WACE ATAR Earth & Environmental Science flashcards
WACE ATAR Earth & Environmental Science · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Lithosphere
- The rigid outer shell of Earth comprising the crust and uppermost mantle. It is broken into tectonic plates that move over the weaker asthenosphere beneath.
- Isostasy
- The state of gravitational balance where the lithosphere floats on the denser mantle. Thicker or less dense crust stands higher, producing mountains and continental roots.
- Mineral
- A naturally occurring, inorganic, crystalline solid with a definite chemical composition or limited range. Examples include quartz, feldspar, calcite and halite.
- Mohs hardness scale
- A relative scale from 1 (talc) to 10 (diamond) ranking mineral resistance to scratching. A mineral scratches those softer than itself and is scratched by harder ones.
- Bowen's reaction series
- The sequence in which silicate minerals crystallise from cooling magma. High-temperature minerals such as olivine form first; quartz and muscovite form last.
- Igneous rock
- Rock formed by crystallisation of magma or lava. Slow cooling underground gives coarse-grained intrusive rock; rapid cooling at the surface gives fine-grained extrusive rock.
- Foliation
- Parallel alignment of platy minerals such as mica in metamorphic rock, produced by directed pressure. It creates the layered appearance of slate, schist and gneiss.
- Clastic sedimentary rock
- Rock made of fragments of pre-existing rock, classified by grain size. Examples range from conglomerate and sandstone to siltstone and shale.
- Seafloor spreading
- The process where new oceanic crust forms at mid-ocean ridges as magma rises and spreads laterally. Symmetrical magnetic stripes record this motion.
- Subduction zone
- A convergent boundary where denser oceanic lithosphere descends into the mantle. It produces trenches, deep earthquakes, volcanic arcs and mountain belts.
- Hotspot
- A fixed mantle plume that melts the overriding plate, producing volcanoes. Plate motion over the plume creates age-progressive chains such as Hawaii.
- Normal fault
- A fault where the hanging wall moves down relative to the footwall, caused by tensional stress. It typically occurs at divergent boundaries and in rift valleys.
- Unconformity
- A surface representing a gap in the geological record, where erosion removed rock before new sediment was deposited. Angular and nonconformity types exist.
- Radiometric dating
- A method of dating rocks using the decay rate of radioactive isotopes into daughter products. It requires a closed system and known half-life.
- Environmental lapse rate
- The rate at which air temperature decreases with height in the troposphere, averaging about 6.5 degrees Celsius per kilometre. It varies with humidity and weather.
- Coriolis effect
- The apparent deflection of moving air or water caused by Earth's rotation. It deflects motion right in the Northern Hemisphere and left in the Southern Hemisphere.
- Greenhouse effect
- The warming of Earth's surface as atmospheric gases absorb and re-emit outgoing infrared radiation. It is enhanced by rising carbon dioxide and methane.
- Thermohaline circulation
- A slow global ocean circulation driven by differences in temperature and salinity, which control density. It transports heat and nutrients between ocean basins.
- Aquifer
- A permeable rock or sediment unit that stores and transmits groundwater in usable quantities. It must have both porosity and connectivity between pores.
- Water table
- The upper boundary of the saturated zone in unconfined groundwater, below which all pores are filled with water. It rises and falls with recharge.
- Eutrophication
- Nutrient enrichment of water, often by nitrogen and phosphorus, causing algal blooms and oxygen depletion. It can create dead zones and fish kills.
- Cation exchange capacity
- The capacity of soil to hold positively charged nutrient ions on clay and organic matter surfaces. Higher values indicate greater nutrient retention.
- Nitrogen fixation
- The conversion of atmospheric nitrogen gas into ammonia by bacteria, lightning or industrial processes. It is the key entry point of nitrogen into ecosystems.
- Soil profile
- A vertical section through soil showing horizons O, A, B, C and R. Horizons reflect organic input, leaching, accumulation and weathering.
- Sustainability
- Meeting present needs without compromising the ability of future generations to meet theirs. It balances environmental, economic and social objectives.
- Ecological footprint
- A measure of the productive land and water area needed to supply resources and absorb wastes for a population. It is compared with available biocapacity.
- Environmental impact assessment
- A structured process predicting the environmental effects of a proposed project before approval. It identifies mitigation measures and allows public review.
- Moment magnitude scale
- A logarithmic measure of earthquake size based on energy released. Each whole number increase represents about 32 times more energy.
- Stratovolcano
- A steep-sided volcano built from alternating lava flows and ash layers. It forms from viscous felsic magma and produces explosive eruptions.
- Cold front
- The leading edge of advancing cold air that pushes under warmer air. It typically brings rapid cloud development and short, heavy rainfall.
- Ice-albedo feedback
- A positive feedback where melting ice exposes darker land or ocean, increasing heat absorption and causing further warming and further melting.
- Darcy's law
- A formula describing groundwater flow: discharge equals hydraulic conductivity times cross-sectional area times hydraulic gradient. It predicts flow through porous media.