Yellowstone, the sleeping giantYellowstone National Park is not exactly a volcano, nor does it visibly have a specific mountain from which lava or ash erupts, but it is a highly volcanic area. Only a few eruptions have occurred in Yellowstone over the past millennia, but they have been powerful and destructive. There have been no major eruptions that humans can remember, but that doesn't mean more won't occur in the near future. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Yellowstone Park currently sits in a giant caldera resulting from a previous eruption that occurred approximately 640,000 years ago. The park is a hot spot or area of ​​high volcanic activity. Yellowstone, along with most of the continent, sits on an Earth plate that, along with other adjacent plates, rests on the fluid core of the planet's mantle. The section of the sliding mantle is called the asthenosphere, while the set of plates is called the lithosphere. In the asthenosphere, a thermal plume pushes magma against the lithospheric plate. How the thermal plume is created is a long and difficult process to explain, but fundamentally the asthenosphere (mantle core) is stationary, while the plate is not (Hendrix, 8). There were multiple volcanic eruption areas before Yellowstone, such as the Picabo and Twin Falls volcanic fields, and they all follow a path. At first impression, this path appears to be a trail left by the thermal plume, but since the plume is not moving, the trail actually reflects the opposite path of the moving North American plate (Breining, 27; Hendrix, 6, 7, 130) . It can be comparable to stitches on clothes made by a sewing machine: the stitches are made by the needle (thermal plume) but the needle does not move; clothing does (lithospheric plate). As it happens, Yellowstone was the next section of the plate that the thermal plume could have easily breached and caused large eruptions three times (Hendrix, 130). The Yellowstone area is still active today. If it weren't active, there would be no Old Faithful, no geysers, no sulfur-smelling springs, no hot mud pools. (Breining, 17; Hendrix, 1). The thermal plume makes up the current volcano beneath Yellowstone: one so immense that it is known as a supervolcano. A common misconception about a volcano is that of a tall, menacing mountain that erupts both clouds of ash and lava, but in reality a volcano can erupt a lot of lava or a lot of ash. The type of volcano depends on the viscosity, or thickness, of the lava and magma. If the mountain's magma has a high viscosity, it will harden easily on the outside, building the mountain to a great height, and harden on the inside, where it will block volcanic tubes and increase pressure until pyroclastic clouds explode, creating is a composite volcano. If the magma has low viscosity, it will not harden easily and will flow and spread, forming a shield volcano. The lava will not build the mountain to a great height, and will not even block the pressure channels, but will cover a great distance on the ground (Cain, 1). Yellowstone is no longer any of these. It was originally a composite volcano that had already erupted and taken away much of the mountain. The viscosity of lava depends on the amount of silica it contains; if there is a lot of silica it is felsic, otherwise the lava is mafic. Rhyolite, which is a felsic rock, is abundant throughout Yellowstone. There are also traces of basalt, which is a mafic rock, but the amount pales in comparison to the amount of felsic rock (Hendrix, 157). Basically, Yellowstone is located in the remains of a giant composite volcano that erupted in.