Geology and Plate Tectonics Lecture Review

Flashcards covering key vocabulary terms related to Earth's structure, geology, plate tectonics, earthquakes, volcanoes, rock cycle, soil erosion, and solar intensity, based on lecture notes.

Geology

The science that deals with the Earth's physical structure and substance, its history, and the processes that act on it.

Crust

The outermost solid layer of the Earth's structure.

Oceanic Crust

Basalt-rich, approximately 7 miles thick, forming ocean basins, and is more dense than continental crust.

Continental Crust

Granite-rich, 20-30 miles thick, stratified, denser with depth, and composed of rocks.

Mantle

Composed of iron, magnesium, aluminum, and silicon-oxygen compounds, where convection currents circulate magma.

Lithosphere

Composed of Earth’s crust plus the solid upper mantle.

Asthenosphere

The viscous upper mantle, consisting of semi-molten rock (semi-solid).

Convection Currents

Circulations of magma (molten rock) found within the mantle.

Core

The innermost part of the Earth, composed of nickel and iron.

Inner Core

The solid, innermost part of the Earth's core, mostly iron.

Outer Core

The liquid part of the Earth's core.

Plate Tectonics

The theory that Earth’s lithosphere is divided into plates which are in constant motion, creating mountain ranges and canyons.

Continental Drift Theory

Alfred Wegener's theory that the world’s continents had once been joined in a single land mass called Pangaea.

Pangaea

A supercontinent that Alfred Wegener proposed all of the Earth's continents were once joined as.

Transform Plate Boundaries

Areas where plates slide past each other, building friction and stress on faults, which is released as earthquakes.

Earthquakes

Events caused by the release of stress buildup from plates sliding past each other along transform plate boundaries, or by convergent plate boundaries in the ocean.

Richter Scale

A logarithmic scale used to measure the strength or magnitude of an earthquake.

Seismograph

An instrument that records earthquake strength, creating a seismogram.

Epicenter

The point on the ground directly above the focus of an earthquake.

Focus

The underground point where an earthquake originates.

Ring of Fire

A major area in the Pacific Ocean where more than 80% of all earthquakes and volcanoes occur.

Tsunami

A series of waves created when a body of water is rapidly displaced, usually by an earthquake in the ocean that displaces a large amount of water.

Divergent Plate Boundaries

Areas where two plates slide apart from each other, making new crust.

Seafloor Spreading

A process occurring at divergent boundaries in which rising magma forms new oceanic crust on the seafloor.

Convergent Boundaries

Areas where two plates slide toward each other.

Subduction Zone

An area where a denser plate goes beneath another plate into the mantle, triggering the release of magma as volcanoes erupt.

Island Arc Formation

The creation of island chains through the convergence of oceanic crust and an oceanic crust, leading to subduction zones (e.g., Japan, Philippines).

Igneous Rock

Rocks classified by their silica content, formed from the solidification of molten rock.

Intrusive Igneous Rock

Igneous rock that solidifies under Earth’s surface (e.g., granite).

Extrusive Igneous Rock

Igneous rock that solidifies above Earth’s surface (e.g., volcanic rock, basalt, obsidian).

Metamorphic Rock

Rocks with high quartz content, often formed from sandy soil (e.g., diamond, marble, asbestos, slate, anthracite coal).

Sedimentary Rock

Rocks formed by the piling and cementing of various materials, where fossils can form.

Volcano

A mountain or hill that has a crater or vent from which lava, rocks, hot vapor, and gas erupt from the Earth’s crust.

Hotspot Volcanism

Rare volcanoes that form outside of plate boundaries where super hot magma weakens the crust.

Island Chain

A series of islands formed in the middle of a tectonic plate due to hotspot volcanism (e.g., Hawaii).

Soil Erosion

The movement of soil by water, wind, and/or human activity, leading to decreased water holding capacity and soil profile destruction.

Splash Erosion

A type of water erosion characterized by raindrop marks.

Sheet Erosion

A type of water erosion where thin layers of soil are forced off uniformly as a sheet by water runoff.

Rill Erosion

A type of water erosion where water runoff makes small, thin channels.

Gully Erosion

A type of water erosion characterized by large, wide channels carved by running water.

Landslides/Mudslides

Masses of rock, earth, or debris moving down a slope due to disturbances in the natural stability of the slope.

Solar Intensity

The amount of solar radiation in an area, dependent on factors like seasons and latitude.

Seasons

Periodic divisions of the year caused by the tilt of Earth’s axis, not its distance from the sun.

Latitude

Geographic coordinates that specify the East-West position of a point on the Earth's surface.

Longitude

Geographic coordinates that specify the North-South position of a point on the Earth's surface.

Insolation

The amount of solar radiation received in an area.

Albedo

A measure of how much solar energy a surface reflects.

High Albedo

Surfaces that reflect much more solar radiation (e.g., polar regions, white surfaces).

Low Albedo

Surfaces that absorb much more solar radiation (e.g., darker, forest regions, black surfaces).