SES4U - Earth and Space Final Exam

SES4U Grade 12 Earth and Space Final Exam 1. Sun, Moon, Earth Terms Spinoff: technology developed in space program that now has common commercial uses Ecliptic: plane of Earth’s orbit around the sun Ejecta: material blasted out of the Moon’s surface as a result of space-object impacts Reflecting Telescope: a device that brings visible light to a focus with mirrors Summer solstice: Earth’s position around June 21, at which the northern hemisphere has its maximum daylight hours Winter solstice: Earth’s position near or on December 21, at which the northern hemisphere has its minimum daylight hours Autumnal Equinox; Earth’s position when the lengths of day and night are equal Synchronous rotation: Moon’s state, in which its rotational period and its orbital period are equal Mare: a dark, smooth plain on the surface of the moon Regolith: a loose, ground-up rock on the Moon’s surface Interferometry: a process of linking separate radio telescopes to act as one Solar Eclipse: the blocking of the disk of the sun by the Moon Albedo: the portion of sunlight reflected by the Moon’s surface Perigee: closest point to Earth in the Moon’s orbit Apogee: farthest point from Earth in the Moon’s orbit 2. Main Ideas: – Electromagnetic spectrum is the arrangement of waves that includes gamma rays, X rays, ultraviolet radiation, visible light, infrared radiation, microwaves and radio wavesaccording to the wavelength and frequency, -The telescope that uses lenses to bring visible light to a focus is a refracting telescope

-Telescopes are placed above the atmosphere in order to most effectively collect infrared and ultraviolet radiation, X-rays, and gamma rays -The space exploration program that landed astronauts on the Moon was Apollo -The Moon’s surface is very different from the surface of Earth because the Moon has no erosion -The theory that suggests the Moon was formed at about the same time as Earth andfrom similar materials is called the simultaneous formation theory -The daily rising and setting of heavenly objects like Sun is caused by the rotation of Earth -One reason different seasons occur on Earth is because Earth’s axis is tilted 23.5 o relative to the ecliptic -When the Moon waxes during its lunar cycle, the amount of its sunlight portion that wesee appears to increase in size -A lunar eclipse occurs when Earth passes between the Sun and Moon -A lunar eclipse can only occur during the phase of the full moon 3. Earth Moon Mystery Article Q&A 1) Is the moon geologically active? -Moon is geologically not active -Moon is like a control- it is not as complicated as the earth is- no weathering, no platetectonics 2) What was the Lunar Magma Ocean? Describe some of its characteristics -sea of molten rock; very hot about 1 200 degrees, several hundred miles deep 3) What are the bright whitish areas called on the moon’s surface? What are the darkerareas called? -Bright whitish-gray areas are mountains called Lunar Highlands which is made ofanorthosite (light minerals) -Flatter grayish-black areas are called Lunar Mare which is made of basalt (lavaoutpourings) 4) Outline four main models of lunar formation 1. The intact capture model: earth and moon are formed separately in solar system; relatively non-violent

2. The co accretion model: both bodies form from the same material at the same time 3. Earth Fission model: earth divides out due to molten and rapid rotation 4. Collision Ejection model: mars sized object collides with earth and moon forms out of rings of debris ejected 5) Is there a difference between the oxygen isotope data on the moon and the earth?Which model does this data support? -Comparison of 0 isotopes in crust- similar in both the moon and earth -> supports the earth fission model and the co accretion model 6) Which model is currently favored? -Collision Ejection Model -> because it answers some questions about the Earth’s change in notation and its apparent change in axis 4. Drake Equation -terms involved in estimating the number of technological civilizations that may exist inour galaxy -identifies specific factors thought to play a role in the development of such civilizations N=R * f p n e f l f i f c L – N = the number of communicative civilizations – R * = the rate of formation of suitable stars (such as sun) – f p = the fraction of those stars with planets (current evidence indicates that planetary systems may be common for stars like the sun) – n e = the numbers of Earth-like worlds per planetary system – f l = the fraction of those Earth-like planets where life actually develops – f i = the fraction of life sites where intelligence develops – f c = the fraction of communicative planets (those on which electromagnetic communication technology develops) – L = the “lifetime” of communicating civilization

*Problem with this equation is that everything passed f p is really unknown. 5. Seasons -Moon did influence season early in our history- the collision that may have formed themoon tilted the earth’s axis at 23.5 degrees from normal -Moon stabilized earth’s wobble -Moon does not influence seasons now -Seasons are not driven by how close or far we are from the sun; we are actually closerin the winter; further in the summer -Seasons are driven by the tilt of the earth and what part of what hemisphere is facingthe sun at which time of the year 6. Gravity -The strength of the force of gravitation (F G ) between two objects depends on the mass of the objects and the distance separating them -F G is directly proportional to the product of masses -F G a m 1 m 2 -> F G is measured in newtons -> m 1 & m 2 measured in kilograms -Let m 1= mass of earth & m 2 = your mass -> if mass of earth is doubled, F G between you and the Earth is doubled -> if m 2 is doubled, F G between you and the Earth is doubled -> if both mass of earth and m 2 is doubled, F G between you and the Earth is quadrupled -F G is inversely proportional to the square of the distance between the centers of the objects -> F G a 1/d 2 -The combined expression: F G = Gm 1 m 2 , where G= 6.67 x 10 -11 N * m 2 d 2 kg 2 -Therefore, gravity is a weak force -For F G to be great, the interacting masses must be large

and/or separation must be small -Why does gravitational field strength at Earth’s surface vary between 9.78m/s 2 and 9.83m/s 2 ? ● “g” is greater than average at the poles because Earth’s radius at the polesis at its smallest ● “g” is lesser than average at the equator because Earth’s radius at theequator is at its largest 7. Tides ● Tides are the result of the gravitational effects of the Sun and Moon onEarth’s oceans Spring Tide: -The difference between high and low tide is at its greatest -Occurs just after a new or full moon Neap Tide: -The difference between high and low tide is at its lowest -Occurs at the first and third quarters of the moon ● Why do astronauts appear to be weightless when they are in orbit? ● Microgravity= apparent weightlessness ● g= 9.8m/s 2 at Earth’s surface, for everything! 8. Origins: The Earth is Born – Early Earth is described as hellish, hot, bombarded and lifeless -Sun formation may have triggered by supernova; elements such as H, He, Fe, C, allelements beyond Fe were found -Early Earth have grown due to collision between rocks, gravitational attraction andaccretion

-Asteroids and meteorites will help us get the snapshot of the early Earth -Carbon, water and radioactive isotopes are found on that meteorite and gives us theage of solar system -Age is about 4-4.5 billion years -Conditions such as molten planet, bombarded from space, radioactive decay gave riseto Iron Catastrophe -* Iron Catastrophe: heavy metals like iron and nickel migrate to the core ->this lead to differentiated planet -* Spinning core: it protects earth by: the molten core spinning and swirling which creates electric current and magnetic field then deflects the solar wind and eventuallyprotects the planet – Nebula: debris exists with a vast cloud of gas and dust called a nebula 9. Discoveries of Galileo -Moon surface= rough and uneven -> the surface is covered with craters, mountains andvalleys -sunspots, landscape on moon, Jupiter moons, jail, ideas of universe -supports Copernican idea that Earth and other planets orbit the Sun 10. Additional information from articles 1. Describe what happened to Mars: ● Mars too small; core cooled and solidified; no more magnetic field; nobarrier to solar wind; solar wind strips atmosphere 1. How was the Moon formed? ● Formed as same time as Earth 1. What did astronauts find out about age of Moon? ● Younger than the earth; some compositions as the outer part of the earth 1. What did the new Moon do for the early Earth? ● Stabilized the earth rotation; reduced the earth’s wobble; 23.5 degrees fromnormal gives the earth seasons 1. Where did life begin? ● Under the surface (refuge from bombardment) ● Under the oceans (hydro thermal vents) ● Opposition: the term used to describe two celestial bodies as being opposite each other in the sky, relative to the observer. An exam is whenthe Moon is opposite the Sun, with the observer on the Earth in the middle

11. Geologic Time -Geologic Time Scale: record of Earth’s history from its origin 4.6 billion years ago to the present -> By studying rock layer and fossils within them, geologists can reconstruct aspects ofEarth’s history and interpret ancient environment ->Enables to organizes time into meaningful “chunks”, context to understand timeframes -Eon: the largest of time units (Hadean, Archean, Proterozoic, Phanerozoic) -Precambrian: unit of geologic time consisting of the first three eons during which Earthformed and became hospitable to life; makes up nearly 90% of geologic time -Era: ten-hundreds of millions of years in duration (Paleozoic, Mesozoic, Cenozoic) -Periods: tens of millions of years in duration -Epochs: hundreds of thousands to millions of years in duration -Basically: Eon > Era > Period > Epoch Phanerozoic > Cenozoic > Neogene > Holocene Phanerozoic > Mesozoic > Cretaceous Phanerozoic > Paleozoic > Silurian Phanerozoic > Paleozoic > Cambrian -Why do scientists know more about the Cenozoic than they do about other eras? ● We live in it; shorter time phrase; no time for material(rocks) and fossils todisappear -Why do scientists know so little about Precambrian Era? ● Long time frame; we aren’t there; lots of time for erosion -Extinction events determine the divisions of eras and periods on the geologic time scale -Cenozoic era is divided into both periods and epochs

-Geologists study fossils for paleo ecology where they can find out the patterns of life,predict and/or protect future -We live in Holocene epoch, Quaternary period and Cenozoic era -Major divisions of Earth’s history are Eras -Each major division may be divided into periods -The Cenozoic Era is divided into epochs -Clues to which organisms lived in different eras are found in fossils -A gradual change in life-forms over time is organic evolution -After major changes in Earth’s environments, species either died out or adapted -Organisms with traits that are suited to an environment survive by the process of naturalselection -Plate tectonics caused collision and separation of continents -Many species adapted or became extinct because plate tectonics caused theirenvironments to change when the continents collided or separated -Proterozoic era lasted the longest -Hadean era is the oldest Order of which species appeared on Earth: ● iron catastrophe-> origin of the moon -> great bombardment -> Origin ofLife-> Cyanobacteria -> oxygen & ozone layer -> shielding of Earth fromultraviolet rays -> complex organisms (multicellular)-> invertebrates ->organisms with hard parts (shells) -> fish –amphibians -> reptiles ->Pangaea (all Earth) -Why did coal deposits begin to form in the Paleozoic Era? -> Formation of vast forest + swamps Mass Extinction: many groups of organisms disappear from the rock record at about thesame time ● the end of Paleozoic Era is marked by the largest mass extinction event inEarth; formation of Pangea and Catastrophe caused Mass Extinction in thatera

What happened to all of the continental plates near the end of the Paleozoic Era? –theymerged into one 12. Key Concepts in development of Geologic Time -Up to late 1700s, Earth history was based on biblical interpretation only – Catastrophism: a belief that the varied landscapes were created by great catastrophes in history; e.g. Noah and the Flood – Uniformitarianism: the physical, chemical and biological laws that operate today have also operated in the geological past- “the key to the present is the key to the past” -time/geology/history of planet/challenge to religion point of view 13. Fossils -The preserved remains or traces of once-living organisms -> provided evidence that species have changed over time on this planet ● fossils help determine sequence of rock layers and the relative ages ofrocks ● shows the succession of life forms 14. Index Fossils: ● The fossil remains of an organism that lived in a particular geologic age,used to identify or date the rock or rock layer in which it is found ● The best type of index fossils are usually those of swimming or floatingorganisms that evolved quickly and were able to spread over large areas(such as ammonites & graptolites) ● More useful than other fossils; easily recognized, abundant, widelydistributed, short time frame 15. Relative Dating vs. Absolute Dating -Absolute Dating: used to give an actual age (ex. Radioactive decay) -Relative-age Dating: used to establish the order of past geologic events (through different principles) Principles of Relative Dating – Original horizontality: the principle that sedimentary rocks are deposited in horizontal or nearly horizontal layers

– Cross-cutting relationships : an intrusion is younger than the rock it cuts across – Superposition: the principle that in an undisturbed rock sequence, the oldest rocks are at the bottom and each consecutive layer is younger than the layer beneath it Absolute Dating – Radioactive Decay -The atoms of some chemical elements have different forms called isotopes. Thesebreak down over time in a process called radioactive decay. Each original isotope calledthe parent gradually decays to form a new isotope called the daughter. When thenumber of parent atoms decreases, the number of daughter atoms increases by thesame amount. Isotopes are important because each radioactive element decays at aconstant rate. These rates of decay are known so that one can measure the proportionof parent and daughter isotopes in rocks now; one can calculate when the rocks wereformed Principle of inclusions : the fragments called inclusions in a rock layer must be older than the rock layer that contains them – Unconformities: gap in the rock record caused by erosion or weathering – Disconformity: when a horizontal layer of sedimentary rock overlies another horizontal layer of sedimentary rock (harder to see b/c they are flat) – Nonconformity: a layer of sedimentary rock overlies a layer of igneous or metamorphic rock such as granite or marble, the eroded surface is easier to identify – Angular unconformity: a horizontal layer of sedimentary rock is later laid down on top of the tilted eroded layers 16. Structure of Earth: chemical vs. physical properties Chemical properties: Crust (silicates) – Mantle (Silicates) – Core (Iron) Physical properties: 1. Lithosphere: Rigid outer; subdivided into continental and oceanic lithosphere 2. Asthenosphere(plastic): underlies the lithosphere; soft, partially molten layer 3. Mesosphere(solid): main bulk of planet- highly viscous (firm-plastic) 4. Outer core: liquid material 5. Inner core: solid, high-density, nickel-iron sphere; it spins and is the source of the earth’s magnetic field

17. Plate tectonics & Sea Floor Spreading -The theory of plate tectonics describes how the plates move, interact, and change the physical landscape -The surface of earth is broken into large plates; the size and position of these plateschange over time; the edges of these plates are sites of intense geologic activity such asearthquakes, volcanoes, and mountain building -Sea Floor Spreading -> the hypothesis that new ocean crust is formed at mid-ocean ridges and destroyed atdeep-sea trenches; occurs in a continuous cycle of magma intrusion and spreading Key Evidences to Sea Floor Spreading: 1. Sonar ● Allowed for mapping of ocean floor ● Ocean has ridges and under water mountains; Mid-Atlantic Ridge and deeptrenches 1. Magnetometer ● Picked up background hiss- turned out to be magnetic signature in theocean rocks ● When rocks are newly formed, any magnetic components in the rock willline up in the direction of magnetic north pole 1. Patterns in Ocean rock magnetism ● Rocks flipped between north & south poles in a defined pattern ● Reversal pattern leading away from the ridge all the way to the continentalshelves *Old rock is pushed aside by a new rock 1. Age of Ocean Rocks also varied ● Ridge rocks- youngest, ocean floor- furthest away from the ridge being theoldest 1. Deposition of Sediment ● Ocean floor= spreading apart from the middle (meaning older) and is beingdestroyed in the trenches 18. Boundaries: ● Convergent Boundaries: two plates move towards each other resulting in one plate sliding underneath the other ● Divergent Boundaries: as two plates on either side of magma chamber are pulled apart, they create a void that is filled with new magma thatsolidifies and creates new oceanic crust ● Transform Boundaries: two plates are sliding horizontally past one another

19. Driving Mechanisms 1. Convection: crust cools and heats repetitively and plate pulls apart due totension 1. Ridge Push 1. Slab Pull 20. Henry Hess ● Figured out how plate tectonics worked ● Worked on origin of ocean basins & island arcs, mountain building and themovement of continents ● Suggested that continents do not move across oceanic crust but rather thatthe continents and oceanic crust move together; states that the seafloorseparates at oceanic ridge where new crust is formed by upwelling magma;as the magma cools, the newly formed oceanic crust moves laterally awayfrom the ridge 21. Subduction zone ● An area where two plates move towards one another and one moves underthe other; creates a trench ● Creates earthquakes since subduction zone is a place where crustal platesare being forced down into the mantle below other crustal plates; the frictioncauses the plates to lock in position until the stress exceeds the shearstrength of the fault zone 22. Problem in Australia -> their geological location do not provide enough nutrient -> they do not have earthquakes, volcanoes or any other kind of eruptions where theymight help carry minerals and soils to the ground as it explodes -> lacks of glaciers

23. Continental Margins 1. Passive Margin: ● Not a plate boundary; both continent and oceans are locked together aspart of same plate; no trenches; volcanoes; or earthquakes ● Ex) North America & Southern and Western margins of Australia 1. Active Margin: ● At or near plate boundaries ● Ex) Iceland- Western North America; Nasca- South American Plate 24. Continental Breakups- “Breaking Up is hard to do” ● Mid-continental break is preceded by continental uplift (dome); thedevelopment of mid-continental rifts ● As continent drifts over a hotspot, it is lifted ● As continent rises, it fractures- and rift valley is born ● Breaking of (continental crust) involves the formation of a y-shaped breakcalled a triple-junction; each arm is called GRABEN ● Failure structures are called AULACOGENS; and are typically when largerivers and lakes are found 25. Magma/Intrusions/Volcanoes ● Magma: mixture of molten rock, mineral grains and dissolve gas ● Some factors that affect formation of Magma- to melt rock- include increasein temperature, decrease in pressure; and addition of water ● Types of Magma 1. Basaltic: -low silica content; low viscosity; least explosive; from upper mantle; linked to shieldvolcanoes

1. Andesitic: -medium silica; medium viscosity; medium explosive -along continental margins at subduction zones -from oceanic crust and oceanic sediments -linked to both cinder and composite volcanoes 1. Rhyolitic: -highest silica; highest viscosity; most explosive -from continental crust where interaction with silica is greatest -linked to composite volcanoes ● Types of volcanoes 1. Shield Volcanoes: -Largest of the three types of volcanoes -Basaltic Lava -Quiet eruptions 1. Cinder Cones: -Smallest of the three types of volcanoes -Andesitic Lava -Explosive eruptions 1. Composite volcanoes: -Considerably larger than cinder cones -Rhyolitic Lava

-Most explosive eruptions ● Intrusions 1. Plutons: intrusive igneous rock bodies 2. Batholiths: irregular shaped masses of coarse grained rocks which is found in the interior of mountains 3. Stocks: irregularly shaped plutons that are similar to batholiths but smaller in size 4. Laccoliths: mushroom shaped pluton with round top and flat bottom; cause overlying rocks to curve upwards 5. Sill: Pluton that intrudes parallel to rock layers 6. Dyke: Pluton that cuts across rock layers 26. Pressure and Water influence 1. Pressure: -higher pressure increases the temperature for melting -Why? -> the pressure helps hold the atoms in place; the more pressure, the more tightlythe atoms are held, the greater temperature required to split them apart -Therefore, high pressures in the mantle rocks prevent atoms within mineral frombreaking chemical bonds and moving freely from one another to form a liquid (magma) -when pressure is reduced the result is melting of the rock & when pressure increasesthe tock becomes hardened 1. Water: -small amounts of water in rock will result in a decrease in a melting temperature -electrical polarization causes a decrease in bond strengths within minerals and so therock will melt at lower temperatures -in essence, the water interferes with the chemical bonds in the rock making it easier tobreak apart and for a liquid 27. Types of Lava

-> pahoehoe lava: -surface looks silky and smooth but its texture is unpleasantly gritty and coarse becausethe sugar crystals, while few, have grown large ->’a’a lava: more rough and broken surface ->The major difference comes from their appearance of the surfaces and they also differin the way they flow 28. Scales ● Mercalli: -based on damage -relative scale which means that it is not based on real earthquake but rather on humaninfrastructure ● Richer: -Describes the earthquake’s magnitude by measuring the seismic waves that cause theearthquake 29. Stress/Fault/Boundary Stress Compression Tension Shear

Fault Reverse Normal Strike Slip Boundary Convergent Divergent Transform 30. Waves 1. Body Wave -a seismic wave that moves through the interior of the earth – P wave: Primary -> compressional-> travels in a straight line ->squeezes and pulls rocks in the same direction as wave travels – S wave: Secondary ->goes up and down; more damage 1. Surface Wave -a seismic wave that travels near the surface of the earth – Love wave: -> a surface wave having a horizontal motion that is transverse (perpendicular) to thedirection the wave is traveling – Rayleigh Wave:

->a seismic surface wave causing the ground to shake in an elliptical motion, with notransverse (가로지르다) or perpendicular motion 31. Hypocenter & Epicenter Hypocenter: the location of earthquake under the surface Epicenter: the point of earth’s surface directly above the focus of an earthquake 32. Minerals -Minerals are naturally occurring, solid, inorganic material, often in crystal form; there are 4000 known minerals; ex. Halite, gold, diamond -More than 90% of minerals are made up of oxygen and silicon -Most minerals are compounds of various elements- top 8 make up 98.5% of the crust’smass -re-crystallization or formation of new minerals is response to pressure -as pressure and temperature increase; continued re-crystallization and formation of newmineral assemblages How do we identify minerals? ● Rely on several simple tests: based on a mineral’s physical and chemicalproperties which are crystal form, luster, hardness, cleavage, fracture,streak, color, density, specific gravity and special properties Crystal form: some minerals form in such distinct crystal shapes Luster: the way minerals reflect light from its surface Hardness: a measure of how easily a mineral can be scratched Cleavage: when mineral splits relatively easily

Fracture: minerals that break with rough or jagged edges Streak: colour of a mineral when it is broken up and powered Colour: Caused by the presence of trace elements or compounds within a mineral Types of Minerals 1. Silicates: -contains silicon and oxygen, and usually one or more other elements -basic building block of the silicate is silica tetrahedron, a geometric solid having foursides that are equilateral triangles, resembling pyramid 2) Carbonates: -composed of one or more metallic elements and the carbonate ion 3) Oxides: -compounds of oxygen and a metal 4) Other groups -include sulfides, sulfates, halides, and native elements 5) Ores: -a mineral is an ore if it contains a valuable substance that can be minded at a profit 6) Gems: -Valuable minerals that are prized for their rarity and beauty (rubies, emeralds,diamonds) *Minerals are used as resources such as construction, energy production and jewelrymaking** 33. Rocks

Types of Rocks: IgneousRock -Form from cooling magma or lava-> Intrusive rock (plutonic): cooled underground and solidified slowly;individual crystals can be easily seen by the naked eye -> ex. granite -> Extrusive rock (volcanic): cooled quickly and solidified only after erupting onto the surface; individual crystalscannot be easily seen by the naked eye ->ex.basalt Characteristics -interlocking texture of grains; may display two differentgrain sizes; usually dark-coloured and dense; some haveholes; composed of crystals SedimentaryRock -Form from the bonding of rock fragments such as sand,silt, or clay; from organic materials; and from chemicalsdissolved in water- Clastic: formed from weathered and eroded rocks; these chunks of rocks are essentiallycemented into a new rock – Chemical: formed when minerals dissolved in water precipitate out – Organic: formed from remains of living things such as clamshells, plankton skeletons, dinosaur bones, andplants -ex. Limestone, shale Characteristics Grains cemented together; may sow presence of fossils;usually light-coloured and low density; show layers orbands MetamorphicRock -Form when other rocks are changed by heat, pressureand chemical deep inside the earth-Foliated: mineralgrains re-align themselves into bands

-Non-foliated: mineral grains do not re-align themselvesinto bands Characteristics Interlocking texture of large grains; generally showfoliation (layer); often show banded light and dark colors;often make “ching” sound instead of “chung”