Texas Science Teacher Resource Hub

💡 What This Standard Actually Means

Earth's surface looks the way it does because nature has been shaping it for a very long time. Three big forces do most of the heavy lifting: wind, water, and ice. Each one moves dirt, sand, and rock around in different ways, and over thousands or millions of years, they build the landforms we see today.

Water is the most powerful sculptor in most parts of the world. A river running over the same path for millions of years can cut a deep canyon through solid rock. The Grand Canyon was made this way by the Colorado River. When that same river finally reaches the ocean, it slows down and drops the dirt and sand it was carrying, building a fan-shaped delta at the river's mouth. The Mississippi River dumps so much sediment into the Gulf of Mexico every year that the delta keeps growing. Wind moves smaller pieces, mostly sand and dust. In dry, sandy places, wind piles sand into sand dunes like the ones in the Sahara Desert or at White Sands National Park. Dunes can move and reshape themselves with every wind storm. Ice, in the form of glaciers, slowly grinds across the land, carving valleys and dropping huge amounts of rock and dirt as the glaciers melt.

The takeaway: every landform tells a story about which force built it. A deep canyon was carved by a river. A delta was built up by a river dropping its load. A sand dune was sculpted by the wind. Once kids can match the landform to the agent, they can read any landscape they fly over and explain how it got that way.