Geology Video flashcards: Plate Tectonics, Dating, Hazards, and Coastal Processes

Vocabulary flashcards covering key terms and definitions from the video notes on continental drift, plate tectonics, dating, hazards, and coastal processes.

Continental Drift Hypothesis

A theory proposed by Alfred Wegener that continents move due to plate motions, and this movement continues today.

Alfred Wegener

Scientist who proposed the Continental Drift Hypothesis.

Continental Fit

The idea that the shapes of Earth's continents appear to fit together like puzzle pieces.

Fossil Evidence

Similar fossils found on continents now separated by oceans, supporting past connections.

Similar Rocks and Mountain Belts

Comparable rock types and mountain ranges across continents indicating a former connected landmass.

Glacial Evidence

Signs of past glaciation in now-distant regions, suggesting a once-united continent.

Plate Tectonics Theory

Theory that the lithosphere is made of rigid plates that move relative to each other.

Lithosphere

The rigid outer layer of the Earth, comprising the crust and upper mantle.

Plate

A large, rigid piece of the lithosphere that moves as part of the plate tectonics system.

Plate Boundaries

Zones where tectonic plates interact and move relative to each other.

Divergent Boundaries

Boundaries where two plates move apart, often with magma rising to create new crust.

Convergent Boundaries

Boundaries where two plates collide or move toward each other.

Oceanic-Continental Convergence

An oceanic plate sinks beneath a continental plate due to higher density.

Oceanic-Oceanic Convergence

Two oceanic plates collide; the denser one sinks beneath the other.

Continental-Continental Convergence

Two continental plates collide, often forming mountains.

Transform Plate Boundaries

Places where plates slide horizontally past one another.

Confining Stress

Stress that acts uniformly in all directions, usually when rocks are buried.

Directed Stress

Stress that acts in a single direction, linked to tectonic activity.

Tension

Pulling or stretching stress that lengthens rocks.

Compression

Squeezing or pushing stress that shortens and thickens rocks.

Shear

Stress causing rocks to slide past one another in opposite directions.

Elastic Deformation

Deformation that is reversible; rock returns to original shape when stress is removed.

Ductile Deformation

Rocks deform plastically and reshape without breaking.

Brittle Deformation

Rocks fracture and break under stress.

Folds

Wave-like bends in rocks formed during mountain building.

Faults

Displacements where rocks slide past each other along fractures.

Stratification

Formation of sedimentary rock layers.

Stratigraphy

Science of studying rock layers and layering.

Law of Original Horizontality

Sediments are deposited horizontally under normal conditions.

Law of Lateral Continuity

Sedimentary layers extend laterally until they thicken the depositional basin or thin out.

Law of Superposition

In an undisturbed sequence, older rocks sit below younger rocks.

Cross-Cutting Relationship

Geologic features that cut across others are younger than the rocks they cut.

Relative Dating

Dating rocks and events in sequence without assigning a numerical age.

Absolute Dating

Determining the exact numerical age of rocks or fossils using isotopes.

Half-Life

Time required for half the radioactive nuclei in a sample to decay.

Geologic Time Scale

A timeline dividing Earth's history into Eons, Eras, Periods, and Epochs.

Eons

Largest divisions of geologic time composed of multiple eras.

Eras

Subdivisions of geologic time within an eon.

Periods

Subdivisions of eras in the geologic time scale.

Epochs

Shortest divisions of geologic time within a period.

Hypocenter / Focus

Actual location within the Earth where an earthquake originates.

Epicenter

Point on the Earth's surface directly above the earthquake focus.

Ground Shaking

Vibration of the ground produced by an earthquake.

Liquefaction

Soils lose strength and behave as a liquid during shaking.

Surface Faulting

Displacement of the ground surface along faults due to earthquakes.

Basal Flow

Dense mixture of gas, ash, and volcanic rocks that flows along the ground.

Turbulent Ash Cloud

Clouds of ash that rise and move with volcanic eruptions.

Lahar

Volcanic mudflow formed when volcanic material mixes with water.

Rockfall

Sudden fall of loose or fractured rock from cliffs or slopes.

Earthflow

Flow of saturated earth downslope due to water content.

Mudflow

Flow of water and volcanic materials down slopes.

Tsunami

Massive sea wave generated by underwater earthquakes, landslides, or eruptions.

Tropical Cyclone

General term for a rotating storm system formed over warm tropical seas.

Hurricane

Tropical cyclone used for storms in the North Atlantic and northeast Pacific.

Typhoon

Tropical cyclone used for storms in the northwest Pacific.

Cyclone

Tropical cyclone term used in the South Pacific and Indian Ocean.

PAGASA Classifications (TD/TS/STS/TY/STY)

Regional categories for typhoon intensity: Tropical Depression, Tropical Storm, Severe Tropical Storm, Typhoon, Super Typhoon, with escalating wind speeds.

Thunderstorm

Tall, buoyant cloud system producing lightning, thunder, rain, and gusty winds.

Tornado

Rotating column of wind that extends from a thunderstorm to the ground.

Flood

Excessive water accumulation that overwhelms the land and waterways.

Coastal Zone

Region where land meets the sea and interacts with both processes.

Waves

Undulations on the water surface caused by wind energy transfer.

Destructive Waves

High-energy waves with strong backwash that erode shorelines.

Constructive Waves

Waves with strong swash that build up beaches.

Tides

Regular rise and fall of sea level driven by Moon and Sun gravity.

Storm Surges

Abnormally high coastal water levels produced by storms.

Erosion

Process of wearing away rocks and soils by wind, water, or ice.

Coastal Erosion

Erosion processes affecting coastlines and shorelines.

Accretion

Gradual accumulation of sediment and land along the coast.

Submersion

Sediment or land being submerged under water and later exposed.

Abrasion

Erosion of rocks by waves or wind-driven particles.

Attrition

Particles breaking down as they collide and grind together.

Corrosion

Chemical dissolution of rocks by acidic seawater.

Bioerosion

Erosion caused by living organisms like mollusks or urchins.

Seawalls

Structures built parallel to shore to protect against wave action.

Groins

Structures built at right angles to trap sediments and manage longshore drift.

Jetties

Perpendicular structures built to maintain inlets and navigation channels.

Sandbags

Barrier bags filled with sand used for protection during storms.

Offshore Breakwaters

Structures parallel to shore to absorb wave energy and create calm water.

Beach Nourishment

Adding sand to beaches to rebuild eroded shores (expensive).

Dunes

Wind-formed sand deposits that shield inland areas from erosion.

Revegetation

Planting vegetation to stabilize slopes and reduce erosion.