Earth Science Term 1 Exam Flashcards
Structure of the Earth:
Describe the Earth’s internal differentiation into layers
These processes took place during the early stages of earths formation about 4.5 billion years ago
This was formed by melting would have caused denser substance to sink towards the cent while less dense material would have migrated to the crust. Forming earth layers.
This was led to formation of a core, a curst and eventually continents
Evaluate how seismic waves and meteorites provide evidence for this structure
Seismic waves behave as they move through different materials enable us to know about the layers that make up earth.
Their paths are curved as the waves refract due to the gradually changing density of the layers.
Seismic waves tell us that the Earth’s interior consists of a series of concentric shells, with a thin outer crust, a mantle, a liquid outer core, and a solid inner core
Scientist can calculate the composition of rocks of the earth by studding the materials found in meteorite.
Energy and the Earth’s core
Earth has two energy sources:
Solar Energy: Reaching the earth from the sun
Solar energy: Reaches the earth in a form of radiant energy and is made up of 99.87% of energy received by the earth
Internal- Reaching the surface of the earth the earth itself
Earths inner core is the innermost layer of plant earth
Is a solid ball with a radius about 1,220 km
Earth’s core is usually made of Iron
Decay of radioisotopes
Radioactive decay is happening in all rocks.
It’s a part of earths natural system
Is caused by heat inside the earth
Driving forces such as tectonic system which leads to volcanoes, earthquakes and plate tectonics
The Rock Cycle
Igneous rocks are formed from melted rocks deep inside the earth
Example: Obsidian
Sedimentary rocks are formed from layers of sand. Silt, dead plants, and animal skeletons
Examples: Sandstone
Metamorphic rocks are formed from heat and pressure underground formed for other rocks
Example:
Marble
Effect of melting and crystallisation, weathering and erosion, heat and pressure and compaction and cementation
Effect on melting and crystallisation, weathering and erosion, heat and pressure and compaction and cementation are factors that influence the formation of rock types. Theres factors affect and change the rock types using the rock cycle.
Example: Weathering and erosion from Metamorphic rock will turn it into sediments which compaction and cementation turns it into sedimentary rocks.
Intrusive and extrusive igneous rocks
There are two main types of igneous rocks, and they are extrusive and intrusive
Extrusive rocks are formed on the surface of the Earth from Lava, then is when magma that has emerged from underground.
Intrusive Rocks are formed magma that cools and solidifies within the curst of the planet
So basically Extrusive is magma cooling on the surface of earth while Intrusive is inside of earths that cools and solidifies with the crust.
Mafic and felsic rocks and their mineral composition
Mafic: Enriched d in iron, magnesium, and calcium and typically dark in colour
Mafic has less silica giving it darker colour
Felsic: Typically light in colour, enriched in aluminium, sodium, silicon and potassium.
Felsic has a high amount of silica giving whiter colour
Three types of volcanoes
- Cinder Cone Volcanoes.
- Composite Volcanoes
- Shield Volcanoes.
Effect of silica on lava viscosity
Magma that have high silica content will emphasis greater degrees of polymerization and have higher viscosities than those with lows levels of silica content.
Three types of plate boundaries
- Divergent boundaries -where new crust is generated as the plates pull away from each other.
- Convergent boundaries -where crust is destroyed as one plate dives under another.
- Transform boundaries –where crust is neither produced nor destroyed as the plates slide horizontally past each other.
Magnetic anomalies
Earths Magnetic field results from variations in the chemistry or magnetism of the rocks. Mapping over an area is valuable in detecting structures.
A marine magnetic anomaly is a variation in strength of Earth’s magnetic field caused by magnetism in rocks of the ocean floor
Examine how the transformations of kinetic, gravitational and thermal energy create movement of tectonic plates
Heat energy stored and generated in Earths interior creates convection currents on a massive scale that results in the movement of sections of the Plates.
Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth’s crust.
Principles of stratigraphy
- Lateral continuity.
- Original horizontality.
- Faunal succession.
- Cross-cutting relations.
- Superposition.
Stratigraphy is the study of rock layers
Their sequence and their relationship with each other
Provides to interpret geologic events
Deduce age relationships
Stratigraphy can find geological age using the study of rock layers and their relationship with each other. The rock layers usually determine their geological age by their layers.
Index fossils
Index fossils are used to identify geological periods/time.
Index fossils are usually any animal or plant preserved in the rock record of the earth
The Geological Timescale
Basically the “calendar: for events in earths history
usually are major events that happened in earths history like eras
Subdivides all time into named units of time called – in descending order of duration-eons, ears, periods, epochs and ages.
describe the water cycle, including the terms
The water cycle shows the movement of water within the earth and atmosphere.
Is a complex system that includes different processes.
Liquid/water evaporates into wat vapor then forms clouds, then precipitates back to earth in the form of rain and snow
Of the many processes involved in the water cycle, the most important are evaporation, transpiration, condensation, precipitation, and runoff.
explain and investigate the relationship between thermal and light energy from the Sun and phase changes of water as it relates to the water cycle
Thermal and light energy from the sun plays a key factor in the water cycle
Sun provides almost everything on earth
Heat causes liquid and frozen water to evaporate into water vapor gas which forms clouds which rain and snow
Overall, The water cycle is dependent on the Sun because its make these factors process.
demonstrate on a flow chart to show the transfer, transformation and storage of energy in the water cycle
The water cycle is driven primarily by the energy from the sun. This solar energy drives the cycle by evaporating water from the oceans, lakes, rivers, and even the soil. Other water moves from plants to the atmosphere through the process of transpiration
explain the cycling of nitrogen between Earth systems
Nitrogen Cycle: This first stage
Bacteria in the soil form nitrates out of Nitrogen in the air
The second is through lightning: During electrical storms, large amounts of nitrogen or oxidized and united with water to produce rainfall and deposits Nitrates in the soil
explain the cycling of phosphorus between Earth systems
Phosphorus cycle: Moves through rocks, water, soil, sediments, and organisms. It starts with weathering of rocks cause to release phosphate ions and other minerals. This is distributed in soils and water. Then Absorb by plant or animals.
Steps of Phosphorus Cycle
• Weathering.
• Absorption by Plants.
• Absorption by Animals.
• Return to the Environment through Decomposition.
describe solar energy as electromagnetic radiation, including ultraviolet radiation
Solar radiation, often called sunlight
Is a term for Electromagnetic Radiation emitted by the sun
Solar radiation can be captured and turned into useful forms of energy, such as heat and electricity.
Ultraviolet Radiation- 4 percent of sunlight that reaches the ground is ultraviolet
Is a form of electromagnetic radiation with wavelength from 10 nm to 400 nm.
UV radiation is present in sunlight and is used for solar panels that produce renewable energy.
• analyse how the transfer of solar energy to the Earth’s surface is influenced by: impeded transfer of ultraviolet radiation due to its interaction with atmospheric ozone
The ozone extreme valuable since it absorbs most of the ultraviolet energy
When Ozone absorbs UV Radiation converted into heat
analyse how the transfer of solar energy to the Earth’s surface is influenced by: physical characteristics of the Earth’s surface
o Physical characteristics of the earths surface has a major impact on the transfer of solar energy. This is because of the geological factor of Oceans and polar ice caps.
o Water can uptake a lot of this energy while the polar ice caps reflect most of the energy back
Analyse how the transfer of solar energy to the Earth’s surface is influenced by: Albedo
Albedo is a quantity that indicates how well a surface reflects solar energy
Albedo varies between 0 and 1.
0 Meaning black
1 meaning white
Snow, ice, and clouds have high albedos (typically from 0.7 to 0.9) and reflect more energy than they absorb. Earth’s average albedo is about 0.3. In other words, about 30 percent of incoming solar radiation is reflected back into space and 70 percent is absorbed.
What are three atmospheric processes that modify incoming solar
Scattering- Small particles and gas molecules diffuse part of the incoming solar radiation in random directions without any alteration to the wavelength of the electromagnetic energy
Absorption: Solar radiation is retained by a substance and converted into heat energy. The creation of heat energy also cases the substance to emit its own radiation (Long Wave).
Reflection: Sunlight is redicrtly by 180 degrees after it strikes an atmospheric particle. This redirection causes a 100 percent loss in onsoloation.
explain how thermal radiation is absorbed and emitted from the Earth’s surface
Earth’s surface and atmosphere absorbs solar radiation and re-radiates it as a longwave radiation
This longwave radiation we feel it as heat
Energy radiated from earths surface as heat is absorbed and re-radiated by greenhouse gases.
Greenhouse gases in the atmosphere such as water vapor and carbon dioxide absorb most of the Earths emitted longwave infrared radiation.
In total approximately 70% of incoming radiation is absorbed by the atmosphere and the Earth’s surface
while around 30% is reflected back to space and does not heat the surface.
compare the major greenhouse gases and their sources, including carbon dioxide, methane and water vapour
Greenhouse Gas Major Sources
Carbon Dioxide: Fossil fuel combustion; Deforestation; Cement production
Methane: landfills, oil and natural gas systems, agricultural activities, coal mining, stationary
Water Vapour: Evaporation of water and ice melting cause water vapour
Nitrous Oxide Fertilizer application; Fossil fuel and biomass combustion; Industrial processes
explain how greenhouse gases can reflect or scatter some infrared radiation, leading to the greenhouse effect
Greenhouse gases absorb infrared radiation and emit back towards earth’s surface
Water vapor, carbon dioxide, methane, and other trace gases in Earth’s atmosphere absorb the longer wavelengths of outgoing infrared radiation from Earth’s surface.
A substance than will turn into heat energy
The greenhouse effect is a process that occurs when energy from a planet’s sun goes through its atmosphere and warms the planet’s surface, but the atmosphere prevents the heat from returning directly to space, resulting in a warmer planet.
Green house Affect
What is a greenhouse effect
Occurs when energy from the sun goes through earths atmosphere and the warms the earths surface, but the atmosphere prevents the heat from returning directly to space resulting in a warming plant
A natural porcess that warm the surface of the earth
• Solar radiations
• Warms surface materials
Re radiated to atmosphere and space as Infared
• Some absorbed by greenhouse gases
• Re emitted- further warming atmosphere and land.
Energy coming in and not be Abling to come back out
Overall keeps earth surface warm
- relatively stable over short geological periods
- Feedback mechanisms over longer periods can change gas ratios and hence energy flux
- Artificial changes to the ratios will also change the flux
