Stratovolcanoes

Stratovolcanoes, also known as composite volcanoes, are steep-sided volcanic cones built by the eruption of viscous lava flows, explosive eruptions, and pyroclastic flows. These volcanoes are characterized by their symmetrical cone shape, which is formed by alternating layers of lava, ash, and volcanic rocks.

Formation of Stratovolcanoes

Stratovolcanoes are formed through a combination of lava flows and explosive eruptions. The lava flows from stratovolcanoes are typically viscous and can't travel very far from the vent, causing them to build up and create steep slopes. The explosive eruptions produce pyroclastic flows, which are fast-moving streams of hot gas and volcanic particles that can travel down the slopes of the volcano at high speeds.

Key Features of Stratovolcanoes

• Steep Sides: The steep sides of stratovolcanoes are a result of the accumulation of viscous lava flows and pyroclastic deposits over time.
• Concave Shape: The concave shape of the volcano is formed as the alternating layers of lava, ash, and volcanic rocks build up around the vent.
• Crater at the Summit: Stratovolcanoes typically have a summit crater, which is formed by the collapse of the volcano's summit during an eruption or by the explosive ejection of volcanic material.
• Associated Hazards: Due to their explosive nature, stratovolcanoes pose hazards such as pyroclastic flows, ash fall, lahars (mudflows), and volcanic gases.

Examples of Stratovolcanoes

Some well-known examples of stratovolcanoes include Mount St. Helens in the United States, Mount Fuji in Japan, Mount Vesuvius in Italy, and Mount Pinatubo in the Philippines.

Study Guide

When studying stratovolcanoes, it's important to understand the processes that lead to their formation, the key features that distinguish them from other types of volcanoes, and the associated hazards. Additionally, familiarizing yourself with specific examples of stratovolcanoes can provide insight into the diverse nature of these volcanic structures.

Key topics to focus on when studying stratovolcanoes include:

1. The formation of stratovolcanoes through the accumulation of lava flows and explosive eruptions
2. The distinctive features of stratovolcanoes, including their steep sides, concave shape, and summit crater
3. The hazards associated with stratovolcanoes, such as pyroclastic flows, ash fall, lahars, and volcanic gases
4. Specific examples of stratovolcanoes and their unique characteristics

By understanding these key concepts, you can develop a comprehensive understanding of the formation, features, and hazards of stratovolcanoes.