Chapter 8 Section 2 Types Of Volcanoes Flashcards
What does mafic mean?
A term that describes magma, lava, and rocks that are rich in iron and magnesium. they are dark in color like basalt.
What is lava?
Magma flows onto earths surface, the rock that forms when lava cools and solidifies
Describe the lava of the forms at divergent plate boundaries.
Mafic lava is runny and not sticky. this type of lava generally produces non explosive eruptions.
What is Sea-floor spreading?
The Process in which a new seafloor forms is older seafloor is pulled apart.
How did iceland form?
Activity at the mid Atlantic Ridge has built up an island
Explain how mantle plumes generate the volcanic activity at hotspots
Convection in the mantle plume causes a column of hot solid rock to rise. it liquefies when it reaches the lithosphere and releases large volumes of magma
Describe the lava at hotspots
Because lava at hotspots comes from the mantle, the lava is mafic and fluid. As a result most eruptions are nonexplosive.
What are the four types of lava.
A’a, pahoehoe, pillow lava and blocky lava
Describe how earthquakes are related to volcanic eruptions.
The movement of magma through rock causes small earthquakes that can be used to predict An eruption.
What is the relationship between high silica content in magma and explosive eruptions?
Silica rich magma tends to crap water and gas bubbles which causes enormous gas pressure to develop within the magma. As the gas filled magma rises to earth surface pressure is rapidly released. This change results in a powerful explosive eruption.
What does felsic mean?
The term felsic is used to describe magma, lava, and rocks that are rich in silica and feldspars.
what does pyroclastic mean?
Material that forms when magma explodes from a volcano and solidifies in the air
How do you send her Convo Cano’s differ from composite volcanoes?
Cindercone volcano is usually a reptile only once in their lifetime. Composite volcanoes may generate many irruption’s at intervals of 100 years or more
