a phenomenon which causes the orientation of the axis of rotation of a spinning astronomical object to vary over time. It is caused by the gravitational forces of other nearby bodies acting upon the spinning object.

two or more objects orbiting each other also have a center of mass. It is the point around which the objects orbit.

When an object turns around an internal axis (like the Earth turns around its axis). The Earth does this every 24 hours.

When an object circles an external axis (like the Earth circles the sun). This occurs every 365 ¼ days.

union of atomic nuclei to form heavier nuclei resulting in the release of enormous amounts of energy. This process powers the sun.

A process that releases heat energy by the splitting apart of atoms.

the entire range of wavelengths or frequencies of electromagnetic radiation extending from gamma rays to the longest radio waves and including visible light

the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.

hot fluid or semifluid material below or within the earth's crust from which lava and other igneous rock is formed on cooling.

Magma that reaches the surface of our planet through a volcano vent.

When a physical force breaks down rocks. Examples include ice wedging, plants and animals, abrasion, and thermal stress

When rocks are broken down by chemical reactions.

The transfer of heat through the movement of a fluid, such as water or air.

The transfer of heat from a warmer object to a cooler object through direct contact

The transfer of heat through electromagnetic rays.

Gravitational force that causes a plate to move away from the crest of an ocean ridge, and into a subduction zone

As a crustal plate moves further from an oceanic ridge, it cools and becomes increasingly dense. This causes it to sink beneath the continental crust in a subduction zone, causing a major pulling action, which causes the rest of the plate to be pulled downward.

The earth’s crust and the rigid layer of the mantle that is connected to the crust. Broken into large tectonic plates.

Plastic-like layer of the mantle that tectonic plates move on top of.

The boundary between plates moving toward each other.

The boundary between plates that are moving apart. Can form ridges and rift valleys.

The boundary between plates sliding past each other

a destructive mudflow on the slopes of a volcano.

This is the fastest kind of seismic wave, and, the first to 'arrive' at a seismic station. Can move through solid rock and fluids

The second wave you feel in an earthquake. Slower and can only move through solid rock

The point on the earth’s surface that’s closest to the focus of an earthquake (where the earthquake begins)

a type of island made up of long stretches of sand that are parallel to the mainland. Act as a habitat and a form of protection.

a fault on which the two blocks slide past one another. The San Andreas Fault is an example.

A geologic fault in which the hanging wall has moved upward relative to the footwall

a dip-slip fault in which the block above the fault has moved downward relative to the block below.

The removal of weathered materials. The main forces include water, ice, gravity, and wind.

The process of water or wind depositing or dropping sediment.

a situation in which there are too many cows or other animals eating grass in an area, which damages the environment:

the process by which large numbers of people become permanently concentrated in relatively small areas, forming cities.

the process by which tubing is bored through the Earth's surface and a well is established. A pump is connected to the tube and the petroleum under the surface is forcibly removed from underground

a measurement that compares the amount of matter an object has to its volume

the portion of land drained by a river and its tributaries. It encompasses all of the land surface dissected and drained by many streams and creeks that flow downhill into one another

a body of permeable rock that can contain or transmit groundwater.

a gradual settling or sudden sinking of the Earth’s surface.

Freshwater that is safe to drink.

the phenomenon of sediment or gravel accumulating

Pollution coming from indistinguishable sources. Results from land runoff, precipitation, and drainage

any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack

The atmospheric layer closest to Earth that we live in, which contains most of the weather.

The amount of humidity in the air compared to how humidity is usually reported.

The air temperature at which dew forms on surfaces. This depends on the amount of water vapor in the air and the air pressure.

When water droplets in clouds get large and heavy and fall from the atmosphere back to earth- as rain, snow, hail, and sleet.

When a liquid changes to water vapor through heating. The sun’s rays heat water in oceans and on the ground, transforming it into water vapor that rises into the atmosphere.

the process by which precipitation or water soaks into subsurface soils and moves into rocks through cracks and pore spaces

rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm

Chloroflourocarbons, which are used in refrigerators and aerosol spray bottles. These chemicals damage the ozone layer.

the state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain, etc.

The average weather conditions of an area over a long period of time, in terms of temperature and precipitation.

When the seawater in the Pacific Ocean cools downs or warms up more than usual. This is when it warms up more than usual.

darker, cooler areas on the surface of the sun in a region called the photosphere.

A certain gas that traps heat in the atmosphere. Examples are carbon dioxide and sulfur dioxide.

The warming of the atmosphere by gases that trap heat. This is necessary for Earth to be livable, but it can warm the earth too much.

the clearing or thinning of forests by humans.

a metropolitan area that's a lot warmer than the rural areas surrounding it. Heat is created by energy from all the people, cars, buses, and trains in big cities

This includes every part of Earth where organisms can survive. All of the ecosystems on Earth combined.

The diversity (number and variety of species) of plant and animal life within a region.

Nonliving parts of an ecosystem. Like air and sunlight.

Living and once-living parts of an ecosystem, like plants and animals.

an organism that causes ecological or economic harm in a new environment where it is not native (originally from).

Harvesting a renewable resource to the point of diminishing returns. When a population is harvested at an unsustainable rate.

The largest number of organisms an ecosystem can support. This is determined by limiting factors.

Any environmental factor that is of importance in restricting/limiting the size of a population

These rocks are formed by cooling magma. As magma cools, atoms crystallize and form mineral grains. They can be intrusive or extrusive.

Through intense heat and pressure, these rocks can be transformed into this rock type.

Rocks that are formed when sediment is compacted and cemented together. Usually formed layer by layer.

The magnitude of an earthquake is measured using this. The scale is based on the magnitude of seismic waves.

A place where tons of boiling magma pushes towards the surface in one spot of Earth’s crust.

Water in the cracks of rocks freezes and expands, forcing the crack to widen. This process repeats and rocks are pushed farther apart.

A thin layer of gas surrounding the planet, which allows life to exist on Earth.

A layer of O3 molecules which are located in the lower stratosphere. This layer protects us from sun’s ultraviolet rays.

the formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid-ocean ridges and its subsequent outward movement on either side.

a resource that can be used repeatedly and replaced naturally. Very hard or impossible for it to run out.

a natural substance that is not replenished with the speed at which it is consumed. Supply is limited because it is used quicker than it is replaced.