Sciece Quiz
What are volcanic bombs?
Solid rock from an erupted volcano.
What is subduction?
Subduction is the movement under another.
What are two factors scientists monitor that could indicate a volcano might erupt?
A rise in gases like sulfur dioxide, a rise in the amount of magma there is which leads to a hotter temperature, a change in the volcano's shape, and more frequent earthquakes.
What is a shield volcano?
A shield volcano is built of layers of lava released from repeated nonexplosive eruptions.
What is a lava plateau?
A wide, flat land form resulting from repeated nonexplosive eruptions that spreads over a large area.
What is a tectonic plate boundary?
Areas where Tectonic Plates collide or separate.
Why is a decrease in pressure the most common cause of magma formation?
Because when the pressure decreases temperature increases.
What is Blocky lava?
Blocky lava is cool stiff lava that does not travel far from the erupting vent. It usually oozes from a volcano and forms jumbled heaps of sharp-edged lava.
What is Pahoehoe lava?
Flows slowly and is like obsidian or glass with rounded wrinkles.
What is volcanic ash?
Forms when the gases in stiff magma expand rapidly and the walls of the gas bubbles explode into tiny glass like slivers.
What is the consistency of the rock in the Earth's mantle?
It has a putty like consistency.
What are volcanic bombs?
Large blobs of magma that harden in the air. The magma spins as it cools.
What is Aa lava?
Lava that pours out quickly and forms brittle crust. The crust is torn into jagged pieces as molten lava continues to flow underneath.
Where are the Hawaiian islands located?
They are located on a hot spot which is a group of volcanoes far away from any tectonic plate boundary.
How does magma behave like air bubbles in a jar of honey?
They rise to the surface slowly.
When does rock usually melt to form magma?
When the temperature increases or the pressure on the rock decreases.
How does new oceanic crust form at a divergent boundary?
When the two tectonic plates separate magma rise and lays itself on top of the old oceanic crust and hardens.
What is a Volcano?
a vent or fissure in Earth's surface through which magma and gases are expelled
Where do a large number of the world's active volcanoes lie?
Ring of Fire
What is an area of deep cracks that form between two tectonic plates that are pulling away from each other?
A rift zone.
What forms when the roof over a magma chamber collapses?
A caldera
What is a cinder cone volcano?
A cinder cone volcano is made up of pyroclastic material usually from moderate explosive eruptions.
What is a composite volcano?
A composite volcano is formed from explosive eruptions of pyroclastic material followed by quieter flows of lava.
What is a crater?
A funnel shaped pit around the top of a volcanoes central vent.
What does lava from underseas rift zones create.
Mid-ocean ridges
What is lapili?
Pebblelike bits of magma that harden before they hit the ground.
What is Pillow lava?
Pillow lava erupts from an underwater vent. Because it hits the water it becomes a hollow bubble of lava.