The lava and toxic sulfur dioxide that continue to spew out of Kilauea Volcano on the Big Island of Hawaii has been all over the news lately. However, many people have a limited understanding of volcanoes, and we’ve seen a lot of debate surrounding what exactly is happening in Hawaii. In order to clear things up, we want to clarify what type of volcano Kilauea is, and how it is different from other types of volcanoes.
Kilauea is a shield volcano, which are typically made up almost entirely of fluid lava flows. Shorter than the other volcanos, shield volcanos take advantage of their expansive horizontal surface. As shown in the image below, lava flows through different tubes underground, and when the volcano erupts, some of these tubes burst and lava flows out and onto land. This is unlike the kind of explosion you’d typically expect when lava bursts out of the top. The videos and images of lava leaking out of the sides of Kilauea are indicative of this type of volcano.
The next type of volcano is a composite volcano. This is the kind of volcano that when it erupts, the lava comes out of the top, making it known as the “Hollywood Volcano.” Built by layers of hardened lava and ash, composite volcanos are tall and steep and are the most common type of volcano on Earth. They typically form at tectonic plate boundaries or subduction zones, when one plate slides beneath another. The structure is favorable for explosive volcanic eruptions because water is sometimes released into the mantle rock. This release of water then forces the magma to rise up to the top of the volcano and explode out.
The final type of volcano is a cinder cone volcano. This type of volcano looks like a steep hill that is made up of volcanic debris that accumulates near a volcanic vent. Due to its proximity to a vent, it is found either near a composite or shield volcano. This type of volcano typically only erupts once in its lifetime, and these eruptions tend to be low-impact.