Magma is a molten mixture of a rock-forming substance, gases, water from mantle.
100
What is viscosity?
Viscosity is the resistance of a liquid to flow. The greater the viscosity the slower it flows. The lesser the viscosity the faster it flows.
100
What is a crater in a volcano?
A crater in a volcano is a bowl-shaped area that may form at the top around the central vent.
100
Explain a dormant volcano.
A dormant volcano is sleeping and is expected to awaken in the near future and become active.
100
What is a volcano?
A volcano is a weak spot in the crust where magma and gases come up.
200
What is a volcanic belt?
A volcanic belt forms along plate boundaries. At a volcanic belt, magma can reach the surface when plates converge or diverge and fracture crust.
200
What is a magma chamber?
A magma chamber is a pocket in a volcano that collects magma.
200
Explain quiet eruptions. Where can you find some volcanoes with this flow?
Quiet eruptions are low in silica and have low viscosity, which means that they flow easily. The lava oozes out quietly and flows for many kilometers. They set fire and buries everything in its path. It also contains pahoohoe and Aa lava flow. You can find some of these volcanoes at the Hawaiian islands.
200
Explain an extinct volcano.
An extinct volcano is dead, and is unlikely to erupt again.
200
What is a caldera? Give an example.
A caldera is huge hole left by a collapsing volcano. An enormous eruption has previously emptied the vent and chamber leaving it hollow with no support. Sometimes it fills with rain. An example would be Crater Lake in Oregon.
300
What is the Ring Of Fire?
The Ring Of Fire is a major volcanic belt, and is found in the Pacific Ocean. If you look high enough, and from a birds eye view, it contains many glowing circles, or rims.
300
What is a pipe in a volcano?
A pipe in a volcano is a tube that connects the magma chamber to the surface.
300
Explain explosive eruptions. Where can you find a volcano with one of these eruptions?
Explosive eruptions are high in silica and high viscosity which makes them thick and sticky. They build up in the pipe, and . plugs like a cork. There are trapped gases that build up pressure until they explode. It breaks the lava into fast cooling pieces. Mt. St. Helens is one example.
300
What is a shield volcano? Give an example.
A shield volcano is a wide, gently sloping mountain made of layers of lave from quiet eruptions. An example would be the Hawaiian islands.
300
Give 3 land forms formed by volcanoes.
1. craters
2. calderas
3. lava plateaus
400
What is an island arc? And whats an example?
An island arc is a string of volcanic islands, formed from subduction at converging oceanic plates. An example would be the Japan islands, Caribbean islands, or the Hawaiian islands.
400
What is a vent in a volcano?
A vent in a volcano is an opening thru which molten rock and gases leave. There is usually a central vent at the top of a volcano, and there are sometimes vents on the sides.
400
What is pyroclastic flow?
Pyroclastic flow is what an explosive eruption flows out. It is a mixture of hot gases, ash, lapilli, bombs, and blocks.
400
What is a cinder-cone volcano? Give an example.
A cinder-cone volcano is a steep cone-shaped hill or small mountain made of pyroclastic material. An example is the Mexican Partucutin.
400
True or false. Scientists can predict when a volcano will erupt.
False
500
What are hot spots? (volcano related)
Hot spots are where the magma melts through the crust. It is found n the middle of plates along plate boundaries. Volcanoes can form above these hot spots.
500
What is lava flow?
Lava flow is the area covered by lava as it pours out of the vent.
500
Explain an active volcano.
An active volcano is live and erupting, or is showing signs or erupting in the near future.
500
What is a composite volcano? Give an example.
A composite volcano is a tall cone-shaped mountain formed by explosive and non-explosive eruptions. An example is Mt. St. Helens.
500
True or false. A scientist who studies volcanoes is a volcanologist.