1. Earth’s Changing Surface

2. Weathering Earth’s crust is made mostly of rock.
Rocks are broken into pieces by weathering.
Weathering is a destructive force.

3. There are two types of Weathering
Physical Weathering
Chemical Weathering
Mechanical/physical weathering is the breaking of larger rocks into smaller pieces.
Smaller pieces of rock are called sediment
Caused by ice, wind, water and temperature
Chemical weathering is usually caused by water mixing with an acid or chemical
Chemical weathering can create caves, rust, and dissolved rock
Ex. Acid rain, rust

4. Physical Weathering
Water gets into cracks of rocks and freezes. Ice expands and rocks break apart
Blown sand or rushing water hit rocks, causing them to crack or crumble over time
Plants can grow through cracks and break apart rocks

5. Chemical Weathering
Water trickling through the ground and mixing with acids can cause rocks to dissolve under the surface and create caves, and sinkholes
Chemical weathering can cause rocks to dissolve and rust to form on metals

6. Erosion The carrying away of sediments by moving water, ice or wind
Rivers often begin high in a mountain and pick up rocks and sediment as it flows. Over time, the stream becomes wider and deeper

7. Erosion
A sea Arch is formed when water and sediment carve away rocky land that juts into the water

8. Erosion
Erosion can cause caves, sinkholes and landslides when the erosion carries away sediment

9. Deposition