Albedo: The amount of sunlight reflected by a surface.

Aquifer: An underground layer that stores groundwater.

Atmosphere: The layer of gases surrounding the Earth.

Asthenosphere: A soft layer of the upper mantle that allows plate movement. 

Barometer: Instrument that measures air pressure.

Basalt: Dark volcanic rock formed from lava.

Bedrock: Solid rock beneath soil.

Biosphere: All living organisms on Earth.

Climate: The long-term weather pattern of a place.

Conduction: Transfer of heat through direct contact.

Convection: Heat transfer by movement of fluids or gases.

Convection current: Heat-driven movement in fluids or mantle material.

Convergent Boundary: Area where tectonic plates move toward each other.

Crust: The outermost layer of the Earth. 

Delta: Land formed where a river deposits sediment into water.

Deposition: The process where sediments are dropped.

Divergent Boundary: Where tectonic plates move apart. 

Earthquake: Shaking of the ground caused by tectonic movement.

Epicenter: Point on Earth’s surface above an earthquake’s focus.

Erosion: The wearing away of rocks by wind, water, or ice.

Evaporation: Liquid water changing into vapor. 

Fault: A crack in Earth’s crust where movement occurs.

Fossil: Preserved remains of ancient organisms.

Focus: Underground point where an earthquake begins.

Fossil fuel: Energy source formed from ancient plants and animals. 

Geosphere: Solid part of Earth.

Glacier: Large moving mass of ice.

Greenhouse effect: Trapping of heat by gases.

Groundwater: Water stored underground.

Hot spot: Area of volcanic activity away from plate edges.

Hurricane: Powerful tropical storm.

Humidity: Amount of water vapor in air.

Hydrosphere: All water on Earth.

Ice cap: Large ice-covered land area.

Igneous rock: Rock formed from magma or lava.

Infiltration: Water soaking into soil.

Insolation: Incoming solar radiation.

Jet stream: Fast-moving air current.

Joint: Crack in rock with no movement.

Jurassic: Geologic period of dinosaurs.

Karst: Landscape formed from dissolved limestone.

Kinetic energy: Energy of motion.

Kimberlite: Rock that may contain diamonds.

Landslide: Rapid movement of rock or soil downhill.

Latitude: Distance north or south of the equator.

Lava: Magma on Earth’s surface.

Lithosphere: Earth’s crust and upper mantle.

Magma: Molten rock beneath Earth’s surface.

Mantle: Layer beneath the crust.

Meteorology: Study of weather.

Monsoon: Seasonal wind bringing heavy rain.

Natural resources: Materials from Earth used by humans.

Neutralization: Reaction between acid and base.

Nucleus: Central part of an atom.

Nutrient cycle: Movement of nutrients through environment.

Ocean current: Movement of ocean water.

Outcrop: Exposed rock at Earth’s surface.

Oxidation: Reaction with oxygen.

Ozone layer: Protects Earth from UV radiation.

Plate tectonics: Movement of Earth’s plates.

Precipitation: Rain, snow, sleet, or hail.

Pressure: Force applied over an area.

Quake: Sudden shaking of Earth.

Quaternary: Most recent geologic period.

Quartz: Common mineral made of silica.

Quality of soil: Ability of soil to support plants.

Radiation: Energy traveling as waves.

Rift valley: Valley formed by plates pulling apart.

Rock cycle: Process of forming and changing rocks.

Runoff: Water flowing over land.

Sedimentary rock: Rock formed from sediments.

Seismograph: Instrument measuring earthquakes.

Soil: Top layer of Earth supporting plants.

Subduction: One plate sinking beneath another.

Tectonic plates: Large moving pieces of Earth’s crust.

Topography: Shape of Earth’s surface.

Troposphere: Lowest layer of atmosphere.

Tsunami: Large ocean wave caused by earthquakes.

Uniformitarianism: Present processes shaped Earth’s past.

Upwelling: Rising of deep ocean water.

Uplift: Rising of Earth’s crust.

Valley: Low land between hills or mountains.

Vent: Opening releasing volcanic material.

Viscosity: Thickness of a liquid.

Volcano: Opening where magma reaches surface.

Water cycle: Movement of water on Earth.

Watershed: Land draining into a river.

Weathering: Breaking down of rocks.

Wind erosion: Movement of soil by wind.

Xenolith: Rock fragment inside magma.

Xerophyte: Plant adapted to dry conditions.

X-ray diffraction: Method to study minerals.

Year: Time Earth takes to orbit the Sun.

Yield: Amount of crops soil can produce.

Young mountains: Recently-formed mountains.

Zone of saturation: Area where soil is fully soaked.

Zooplankton: Tiny drifting ocean animals.

Ziggurat: Ancient structure used in flood studies.