Plate Tectonics, Mountain Building, and Earth's Changing Surface

Comprehensive vocabulary flashcards covering plate tectonics, Earth's internal layers, plate boundary interactions, mountain dynamics, weathering, erosion, deposition, and geological dating methods based on student notes and investigations.

Elevation

The height of a geographical feature or landmass measured above sea level.

Magnitude

A measurement scale describing the size and energy strength of an earthquake.

GPS (Global Positioning System)

A satellite-based tracking tool that utilizes receivers to detect subtle tectonic and mountain movements as small as a millimeter.

Fault

A large crack or fracture in the Earth's crust along which blocks of land push, pull, or slide past one another.

Earthquake

Ground shaking caused by a rapid release of accumulated pressure and seismic energy when tectonic sections push, collide, or slide past each other.

Crust

The thin, outermost rocky layer of the Earth, spanning between $5\text{--}70\,\text{km}$ in thickness, representing $1\%$ of Earth's volume at an average temperature of approximately $16\,^\circ\text{C}$, composed predominantly of igneous rocks containing oxygen, silicon, aluminum, and iron.

Lithosphere

The rigid, solid outer shell of the Earth composed of the entire crust and the brittle uppermost portion of the mantle.

Asthenosphere

A ductile, solid yet bendable layer of the upper mantle situated directly beneath the lithosphere.

Mantle

The thick layer beneath the crust measuring approximately $2900\,\text{km}$ thick and comprising $84\%$ of Earth's volume, composed primarily of hot magma rich in magnesium, silicon, and iron at temperatures near $4,000\,^\circ\text{C}$.

Outer Core

A molten liquid metallic layer approximately $2200\,\text{km}$ thick composed of nickel and iron at temperatures around $5,000\,^\circ\text{C}$, surrounding the inner core.

Inner Core

A dense, solid ball of metal at Earth's center measuring roughly $1250\,\text{km}$ in radius with temperatures reaching approximately $6,000\,^\circ\text{C}$.

Convection Currents

A continuous thermal cycle in the mantle where warm rock rises and cooler rock descends, generating the lateral dragging motion that moves overlying tectonic plates.

Convergent Boundary

A tectonic plate boundary where two plates collide or push toward each other, causing subduction or crustal buckling that generates mountain ranges such as the Himalayas.

Subduction

The geological process occurring at convergent boundaries where a denser oceanic plate slides beneath a continental plate into the mantle.

Divergent Boundary

A tectonic plate boundary where plates pull apart from each other, allowing magma from the interior to ascend, fill the gap, and produce new crust via sea floor spreading.

Transform Boundary

A tectonic plate boundary where two plates slide horizontally past one another, building friction and stress that release as earthquakes.

Mid-Ocean Ridge

A major underwater divergent plate boundary running through the Atlantic and Indian Oceans where magma constantly ascends to create new ocean floor.

San Andreas Fault

A prominent transform boundary in California where the Pacific Plate and North American Plate slide past each other, projected to move Los Angeles north of San Francisco in $16\,\text{million years}$.

Pangea

The most recent supercontinent, existing approximately $200\text{--}335\,\text{million years ago}$, that assembled all continental plates into one continuous landmass.

Theory of Continental Drift

The hypothesis proposed by Alfred Wegener in the early 1900s stating that all continents were formerly united in a single landmass before breaking apart and traveling across the globe.

Contraction Theory

An early geological idea proposing that the Earth was initially an incandescent globe of hot gas that shrank and crumpled as it progressively cooled.

Mechanical (Physical) Weathering

The physical breakdown of rocks into smaller fragments and sediment without altering their underlying chemical composition, driven by processes like freezing, thawing, pressure release, or plant growth.

Chemical Weathering

The decomposition of rock caused by chemical reactions with substances such as water or oxygen, changing the rock's minerals, color, and chemical makeup.

Erosion

The removal and transportation of weathered rock particles, sediments, and soil from one place to another by forces such as wind, moving water, glaciers, or gravity.

Deposition

The geological process by which eroded rock materials and sediments are dropped, laid down, and accumulated in a new location to build new landforms.

Law of Superposition

A relative dating principle stating that in undeformed horizontal sedimentary rock strata, the oldest layer is at the bottom and layers become progressively younger toward the top.

Index Fossil

A fossil of an organism that lived during a short, well-defined geological timeframe, making it exceptionally useful for determining the relative age of rock layers.

Relative Dating

The technique of establishing the sequential chronological order of historical events and rock strata without specifying exact numerical ages in years.

Absolute Dating

A method that determines the specific calendar age in years of a rock or fossil by measuring the radioactive decay rates of unstable isotopes.

Radiocarbon Dating

A radiometric dating method used by scientists to establish the absolute age of carbon-bearing materials up to $50,000\,\text{years}$ old.

Geological Time Scale

A standard calendar system dividing Earth's entire $4.6\text{-billion-year}$ history into distinct chronological intervals based on significant geological and biological milestones.

Rock Strata

Stacked, horizontal layers of sedimentary rock that preserve fossil evidence, environmental conditions, and sediment types from specific historical periods.

Mount Everest

A mountain located between Nepal and China standing at $29,032\,\text{ft}$ ($8851.2\,\text{m}$) that grows $2\,\text{cm}$ taller each year and shifts northeast by $4\,\text{cm}$ annually due to active convergent plate collision.

Mount Mitchell

An ancient mountain in North Carolina's Appalachians ($6684\,\text{ft}$ / $2038\,\text{m}$) formed $280\,\text{million years ago}$ that is shrinking at a net rate of $-4\,\text{mm}/1,000\,\text{years}$ because its erosion rate ($5\,\text{mm}/1,000\,\text{years}$) outpaces its uplift rate ($1\,\text{mm}/1,000\,\text{years}$).

Mount Hotaka

A peak in the Hida Mountains of Northern Japan ($3192.07\,\text{m}$ / $10,470\,\text{ft}$) with active volcanic surroundings that grows $4\,\text{mm}$ annually and moves southwest by $1\,\text{cm}$ yearly.

Mount Aoraki

A mountain in New Zealand's Southern Alps ($3725\,\text{m}$ / $12,218\,\text{ft}$) that experiences regular earthquakes and increases in elevation by $2\,\text{cm}$ per year.

Mount Aconcagua

A peak on the western coast of South America standing at $6962.8\,\text{m}$ ($22,838\,\text{ft}$) that contains ancient marine fossils, drifts north by $3\,\text{cm}$ each year, and increases in height by $10\,\text{mm}$ every 10 years.

Mount Narodnaya

An ancient Ural mountain formed $340\text{--}300\,\text{million years ago}$ situated between the Arctic Circle and Kazakhstan ($1894\,\text{m}$ / $6214\,\text{ft}$) that drifts east at $2.5\,\text{cm}$ per year with virtually no earthquake activity and no height growth.