Types of Volcanoes
Hot magma rises and collects in a magma chamber deep below the surface. Magma flows through a conduit up to a vent on the surface, and causes an eruption
What is a Volcano?
Area where molten rock collects below a volcano.
What is a Magma Chamber?
Avalanches of high-temperature rock, ash, and gas that race downslope from a volcano during explosive eruptions. They are extremely dangerous because they can reach temperatures of 1500 degrees Fahrenheit and speeds up to 450 miles per hour. At that temperature and speed, they can obliterate anything in their path.
What is a Pyroclastic Flow?
When magma is erupted from a volcano, it moves down the slope of the volcano and surrounding topography as it cools. It can flow for distances of over 100km, and at speeds near 30 miles per hour.
What are Lava Flows?
The name of the oldest volcano on Hawaii Island.
What is Kohala Mountain?
Peaks formed when pyroclastic materials are ejected into the air from a vent and fall back to the ground around the vent in a cone-shaped pile usually on the side of another volcano.
What is a Cinder Cone?
Plumbing system of the volcano.
What is a Conduit?
Solid or molten rock fragments of any size ejected from a volcano.
What is Tephra?
After an eruption, the pressure inside of the volcano is decreased, because large volumes of magma and gas have been released. The empty system of conduits and shallow reservoirs cannot support the weight of the mountain above it, so the volcano collapses on itself.
What is a Caldera?
The most active volcano in the world.
Also called strato-volcanoes, they are made from many layers of rock, ash, hardened lava and volcanic mudflows. Explosive eruptions because of high viscosity lava. Typically very steep and found near subduction zones.
What is a Composite Volcano?
Layer of Earth that fills the Magma Chamber with Magma.
What is the Mantle?
Steam (water vapor), Carbon dioxide (CO2), sulfur compounds, and chlorine compounds are all types of these.
What are Volcanic Gases?
The circular surface depression caused by volcanic activity, usually on the summit or flank of a volcano.
What is a Crater?
The volcano that IPCS sits on.
What is Hualalai?
Very broad with large bases due to the low viscosity of the magma. Usually have slow, gentle eruptions that produce large volumes lava. Type of volcano we have in Hawaii.
What is a Shield Volcano?
Molten, pressurized magma intrudes into the solid volcanic rock and cuts across volcanic rock layers cooling to becomes an intrusive igneous rock.
What are Dikes or Sills?
Debris flows and mudflows that originate from a volcano. They contain rock debris and water.
What are Lahars?
Vents and fissures in areas where a magma conduit passes through the water table, heat from the magma causes water to become steam. As the steam rises it carries volcanic gases such as hydrogen sulfide (H2S) to the surface.
What is a Fumarole?
The largest volcano in the world by volume.
They form when magma below the surface has great upward pressure. This pressure causes the most viscous magmas to move toward the surface, forming steep-sided and bulging mountains.
What is a Lava Dome?
Often is located at or near the summit of the volcano. This is where most eruptive activity occurs.
What is the Main Vent?
Liquid or semi-solid material ejected from a volcano that is larger than 64 millimeters in diameter.
What is a volcanic bomb?
Lava Flows that persist for many hours can solidify on the top and sides of the stream, leaving a canal for the liquid lava to flow through. The solidified lava is a good thermal insulator, so the lava flowing inside remains liquid much longer than an exposed flow.
What is a Lava Tube?
The cause of the Hawaiian volcanoes.