Picture a volcano. You are probably imagining a tall, cone-shaped mountain that will shoot thick lava and ash into the air during an eruption. This, however, is just one type of volcano, called a stratovolcano. Mount St. Helens is an example of a stratovolcano. Other volcanoes, like Mauna Loa in Hawaii, can have broad gentle slopes that more resemble a warrior's shield. These are aptly named shield volcanoes. Shield volcanoes typically have lava with lower viscosity (more watery) which means it can spread across large distances. A less common volcano type is a tuya volcano, which has a flat top and steep sides. They are typically formed when volcanoes exist under glaciers. Fagradalsfjall is a tuya volcano that recently erupted in Iceland on December 19, 2023.
Fagradalsfjall also erupted in 2019 and 2021. The effusive eruption in 2021 caused a series of fissures where lava erupted without any explosivity. In the past months, seismologists had registered a dramatic increase in seismic activity indicating that an eruption might be imminent—and they were right! Thankfully, officials evacuated the nearby town of Grindavik in November. While homes may be in danger, there is no risk to human life at present.
At the same time that Fagradalsfjall was erupting, nearly 3,000 miles away in a classroom in NYC students were building and testing their own volcano models using salt and flour dough. Here’s how we did our volcano models!