Kilauea is a shield volcano. These volcanoes are often very large with a shallow, gradual slope instead of steep sides. Most volcanoes have a crater, called a caldera, at the top where lava pools and escapes during an eruption. Kilauea has a caldera, but this eruption didn’t come from it. It came from the newly formed fissures in the volcano’s side.
How lava moves mainly depends on its silica content. Silica is a compound commonly found in quartz and sand. The higher the lava’s silica content, the more violent the eruption and the faster the lava flows. Kilauea’s lava has low amounts of silica, so the eruption has been slow and steady. It is very “well-behaved” says McKinnon.
A wide area is being evacuated, however, because it is very difficult to predict where the lava might flow. “You can’t prevent the lava from flowing where it wants to go,” says McKinnon. “You can just get out of the way.”
According to McKinnon, the main risk at this point is loss of property, not loss of life. Scientists caught the eruption as it was brewing, and Hawaii has an emergency alert system. The system gave residents plenty of time to evacuate. The fact that the eruption began during the day was also helpful. That’s because residents were awake and scientists could clearly observe the volcano.
McKinnon says, “this was a best case scenario. It’s going as smoothly as can be, considering it’s a volcano erupting.”