Volcanic Theory 2 Flashcards
What is a caldera, and how is it formed?
A caldera is a large depression formed when a volcano erupts so violently that the magma chamber empties, causing the ground above to collapse.
List the primary volcanic hazards:
Lava Flows: Molten rock flows downhill, destroying property but rarely causing loss of life.
Pyroclastic Flows: Fast-moving clouds of hot gases, ash, and rocks—extremely deadly.
Lahars: Mudflows from volcanic ash mixed with water.
Ash Clouds: Can disrupt air travel and cause respiratory issues.
Gases: Toxic emissions like sulfur dioxide and carbon dioxide.
What are hot spots, and how do they form chains of intra-plate volcanoes?
Hot spots are areas where plumes of magma rise through the mantle.
As the tectonic plate moves over the hot spot, a chain of volcanoes forms (e.g., Hawaiian Islands).
How are volcanic eruptions measured?
The Volcanic Explosivity Index (VEI) measures eruptions on a scale from 0 (gentle) to 8 (cataclysmic).
