]> SWEET Ontology A volcano constructed by the ejection of debris and lava flows from a central point, forming a more or less symmetrical volcano. A volcano that consists of a complex of two or more vents, or a volcano that has an associated volcanic dome, either in its crater or on its flanks. A volcano built by a single eruption. A volcano composed of both lava flows and pyroclastic material. A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time. [Wikipedia] Where this association of flood basalts with continental rifting is observed, it is not uncommon to find linear chains of volcanic islands [Wikipedia] In geology, geothermal refers to heat sources within the planet. Strictly speaking, geo-thermal necessarily refers to the Earth but the concept may be applied to other planets. Geothermal is technically an adjective (e.g., geothermal energy) but in U.S. English the word has attained frequent use as a noun (otherwise expressed as g. heat, g. source, or geotherm). The planet's internal heat was originally generated during its accretion, due to gravitational binding energy, and since then additional heat has continued to be generated by the radioactive decay of elements such as uranium, thorium, and potassium. The heat flow from the interior to the surface is only 1/20,000 as great as the energy received from the Sun. In geology, a hotspot is a location on the Earth's surface that has experienced active volcanism for a long period of time. [Wikipedia] A doming or small mound on the crest of a lava flow caused by pressure due to the difference in the rate of flow between the cooler crust and the more fluid lava below. Island arcs that develop along the edges of a continent (for example, large parts of the Andes/ Central American/ Canadian mountain chain) may be known as a volcanic arc or volcanic chain. [Wikipedia] A volcanic field is a spot of the earth's crust that is prone to localized volcanic activity. They usually contain 10 to 100 volcanoes, such as cinder cones and are usually in clusters. Lava flows may also occur. They may occur as a monogenetic volcanic field or a polygenetic volcanic field. [Wikipedia]