Volcanoes Flashcards
Describe the significance of plate tectonics
late tectonics explain the formation of landforms.
Create earthquakes
Form volcanoes
where would each of these rock types (basalt, andesite and rhyolite) be found?
Basalt: mid-ocean ridges
Andesite: subduction-related volcanoes
Rhyolite: above a hotspot
How are volcanoes measured?
Volcanic Explosivity Index (VEI)
Describe the relationship between silica content, temperature and viscosity in magma
The higher the silica content, the higher the viscosity and the higher the temperature.
What is meant by silica content?
The amount of silicon dioxide (SiO) in a volcanic rock.
What role do dissolved gasses play in volcanism?
The more gas is dissolved the higher the explosivity.
Stratovolcanoes typically are associated with what type of plate tectonic feature?
Subduction zone
What is a stratovolcano and illustrate to me an example
Volcanos that have pyroclastic eruptions and have steep sides built up of alternating layers of lava- usually a mountain.
What are shield volcanoes and give me an example
Volcanos that have mild eruptions and are built up of many lava flows- islands built from volcanoes like Hawaii.
What are pyroclastic flows?
Dangerous and fast hot gas that sometimes occurs with a stratovolcanic eruption.
What are Lahar flows?
Lahars are mudflows made of water, volcanic ash and debris
How are volcanoes measured?
Volcanic Explosivity Index (VEI)
What is a volcano?
An opening in the Earth’s crust through which lava, volcanic ash and gases escape.
