Earth Science

epicentre

the point on Earth's surface directly above the focus of an earthquake

erosion

the gradual wearing away and removal of rock at the surface of Earth 

igneous rock

a type of rock formed by the cooling and solidification of magma or lava 

lava

molten rock above Earth's surface

lithification

the process in which sediments come together to form sedimentary rock

lithosphere

a layer of earth consisting of the crust and the lithospheric mantle

magma

molten rock located below Earth's surface

metamorphic rock

a type of rock formed by heat and pressure

mineral

a naturally-occurring, inorganic solid substance

protolith

The original rock that has undergone metamorphism.

rock cycle

an idealised series of processes undergone by rocks in Earth's crust that change rocks from one type to another

sedimentary rock

type of rock formed by the accumulation and lithification of sediment

subduction

a geological process at convergent boundaries where one tectonic plate sinks beneath another plate

tsunami

a large ocean wave (or series of waves) caused by the displacement of large amounts of water, typically due to an earthquake or large landslide

weathering

the gradual breakdown of rock while it remains in the same place; weathering can be caused by many things, including heating, cooling, wind, rain, chemical reactions, plant roots and human activity

describe the geosphere

earth’s metallic core, solid rock, molten rock, sediments

describe the hydrosphere

water in all its forms: ice, water vapour, liquid water in the atmosphere, oceans, lakes, rivers, streams, soils, groundwater

describe the atmosphere

mixture of gases surrounding the planet

describe the biosphere

living things

recall the 4 steps in the carbon cycle

1. photosynthesis

2. consumption and assimilation

3. respiration and decomposition

4. combustion

describe the process of photosynthesis

carbon is removed from air and enters food chains via photosynthesis in producers

describe the process of consumption and assimilation

carbon is transferred between organisms in organic matter (food) via feeding and assimilation into biomass

describe the process of respiration and decomposition

carbon leaves organisms and is added to the air as a result of cellular respiration (excreted as CO₂) and also during decomposition (CO₂ and CH₄)

describe the process of combustion

burning wood and fossil fuels adds carbon to the air (CO₂, CO and CH₄)

recall the 4 steps of the nitrogen cycle

1. ammonification

2. nitrogen fixation

3. nitrification

4. denitrification

describe ammonification

the production of ammonia (NH₃) from proteins in dead organisms and urea in urine

describe nitrogen fixation

conversion of nitrogen gas (N₂) into nitrogen compounds eg. ammonia (NH₃) and nitrate (NO₃^-)

describe nitrification

conversion of ammonia (NH₃) into nitrites (NO₂^-) and then into nitrates (NO₃^-)

describe denitrification

conversion of soil nitrates into nitrogen gas

recall the bacteria involved in the nitrogen cycle

1. decomposer bacteria

2. nitrogen fixing bacteria

3. nitrifying bacteria

4. denitrifying bacteria

describe decomposer bacteria

breaks down dead material and waste

describe nitrogen fixing bacteria

converts atmospheric nitrogen into ammonia or nitrates, located in soil or root nodules, eg of mutualism

describe nitrifying bacteria

converts ammonia (NH₃) and nitrites (NO₂^-) into nitrates (NO₃^-)

describe denitrifying bacteria

converts nitrates (NO₃^-) and nitrites (NO₂^-) back into atmospheric nitrogen (N₂)

recall the layers of the earth in order of increasing depth

1. crust

2. mantle

3. outer core

4. inner core

describe the inner core

solid mixture of iron and nickel, depth: 5972km, temp: 5968 degrees celsius, pressure: 563 GPa

describe the outer core

liquid mixture of iron and nickel, flow generates earth’s magnetic field, depth: 3243km, temp: 4056 degrees celsius, pressure: 166 GPa

describe the mantle

thickest of 4 layers, made of solid + partially melted rocks, mostly silicon and oxygen, depth: 1184km, temp: 1706 degrees celsius, pressure: 57GPa

describe the general crust

layer of solid rock (5km-70km thick)- thickest under continents

describe the oceanic crust

not as thick, main rock type is basalt, young rocks, higher density

describe continental crust

thicker, mostly made of granite, old rocks, lower density

recall the three types of rock

igneous, sedimentary and metamorphic 

recall the types of weathering

mechanical and chemical