Plate Tectonics, Earthquakes, and Volcanoes Review

Vocabulary flashcards covering plate tectonics, boundary classifications, earthquake measurement scales, and volcanic structures based on the test review guide.

Convection Currents

Heat-driven circular movements in the Earth's mantle that enable the movement of tectonic plates over the Earth's thin crust.

Convergence / Destructive Plate Boundary

A plate boundary where two tectonic plates move toward each other, leading to subduction or crustal compression and associated natural disasters.

Divergence / Constructive Plate Boundary

A plate boundary where tectonic plates move apart from one another, allowing new crust to form as magma rises.

Transform / Conservative Plate Boundary

A plate boundary where tectonic plates slide horizontally past one another without creating or destroying crust.

Subduction Zone

A geological region where one tectonic plate is forced downward beneath another plate into the Earth's mantle.

Recycling of Plates

The tectonic process where older oceanic lithosphere is driven into the mantle at subduction zones while new oceanic crust forms at divergent boundaries, making oceanic plates younger than continental plates.

Hot Spot Theory

The geological theory that explains intense volcanic activity situated away from plate boundaries, fueled by unusually hot plumes in the mantle.

Focus

The exact underground point of origin where an earthquake's seismic energy is released.

Epicentre

The point on the Earth's surface directly vertically above the subterranean focus of an earthquake.

Magnitude (Richter Scale)

A measure of the total amount of energy released by an earthquake, historically quantified using the Richter Scale.

Intensity (Mercalli Scale)

A measure of the observable effects and degree of ground shaking caused by an earthquake at a specific location, assessed using the Mercalli Scale.

Magma Chamber

A large pool or reservoir of molten rock located beneath the Earth's crust beneath a volcano.

Vent

A pipe-like opening or fissure through which magma, ash, and volcanic gases escape to the Earth's surface during an eruption.

Cone

The conical landform built up around a volcanic vent through the accumulation of ejected volcanic material.

Secondary Cone

A smaller parasitic cone that forms on the flank or side slope of a larger main volcano from secondary vents.

Shield Volcano

A broad volcano with gently sloping sides formed by low-viscosity, fast-flowing lava flows.

Cinder Volcano

A steep-sided, small volcanic cone constructed primarily from loose, fragmented pyroclastic debris and cinders accumulated around a single vent.

Dome Volcano

A rounded, steep-sided mound formed when thick, highly viscous lava erupts slowly and piles up near the volcanic vent.

Composite Volcano

A tall, symmetrical, steep-sided volcano built from alternating layers of hardened lava flows, volcanic ash, cinders, and blocks.

Tsunami

A series of powerful, high-energy ocean waves typically triggered by undersea earthquakes, volcanic eruptions, or submarine landslides.

Convergence

A destructive plate boundary.

Divergence

A constructive plate boundary.

Transform

A conservative plate boundary.

Convection currents in the mantle

Currents that, combined with the thin nature of the crust, make it possible for tectonic plates to move.

Movement of the continents

The motion of landmasses across the earth's surface over the past $200\text{ million years}$.

Evidence for continental drift and plate tectonics

Demonstrated by at least $3$ to $4$ scientific discoveries proving that continental movement actually occurs.

Plate boundaries

Geological regions where most earthquakes and volcanoes occur.

Recycling of plates

The tectonic process that accounts for why oceanic plates are newer than continental plates.

Oceanic plates

Plates that are newer than continental plates as a result of plate recycling.

Magnitude

An earthquake term associated with measurement via the Richter Scale.

Richter Scale

The scale linked with measuring earthquake magnitude.

Intensity

An earthquake term associated with measurement via the Mercalli Scale.

Mercalli Scale

The scale linked with measuring earthquake intensity.

Four types of Volcanoes

Shield, Cinder, Dome, and Composite.

Products of volcanic eruptions

The types of material that can be ejected from volcanic vents.

Vent

The volcanic opening from which products of volcanic eruptions can be ejected.