Fichas
Earth Structure
Fichas del conjunto (21)
- 1The 4 Terrestrial PlanetsMercury
Venus
Earth
Mars - 2Where does the asteriod belt lie, what does it contain?Betwen Mars and Jupiter
Left over from the formation of the solar system
Thought to be remains of planets that failed to form - 3The 4 gas giantsJupiter
Saturn
Uranus
Neptune - 4Formation of the solar systemMolecular cloud of gas and dust collapsed when it was hit by an exploding star (supernova)
Material formed a rotating disc triggering a nuclear reaction forming the Sun
Accreation formed the planets - 5Asteriods Meteorites CometsRocky objects which failed to form a planet
Fragments of rock which fall to Earth from Space
Made from dust and ice which turns into vapours when its close to the sun - 6Types of meteoritesIRON - alloy of Iron and nickel, thought to represent core of small planet like objects
STONY - silicate minerals, thought to represent the mantle
CARBONACEOUS CHONDRITES - type of stony, water anf organic compounds, similar in composition to the Sun - 7Impact craters cause...Material to be ejected
Quarts grains violently shocked
Rock strata tilted
Material brecciated
Ejected material falls back to surface woth sequence of rocks inverted - 8Age of Earth and Solar System4550 million years
- 9Method used to date rocksRadiometric dating
- 10Depths of layers of the EarthCrust (0-35km)
Upper mantle (35-700km)
Lower Mantle (700-2900km)
Outer core (2900-5100km)
Inner core (5100-6400km) - 11State and composition of the layers lf the EarthUpper mantle - Solid silicates, peridotite
Lower mantle - Solid, silicate material
Outer core - Liquid, iron and nickel
Inner core - Solid due to extreme pressure, iron and nickel - 12Direct evidence for the structure of the EarthDeep mines (5km) - have direct access to higher levels of the crust
Boreholes (13km) - samples of rock and microfossils can be brought up
Volcanoes - magma that feeds volcanoes originates in crust/upper mantle so carries up samples
Kimberlite pipes
Oophiolite suites - sections of oceanic crust that break off during collisions - 13Indirect evidence of Earth StructureSeismic waves - p and s waves
- 14P wave shadow zone103° - 142°
Refracted by outer core at Gutenburg
Still travel through the core at a slower speed - 15S wave shadow zone103° - 103°
Refracted by outer core at Gutenberg
Stopped at the core as S waves can't pas through because liquid has 0 rigidity
S waves can still be generated in the core by P waves - 16Origin of Earth's magnetic fieldConvecting mass of molten iron in the outer core will generate electricity and induce magnetism
This is called the self exciting dynamo effect - 17PalaeomagnetismAncient magnetism preserved in rocks
- 18Magnetic reversalsFe rich magnetic minerals (magnetite) align with Earth's magnetic field and as they cool, retain this magnetism permanently
Act like 'frozen compasses' showing direction to the poles at the time of their formation - 19Magnetic inclinationANGLE OF DIP OF THE LINES OF A MAGNETIC FIELD
Following the lines of the Earth's magnetic field, a freely suspended compass needle lies vertical at the poles. At the equator lines horizontal. We can measure the inclination of a rock to find its latitude when it formed - 20Remanent magnetismMagnetism shown by rocks due to the alignement of their magnetic minerals according to the Earth's magnetic field at the time of their formation
- 21Polar wandering curvesSome believed that the poles were moving (wandering)
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- A Levels (Unit 1: Plate Tectonics) Geology (AS) Fichas sobre Earth Structure, creado por cherryl97 el 07/05/2015.
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- cherryl97
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