Читать книгу Geology For Dummies - Alecia M. Spooner - Страница 21

On a smaller than global scale, rocks are constantly being moved around on Earth’s surface. Surface processes in geology include changes due to gravity, water, ice, wind, and waves. These forces sculpt Earth’s surface, creating landforms and landscapes in ways that are much easier to observe than the more expansive processes of rock formation and tectonic movement. Surface processes are also the geologic processes humans are more likely to encounter in their daily lives.

 Gravity: Living on Earth you may take gravity for granted, but it is a powerful force for moving rocks and sediment. Landslides, for example, result when gravity wins over friction and pulls materials downward. The result of gravity’s pull is mass wasting, which I explain in Chapter 11.

 Water: The most common surface processes include the movement of rocks and sediment by flowing water in river and stream channels. The water makes its way across Earth’s surface, removing and depositing sediment, reshaping the landscape as it does. The different ways flowing water shapes the land are described in Chapter 12.

 Ice: Similar to flowing water but much more powerful, ice moves rocks and can shape the landscape of an entire continent through glacier erosion and deposition. The slow-flowing movement of ice and its effect on the landscape are described in Chapter 13.

 Wind: The force of wind is most common in dry regions, and you are probably familiar with the landforms it creates, called dunes. You may not realize that the speed and direction of wind create many different types of dunes, which I describe in Chapter 14.

 Waves: Along the coast, water in the form of waves is responsible for shaping shorelines and creating (or destroying) beaches. In Chapter 15, I describe in detail the various coastal landforms created as waves remove or leave behind sediments.