1932
Public
19,667
Broncos
Mountain West
Wrestling[a]
1987–88
2016–17

University of California, Davis
Davis, California
1905
Public
34,155
Aggies
Big West
Wrestling
1992–93
2009–10

University of California, Santa Barbara
Santa Barbara, California
1909
Public
20,559
Gauchos
Big West
Men's swimming & diving[b]
2010–11
2014–15

California Polytechnic State University
San Luis Obispo, California
1901
Public
19,777
Mustangs
Big West
Men's swimming & diving[b]
2010–11
2014–15

California State University, Fresno
Fresno, California
1911
Public
23,060
Bulldogs
Mountain West
Wrestling[c]
1986–87
1990–91

California State University, Fullerton
Fullerton, California
1957
Public
38,325
Titans
Big West
Wrestling
1986–87
2010–11

Eastern Washington University
Cheney, Washington
1882
Public
13,453
Eagles
Big Sky
Baseball
1982–83
1989–90

Gonzaga University
Spokane, Washington
1887
Private
7,229
Bulldogs
WCC
Baseball
1982–83
1994–95

Portland State University
Portland, Oregon
1946
Public
29,452
Vikings
Big Sky
Baseball
1982–83
1997–98

Wrestling
1998–99
2008–09

Portland !University of Portland
Portland, Oregon
1901
Private
3,200
Pilots
WCC
Baseball
1982–83
1994–95

San Jose State University
San Jose, California
1857
Public
31,278
Spartans
Mountain West
Wrestling
1986–87
1987–88

Utah State University
Logan, Utah
1888
Public
28,796
Aggies
Mountain West
Wrestling
1986–87
1988–89

text:
Jump up ^ Boise State dropped wrestling after the 2016–17 season.
^ Jump up to: a b This team now competes in the Mountain Pacific Sports Federation.
Jump up ^ Fresno State eventually dropped wrestling after the 2005–06 season. The program was revived in 2017 and now competes in the Big 12 Conference.

tag: ol

text: Facilities[edit]

text:
School
Football stadium
Capacity
Basketball arena
Capacity
Baseball stadium
Capacity

Arizona
Arizona Stadium
56,037[19]
McKale Center
14,655[20]
Hi Corbett Field
9,500[21]

Arizona State
Sun Devil Stadium
56,232[22]
Wells Fargo Arena
10,754[23]
Phoenix Municipal Stadium
8,775[24]

California
California Memorial Stadium
62,467[25]
Haas Pavilion
11,877[26]
Evans Diamond
2,500[27]

Colorado
Folsom Field
53,613[28]
Coors Events Center
11,064[29]
Non-baseball school

Oregon
Autzen Stadium
54,000[30]
Matthew Knight Arena
12,346[31]
PK Park
3,600[32]

Oregon State
Reser Stadium
43,363[33]
Gill Coliseum
9,604[34]
Goss Stadium at Coleman Field
3,248[35]

Stanford
Stanford Stadium
50,424[36]
Maples Pavilion
7,233[37]
Klein Field at Sunken Diamond
4,000[38]

UCLA
Rose Bowl
91,936[39]
Pauley Pavilion
13,800[40][41]
Jackie Robinson Stadium
1,820[42]

USC
Los Angeles Memorial Coliseum
93,607[43]
Galen Center
10,258[44]
Dedeaux Field
2,500[45]

Utah
Rice-Eccles Stadium
45,807[46]
Jon M. Huntsman Center
15,000[47]
Smith's Ballpark
15,411[48]

Washington
Husky Stadium
70,138[49]
Hec Edmundson Pavilion
10,000[50]
Husky Ballpark
2,212[51]

Washington State
Martin Stadium
32,740[52]
Beasley Coliseum
11,671[53]
Bailey-Brayton Field
3,500[54]

text: Key personnel[edit]

text:
School
Athletic director
Football coach
Men's basketball coach
Women's basketball coach
Baseball coach

Arizona
Dave Heeke
Kevin Sumlin
Sean Miller
Adia Barnes
Jay Johnson

Arizona State
Ray Anderson
Herm Edwards
Bobby Hurley
Charli Turner Thorne
Tracy Smith

California
H. Michael Williams
Justin Wilcox
Wyking Jones
Lindsay Gottlieb
David Esquer

Colorado
Rick George
Mike MacIntyre
Tad Boyle
JR Payne
No team

Oregon
Rob Mullens
Mario Cristobal
Dana Altman
Kelly Graves
George Horton

Oregon State
Scott Barnes
Jonathan Smith
Wayne Tinkle
Scott Rueck
Pat Casey

Stanford
Bernard Muir
David Shaw
Jerod Haase
Tara VanDerveer
Mark Marquess

UCLA
Dan Guerrero
Chip Kelly
Steve Alford
Cori Close
John Savage

USC
Lynn Swann
Clay Helton
Andy Enfield
Mark Trakh
Dan Hubbs

Utah
Chris Hill
Kyle Whittingham
Larry Krystkowiak
Lynne Roberts
Bill Kinneberg

Washington
Jennifer Cohen
Chris Petersen
Mike Hopkins
Jody Wynn
Lindsay Meggs

Washington State
Pat Chun
Mike Leach
Ernie Kent
June Daugherty
Marty Lees

text: Academics[edit]

text: Eight of the twelve member schools are members of the Association of American Universities (AAU), including all four California-based schools.[55] The only FBS conference with more AAU members is the Big Ten with 13 out of 14 member institutions having AAU membership.

text:
University of Arizona
University of California, Berkeley
University of California, Los Angeles
University of Colorado Boulder
University of Oregon
University of Southern California
Stanford University
University of Washington

tag: ul

text: Additionally, these member schools are also highly ranked nationally and globally by various groups, including the Academic Ranking of World Universities (ARWU) and Times Higher Education World University Rankings (Times). As of 2014, four Pac-12 institutions are ranked in the top 20 universities in the world, the most out of all conferences outside the Ivy League with Stanford ranked 2nd, UC Berkeley ranked 4th (the highest ranking of any public university), UCLA ranked 12th, and the University of Washington ranked at 15th. In 2014, of the twelve member schools, nine were ranked in the top 100 universities in the world.[56]

text: Athletic department revenue by school[edit]

text: This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2017) (Learn how and when to remove this template message)

text: Total revenue includes ticket sales, contributions and donations, rights and licensing, student fees, school funds and all other sources including TV income, camp income, concessions, and novelties. Total expenses includes coach and staff salaries, scholarships, buildings and grounds, maintenance, utilities and rental fees, recruiting, team travel, equipment and uniforms, conference dues, and insurance.

text: The following table is updated to show institutional reporting to the Department of Education as shown on the DOE Equity in Athletics website for the 2013–14 academic year. The national ranking of revenue is based on 2075 institutions reporting to the Department of Education that year. Source: http://ope.ed.gov/athletics.

text:
Conf
rank
(2013–14)
National
rank
(2013–14)
Institution
2013–14
Total revenue
from athletics
2013–14
Total expenses
on athletics

1
12
Stanford University
$110,240,490
$110,240,490

2
13
University of Southern California
$106,528,649
$106,528,649

3
19
University of Washington
$100,275,186
$86,097,136

4
22
University of Arizona
$97,630,769
$93,273,995

5
27
University of California, Berkeley
$90,262,140
$76,446,272

6
33
University of California, Los Angeles
$86,426,780
$86,426,780

7
35
University of Oregon
$81,546,443
$79,961,755

8
45
Arizona State University
$72,775,808
$72,599,644

9
55
Oregon State University
$67,033,751
$67,033,751

10
60
University of Colorado
$64,303,098
$64,303,098

11
62
Washington State University
$60,727,273
$60,727,273

12
65
University of Utah
$59,005,590
$57,819,434

text: History[edit]

text: Pacific Coast Conference[edit]

text: The roots of the Pac-12 Conference go back to December 2, 1915, when the Pacific Coast Conference (PCC) was founded at a meeting at the Imperial Hotel in Portland, Oregon.[57] Charter members were the University of California (now University of California, Berkeley), University of Washington, University of Oregon, and Oregon Agricultural College (now Oregon State University). The PCC began play in 1916.

text: One year later, Washington State College (now Washington State University) joined the league, followed by Stanford University in 1918.

text: In 1922, the PCC expanded to eight teams with the admission of USC and Idaho. Montana joined the Conference in 1924, and in 1928, the PCC grew to 10 members with the addition of UCLA.

text: For many years, the conference split into two divisions for basketball and baseball – a Southern Division comprising the four California schools and a Northern Division comprising the six schools in the Pacific Northwest.

text: In 1950, Montana departed to join the Mountain States Conference. The PCC continued as a nine-team league through June 1959.

text: AAWU (Big Five and Big Six)[edit]

text: Following "pay-for-play" scandals at California, USC, UCLA, and Washington, the PCC disbanded in June 1959. Ten months earlier in August 1958, these four schools agreed to form a new conference that would take effect the following summer.[58][59] When the four schools and Stanford began discussions for a new conference in 1959, retired Admiral Thomas J. Hamilton interceded and suggested the schools consider creating a national "power conference" (Hamilton had been a key player, head coach, and athletic director at Navy, and was the current athletic director at Pittsburgh). Nicknamed the "Airplane Conference,"[60][61][62] the five former PCC schools would have played with other major academically-oriented schools, including Army, Navy, Air Force, Notre Dame, Penn, Penn State, Duke, and Georgia Tech among others.[60][63] The effort fell through when a Pentagon official vetoed the idea and the service academies backed out.[64]

text: On July 1, 1959, the new Athletic Association of Western Universities was launched, with California, UCLA, USC, and Washington as the four charter members.[65] Stanford joined during the first month.[59][66] Hamilton left Pittsburgh to become the first commissioner of the AAWU,[65][67] and remained for twelve years.[68] The conference also was popularly known as the Big Five from 1960 to 1962.[69] When Washington State joined in 1962,[70] the conference became informally known as the Big Six.[69][71]

text: Oregon and Oregon State joined in the summer of 1964.[72][73] With the addition of the two Oregon schools, the conference was known unofficially as the Pacific Athletic Conference,[74][75][76][77][78] and then the Pacific-8 (as there already was a major conference called the Big Eight). In 1968, the AAWU formally renamed itself the Pacific-8 Conference, or Pac-8 for short. The Pac-8 did not allow a second bowl team from the conference until the 1975 season.[79]

text: Idaho was never invited to join the AAWU[citation needed]; the Vandals were independent for four years until the formation of the Big Sky Conference in 1963, and were independent in football until 1965.

text: In 1978, the conference added Arizona and Arizona State from the Western Athletic Conference, becoming the Pacific-10 Conference or Pac-10. The invitations to the schools were extended in December 1976,[80] and the expansion formally announced in May 1977.[81]

text: In 1986, the Pac-10 began sponsoring women's athletics. Prior to this time members' women's teams competed with other large universities on the Pacific coast in either the Northern Pacific Conference or the Western Collegiate Athletic Association.

text: In the mid-1990s the conference expressed interest in admitting the University of Colorado and the University of Texas after the collapse of the Southwest Conference. Texas expressed an interest in joining a strong academic conference, but joined three fellow Southwest Conference schools (Texas A&M, Texas Tech, and Baylor) to merge with the Big Eight Conference to form the Big 12 Conference in 1996. Colorado elected to remain in the newly formed Big 12.[82]

text: Before the addition of Colorado and Utah in 2011, only the Ivy League had maintained its membership for a longer time than the Pac-10 among Division I conferences. Commissioner Larry Scott said on February 9, 2010, that the window for expansion was open for the next year as the conference began negotiations for a new television deal. Speaking on a conference call to introduce former Big 12 commissioner Kevin Weiberg as his new deputy, Scott talked about possibly adding new teams to the conference and launching a new television network.[83] Scott, the former head of the Women's Tennis Association, took over the conference in July 2009. In his first eight months on the job, he saw growing interest from the membership over the possibility of adding teams for the first time since Arizona and Arizona State joined the conference in 1978.

text: In early June 2010, there were reports that the Pac-10 was considering adding up to six teams to the conference: the University of Texas, Texas A&M University, Texas Tech University, the University of Oklahoma, Oklahoma State University, and the University of Colorado.[84]

text: On June 10, 2010, the University of Colorado Boulder officially accepted an invitation to join the Pac-10 Conference, effective starting with the 2012–2013 academic year.[85][86] The school later announced it would join the conference a year earlier than previously announced, in the 2011–2012 academic year.

text: On June 15, 2010, a deal was reached between Texas and the Big 12 Conference to keep Texas, Texas A&M, Texas Tech, Oklahoma, and Oklahoma State in the Big 12. Following Texas' decision, the other Big 12 schools that had been rumored candidates to join the Pac-10 announced they would remain in the Big 12. This deal effectively ended the Pac-10's ambition to potentially become a sixteen-team conference.[87]

text: On June 17, 2010, the University of Utah officially accepted an invitation to join the Pac-10 Conference, effective starting July 2011.[85] Utah was a member of the Western Athletic Conference (WAC) with Arizona and Arizona State before those two left for the Pac-10 in 1978. The Utes left an expanded WAC with seven other schools in 1999 to form the new Mountain West Conference. Utah became the first "BCS Buster" to join a BCS conference, having played in (and won) two BCS games beforehand.

text: On July 27, 2010, the conference unveiled a new logo and announced that the Pac-10 would be renamed the Pac-12 when Utah and Colorado formally joined in July 2011. On October 21, the Pac-12 announced that its football competition would be split into two divisions—a North Division comprising the Pacific Northwest and Bay Area schools, and a South Division comprising the Mountain Time Zone and Southern California schools. On July 1, 2011, the Pac-12 assumed its current alignment when both Colorado and Utah officially joined as full members.

text: On August 15, 2012, the conference debuted the Pac-12 Network. It was the third college sports conference to launch a dedicated network, and the first to completely fund and own their own network outright.

text: To this day, the Pac-12 claims the PCC's history as its own. It inherited the PCC's berth in the Rose Bowl, and the eight largest schools in the old PCC all eventually joined the new league.

text: The Pac-12 is one of the founding members of the Mountain Pacific Sports Federation (MPSF), a conference organized to provide competition in non-revenue Olympic sports. All-Pac-12 members participate in at least one MPSF sport (men's and women's indoor track and field both actually have enough participating Pac-12 schools for the conference to sponsor a championship, but the Pac-12 has opted not to do so). For certain sports, the Pac-12 admits certain schools as associate members.

text: Membership timeline[edit]

text: Full members

text: Sponsored sports[edit]

text: The Pac-12 Conference sponsors championship competition in 10 men's and 13 women's NCAA-sanctioned sports, plus one men's sport that is not sanctioned by the NCAA. Three schools are associate members in a single men's sport.[88]

text: The newest sport to be sponsored by the Pac-12 is women's lacrosse, which begins play in spring 2018 following the elevation of Arizona State's club team to full varsity status.[89]

text:
Pac-12 teams in conference competition

Sport
Men's
Women's

Baseball
11
-

Basketball
12
12

Beach volleyball ^
-
8

Cross country
9
12

Football
12
-

Golf
12
11

Gymnastics
-
8

Lacrosse
-
6

Rowing †
6
7

Soccer
6
12

Softball
-
9

Swimming & Diving
8
9

Tennis
8
11

Track & Field Outdoor
10
12

Volleyball
-
12

Wrestling
5
-

text:
^ — Beach volleyball is a fully sanctioned NCAA sport which held its first national championship in the spring of 2016.[90] The Pac-12 is the second conference (after the Atlantic Sun Conference) to sponsor a championship in the sport.[91]
† — Rowing (M) is sanctioned by the Intercollegiate Rowing Association, not by the NCAA; Rowing (W) is sanctioned by both.

text: Men's sponsored sports by school[edit]

text: Member-by-member sponsorship of the 11 men's Pac-12 sports.

text:
School
Baseball
Basketball
Cross
Country
Football
Golf
Rowing[a]
Soccer
Swimming
& Diving
Tennis
Track
& Field
Outdoor
Wrestling
Total
Sports

Arizona
Y
Y
Y
Y
Y
N
N
Y
Y
Y
N
8

Arizona State
Y
Y
Y
Y
Y
N
N
Y
Y
Y
Y
9

California
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
10

Colorado
N
Y
Y
Y
Y
Y[b]
N
N
N
Y
N
5

Oregon
Y
Y
Y
Y
Y
N
N
N
Y
Y
N
7

Oregon State
Y
Y
N
Y
Y
Y
Y
N
N
N
Y
7

Stanford
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
11

UCLA
Y
Y
Y
Y
Y
N
Y
N
Y
Y
N
8

USC
Y
Y
N
Y
Y
N
N
Y
Y
Y
N
7

Utah
Y
Y
N
Y
Y
N
N
Y
Y
N
N
6

Washington
Y
Y
Y
Y
Y
Y
Y
N
Y
Y
N
9

Washington State
Y
Y
Y
Y
Y
Y[b]
N
N
N
Y
N
6

Totals
11
12
9
12
12
4+2[c]
5+1[d]
6
9
10
3+2[e]
93+3[f]+2[g]

text: Men's sports that are not sponsored by the Pac-12 but are fielded as a varsity sport at Pac-12 schools

text:
School
Fencing
Gymnastics
Ice
Hockey
Lacrosse
Rugby[a]
Sailing[a]
Skiing
Track & Field
Indoor
Volleyball
Water
Polo
Total
Sports

Arizona

PAC

MPSF

2

Arizona State

IND

PAC

MPSF

3

California

MPSF

PAC

MPSF

MPSF
4

Colorado

RMISA
MPSF

2

Oregon

MPSF

1

Oregon State

PAC[b]

1

Stanford
IND
MPSF

PCCSC

MPSF
MPSF
MPSF
6

UCLA

PAC

MPSF
MPSF
MPSF
4

USC

MPSF
MPSF
MPSF
3

Utah

[h]
PAC

RMISA

2

Washington

MPSF

1

Washington State

MPSF

1

Totals
1
2
1
0
1 + 5
1
2
10
3
4
25+5

text:
^ Jump up to: a b c Not an NCAA-sanctioned sport.
^ Jump up to: a b c Club status team competing against varsity teams.
Jump up ^ 4 full varsity teams and 2 club status teams.
Jump up ^ Affiliate: San Diego State
Jump up ^ Affiliates: Cal Poly, Cal State Bakersfield
Jump up ^ Affiliate members with full varsity status.
Jump up ^ Club teams.
Jump up ^ Utah will elevate its club lacrosse team to full varsity status for the 2019 season (2018–19 school year).[92]

text: Women's sponsored sports by school[edit]

text: Member-by-member sponsorship of the 13 women's Pac-12 sports.

text:
School
Basketball
Beach
Volleyball
Cross
Country
Golf
Gymnastics
Lacrosse
Rowing
Soccer
Softball
Swimming
& Diving
Tennis
Track
& Field
Outdoor
Volleyball
Total
Sports

Arizona
Y
Y
Y
Y
Y
N
N
Y
Y
Y
Y
Y
Y
11

Arizona State
Y
Y
Y
Y
Y
Y
N
Y
Y
Y
Y
Y
Y
12

California
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
13

Colorado
Y
N
Y
Y
N
Y
N
Y
N
N
Y
Y
Y
8

Oregon
Y
Y
Y
Y
N
Y
N
Y
Y
N
Y
Y
Y
10

Oregon State
Y
N
Y
Y
Y
N
Y
Y
Y
Y
N
Y
Y
10

Stanford
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
13

UCLA
Y
Y
Y
Y
Y
N
Y
Y
Y
Y
Y
Y
Y
12

USC
Y
Y
Y
Y
N
Y
Y
Y
N
Y
Y
Y
Y
11

Utah
Y
N
Y
N
Y
N
N
Y
Y
Y
Y
Y
Y
9

Washington
Y
Y
Y
Y
Y
N
Y
Y
Y
N
Y
Y
Y
11

Washington State
Y
N
Y
Y
N
N
Y
Y
N
Y
Y
Y
Y
9

Totals
12
8
12
11
8
6
7
12
9
9
11
12
12
129

text: Women's sports that are not sponsored by the Pac-12 but are fielded as a varsity sport at Pac-12 schools

text:
School
Acrobatics
& Tumbling[w 1]
Fencing
Field
Hockey
Sailing[w 1]
Skiing
Squash[w 1]
Synchronized
Swimming[w 1]
Track
& Field
Indoor
Triathlon
Water
Polo
Total
Sports

Arizona

MPSF

1

Arizona State

MPSF
IND
MPSF
3

California

AmEast

MPSF

MPSF
3

Colorado

RMISA

MPSF

2

Oregon
NCATA

MPSF

2

Oregon State

MPSF

1

Stanford

IND
AmEast
PCCSC

IND
IND
MPSF

MPSF
7

UCLA

MPSF

MPSF
2

USC

MPSF

MPSF
2

Utah

RMISA

MPSF

2

Washington

MPSF

1

Washington State

MPSF

1

Totals
1
1
2
1
2
1
1
12
1
5
27

text: ^ Jump up to: a b c d Not an NCAA sanctioned sport.

text: NCAA national titles[edit]

text:
School
Team
Individual

Men
Women
Co-ed†
Total
Men
Women
Co-ed
Total

Arizona
7
11
0
18
83
93
0
177

Arizona State
11
13
0
24
66
46
0
112

California
28
8
0
36
155
86
0
249

UCLA
75
39
0
114
166
103
0
270

Colorado
16
2
8
26
23
15
90
128

Oregon
19
14
0
33
102
42
0
144

Oregon State
3
0
0
3
32
7
0
39

USC
84
20
0
104
319
72
0
392

Stanford
64
51
0
115
265
204
14
497

Utah
2
9
10
21
5
25
72
102

Washington
0
8
0
8
54
17
2
73

Washington State
2
0
0
2
79
6
1
86

Conference total
310
175
18
503
1349
716
179
2244

text: See also: List of NCAA schools with the most NCAA Division I championships, List of NCAA schools with the most Division I national championships, and NCAA Division 1 FBS Conferences

text: Team titles through Sept. 22, 2017; individual titles through July 1, 2016[93]

text: † Co-ed sports include fencing (since 1990), rifle, and skiing (since 1983). Team fencing championships before 1990 and team skiing championships before 1983 were awarded as men's or women's championships and are counted here as such.

text: These totals do not include football national championships, which the NCAA does not officially award at the FBS level. Various polls, formulas, and other third-party systems have been used to determine national championships, not all of which are universally accepted. These totals also do not include championships prior to the inception of the NCAA.

text: USC claims 11 national football championships,[94] California claims 5,[95][96] Washington and Stanford claim 2,[97][98] and Colorado, Utah, and UCLA claim 1.[99][100][101][101][102][103]

text: Conference champions[edit]

text:
Football
Men's basketball
Women's basketball
Baseball
Softball
Gymnastics
Men's soccer
Women's soccer
Women's volleyball

text: Football[edit]

text: Rivalries[edit]

text: Each of the ten schools that were conference members before 2011 has its own in-state, conference rivalry. One is an intracity rivalry (UCLA-USC), and another is within the same metropolitan area (California-Stanford). Colorado and Utah, who joined in 2011, were historic rivals in the Rocky Mountain region prior to 1962 when they suspended the series. These rivalries (and the name given to the football forms) are:

text:
Oregon–Oregon State (The Civil War; the Platypus Trophy, not officially recognized by the Universities, is awarded to the winning alumni association).
California–Stanford (The Big Game; winner gets the Stanford Axe).
Arizona–Arizona State (The Duel in the Desert; winner gets the Territorial Cup).
Colorado–Utah (Rumble in the Rockies).
Washington–Washington State (the Apple Cup; since 1962 the winner receives the Apple Cup trophy).
UCLA–USC (The winner of the annual game gets the Victory Bell; referred among the students as the Gauntlet or the Crosstown Gauntlet, it has now been rebranded as the SoCal BMW Crosstown Cup and is awarded to the athletic department with the most victories[104]).

text: The most frequently played rivalries in the conference are the Civil War between Oregon and Oregon State (120 meetings through 2016) and the Big Game between Stanford and California (119 meetings). These rivalries are among the ten most played rivalries in Division I FBS football.

text: The two newest members, Colorado and Utah, had a football rivalry that had been dormant since 1962 – both were conference rivals previously in the Rocky Mountain Athletic Conference (now a Division II conference), and later the now-defunct Mountain States Conference (also known as the Skyline Conference). Even after Colorado joined what became the Big 12 in 1948 (the conference was then known popularly as the Big 7 Conference), the two schools continued their football rivalry for over a decade before ending it after the 1962 season. With the two schools being placed in the same division for football starting in 2011, the rivalry was revived with their 58th meeting during the 2011 season.

text: All of the California schools consider each other major rivals, due to the culture clash between Northern and Southern California.[105] California and UCLA have a rivalry rooted in their shared history as the top programs within the University of California system. Stanford and USC have a rivalry rooted in their shared history as the only private schools in the Pac-12. California and USC also have a long history, having played each other every year in football since 1916.

text: Oregon, Oregon State, Washington, and Washington State all consider each other major rivals due to their proximity and long history. The Oregon–Washington rivalry is sometimes referred to as the Border War.[106]

text: Arizona and New Mexico have a recently renewed rivalry game, based upon when they were both members of the WAC and both states were longtime territories before being admitted as states in 1912. They played for the Kit Carson Rifle trophy, which was no longer used starting with their meeting in the 1997 Insight Bowl.[107][108]

text: USC and Notre Dame have an intersectional rivalry (See Notre Dame–USC rivalry). The games in odd-numbered years are played in South Bend in mid-October, while the games in even-numbered years are played in Los Angeles, usually in late November.

text: Stanford and Notre Dame also have an intersectional rivalry (See Notre Dame–Stanford football rivalry). The schedule of the Stanford–Notre Dame rivalry mirrors that of USC–Notre Dame. The games in even-numbered years are played at Notre Dame in mid-October, while the games in odd-numbered years are played at Stanford in late November.

text: The isolated rural campuses of Washington State and Idaho are eight miles (13 km) apart on the Palouse, creating a natural border war known as the Battle of the Palouse. Idaho rejoined FBS in 1996.

text: Utah and BYU have a fierce rivalry nicknamed the Holy War that goes back to 1896.

text: Colorado also has a rivalry with in-state rival Colorado State called the Rocky Mountain Showdown.

text: With the NCAA permanently approving 12-game schedules in college football beginning in 2006, the Pac-10– alone among major conferences in doing so – went to a full nine-game conference schedule. Previously, the schools did not play one non-rival opponent, resulting in an eight-game conference schedule (four home games and four away). In 2010, the last season before the arrival of Colorado and Utah, the only other BCS conference that played a round-robin schedule was the Big East. The schedule consisted of one home and away game against the two schools in each region, plus the game against the primary in-state rival.

text: Divisions[edit]

text: On October 21, 2010 the Pac-10 announced the creation of divisions and a championship game in football, to be used when Colorado and Utah joined the conference effective July 1, 2011. The twelve members were split into two divisions for football only: a North Division comprising the Pacific Northwest and Bay Area schools, and a South Division comprising the Mountain Time Zone and Los Angeles schools.[109] The four California schools (gray background below) will still play each other every season despite spanning both divisions.

text:
North Division
South Division

Oregon
Arizona

Oregon State
Arizona State

Washington
Colorado

Washington State
Utah

California
UCLA

Stanford
USC

text: A nine-game conference schedule is being maintained, with five games within the assigned division and four games from the opposite division. The four California teams will play each other every season. Consequently, the four non-California teams in each division will only play one of the two California teams from the opposite division each year.

text: The Pac-12 Football Championship Game features the North Division Champion against the South Division Champion. The divisional champions are determined based on record in all conference games (both divisional and cross-divisional). The first three championship games was played at the home stadium of the participant with the better overall conference record.[110] Since 2014, the Championship Game has been hosted at Levi's Stadium in Santa Clara, California.

text: Bowl games[edit]

text: As of the 2017 college football season, the following is the selection order of bowl games with Pac-12 tie-ins. If a Pac-12 team is selected to participate in the College Football Playoff, all other bowl-eligible teams move up one spot in the order.

text:
Pick
Name
Location
Opposing
conference
Opposing
pick

1
Rose Bowl
Pasadena, California
Big Ten
1

2
Alamo Bowl
San Antonio, Texas
Big 12
2

3
Holiday Bowl
San Diego, California
Big Ten
4

4
Foster Farms Bowl
Santa Clara, California
Big Ten
6

5
Sun Bowl
El Paso, Texas
ACC
4

6
Las Vegas Bowl
Las Vegas, Nevada
MWC
1

7
Cactus Bowl
Tempe, Arizona
Big 12
5

text: Pac-12 All-Century Football Team[edit]

text: In honor of the 100th anniversary of the establishment of the conference, an All-Century Team was unveiled on December 2, 2015, voted on by a panel of coaches, players, and the media.[111]

text:
Quarterbacks: John Elway, Stanford; Marcus Mariota, Oregon; Jim Plunkett, Stanford; Andrew Luck, Stanford; Matt Leinart, USC
Running backs: Marcus Allen, USC; OJ Simpson, USC; Charles White, USC; Reggie Bush, USC; Mike Garrett, USC
Wide receivers: Keyshawn Johnson, USC; Lynn Swann, USC; Marqise Lee, USC; JJ Stokes, UCLA; Ken Margerum, Stanford
Tight ends: Tony Gonzalez, California; Charles Young, USC;
Offensive line: Jonathan Ogden, UCLA; Ron Yary, USC; Tony Boselli, USC; Anthony Muñoz, USC; Lincoln Kennedy, Washington; Brad Budde, USC; Randall McDaniel, Arizona State
Defensive ends: Tedy Bruschi, Arizona; Terrell Suggs, Arizona State; Willie McGinest, USC; Andre Carter, California; Jim Jeffcoat, Arizona State
Defensive tackles: Steve Emtman, Washington; Haloti Ngata, Oregon; Rob Waldrop, Arizona; Leonard Williams, USC; Ed White, California
Linebackers Junior Seau, USC; Jerry Robinson, UCLA; Ricky Hunley, Arizona; Richard Wood, USC; Chris Claiborne, USC
Cornerbacks Joey Browner, USC; Mel Renfro, Oregon; Chris McAlister, Arizona; Antoine Cason, Arizona
Safeties: Ronnie Lott, USC ; Kenny Easley, UCLA; Troy Polamalu, USC; Mark Carrier, USC
Kicker: Jason Hanson, Washington State
Punter: Tom Hackett, Utah
Returner: Reggie Bush, USC
Coach: John McKay, USC

text: Note: Bold Italic notes Offensive, Defensive and Coach of the Century selections; The voting panel was made up of 119 former players, coaches and media.[112]