Earth’s Changing Surface

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

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

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

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

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

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

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

Deposition