Every volcano has its own eruptive history, and most can be classified into three main types that are based on the volcano's general form and eruptive pattern. Categorizing a volcano as active, dormant or extinct is one way of acknowledging its eruptive history, though these categories are necessarily inexact and subjective.Know More
A volcano is considered active if it has erupted within known history, which, according to the Global Volcanism Program, is usually defined as within the past 10,000 years or since the Ice Age. Volcanoes that are currently erupting or have shown signs of unrest, such as gas discharges or triggering earthquakes, are also classified as active volcanoes.
A dormant volcano is one that has not erupted for the past 10,000 years but could erupt again. Once a dormant volcano erupts, it then falls into the category of active volcano. The Yellowstone Caldera in Yellowstone National Park, for example, has not erupted for 600,000 years as of 2014, but scientists believe it is a sleeping or dormant volcano and could still erupt in the future.
An extinct volcano, on the other hand, is one that experts don't expect to erupt ever again because it has been cut off from its supply of magma. Classic examples of extinct volcanoes include the chain that created the Hawaiian Islands.Learn more about Volcanoes
The reason there are no active volcanoes in the United Kingdom is that the U.K. lies far from the edge of any tectonic plates. Typically, most volcanoes occur near plate boundaries where impacts allow magma to well up from below the Earth's crust.Full Answer >
Based upon the number of large explosions over the past 10,000 years, the most active explosive volcanoes are, in order: Shiveluch in Russia, Pel?e in Martinique, Cotopaxi in Ecuador, Katla in Iceland, Arenal in Costa Rica, Hekla in Iceland, Ibusuki Volcanic Field in Japan, Taupo in New Zealand, Vesuvius in Italy and Avachinsky in Kamchatka. Shiveluch has erupted the most, 43 times, compared to 22 times for Pel?e.Full Answer >
Indonesia has 147 volcanoes, 76 of which are still active making it the world's most active volcano country. The country consists of a chain of more than 13,000 islands that are spread out over an area similar in size to the continental United States.Full Answer >
The inside of a volcano has one or more vents through which gas and lava flow during eruptions. Below the vent is the magma, which is the molten rock that flows upward due to the divergence or convergence of tectonic plates in the Earth's crust. The number of vents and shape of the buildup of magma inside the magma chamber depends upon the type of volcano.Full Answer >