6. What Are the Key Differences Between Shield Volcanoes and Stratovolcanoes?

When we talk about volcanoes, there are two main types: shield volcanoes and stratovolcanoes. Each type has its own special features that make them interesting to learn about.

Shield Volcanoes:

• Shape and Structure: Shield volcanoes are wide and have gentle slopes. They look like a warrior's shield lying flat on the ground. The slopes are usually less than 10 degrees.
• Lava Type: They mostly erupt basalt lava, which is very runny. This runny lava can travel far and helps create the broad base of the volcano.
• Eruption Style: Eruptions are usually not explosive and happen often. Over time, this builds up layers on the volcano. A well-known example is Mauna Loa in Hawaii.

Stratovolcanoes:

• Shape and Structure: In contrast, stratovolcanoes have taller, steeper shapes. Their slopes can be as steep as 35 degrees, making them look more like a triangle from the side.
• Lava Type: They erupt thicker lava, like andesitic or rhyolitic lava. Because this type of lava doesn’t flow as easily, pressure can build up before an eruption.
• Eruption Style: Eruptions are often explosive and happen less frequently. This can lead to dangerous flows of hot gas and volcanic rock. Mount St. Helens in the USA is a well-known stratovolcano.

In summary, the main differences between shield volcanoes and stratovolcanoes are their shapes, the type of lava they erupt, and how they erupt. Knowing these differences helps us understand volcanic activity and the risks it can pose.