This type of eruption is characterized by relatively calm outpourings of lava.
What is a nonexplosive eruption?
100
This type of formation is ropy and occurs when lava hardens quickly.
What is pahoehoe lava?
100
This type of pyroclastic material is the largest.
What are volcanic blocks?
100
This is a funnel shaped pit that is found at the top of the central vent in most volcanoes.
What is a crater?
200
These are volcanoes that have not erupted in recorded history and probably never will again.
What is an extinct volcano?
200
This type of eruption is characterized by blasting both molten and solid rock from a volcano.
What is an explosive eruption?
200
This lava is so thick in consistency that is barely creeps along the ground.
What is blocky lava?
200
This type of pyroclastic material consists of large blobs of magma that harden in the air.
What are volcanic bombs?
200
This is name for the tectonic plate boundaries surrounding the Pacific Ocean that has a lot of volcanoes.
What is the Ring of Fire?
300
This type of volcano is formed by explosive eruptions followed by quieter outpourings of lava.
What is a composite volcano?
300
A volcano is more likely to erupt explosively if its magma has a high water content and this.
What is a high silica content?
300
This lava erupts underwater, forming rounded lumps.
What is pillow lava?
300
This type of pyroclastic material is the smallest in size.
What is ash?
300
These are placed on the Earth's surface that are located directly above mantle plumes.
What are hot spots?
400
This type of volcano is built out of layers of lava from repeated nonexplosive eruptions.
What is a shield volcano?
400
These 3 factors are considered when predicting a volcanic eruption.
What are seismic activity, internal temperature, and change in the cone's shape?
400
This lava pours out quickly, forming a brittle crust that is torn into jagged pieces as the molten lava underneath continues to move.
What is Aa lava?
400
This results from volcanic dust and ash remaining in the atmosphere for months and years.
What are increased solar reflection and lower temperatures?
400
Mount St. Helens, in Washington, which covered the city of Spokane with tons of ash had this type of eruption.
What is an explosive eruption producing pyroclastic material?
500
This type of volcano is made entirely of pyroclastic material.
What is a cinder cone volcano?
500
This type of magma often produces a violent eruption.
What is thick due to high silica content?
500
This is a river of red hot lava.
What is a lava flow?
500
This type of pyroclastic material pebble-like bits of magma that become solid before they hit the ground.
What is lapilli?
500
This forms when a magma chamber that supplies material to a volcano empties and its roof collapses, causing the ground to sink leaving a large circular depression.