Shield Volcanoes

A shield volcano is a type of volcano that has a broad, flat shape and is built by the flow of low-viscosity lava. These volcanoes are typically found at divergent plate boundaries and hot spots. They are characterized by their gentle slopes and large size, and they are known for their relatively non-explosive eruptions.

Formation of Shield Volcanoes

Shield volcanoes are formed by the accumulation of successive lava flows over time. The lava that erupts from these volcanoes is basaltic in nature, which means it has low viscosity and can flow easily. As the lava flows out of the vent, it spreads out in all directions, creating a broad, shield-like shape.

Structure of Shield Volcanoes

The structure of a shield volcano is characterized by its gentle slopes, which are formed by the accumulation of thin layers of basaltic lava. The central vent at the summit of the volcano is where the lava erupts from, and as it flows down the sides of the volcano, it creates a broad, shield-shaped structure.

Eruptions of Shield Volcanoes

Shield volcanoes are known for their relatively non-explosive eruptions. The low-viscosity lava flows easily and can travel long distances from the vent, creating extensive lava fields. The eruptions are typically effusive, with the lava flowing steadily rather than explosively.

Study Guide

Here are some key points to remember about shield volcanoes:

1. Shield volcanoes have a broad, flat shape and are built by the flow of low-viscosity lava.
2. They are typically found at divergent plate boundaries and hot spots.
3. The lava that erupts from shield volcanoes is basaltic in nature and has low viscosity.
4. Shield volcanoes are characterized by their gentle slopes and relatively non-explosive eruptions.
5. They are formed by the accumulation of successive lava flows over time.
6. The structure of a shield volcano includes a central vent at the summit and broad, shield-shaped slopes.
7. The eruptions of shield volcanoes are effusive, with the lava flowing steadily rather than explosively.

When studying shield volcanoes, it's important to understand their formation, structure, and eruption characteristics. Additionally, it's helpful to compare and contrast shield volcanoes with other types of volcanic structures, such as stratovolcanoes and cinder cone volcanoes.

Understanding the geological processes and features associated with shield volcanoes can provide valuable insights into the dynamic nature of Earth's crust and the impact of volcanic activity on the environment.