Plate tectonics is the theory that Earth’s outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. This movement is responsible for continental drift, earthquakes, and volcanic activity.
Key Characteristics / Core Concepts
- Earth’s lithosphere is broken into numerous plates.
- These plates float on the asthenosphere (semi-molten upper mantle).
- Plate movement is driven by convection currents in the mantle.
- Plate boundaries are where most geological activity occurs.
- There are three main types of plate boundaries: divergent, convergent, and transform.
How It Works / Its Function
Convection currents within the Earth’s mantle cause the plates to move. Hot material rises, cools, and sinks, creating a cycle of movement that pushes and pulls the plates. This movement leads to the creation and destruction of crust at plate boundaries.
Examples
- The Mid-Atlantic Ridge, where the North American and Eurasian plates are diverging.
- The Himalayas, formed by the collision of the Indian and Eurasian plates.
- The San Andreas Fault, a transform boundary where the Pacific and North American plates slide past each other.
Why is it Important? / Significance
Understanding plate tectonics is crucial for predicting and mitigating natural hazards like earthquakes and volcanoes. It also helps us understand the formation of mountains, ocean basins, and the distribution of resources.
Related Concepts
- Continental Drift
- Seafloor Spreading
- Subduction
Plate tectonics provides a framework for understanding Earth’s dynamic processes.