Earth's Landforms: Mountains, Plains, and Islands: Second Grade Social Studies
A landform is a natural physical feature on Earth's surface, such as a towering mountain, a flat plain, a deep valley, or a sea-swept island.
Exploring Earth's Varied Surface
Our planet is not flat and uniform. If you took a road trip across the country, you would see steep jagged peaks rising into the clouds, wide flat grasslands stretching as far as the eye can see, deep rocky canyons carved by rivers, and sandy islands surrounded by sparkling ocean waves. These diverse shapes of dry land are called landforms.
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| COMMON LANDFORMS ON EARTH |
| |
| ^^^ |
| / \ [ MOUNTAIN ] |
| / \ [ PLATEAU ] |
| / \____ +-------------+ |
| \ [VALLEY]| | |
| \_________/ \___ [ PLAINS ] |
| ~~~~~~~~~~~ |
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Major Landforms Explained
Each landform is formed over thousands or millions of years by natural forces like volcanic eruptions, tectonic plate movements, water flow, and wind erosion.
Mountains: Earth's Giants
A mountain is a very tall landform that rises steeply above the surrounding land, usually ending in a sharp peak or summit. Mountains are much higher and steeper than hills. When several mountains stand in a long row, they form a mountain range, such as the Rocky Mountains in North America or the Alps in Europe. Mountain tops are often snowy and cold because temperature drops as elevation rises.
Hills: Gentle Slopes
A hill is a raised area of land that is smaller, lower, and less steep than a mountain. Hills typically have rounded tops and are easier to climb. Many towns and farms are built on rolling hills.
Plains: Wide Open Spaces
A plain is a large area of flat or gently rolling land with very few trees. Because plains have level ground and deep, fertile soil, they are ideal for farming wheat, corn, and soybeans, as well as grazing cattle. The Great Plains in central North America stretch for hundreds of miles.
Valleys: Sheltered Lowlands
A valley is a low area of land situated between hills or mountains. Valleys are often shaped like a letter V or U, carved over thousands of years by flowing rivers or moving glaciers. Because water flows downhill into valleys, they are fertile, green, and popular locations for towns and settlements.
Plateaus: High Flat Tables
A plateau is a large, flat elevated area of land that rises sharply above the surrounding land on at least one side. It looks like a giant flat table made of rock. The Colorado Plateau in the American Southwest features spectacular red rock formations and canyons.
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| LANDFORM | DEFINING CHARACTERISTIC |
+---------------------+---------------------------------------+
| Mountain | Steep, high elevation with peak/summit|
| Hill | Rounded, lower elevation than mountain|
| Plain | Broad, flat or gently rolling land |
| Valley | Low land between mountains or hills |
| Plateau | Elevated flat tableland with cliffs |
| Island | Land completely surrounded by water |
| Peninsula | Land surrounded by water on 3 sides |
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Islands: Land Surrounded by Water
An island is an area of land completely surrounded by water on all sides. Some islands, like Hawaii, were formed by underwater volcanoes pouring lava that hardened into rock. Other islands are coral atolls or fragments separated from continents. Hawaii, Puerto Rico, and Greenland are well-known islands.
Peninsulas: Land Reaching into Water
A peninsula is a piece of land surrounded by water on three sides while remaining connected to the mainland on the fourth side. The state of Florida is a famous peninsula reaching into the Atlantic Ocean and Gulf of Mexico.
How Landforms Shape Human Communities
Landforms directly influence where and how people build communities, travel, and make a living.
Living on Plains Versus Mountains
People living on flat plains find it easy to build straight roads, construct houses, and farm large fields. In contrast, people living in mountain regions build winding switchback roads, design homes with steep roofs to shed heavy winter snow, and often work in timber harvesting, mining, or mountain tourism.
Exercises and Review
Exercise 1: Compare a mountain to a plain by describing the elevation and surface shape of each landform.
Exercise 1 Solution: A mountain has very high elevation, rising steeply above the surrounding land with rugged slopes and a sharp peak or summit. In contrast, a plain has low to moderate elevation with a broad, flat, or gently rolling surface that stretches for miles, making it suitable for growing crops and grazing farm animals.
Exercise 2: Define what an island is and explain how a peninsula differs from an island.
Exercise 2 Solution: An island is a body of land that is completely surrounded by water on all four sides. A peninsula is also bordered by water, but only on three sides, remaining connected to the mainland on its fourth side.