Encyclopedic Entries

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

Speciation is how a new kind of plant or animal species is created. Speciation occurs when a group within a species separates from other members of its species and develops its own unique characteristics.

Best For
Grades 4-12+ (Ages 9+)

Subjects
Geography, Science

Appropriate For
T I F S 

A swamp is an area of land permanently saturated, or filled, with water

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

The tropics are regions of the Earth that lie roughly in the middle of the globe

Best For
Grades 5-12+ (Ages 10+)

Subjects
Vocational Education, Geography, Science

Appropriate For
T I F S 

The water table is a line beneath the surface of the Earth

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

A waterfall is a steep descent of a river or other body of water over a rocky ledge.

Best For
Grades 4-12+ (Ages 9+)

Subjects
Science, Geography, Informal Education

Appropriate For
T I F S 

A wetsuit is a special suit worn by people who want to spend a lot of time in the water

Best For
Grades 4-12+ (Ages 9+)

Subjects
Geography, Science

Appropriate For
T I F S K

"Woodland" is often just another name for a forest

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S 

A xenolith is a piece of rock trapped in another type of rock

Best For
Grades 5-12+ (Ages 10+)

Subjects
Arts, Geography, Social Studies, Science

Appropriate For
T I F S 

A yurt is a moveable, circular dwelling made of a lattice of flexible wood and covered in felt

Best For
Grades 4-12+ (Ages 9+)

Subjects
Geography, Science

Appropriate For
T I F S 

A rain shadow is a patch of land that has been forced to become a desert because mountain ranges blocked all plant-growing, rainy weather

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S 

A rift valley forms where the Earth’s crust, or outermost layer, is spreading or splitting apart

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S 

A season is a period of the year that is distinguished by special climate conditions

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Social Studies, Science

Appropriate For
T I F S 

A village is a small settlement usually found in a rural setting.

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S 

Scientists divide the Earth’s land into what are called vegetation regions

Best For
Grades 3-12+ (Ages 8+)

Subjects
Geography, Social Studies, Science

Appropriate For
T I F S K

A zone is an area separated from other areas in some artificial or natural manner.

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

Zealandia is a long, narrow microcontinent that is mostly submerged in the South Pacific Ocean

Best For
Grades 5-12+ (Ages 10+)

Subjects
Cross-Disciplinary, Geography, Science

Appropriate For
T I F S 

“Yankee” is a word almost everyone has heard, but most of us don't know quite what it means.

Best For
Grades 6-12+ (Ages 11+)

Subjects
Science, Geography, Health, Informal Education

Appropriate For
T I F S 

Xeriscaping is the practice of designing landscapes to reduce or eliminate the need for irrigation

Best For
Grades 6-12+ (Ages 11+)

Subjects
Science, Geography, Informal Education

Appropriate For
T I F S 

A wilderness is an area of land that has been largely undisturbed by modern human development

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

One of the first things you probably do every morning is look out the window to see what the weather is like

Best For
Grades 5-12+ (Ages 10+)

Subjects
Science, Geography, Informal Education

Appropriate For
T I F S 

UNESCO is the United Nations Educational, Scientific and Cultural Organization

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

Trees grow all over the world, in many different types of weather

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S 

A storm surge is a rise in sea level that occurs during tropical cyclones, intense storms also known as typhoons or hurricanes

Best For
Grades 4-12+ (Ages 9+)

Subjects
Science, Geography, Health, Informal Education

Appropriate For
T I F S 

Smog is air pollution that reduces visibility

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S K

A sinkhole is a hole in the ground that forms when water dissolves surface rock

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S K

A reservoir is an artificial lake where water is stored

Best For
Grades 3-12+ (Ages 8+)

Subjects
Geography, Science

Appropriate For
T I F S K

Rapids are areas of shallow, fast-flowing water in a stream

Best For
Grades 5-12+ (Ages 10+)

Subjects
Geography, Science

Appropriate For
T I F S 

Runoff occurs when there is more water than land can absorb

Best For
Grades 6-12+ (Ages 11+)

Subjects
Geography, Science

Appropriate For
T I F S 

Weathering is the breaking down or dissolving of rocks and minerals on Earth’s surface. Water, ice, acids, salt, plants, animals, and changes in temperature are all agents of weathering.

Best For
Grades 4-12+ (Ages 9+)

Subjects
Geography, Science

Appropriate For
T I F S K

Upwelling is a process in which currents bring deep, cold water to the surface of the ocean. Upwelling is a result of winds and the rotation of the Earth.