Volcanoes

These flashcards cover essential vocabulary related to the characteristics, types, and impacts of volcanoes.

Volcano

• An opening in the Earth's crust where magma escapes to the surface\n- Becomes lava once it is extruded onto the exterior

Lava

• Molten rock found on the surface of the Earth\n- Ejected from a volcano or fissure during an active eruption

Active Volcano

• A volcano that has erupted in recent history\n- Possesses high probability of erupting again

Dormant Volcano

• A volcano that has not erupted for a significant period of time\n- Still considered capable of future eruptions

Extinct Volcano

• A volcano that has not erupted for thousands of years\n- No longer likely to erupt due to lack of magma supply

Acidic Lava

• Contains high silica content (>63\%\n- High viscosity and typically associated with explosive eruptions

Basic Lava

• Contains low silica content ($45-52\%$\n- Low viscosity which allows it to flow easily over long distances

Pyroclastic Flow

• A superheated current of gas and volcanic matter\n- Moves down slopes at speeds exceeding $100$ km/h

Shield Volcano

• Broad, gently sloping volcanic mountain\n- Formed primarily from repeated eruptions of low-viscosity basic lava

Stratovolcano

• Steep-sided cone composed of layers of lava and tephra\n- Often results in highly explosive and dangerous eruptions

Divergent Boundary

• Where tectonic plates pull apart from each other\n- Characterized by the eruption of basic lava at rift zones

Convergent Boundary

• Where tectonic plates collide or subduct\n- Frequently creates explosive volcanoes due to high silica concentrations

Geothermal Energy

• Energy produced by heat originating from the Earth’s interior\n- Often extracted in volcanic regions for electricity or heating

Volcanic Plug

• Object created when magma hardens within a volcanic vent\n- Often remains standing after the outer cone erodes away

Tephra

• Any fragmented material ejected by a volcanic eruption\n- Includes particles such as ash, lapilli, and volcanic bombs

Lahar

• A mudflow or debris flow on the side of a volcano\n- Triggered by volcanic activity mixing with water from ice or rain

Volcanic Eruption

• The discharge of gas, ash, and lava from a vent\n- Driven by pressure buildup from dissolved gases in magma

Magma

• Molten rock located beneath the Earth's crust\n- Consists of liquid rock, dissolved gases, and solid crystals

Caldera

• Large basin-shaped depression at the summit of a volcano\n- Formed when a volcano collapses into its emptied magma chamber

Hotspot

• Volcanic activity occurring far from plate boundaries\n- Caused by a mantle plume rising to the crust, such as in Hawaii

Magma Chamber

• A large reservoir of molten rock beneath the Earth's surface\n- Serves as the primary source for volcanic eruptions

Fumarole

• An opening in the ground that emits steam and volcanic gases\n- Indicators of high heat flow and active hydrothermal systems

Ash Cloud

• A large cloud of pulverized rock and glass fragments\n- Can travel thousands of miles and disrupt air travel

Fissure Eruption

• Volcanic eruption that occurs along a narrow crack in the crust\n- Usually produces large volumes of fluid basic lava flows