Plate tectonics is the scientific theory that Earth's outer layer is divided into several pieces, or plates, that move and interact with one another. These interactions are responsible for many of Earth's geological features, including earthquakes, volcanic activity, and the formation of mountain ranges.

Key Concepts

Tectonic Plates: The Earth's lithosphere is divided into several large and small plates that float on the semi-fluid asthenosphere beneath them.
Plate Boundaries: The edges of tectonic plates, where they interact with each other, are known as plate boundaries. There are three main types of plate boundaries: divergent, convergent, and transform.
Seafloor Spreading: This is a process that occurs at divergent boundaries where new oceanic crust is formed through volcanic activity and gradually moves away from the mid-ocean ridges.
Subduction: At convergent boundaries, where two plates move towards each other, one plate is forced beneath the other in a process known as subduction.
Continental Drift: The theory of continental drift proposed by Alfred Wegener suggests that the Earth's continents were once joined together in a single landmass called Pangaea and have since drifted apart to their current positions.

Study Guide

Here are some key points to remember when studying plate tectonics:

Identify and describe the three types of plate boundaries.
Explain the process of seafloor spreading and its significance in plate tectonics.
Discuss the theory of continental drift and the evidence that supports it.
Describe the features and phenomena associated with plate tectonics, such as earthquakes, volcanic activity, and mountain formation.
Examine the impact of plate tectonics on the Earth's surface and how it continues to shape our planet.

Understanding plate tectonics is crucial for comprehending the dynamic processes that shape the Earth's surface and the distribution of natural resources and hazards. It also provides valuable insights into the geological history of our planet.