AEPA Earth Science AZ045 flashcards
AEPA Earth Science AZ045 · 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.
- Controlled experiment
- An investigation that changes one factor at a time while holding other conditions constant so that observed effects can be attributed to the manipulated variable.
- Independent variable
- The factor deliberately manipulated or selected by the investigator in an experiment; its values are set independently of the responding variable being measured.
- Scientific theory
- A well-tested explanation for a broad set of observations, supported by multiple lines of evidence and capable of generating predictions; it is not a guess.
- Correlation and causation
- A correlation means two variables change together, while causation means one produces the other; correlation alone cannot establish a cause-and-effect relationship.
- Peer review
- Evaluation of a study by independent experts who check methods, evidence, and conclusions before publication, helping identify errors and improve scientific quality.
- Accuracy and precision
- Accuracy is closeness to the true value; precision is closeness of repeated measurements to one another. A measurement can be precise but inaccurate.
- Rock cycle
- The set of processes that transform Earth materials among igneous, sedimentary, and metamorphic rocks through melting, cooling, weathering, erosion, deposition, compaction, and metamorphism.
- Mohs hardness scale
- A relative scale from one to ten ranking mineral scratch resistance, with talc at one and diamond at ten; harder minerals scratch softer ones.
- Divergent plate boundary
- A boundary where two lithospheric plates move apart, creating new crust as magma rises; examples include mid-ocean ridges and continental rift zones.
- Subduction zone
- A convergent boundary where one lithospheric plate descends beneath another, producing trenches, earthquakes, volcanic arcs, and magma from released water.
- S waves
- Shear seismic waves that move particles perpendicular to wave travel and cannot pass through liquids, revealing that Earth's outer core is liquid.
- Earth's outer core
- The liquid iron-rich layer between the solid inner core and the mantle; its convection generates Earth's magnetic field through the geodynamo.
- Isostasy
- The gravitational balance of lithospheric plates floating on the denser mantle, so thicker or less dense crust stands higher and adjusts as loads change.
- Principle of superposition
- In undisturbed sedimentary sequences, older layers lie below younger layers; this principle allows relative ages to be inferred from vertical order.
- Index fossil
- A fossil of an organism that lived over a short geologic interval but was geographically widespread, making it useful for correlating rock layers and assigning relative ages.
- Radiometric half-life
- The time required for half of a radioactive parent isotope in a sample to decay into daughter products; repeated half-lives allow absolute ages to be calculated.
- Unconformity
- A surface in rock record representing missing time, formed by erosion or nondeposition; it separates rock units of distinctly different ages.
- Cross-cutting relationships
- A geologic principle stating that a fault, intrusion, or other feature cutting across rock layers is younger than the layers it cuts.
- Geologic time scale
- A chronological framework dividing Earth history into eons, eras, periods, and epochs, based on stratigraphy, fossils, and radiometric ages.
- Mass extinction
- A geologically rapid event in which a large proportion of species disappears worldwide, often linked to volcanic activity, asteroid impact, or climate change.
- Coriolis effect
- The apparent deflection of moving air or water caused by Earth's rotation, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
- Thermohaline circulation
- Deep-ocean circulation driven by differences in seawater temperature and salinity, which control density; it transports heat and nutrients around the globe.
- Upwelling
- The rise of cold, nutrient-rich deep water toward the ocean surface, often caused by winds and Coriolis-driven offshore flow; it supports productive ecosystems.
- Greenhouse effect
- Warming of a planet's surface when atmospheric gases absorb and re-emit infrared radiation, reducing heat loss to space; it is essential to Earth's climate.
- Dew point
- The temperature to which air must cool at constant pressure for water vapor to reach saturation and begin condensing into liquid water.
- Albedo
- The fraction of incoming solar radiation reflected by a surface; high-albedo surfaces such as ice and snow reflect more sunlight than dark surfaces.
- Earth's axial tilt
- Earth's rotation axis is tilted about 23.5 degrees relative to its orbital plane, causing seasonal changes in solar angle and daylight as Earth orbits the Sun.
- Moon phases
- The changing appearance of the Moon from Earth as different portions of its sunlit half face us during its roughly monthly orbit around Earth.
- Spring tide
- A tide with the largest daily range, occurring near new and full moon when the Sun, Moon, and Earth align and their gravitational effects combine.
- Kepler's third law
- The square of a planet's orbital period is proportional to the cube of its semi-major axis, relating orbital size to orbital period.
- Light-year
- The distance light travels in one year in vacuum, about 9.46 trillion kilometers; it is a unit of distance, not time.
- Main sequence star
- A star in the long stable stage of hydrogen fusion in its core, plotting along a diagonal band on the Hertzsprung-Russell diagram.