Geology Video: Natural Disasters & Plate Tectonics – Key Terms (Vocabulary Flashcards)

A comprehensive set of vocabulary flashcards covering key terms from the geology lecture notes on natural disasters, the scientific method, rock types, Earth’s layers, plate tectonics, and related processes.

Geology

The scientific study of the Earth—its structure, materials, processes, and history, including natural hazards such as earthquakes and volcanoes.

Natural event

A natural occurrence that happens without human influence (e.g., an earthquake in an unpopulated area).

Natural disaster

A natural event that causes significant harm to humans, property, or the environment.

Observation

The act of noticing and recording phenomena as the first step of the scientific method.

Question

A query that arises from observations and leads to testing a hypothesis.

Hypothesis

A testable, educated guess about a relationship or outcome.

Experiment

A controlled test or procedure to test a hypothesis and collect data.

Data collection

Systematic gathering of information from observations and experiments.

Analysis

Interpreting collected data to draw conclusions about a hypothesis.

Conclusion

A final judgment based on the analysis of data.

Repeat/Revise

Repeating experiments or revising methods based on results.

Theory

A well-tested explanation for a broad set of phenomena (e.g., Plate Tectonics).

Law

A description of a consistently observed phenomenon (e.g., Newton’s Laws).

Mineral

Naturally occurring, inorganic solid with a specific chemical formula and crystal structure.

Rock

A solid mass made of one or more minerals.

Igneous

Rocks formed from cooled magma or lava (e.g., basalt, granite).

Sedimentary

Rocks formed from compacted sediments (e.g., sandstone).

Metamorphic

Rocks changed by heat and pressure (e.g., marble).

Rock Cycle

The process by which rocks change type: igneous → sedimentary → metamorphic (and back).

Hydrologic system

Water movement on Earth, including rivers, glaciers, and rainfall.

Tectonic system

Plate movement, earthquakes, and volcanoes shaping the Earth’s surface.

Sun

Energy source driving the hydrologic cycle and climate systems.

Radioactive decay

Decay of unstable nuclei that releases energy, driving tectonic activity.

Gravity

A force that drives tides, landslides, and other geologic processes.

Extraterrestrial impacts

Rare high-energy events from space (e.g., meteorites) that affect Earth.

Latitude

Distance north or south of the equator; horizontal coordinate.

Longitude

Distance east or west of the prime meridian; vertical coordinate.

Continental crust

Thicker, less dense crust composed largely of granitic rocks.

Oceanic crust

Thinner, more dense crust primarily basaltic.

Mantle

The layer between the crust and core; divided into upper and lower portions.

Core

Earth’s center; outer core is liquid, inner core is solid.

Lithosphere

Rigid outer layer comprising the crust and the upper mantle.

Asthenosphere

Plastic-like layer beneath the lithosphere that accommodates motion.

Mesosphere

Part of the mantle beneath the asthenosphere.

Outer Core

Liquid iron-nickel layer surrounding the inner core.

Inner Core

Solid sphere at Earth's center.

Mountains

Elevated landforms most common on continental crust.

Deep ocean trenches

Very deep underwater troughs associated with subduction zones.

Mid-ocean ridges

Underwater mountain ranges where new ocean crust forms at divergent boundaries.

Volcanic island chains

Islands formed by volcanic activity, often above subduction zones or hotspots.

Continental Drift

Idea that continents move across the Earth’s surface. Proposed by Wegener.

Wegener

Alfred Wegener, proponent of Continental Drift. He theorized that continents were once connected and gradually drifted apart over geological time.

Pangaea

Ancient supercontinent that existed roughly 200 million years ago. It included almost all of the Earth's landmasses, eventually breaking apart into the continents we know today.

Divergent boundary

Plates move apart, creating new crust (e.g., at mid-ocean ridges).

Convergent boundary

Plates move toward each other; can form mountains or subduction zones.

Transform boundary

Plates slide past one another horizontally, causing earthquakes (e.g., San Andreas Fault).

Subduction zone

One plate sinks beneath another into the mantle, forming trenches and arcs. Subduction zones are areas where an oceanic plate is forced beneath a continental plate or another oceanic plate, resulting in geological features such as deep ocean trenches and volcanic arcs.

Ring of Fire

Area around the Pacific Ocean with many subduction zones, earthquakes, and volcanoes.

Continental collision

Two continental plates collide, creating large mountain ranges (e.g., Himalayas).

Mantle plumes

Columns of hot rock rising through the mantle; can cause hotspots independent of plate boundaries. They are believed to form at the core-mantle boundary and can lead to volcanic activity, such as the Hawaiian Islands.

Hot Spots

Fixed heat locations in the mantle where volcanism forms island chains as plates move.

Magnetic stripes

Symmetric patterns on either side of mid-ocean ridges indicating past seafloor spreading. These stripes show the magnetic orientation of rocks as they cool and solidify, recording reversals in Earth's magnetic field.

Seafloor spreading

Process by which new oceanic crust forms at divergent boundaries and moves away from ridges. This process involves the upwelling of magma that creates new ocean floor as tectonic plates shift apart, leading to the formation of mid-ocean ridges and the renewal of oceanic crust.

Radiometric dating

Technique to date rocks by measuring radioactive decay.

East Africa

An example of continental rifting showing how land stretches and may form a new ocean. It is characterized by the East African Rift System, where tectonic forces are pulling the African continent apart, leading to the creation of rift valleys.

Basin and Range

Region in the western United States exemplifying continental extension and rift valleys. It is characterized by a series of long, narrow mountain ranges separated by down-dropped basins. This geological formation is a result of tectonic forces causing the Earth's crust to stretch and thin.

San Andreas Fault

A famous transform boundary in California where plates slide past.

Mid-Atlantic Ridge

A major divergent boundary in the Atlantic Ocean where new crust forms. It is characterized by seafloor spreading, where tectonic plates move apart, allowing magma to rise and create new oceanic crust.

Paleoclimate

Ancient climate conditions inferred from geological evidence. This includes data from ice cores, sediment layers, and fossil records, which help reconstruct past climates and understand Earth's climate history.