Earth and the Universe Flashcards
What are the 4 layers of the earth called
Crust, mantle, inner core and outer core
Summary of mantle
85% of Earth’s mass is mantle. It is 1800 miles long, the largest layer.
Summary of crust
The crust is less than 1% of Earth’s volume, 8km- 40km thick, and its crust is 3x thicker than sea crust
Describe the layer mantle
The first 50 miles are hard rigid rock, the next 150 are hot solid rock and the next several hundred miles are very solid, sturdy rock. The mantle is a viscous solid made from magma
How does the mantle flow and what is the scientific name
The scientific name for mantle flow is mantle convection. The mantle is a viscous solid, meaning it is solid but can slowly flow over a length of time because the cooler mantle will sink while the hotter (less dense) mantle will rise, causing a slow convection. There is also more pressure on the lower part of the mantle so it flows even more slowly
Summary of the outer core
The outer core is liquid, made of iron and nickel and around 4000- 5000 degrees
Summary of inner core
The inner core is solid, made of iron and nickel and around 5000-7000 degrees
Why hasn’t the inner core melted the iron
The great pressure keeps it solid, even past it’s melting point
What gases make up the Earth’s atmosphere
78% nitrogen, 21% oxygen, 0.04% carbon dioxide and less than 1% noble gases
What is the most abundant noble gas
Argon
How many stars are in the solar system
1, the sun
How many planets in the solar system and what are they called
- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune
What objects in the universe give out their own light
Stars
What is a light year
A light year is a measure of distance. It is how long light travels in one year. It is around 9.46 trillion km
What is the nearest star to earth after the sun
Proxima Centauri
What are seasons causes by
The tilt of the Earth’s axis paired with the orbit of the sun
What do the earths crust and upper mantle form
Tectonic plates
What metamorphic rock is made from limestone (a sedimentary rock)
Marble
What is the toughest rock
Diamond then granite
What type of rock is toughest
Metamorphic
How are extrusive igneous rocks formed
The cooling of lava on Earth’s surface
How are intrusive igneous rocks formed
The cooling of magma in the Earth’s crust
How can you tell if an igneous rock is extrusive or intrusive
Extrusive rocks have small crystals ( may virtually appear to have none) because it cooled quickly on the Earth’s surface and had less time to form crystals. Intrusive rocks have large crystals because it cooled slowly in the crust.
How are sedimentary rocks formed
- Weathering and erosion breaks down the rock and the sediment is transported
- Deposition settles the sediment at the bottom of the ocean
- Compaction and cementation causes the build up of sediment and the weight of the upper layers compresses the lower layers (compaction). The minerals in the water can act like cement, binding the particles together
4.Lithification is the process of loose sediment turning into solid rock
How are metamorphic rocks formed
Movements above the crust can cause rocks to be squashed together. As a result, the rock are under great heat and pressure and the minerals are changed chemically, forming metamorphic rock
Examples of sedimentary rock
Sandstone, limestone, chalk and shale
Examples of igneous rock
Granite (intrusive), basalt (extrusive) and obsidian (extrusive)
Examples of metamorphic rock
Marble, slate and gneiss
How do fossils form (fossilisation)
- Animal dies in water and flesh is eaten by marine life
- Over time, rock and silt particles pile up above the bone, due to deposition, and a layer forms, putting the bone under great pressure
3.The bone decays and leaves an imprint of its shape (natural mould) - Mineralisation- Minerals in the water fill the natural mould
- Earthquakes/ erosion surface the fossil
What is the study of fossils
Palentology
Why is the fossil record incomplete
Not all animals died in the water (no rocks can fall on top) and not all fossils surface
What layer of the atmosphere is closest to the Earth
Troposphere
Why don’t you get fossils in metamorphic/ igenous rock
The severe heat and pressure would crush or burn the fossil. However, you may find traces in metamorphic rock because the sedimentary rock before it metamorphosed may have had a fossil but majority would be crushed or burnt
Why is it rare to find soft bodied organisms as fossils
They have no bones and will crush before mineralisation
What kind of fossil is a set of footprints and what does it tell us
It is called a trace fossil and it tells us behaviours of past life
What is a valley
A river between mountains
What are the 4 planets closest to the sun called and what are they made of
Inner/ terrestrial planets and they are made made from rocks, sand, ice etc
What are the furthest 4 planets from the sun called and what are they made of
Outer planets/ gas giants and they are made from gas
Why is Pluto a dwarf planet
It doesn’t follow the same orbiting pattern: it doesnt have enough gravity to pull other bits of rock into their orbit
Mercury summary
Temperature: 170 degrees
Year of discovery: 1885
Rotation time: 58.7 earth days
Orbit time: 88 earth days
Gravity compared to Earth: 0.38
Moons: 0
Jupiter summary
Temperature: -150 degrees
Year of discovery: 1610
Rotation time: 9.84 hours
Orbit time: 4332 earth days
Gravity compared to Earth: 2.3
Moons: 63
Venus summary
Temperature: 482 degrees
Year of discovery: unknown
Rotation time: 243 earth days
Orbit time: 224.7 earth days
Gravity compared to Earth: 0.9
Moons: 0
Earth summary
Temperature: 15 degrees
Year of discovery: N/ A
Rotation time: 1 earth days
Orbit time: 365.25 earth days
Gravity compared to Earth: 1
Moons: 1
Mars summary
Temperature: -53 degrees
Year of discovery: 1580
Rotation time: 24.6 hours
Orbit time: 687 earth days
Gravity compared to Earth: 0.38
Moons: 2
Jupiter summary
Temperature: -150 degrees
Year of discovery: 1610
Rotation time: 9.84 hours
Orbit time: 4332 earth days
Gravity compared to Earth: 0.38
Moons: 63
Saturn summary
Temperature: -180 degrees
Year of discovery: 700BC
Rotation time: 10.2 hours
Orbit time: 10760 earth days
Gravity compared to Earth: 1.16
Moons: 60
Why was Saturn discovered so early
You can see it from Earth
Uranus summary
Temperature: -214 degrees
Year of discovery: 1781
Rotation time: 17.9 hours
Orbit time: 30700 earth days
Gravity compared to Earth: 1.17
Moons: 27
Neptune summary
Temperature: -220 degrees
Year of discovery: 1846
Rotation time: 19.1 hours
Orbit time: 60200 earth days
Gravity compared to Earth: 1.77
Moons: 13
Pluto summary
Temperature: -230 degrees
Year of discovery: 1930
Rotation time: 6.39 earth days
Orbit time: 90600 earth days
Gravity compared to Earth: 0.06
Moons: 3
What are moons also called
Natural satellites
Name 8 space crafts
Apollo, Magellan, Phoenix, Galileo, Messenger, Cassini, Voyager 1&2 and the New Horizons
Where did Magellan go and how long did it take to get there in Earth days
Venus in 15 months
Where did Apollo go and how long did it take to get there in Earth days
Moon in 3 days
Where did Phoenix go and how long did it take to get there in Earth days
Mars in 11 months
Where did Galileo go and how long did it take to get there in Earth days
Jupiter in 6 years
Where did Messenger go and how long did it take to get there in Earth days
Mercury in 6.5 years
Where did Cassini go and how long did it take to get there in Earth days
Saturn in 7 years
Where did Voyager 1&2 go and how long did it take to get there in Earth days
Jupiter, Saturn, Uranus and Neptune
What is the difference between magma and lava
Magma is molten rock beneath the Earth’s surface but lava is molten rock above the Earth’s surface
Give an example of intrusive rock
Granite or Slate
Give an example of extrusive rock
Basalt
What is the hottest planet
Venus
What is the coldest planet
Uranus
Describe the sun
4.5 billion years old, closest star and 99% mass in solar system
What is an asteroid
Bits of rock that orbit the sun in the asteroid belt (between Mars and Jupiter)
What is a comet
An object of ice and dust and produce a tail when passing the sun
What are artificial satellites and what do they do
Artificial satellites are objects or machines purposefully went into orbit. Their uses are navigation, weather forecasting and even carry humans
What are space probes and what do they do
Space probes go to explore the solar system
What is a solar eclipse
The moon blocks the suns rays from reaching earth
Why are solar eclipses rare
The moon, sun and earth all have to be lined up. The moon’s orbit is tilted 5 degrees to Earth’s orbit so the moon often passes above or below the Earth.
What is the umbra
The umbra is where the light source (sun) is completely covered by an object (moon). When there is a solar eclipse, the umbra is on the earth
What is the penumbra
The area where part of the sun is blocked by the moon, causing a partial eclipse
What is a solar eclipse
Occurs when moon passes between sun and earth, casting a shadow over parts of earth and blocking the sun for observers in those locations
What is a lunar eclipse
Happens when earth comes in between the sun and moon, causing earth to blocks the sun’s light reaching the moon and earth casting a shadow on the moon.
Name a tribe belief for solar eclipses
Pomo Nation believed the sun was bit by a bear, causing darkness
How does day and night happen
Day is when the part of earth you are on is pointing towards the sun according to the Earth’s rotation cycle. Night is when your half of the earth is turned away from the sun
Why does the Earth cool down at night
It is no longer being heated by the sun because it is facing away from the sun
What is the lunar cycle
- New moon
- Waxing crescent moon
- First quarter
- Waxing Gibbous moon
- Full moon
- Waning Gibbous moon
- Last quarter
- Waning crescent
How can rocks be recycled
Sedimentary rocks can change to metamorphic due to heat and pressure from movements of the earth. The metamorphic rocks can be weathered/ eroded and transported. They could then settle at the bottom of a lake or sea, eventually forming a sedimentary rock again.
How does a red moon form
During a lunar eclipse, sunlight scatters across Earth’s atmosphere and shorter wavelengths (blue and violet) are scattered in all directions. However, longer wavelengths (red and orange) are less scattered because of their lower energy and refract towards the moon, giving it a red appearance.
What is the summer solstice
When one of the Earth’s poles has its maximum tilt toward the Sun.
What is the winter solstice
When one of the Earth’s poles has its maximum tilt away from the Sun.
What is the season for the southern hemisphere if it is summer in the northern hemisphere
Winter
What is the closest galaxy other than the Milky Way
Andromeda
What is the difference between weathering, erosion and transport
Weathering is the in situ breakdown of rocks while erosion is the breakdown of rock and removal from the rocks original location. Transport is the movement of rock from one location to another.
What would happen if you sprayed a light bulb with cold water and why
The hot glass will rapidly cool but glass contracts when cool and expands when hot. The sudden change causes thermal shock so the glass will crack or shatter
Give an example of chemical weathering
Acid rain, such as sulfuric and nitric acid, in the rain react with minerals in rocks and break them down. In addition, when carbon dioxide dissolves rainwater, it forms carbonic acid so all rain is slightly acidic.
What is physical weathering
When physical processes affect the rock such as temperature, wind, rain and waves
What is an example of physical weathering
When there is a crease (porous/ permeable) in a rock, water fills up the gap and freezes, resulting in a 9% expansion. The rock breaks apart due to water going deeper in the crack. This is called freeze thaw weathering. In addition, onion skin weathering is caused by thermal shock, the outer layer expands in the sun but contracts when it’s cool which creates stress and the outer layers peel away
What is biological weathering
Occurs when plants or animals break down rock
Give an example of biological weathering
Trees growing in cracks of rocks and forcing it apart
What is chemical weathering
When the chemical composition of a rock change
What is the asthenosphere
It’s found just below the lithosphere and convection occurs here so it allows tectonic plates to move
What is a ridge
Where two plates move apart, and magma rises to form new crust (this is called seafloor spreading).
How does a trench form
Trenches form at destructive plate boundaries, where two plates are moving towards each other. When an oceanic and continental tectonic plate meet, the denser oceanic plate sinks under the thicker continental plate. This is called subduction. The result is a trench
Which plate is thicker continental or oceanic
Oceanic is thinner but denser because it is mainly basalt (heavy). Continental is thicker but less dense because it is mainly granite (lighter)
What is a ridge
Where plates move apart (divergent boundary) and magma rises to form new crust, usually oceanic
What is slab pull
As the plate sinks into the mantle at the trench, it pulls the rest of the plate with it. This is one of the main forces moving plates.
What is Wegener’s Puzzle
South America and Africa looked like they used to fit together but driftet apart
What is the continental drift theory
The continents fit together and have the same fossils, suggesting they used to be connected.
What happens during an earthquake
The point inside the Earth where the quake starts is called the focus. The point directly above it on the surface is the epicenter. The energy travels as seismic waves, shaking the ground. Plate movement is the direction where the plates are moving
How is sulphuric acid rain formed
Coal burning factories produce sulphur oxides and they react with rain to form acid rain which damages trees, buildings and crops
Why did CO2 levels in the atmosphere drop before humans
Plants started doing photosynthesis, which absorbed CO₂ from the atmosphere. Carbon dioxide also dissolved in the oceans, where it formed carbonates. Some carbon became locked up in fossil fuels and sedimentary rocks.
Why did oxygen levels rise before humans
Photosynthesis by early algae and plants released oxygen into the atmosphere. As more plants evolved, oxygen levels kept rising.
How does climate change occur
The Greenhouse effect: Sun ought that hits the earth is reflected if becomes heat but greenhouse gases trap heat and warm up the earth
What are the 4 greenhouse gases
Water vapour (H20), Nitrous oxide (N20), Methane (CH4) and Carbon dioxide (CO2) with carbon dioxide being the most plentiful one
How can we control the amount of CO2
Iron seeding- This is when iron is added to parts of the ocean to help tiny plants called phytoplankton grow. Phytoplankton use carbon dioxide for photosynthesis so less CO2 is in the air
Carbon capture- Using machines to trap CO₂ from power stations and factories before it goes into the air. The CO₂ is then transported and stored deep underground in rocks, helping reduce the amount in the atmosphere.
Name 4 environmental issues
- Running out of fossil fuels (finite resources)
- Air pollution causes climate change
- We are destroying habitats-> mass extinction
- Pumping millions of gases into atmosphere, including CO2
Benefits of recycling
- Reduces our dependence on fossil fuels
- Reduces our impact on environment
- Stops tonnes of waste needing up in landfill sites
- Takes less energy to recycle products that it does to produce new ones
