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7.2A L2-4 Vocabulary
| Term | Definition |
|---|---|
| Eruption | the emission of volcanic products such as lava, ash, and gases from a volcano; as a geologic process, volcanic eruptions usually occur as sudden events. |
| Lava | melted rock that is emitted from a volcano or vent and flows onto the surface; also refers to the hardened rock that forms as it cools. |
| Volcanic Ash | small solid particles that are emitted from a volcano during an eruption into the atmosphere. |
| Fumarole | a vent or opening on a volcano that releases high temperature steam and gases. |
| Stratovolcano | a steep-sided, often cone-shaped volcanic peak, formed by layers of ash, relatively sticky lava and other eruption products. |
| Shield Volcano | a broad, dome-shaped volcano with gently sloping sides formed by layers of relatively fluid lava. |
| Fissure Vent | a linear volcanic vent or vents through which lava and gases erupt, usually without any explosive activity. It may consist of a single long vent, or a series of vents oriented along the same linear direction. |
| Caldera | a large volcanic crater, formed by the collapse of the volcano summit as the result of a major eruption. |
| Crust | The solid surface of the Earth (including the seafloor beneath the oceans). |
| Mantle | The semi-solid, thick, very hot layer beneath the crust. |
| Cycling of Matter | the movement of material from the mantle and the crust, upwards through the crust and emitting on Earth’s surface driven by the flow of energy. |
| Melting | to change a solid material into liquid by adding thermal energy. |
| Crystallization | to change a liquid material into a solid by removing or releasing thermal energy. |
| Magma | the melted material from the mantle and crust while it is beneath the surface of the earth. |
| Magma Chamber | the region in the crust beneath a volcano where magma is stored before it is erupted onto Earth’s surface. |
| Continental Crust | Thick crust with expanses of land (North America; South America; Asia) |
| Oceanic Crust | Thin crust beneath Earth’s big oceans (Pacific Ocean; Atlantic Ocean) |
| Thermal Energy Flow | Energy from the mantle moving towards the crust and changing the physical properties of earth materials (melting) and escaping on Earth’s surface (crystallization). |
| Region of Stability | An area on Earth’s surface with little evidence of thermal energy flow and far away from the linear patterns of volcanic and earthquake activity, like the Ring of Fire. |
| Region of Change | An area on Earth’s surface closely associated to high thermal energy flow and/or linear patterns of volcanic and earthquake activity, like the Ring of Fire. |