These eruptions can appear suddenly and then subside within days. Fissure eruptions can be spectacular, as curtains of glowing red lava burst from the ground. Although they don’t usually erupt violently, that runny lava can run a long way! Fissuresįissures are long cracks from which lava erupts.

They are not steep at all, but can cover a lot of area. Shield volcanoes are built from layer after layer of runny lava, like pancake batter. When they erupt, watch out! There might be a lot of ash, steam, and gas. Stratovolcanoes are the big, beautiful cone-shaped volcanoes many people think of when they think “volcano.” Stratovolcanoes are made from many layers of thick lava, ash, and cinders. That breaks it into small chunks called cinders. This lava typically contains a lot of gas and tends to spatter and explode as it erupts. They are made from a jumble of lava fragments. Cinder ConesĬinder cones are relatively small, steep volcanoes. There are several types of volcanoes including cinder cones, stratovolcanoes, shield volcanoes, and fissures. As the plate moves, the stationary plume below it has created a chain of volcanoes. The islands of Hawaii are volcanoes formed by a plume of magma rising from the mantle in the middle of a tectonic plate. Some famous volcanos have formed in the middle of plates. Not all volcanoes form at plate boundaries. That magma can erupt onto the surface as a volcano. Heat and water from the sinking plate rise, causing material above it to melt. The plate begins to melt as it sinks deep into the hot crust. Other volcanoes form where one plate dives beneath another as they collide. That creates volcanoes, such as the ones in Iceland.

Where two plates pull apart, magma can well up from the mantle into the space between. That is the interaction of the huge moving plates that make up Earth’s crust. Like so many other features of our dynamic planet, the location of many volcanoes has a lot to do with plate tectonics. We know those vents and fissures as volcanoes.

Magma rises to the surface through vents and fissures. As pressure builds up in a magma chamber, the magma chamber overflows. Magma also forms within the crust under conditions of high heat, extreme pressure, or both.Īs it rises, magma can pool in big chambers underground called magma chambers. Because of pressure, density, or other factors, magma from the mantle can rise into the crust. Most magma comes from the upper mantle, just below the crust. Earth’s crust is the very thin, brittle layer on the outside, like the eggshell. Above that, like the egg white, is the mantle. Earth’s core is the middle, like the yolk. To understand where magma comes from in the first place, it helps to understand Earth’s layers. Along with lava, volcanoes can erupt steam, ash, and gases. Lava then cools and hardens into volcanic rock. Once the magma reaches the surface, it’s called lava. Volcanoes form where melted rock (called magma) from deep underground erupts onto Earth’s surface. But did you know that volcanoes come in many sizes and shapes, and that they have big impacts on our world? Or that once in a while, a new one even pops up unexpectedly. You probably know something about volcanoes.

Volcanic cinders