Volcanoes Flashcards
Volcano
an opening in the earth that erupts gases, ash, and lava
Magma
molten rock below the Earth’s surface
Crater
steep-walled depression around a vent
Volcanic vent
Opening in Earth’s crust through which magma is released
Fumarole
A type of vent where steam, water vapor, sulfur dioxide, carbon dioxide, and hydrochloride acid are emitted
Lava
Molten rock above the earth’s surface
What can volcanic ash do?
Collapse buildings, block roads, cause lung disease in people and animals destroying everything in its path
Pyroclastic flows
Super hot volcanic ash, cinders, bombs, and other debris rush down the side of the volcano
Acid rain
Sulfurous gases mix with water vapor in the atmosphere
Where can volcanoes form?
Divergent & convergent plate boundary and hot spots
Divergent plate boundary volcanoes
Plates move apart as more lava flows and hardens, it builds up on the seafloor
Rift volcanoes
What divergent plate boundaries form. Can form islands
Convergent plate boundary volcanoes
2 plates move together & collide denser plate sinks or sub ducts into the mantle. violent.
Hot spot
Areas at the boundary between Earth’s mantle and core that are usually hot
Hot spot volcanoes
They form islands. temporary islands due to the moving plates.
Active volcano
Erupted within the last few thousand years
How many active volcanoes are there around the world today?
1,500
Where does the U.S rank in the number of volcanoes?
3rd
What are the two factors that control eruptions?
The amount of water vapor/gases and how much silica is present in the magma
Wet magma
Magma that has a lot of water vapor and can cause explosive eruptions
Silica
Thickness of magma
A lot of silica
Think, pasty
a little bit of silica
Thin, runny
A lot of gas (water)
High pressure, the more explosive
