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 5-12+ (Ages 10+)

Subjects
Science

Appropriate For
T I F S K

Temperature is the degree of hotness or coldness of an object

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.