1. The Earth's Landforms - A Fourth Grade PowerPoint Introduction
©Mike Hyman(CoachHyman), 2014

2. Landforms Words to Know crust mantle outer core inner core
Viewing the Earth from outer space, one might think that the Earth is flat. That is far from true, however. Many natural features occur on the Earth. They are known as landforms. These landforms include mountains, plains, landforms shaped by water, and landforms shaped by wind.
©Mike Hyman(CoachHyman), 2014

3. Landforms shaped by wind Landforms shaped by water
Mountains
Mountains are the tallest landform and easily visible. They either have gentle slopes or steep slopes.
Plains
Plains are the flattest of the landforms. They have few hills and no mountains.
Landforms shaped by wind
Sand dunes are large mounds of sand formed in deserts or on beaches by wind. Wind + water can also change a mountain's steepness or a valley's depth.
Landforms shaped by water
Over time, moving water can shape the land. From channels (smallest), to gullies (larger), to valleys (even larger), and finally to canyons (largest). Water influences the land's shape.
©Mike Hyman(CoachHyman), 2014

4. Water Meeting Land River Deltas
The flow of water always moves downward. When it reaches the bottom of a landform, though, what happens?
River Deltas
River flow slows as lands become more flat. It slows even more as it meets the ocean. The river will leave behind little bits of soil and sand forming a triangular landform known as a delta.
Continental Shelves
Continental shelves are the areas of land off of the beach where the land meets the ocean. The water is shallow and can extend for miles off shore.
Drainage Basins
Drainage basins are areas of land drained by flowing water. Many of the large rivers around the world have land around them that serve as drainage basins.
©Mike Hyman(CoachHyman), 2014

5. Past the Continental Slope
The area off the end of the continental shelf is known as the continental slope. The continental slope angles down toward the ocean floor. Underwater canyons may form there. Where the continental slope meets the ocean floor is known as the continental rise. Most of the ocean floor is relatively flat. However, some areas have large, underwater mountain ranges known as ocean ridges. Underwater volcanoes exist along the ocean floor also.
Ocean ridges are formed by plate tectonics. This uplifting of the ocean floor occurs when currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet.
ocean ridge formation
magma
©Mike Hyman(CoachHyman), 2014

6. Beneath the Surface of the Earth
Beneath the Earth's surface, there are four layers identified by scientists.
·Crust - The crust of the Earth is the outermost layer. The landforms of the Earth and features found underwater are found here. It is also brittle and can crack.
·Mantle - This solid rock layer is below the crust of the Earth. At high temperatures and pressures, though, it can change shape or move.
·Outer Core - Made primarily of liquid iron, this layer is found beneath the mantle.
·Inner Core - The solid, innermost part of the Earth. It is the hottest part also and most likely made up of iron.
©Mike Hyman(CoachHyman), 2014