Crisis Final
Ions
An atom is electrically neutral because of positive charge of protons and negative charge of electrons balancing out Atom with excessive positive or negative charge is an ion. Cation: positive ion. Anion: negative ion
Atomic structure
Atoms - made of nucleus, regroups one or several protons, and zero or more neutrons Protons are positively charged Neutrons are not charged, but affect mass Electrons are negatively charged
Binary Star Systems
Binary star system - two stars orbiting around a common center of mass Most stars (~85%) form binary star systems or multiple-star systems Some systems are so close that the surfaces of the stars are in contact with exchange of material Other binary stars may be separated by a few thousand Astronomical Units with orbital periods of hundreds of years
Continental crust
Continental crust, density is 2.7 g/cm3 or 2700 kg/m3 is a layer of: - sedimentary rock - granitic rock (felsic intrusive rock) - metamorphic rocks (quartzite) Continental crust is thick (average 35-40km) and up to 4b years old
Earth's inclination
Earth's axial tilt: 23 degrees Moon and Earth orbit: 5 degrees Moon's axial tilt: 6 degrees
Earth's magnetosphere
Earth's magnetic field shields us from most charged particles of solar winds and cosmic rays Protects us from ultraviolet radiation with the ozone layer. Without the magnetosphere, the ozone would disappear
Birth of the ocean
Hyrdogen and oxygen form water Water is expelled through volcanic activity Evidence from most ancient sediments point to presence of the ocean as far as 4.4b years ago, when the Earth was only 150m years old
Chicxulub impact crater
Impact of a giant bolide with Earth circa 65m years ago, contributed to extinction of non-avian dinosaurs Impact crater found near Chicxulub, Mexico Left residue of highly concentrated iridium in a thin worldwide layer of cla marking boundary between Cretaceous and Tertiary periods
Asteroids
Main asteroid belt is between the orbits of Mars and Jupiter, made of rocky materials Largest asteroid is Ceres, a dwarf planet Trojans share the orbit of Jupiter around the sun
Edwin Hubble
Observations at Mount Wilson's confirm Slipher's observations to include 39 galaxies All galaxies are moving away Big Bang theory born
Capillary action or capillarity
The ability of a liquid to flow in narrow spaces without the assistance of external forces like gravity Capillarity occurs because of intermolecular forces between the liquid and surrounding solid surfaces The thinner the tube, the stronger the capillarity Capillarity allows plants to pump water and nutrients from the subsurface
Nucleosynthesis
The fusion of nucleons to produce new atomic nuclei. New elements are made from fusion of lighter ones Examples: 2 hydrogens = helium, 4 heliums = oxygen, 3 heliums = carbon
Silicon
The most prolific electron donator, accounting 1 in 4 atoms in Earth's crust and mantle 14Si has 14 positively charged protons Silicon commonly gives away 4 electrons to achieve in the structure of 10 electrons Strong silicon-oxygen bonds are found in almost every rock, notably quartz
15 major plates
- Pacific plate - Juan de Fuca plate - North American plate - Cocos plate - Caribbean plate - Nazca plate - South American plate -Scotia plate - Antarctic plate - African plate - Arabian plate - Eurasian plate - Philippine plate - Indian plate - Indo-Australian plate
Surface tension
the tension of the surface of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid which tends to minimize surface area
Young faint sun paradox
A main sequence star grows gradually in size, passing through the subgiant stage until it reaches the red giant phase The early sun was 30% cooler and less bright than today, not sufficient alone to sustain water in liquid form on Earth Young faint sun paradox questions the conditions that allowed life to form in Earth's history. Greenhouse gases are thought to have provided a thermal blanket Receiving less solar energy, the Earth should have been icy Strong zircon minerals, which contain uranium and can be dated indicates the presence of liquid water in early Earth's history (150m years ago) A cool atmosphere that was maintained by volcanism, greenhouse gases, and methane would have provided organic material
Hotspots
A volcanic hotspot is an area in which the mantle from which heat rises as a thermal plume from deep in the Earth High heat and lower pressure at the base of the lithosphere (tectonic plates) facilitates melting of the rock. This melt called magma rises through cracks and erupts to form volcanoes
Hydrological system - the hydrosphere
All of Earth's water Includes oceans, lakes, streams, underground water, snow and ice Cryosphere - the always frozen parts of the hydrosphere The hydrosphere and atmosphere store, purify, and redistribute water Water in the atmosphere is NOT included in the hydrosphere
Backward spin of Venus
All planets in solar system orbit sun anti-clockwise Most planets rotate on their axis in anti-clockwise direction, but Venus rotates clockwise in retrograde rotation over 243 Earth days---slowest planet rotation
Water on Mars
Almost all water on Mars is ice, enough to cover the planet to a depth of 35m No bodies of water on surface Before ~3.8b years ago, Mars may have had liquid water including an ocean covering 1/3 of the planet Subglacial lake discovered 1.5km below southern polar ice cap, first known liquid water Only microbial life is suspected
Moon rocks
Anorthosite is a major constituent of the Moon's crust Large quantities of anorthosite floated at surface of magma ocean to form mountains 65% of the Moon's surface, the lunar highlands are made of anorthosite Darker regions, maria or seas of basalt Lunar anorthosite dates to 4.9 to 4.5b years ago
Chemical bonds
Each atom reaches equilibrium with 2, 10, or 18 orbiting electrons (explain by quantum mechanics) Atoms like to combine to form chemical bonds (sharing covalent bonds or transferring ionic bond electrons)
Age of Planet Earth
Meteorites date to 4.567b years old. Left over bits from time of solar formation Earth accretion was 4.56b years ago Moon rocks are 4.47b years old Zircons from Australia are 4.4b years old. This indicates crust (differentiation) already existed
Minerals
Normally occurring inorganic, solid material with well defined chemical composition Two characteristics that best allow the study of minerals: crystalline structure - the way the elemental atoms are packed together, composition - the major chemical elements that are present and their proportions
Life of Stars
Stars differ in color (temperature) and size (luminosity) 85% of all stars, including the Sun fall in the main sequence of the H-R diagram Red giants, like Betelgeuse are larger or colder White dwarves are dying stars, fuel for fusion reaction exhausts them The smaller the star, the longer it lives. A 1S star lives 10b years
Granite
The mineral evolution continues with partial melting of basalt, especially in water, to form the rock granite. Most granite hosts a simple mineralogy of four different species Quartz SIO2 erodes to make the first sandy beaches Two kinds of feldspar: one rich in potassium and the other in sodium Every granite also hosts some iron bearing mineral, either blocky pyroxene or sheetlike mica
Remanent magnetism
When magma turns into rock, dipole orientation locks in at temperatures lower than 550 degrees celsius Rock magma points toward location of north magnetic pole when formed Sequence of paleomagnetic directions in lava flows shows history of magnetic polarity
Pillow lava
solidifies as rounded masses from volcanic eruption underwater
Where do elements come from?
Big Bang nucleosynthesis: about 3 minutes after Big Bang, creation of hydrogen (75%), helium (24%), and lithium (1%)
Meteorites
Chondrites: representative of the material in solar nebula, before the formation of the sun and the surrounding planets. About 85% of meteorites that fall on Earth are chondrites Achondrites: differentiated material, representative of the composition of terrestrial planets (NOT Jovian) Oldest meteorites date to 4.56b years old
Stellar nucleosynthesis
Creation of chemical elements by nuclear fusion reactions between atoms within stars and novas Light elements are created in stars Heavier ones are created by a number of astrophysics processes, e.g. novas
Earth's bulk composition
Crust - 71% basalt Mantle - peridotite Outer (liquid) core - iron dominated Inner (solid) core - iron dominated
Comet and asteroid water
Earth was dry 4.5b years ago, oceans are 3.8b years old Surface water came from Earth's mantle through volcanism and from comets and asteroids ESA's (Europeans Space Agency) Rosetta mission found a larger ratio of deuterium to hydrogen than on Earth's water
Origin of Moon
Earth was struck by a planet called Theia, a disc of debris was formed around Earth and knocked it 23 degrees of axis (formation of seasons) Earth reformed and the debris formed the moon
Planetary defense
Encompasses all efforts needed to detect possibility and warn potential asteroid or comet impact with earth Find and track near Earth objects that pose hazards of impact Take measure to deflect or disrupt impact course or mitigate effects of impact that cannot be prevented
Rhythmites
Layers of sediment or sedimentary rock laid down in a repeated pattern Pattern may be varves, which are an annual pattern or shorter or longer term rhythmites Precambrian tidal rhythmites provide constraints on paleo Earth-Moon distance
Chemical weathering
Minerals in igneous and metamorphic rocks form at much higher temperatures and pressures than exist at Earth's surface Chemical weathering occurs as these minerals are exposed and chemically changed into new, more stable minerals The principal agent of chemical weathering is weak carbonic acid which is the result of rainwater (acid rain) dissolving small amounts of carbon dioxide from the atmosphere
Geodesy
Newest evidence of plate motion comes from space geodesy which measures the positions of geodetic monuments with an absolute accuracy of 1cm daily Measuring positions several times a year provides present day plate velocities directly and accurately
Earth's first rock: dunite
Olivine minerals are the first to crystalize because of high melting point Olivine is typically denser than the liquid in which it crystallizes, so the first crystal sink Aggregates of almost pure olivine crystals formed a stunning green rock called dunite Same mineral and rock occurred first on terrestrial planets and moon Dunite is rare today, appearing on Earth's surface when uplifted by mountain-building activity
Big Six
Oxygen, silicon, aluminum, magnesium, calcium and iron outweigh all other heavy elements in rocky terrestrial planets Make up 98% of Earth's mass, mass of Earth's moon, Mercury, Venus, and Mars
Anthropogenic system - the anthroposphere
Part of the environment that is made/modified Also called technosphere Anthropocene - period during which human activity has been the dominant influence on climate and the environment
Blackbody radiator
Radiation emitted by non-reflective body held at constant temperature Wien's law: wavelength of emitted radiation is shorter for bodies at higher temperatures, longer for bodies at lower temperatures According to Wien's law, the temperature of a planet or star can be approximated by looking at the wavelength of emitted radiation
Solar radiations
Radiation energy released in sun's core has very short wavelength and is very energetic As gamma rays move outward from sun's core they're repeatedly absorbed and re-emitted as longer-wavelength, lower-energy radiation Energy from sun varies with wavelength and shape of sun's spectral curve matches that of a blackbody radiator Blackbody radiations exclude radiations due to reflection from other light sources
Rapid water cycle
Surface tension allows droplets to form, allowing rain Other atmosphere fluids, such as CO2 and CH4 just float in the atmosphere in a super-fine mist Property enables the rapid water cycle
Origin of Moon hypotheses
The Moon is the largest in the solar system. Several hypotheses: Gravitational capture: Moon formed separately, smaller planetesimal; it passed close enough to Earth to stay in orbit Co-accretion: posits that Moon formed simultaneously as Earth, much like planet around the sun George Darwin: fission, the Moon represents ejected material from Earth
Melvin Slipher
Discovered 12 galaxies beyond the Milky Way. They showed 'red shift', a doppler effect showing they're speeding away
Atmospheric system - the atmosphere
Mixture of gases that surround Earth Predominantly Nitrogen (78%), Oxygen (21%), Argon (0.9%), Carbon Dioxide (~0.1%), and water (trace) The ozone layer is very thin in context, but it protects the Earth from damaging solar radiation and is the reservoir for oxygen and carbon dioxide The outer boundary of the Earth system
Triton
Triton orbits Neptune in retrograde Orbit is inclined 23 degrees from Neptune's equatorial plane
Paleomagnetism
Reveals the records of magnetic reversals One consequence of the splitting and spreading of oceanic crust is that older curst is farther from the ridge and new lava filling the gap along the ridge becomes magnetized with the polarity of Earth's magnetic field Continents are carried passively along atop the fragments of lithosphere that carry seafloor crust away from ocean ridges
Acid and base
An important characteristic of water is that it is never pure. A fraction of H2O molecules for OH- and H+. H+ with H2O to create hydronium compounds. H3O+ Pure water refers to a fluid with equal amounts of hydroxide and hydronium, exactly 10-7 molecules of H3O+ per liter of water The pH of water measures the amount of free protons or equivalently the amount of hydronium Water of pH6 has 10-6 H3O+ compounds per liter, or ten times more that "pure" water. pH5 has 10-5 H30+ compounds per liter or hundred more than pure water Basic solutions include sea water (pH8), baking soda (pH 9) Acidic solutions include milk (pH6.5), coffee (pH5), lemon juice (pH3)
Anorthosite
Sinking of olivine crystals depleted the remaining hot melts in magnesium, increasing relative concentration in calcium and aluminum Anorthite, a feldspar made of calcium and aluminum silicate began to solidify Unlike olivine, anorthite is less dense than surrounding fluid magma and tends to float forming anorthosite rock Rare on Earth, found in California, major element of the Moon
Formation of continental crust
Basalt, 3x denser than water forms the basement of the oceanic crust and most of the surface of terrestrial planets Granite is 30% lighter than basalt, and therefore eventually floats on top of the oceanic crust, forming continental rafts with deep roots The energy to partially melt basalt comes from internal heat. Smaller planets like Mercury and Mars and Earth's moon did not form deep rooted granitic continents The aggregation of granitic plateaus formed the continental crust
Extrusive and intrusive rocks
Basaltic magma - approaches the surface in two complementary ways Cooled quickly as it reaches the surface, crystallization is short lived; basaltic magma forms extrusive rocks. Basalt contains small crystal grains A significant fraction of basaltic magma never makes it above ground. It cools slowly underground forming intrusive rocks called gabbro made of feldspar and pyroxene crystals Intrusive and extrusive rocks have the same composition but different texture
Silicate minerals
Because of their abundance, oxygen and silicon form the most common rock-forming minerals (quartz, feldspar, olivine, garnet, asbestos, or mica) and the most common mineral group: silicates Other mineral groups: oxides, sulfides, carbonates, sulfates, phosphates 1.3k new species of silicates found every month The silicate compound is: built of silicate anion (tetrahedron) and the anion joins together by sharing oxygen atoms to form chain sheets and polymers (3D networks)
Basalt in Solar Sytem
Black basalt dominates near surface rocks on every terrestrial planet Surfaces of Mercury and Venus are mostly basalt The maria of the surface of Earth's moon represented giant lakes of basaltic lava, now cooled On Earth 71% of the surface, including all of the ocean floor is underlain by basaltic crust
Earth's inner structure and composition
Earth's structure is known for: magnetic field (metallic core), gravitational effects and spin (total mass and the angular momentum), seismic waves (layer interfaces), volcanoes, and meteorites (composition, relative abundance of elements)
Solar nebula and the ecliptic
Ecliptic: the orbital plane that all planets rotate around the sun All planets orbit in the same direction, anti-clockwise as seen from above the North Pole This is explained by the flattening of some solar nebula with some outliers
Formation of oceanic crust
First peridotite was ephemeral, sinking to Earth's mantle Less dense rock is blanketing the surface to every terrestrial planet: basalt Basalt is made of plagioclase feldspar and pyroxene Basalt comes from the partial melting of peridotite. The first melt is less dense and float above the remaining solid substrate
Conduction: thermal gradient
Geothermal gradient - increase temperature as you go deeper in Earth Geothermal gradient varies from place to place and is less pronounced with depth Earth's core calculated to be almost as hot as the sun
Mantle plumes
Coming from hot outer core, mantle plumes convect energy to shallow depth (Earth's surface) Volcanic spots of Hawaii, Iceland, and Yosemite are surface manifestations of Earth's mantle plumes Mantle plumes or mantle upwelling can form large igneous provinces, flood basalt, and ocean islands
Conduction and convection
Conduction - heat energy flows out through solid rocks at Earth's surface Convection - the movement of hot material from inside planet to outside, very efficient to transfer heat from interior surface. Its the driving force for plate tectonics
Cooling of magma ocean
Conduction: heat directly transmitted through substance when there is a difference in temperature between adjoining regions, without movement of materials Convection: transfer of heat by motion of matter in thermal gradient Radiation: emission of energy as electromagnetic waves
Age of oceanic plates
Current chron is brunhes. Normal polarity: magnetic north and geographic north coincide Last reversal was 700k years ago from the Matuyama chron Oldest oceanic crust is ~200m years old Oldest rocks on continent are ~4.4b years old Age of Earth is ~4.5b years old
Isostasy
Differences in density create a buoyancy effect. Isostasy is the static equilibrium (lighter material floats to the top) Pratt isostasy explains the differences in altitude of heterogenous slivers with different densities Airy isostasy explains the depth of continental roots as a function of topography
Arno Penzias and Robert Wilson
Discovered that Earth is bathed in cosmic microwave background radiation (oldest electromagnetic radiation) They confirm the Big Bang Theory
Mineral evolution
Drove the differentiation of Earth into layers of different composition 1. Freezing the magma ocean created the olivine material of dunite, depleting magma of magnesium 2. Continued freezing creating the anorthite mieral, a calcium rich plagioclase feldspar and anorthosite (common on moon) 3. Further cooling formed the pyroxene mineral, which combined with olivine formed the rock peridotite that fills the upper mantle 4. Partial melting of peridotite in upwelling regions formed he magnesium rich mineral plagioclase feldspar, which combined with pyroxene and olivine formed the basalt, the base of oceanic crust 5. Degassing the peridotite created the atmosphere and global ocean. Further partial melting of basalt, especially in water created the rock granite that forms the root of continents
Earth's structure
Earth is covered by two types of crusts that differ fundamentally in composition: - The average curst is 8km thick - The average continental crust is 45km thick but ranges from 30-70km The lithosphere (crust and upper mantle) floats above a denser viscoelastic mantle (solid but flowing over long periods)
The Habitable (Goldilocks) Zone
Earth is the only planet in the solar system with water as a solid, liquid, and gas Habitable or Goldilocks zone satisfies: planet is far enough from the sun for water to be condensed and planet is close enough from sun for water to not freeze most of the time
Birth of Earth's crust
Earth's internal heat: Earth in Hadeon eon is a magma ocean planet Several Earth internal energy sources: - radiogenic heat: main source near surface, accounting for ~66% of interior heat flow, produced by decay of radioactive elements: uranium, thorium, and potassium - accretionary heat: internal heat left over from formation of Earth by countless particles colliding and sticking to each other - tidal heating: generated by internal friction from constant distortion of planet. Duration of early Earth daily rotations: 5 hours, creating tides of super hot magma - core formation: heat from gravitational potential energy of dense core material sinking to center of planet plus heat releasing as innermost material solidified
Planetary differentiation
The process of separating out different constituents of a planetary body as a consequence of their density and chemistry, where the body develops into distinct layers with different compositions Denser materials sink to the center, less dense materials rise to the surface (generally in magma ocean) Such a process creates core and mantle. Sometimes a chemically distinct crust forms on mantle Gravitational potential is converted to heat, accretion heat: planetary interiors are warmer than their surface Denser materials: iron (Fe) and nickel (Ni) are most abundant in Earth's core Lighter materials: hydrogen (H), sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), aluminum (Al), silicone (Si), oxygen (O) are most abundant in Earth's core
Plate tectonics
The unifying theory of geology that provides explanation for the major topography and geologic features seen on Earth's surface Basic principles of plate tectonics: - Lithosphere is made up of a mosaic of moving plates, segments of a spherical shell - Plates are rigid except near their boundaries where relative motion between plates occur - New plates can be created at divergent boundaries and destroyed at convergent boundaries - Total plate area is conserved (conservation of mass)
Salt water
Water's electric polarity makes it a super solvent. Its dipole moment exerts a strong force on other molecules Many elements and compounds dissolve easily in water. Rocks slowly, chemical erosion is an important process at geological time scales As a result ~3.5% of average seawater consists of dissolved salts (sodium, chlorine and six other ions). If these precipitated they would form a layer about 56m thick on the seafloor
Differentiated crust
With the advent of granite, Earth's crust was irreversibly split into two types: denser basaltic oceanic crust and lighter granitic continental crust Continental crust rises far above sea level, forming dry continental masses ~35 km thick Oceanic crust lies 3500m below sea level on average and represents 71% of Earth's surface, ~6km thick
Younger Dryas impact
Younger Dryas impact hypothesis says impact of one or more comets started Younger Dryas period about 12900 before present Younger Dryas ice age lasted 1.2k years causing megafauna extinctions before warmer climate returned The Hiawatha glacier impact crater in Greenland is evidence
Isotopes
Atoms with the same atomic number but different mass numbers All isotopes of the same element have the same number of protons but different number of neutrons Have the same chemical properties but different mass or density Some of radioactive and can be used in radioactive dating Mass dependent fractionation during nebular/planetary processes create isotopic variability in the solar system Hydrogen: 1 proton, 1 electron. Deuterium: 1 proton, 1 neutron, 1 electron (has same chemical properties as hydrogen but heavier) Nearly all deuterium found in nature was produced during the Big Bang 13.7b years ago
Magnetic reversals
Earth's magnetic field is a geomagnetic dynamo driven by movements in the liquid outer core as motion of charged particles induce a magnetic field Motion in the outer core must nearly align with Earth's rotation axis Once formed, this geodynamo reinforces itself, but chaotic fluctuations from nonlinear dynamic perturb and the orientation flips every 4-5m years ~500k years with variability
Oxygen
Earth's master electron acceptor 99.9% of Earth's oxygen is locked into rocks and minerals Oxygen incessant acquisitive urge makes it one of the most reactive corrosive gases
Late Heavy Bombardment
Occurred 4.1-3.8b years ago Happened after the Earth and other rock planets formed and accreted most of their mass
Oceanic crust
Oceanic crust is layered: basaltic lava flow (pillow lava), underlain by sheeted dykes (magma conduits), underlain by gabbros (intrusive rocks) Basaltic crust is 10% lighter than the underlying peridotite in the upper mantle, from which it originates by partial melting A block of basalt 10km thick would emerge by 1km above the peridotite magma in the early Earth (isostasy) creating the first long term topography on the planet
Neutrino tomography of Earth
Atmospheric neutrinos are produced by the interaction of cosmic rays with nuclei in atmosphere As one of these neutrinos crosses Earth, the absorption probability depends on its energy and on the amount of matter traversed which is directly related to its path length The zenith and energy distribution of high energy atmospheric neutrinos observed at a detector encode tomographic information on the matter content of the Earth which can be used to infer Earth's density profile Confirms the presence of Earth's solid inner core
Geological system - the geosphere
The solid Earth Composed mainly of rock and regolith (solid, dust, rock fragment, etc.) Zone where energy that comes into the Earth system from outside sources meets energy that comes from the planet Energy sources combine and compete to build up/wear down the material of Earth's surface
Formation of the Universe
Big Bang - 0 Cosmic inflation: origin of fluctuations - 10-32 seconds Particles form: ordinary matter particles are coupled to light. Dark matter particles start building structures - 10-30 seconds Recombination: ordinary matter particles decouple from light and the Cosmic Microwave Background is released - 380,000 years Dark Ages: ordinary matter particles fall into the structures by dark matter First stars and galaxies - about 400m years First minerals (pure carbon) Galaxy evolution: clusters of galaxies and superclusters form Big Bang expansion is over 13.7b years
Formation of the Earth's most outermost fluids
Earth's oceans and atmosphere developed following differentiation. Primary atmosphere was lost to outer space Secondary atmosphere: gas and water on Earth came from degassing of crust and mantle during cooling Additional water derived from comets, a combination of ice and rock from outer solar system parts Volcanic water vapor outgassed from Earth as it cooled Current volcanoes emit: 50-60% water, 24% carbon dioxide, 13% sulfur dioxide, and 3% other The amount of argon in the atmosphere implies origin of atmosphere and ocean water was degassing of mantle rocks Tertiary atmosphere formed biological processes that enriched it in oxygen
Water
H2O is a combo of two abundant chemical elements that were created in the Big Bang and in the core of stars and widely disseminated by the explosions of supernovas Water is abundant in the cosmos, but not on Earth (0.1%) compared to the chondrites (3%). Some water has been dispersed or is trapped in the planetary interior. Water is commonly found at Earth's surface, but more may be trapped in the mantle. Trapped in minerals, the equivalent of 80 surface oceans may be absorbed in the mantle rocks: peridotite, wadsleyite, and perovskite, each found in the upper mantle, transition zone, and lower mantle Water is blue because it absorbs red (red is not reflected). As Earth is a blackbody radiator that radiated in the infrared, water vapor is an important greenhouse gas Water is a polar molecule because of shape and electric charges of oxygen and hydrogen atoms Electric attraction between moleciles makes water densely packed and water ice very strong Water ice is lighter than liquid water unlike most other elements and compounds that sink in their fluids This allows life to survive in freezing conditions protected by floating ice. Otherwise water based ecosystems would not subsist in temperate regions
Biological system - the biosphere
Includes all the Earth's organisms and matter that hasn't decomposed Biosphere greatly affects the other systems
Intrusive rock
Intrusive or plutonic, igneous rocks form when magma cools slowly below the Earth's surface Most intrusive rocks have large, well formed crystals. Examples: granite, gabbro, diorite, and dunite
Dissolution of feldspar
Kaolinite clay occurs in abundance in soils formed from the chemical weathering of rocks in hot, moist climates Comparing soils along a gradient towards progressively cooler or drier climates, the proportions of koalinite decreases, while the proportion of other clay minerals such as illite (in cooler climates) or smectite (in drier climates) increases Systematic differences in clay mineral content can be used to infer changes in paleo-climates
Supernovas
Life cycle of a massive star ends with the explosion of the super-dense core: a supernova Matter is scattered in the surrounding galaxy, forming a nebula that can accrete into a new solar system The remains of the core collapse into a black hole, so dense that light can't escape
Water on Europa (Moon of Jupiter)
Liquid water layer exists beneath surface, allowed by heat from tidal flexing Outer crust of solid ice is ~10 to 30km thick, including a "warm ice" layer Subsurface liquid ocean may be ~100km deep with a volume greater than 2x Earth's surface
Pyroxene
Magnesium rich pyroxene comes next, common of silicate minerals Dense, olivine and pyroxene minerals dive into the mantle to form rock peridotite Sinking of early peridotite rafts may have ignited mantle convection
Metals
Metals create their electrons to form a giant soup of electrons floating around a cluster of atomic nuclei Electrons are delocalized, so they're free to move around, forming excellent electronic conductors Atom nuclei become positively charged and attracted to the sea of electrons. Attraction called metallic bonding Iron 26Fe ironized in forms Fe2+ and Fe3+ has 8 electrons to share, no single other element can accept it alone. Aluminum has similar characteristics
Chemical elements
Most fundamental substances into which matter can be separated An atom is the smallest individual particle that retains the distinctive properties of a given chemical element Atoms built of protons, neutrons in the nucleus, and electrons orbiting the nucleus Number of protons in the nucleus is the atomic number Electrons are mass-less Sum of neutrons and protons is atomic number
Uranus' strange inclination
Most planets spin on an axis perpendicular to the ecliptic Uranus' spin axis is parallel to ecliptic Unsolved: the equatorial regions are warmer than the poles
Geodynamo
Motion of charged particles induces magnetic field Earth's core is made of conductive material, Earth rotation and internal convection of outer core creates magnetic field: geomagnetic field It's a geomagnetic dynamo Magnetic fields deviate the flow of electrically charged particles
Oceanic crust (plate tectonics)
Oceanic crust is 3 g/cm3, 2900 kg/m3 and relatively young (200m years old max) Typically composed of several layers between ocean floor and mantle: - sediments - basaltic pillow lava - sheeted dykes - layered gabbro - ultramafic cumulates The mohorovicic (moho) discontinuity, a seismic reflector and a compositional boundary separates the crust from the mantle
Kuiper Belt
Outside the orbit of Neptune Includes small ice bodies including dwarf planets (Eres, Haumea, Makemake, Eris) and a double-dwarf planet system (Pluto and Charon) with orbiting moons Home of short period comets (made of ice with dust and rock particles) Long period comets originate farther from Oort cloud
A history of differentiation
Solar system is differentiated into terrestrial planets (Mercury, Venus, Earth, Mars) and jovian ones (Jupiter, Saturn, Uranus, Neptune) Terrestrial ones are differentiated into their core, mantle, and crust Different types of igneous rocks (dunite, anorthosite, peridotite, basalt, granite) present mineral differentiation Life itself is a story of differentiation of organic materials
Greenhouse effect
Solid Earth emits long-wavelength radiations (infra-red) which is absorbed on its way out by the greenhouse gases (water, carbon dioxide, methane, chloroflourocarbons (CFCs), and ozone) Resulting effect is thermal blanket with higher temperature in atmosphere In absence of greenhouse gases, temperature on Earth's atmosphere would be 255 K (-18 degrees celsius or -0.4 degrees fahrenheit). Earth's is 288 K (15 degrees celsius or 59 degrees fahrenheit) Greenhouse effect warms Earth by ~30 degrees celsius
Geodetic strain
Strain is a measure of deformation, i.e., it does not include rigid-body translations or rotations Deformation is concentrated at plate boundaries, sharp or diffuse
Jupiter
The largest (Jovian) planet Similar in composition to the sun (74% hydrogen, 24% helium, 2% heavy elements) 10x larger radius than Earth, 10x smaller radius than the sun "Almost a star" if it was slightly bigger, it would have started fusion and turned into a star