Question

Consider the features of volcanoes and select the true statements:

1. Volcanoes are only found at divergent plate boundaries.
2. Magma is molten rock beneath the Earth's surface, while lava is molten rock that has erupted onto the surface.
3. The Ring of Fire is a horseshoe-shaped region known for its high volcanic activity.
4. Supervolcanoes are capable of producing catastrophic eruptions that can impact global climate

• A. iii only
• B. i, iii
• C. ii, iii, iv
• D. iii, iv

Answer 1

Answer:

C. ii, iii, iv

Volcanoes

• A volcano is a vent or opening in the Earth's crust through which molten rock, gases, and ash can erupt onto the surface.
• These eruptions can vary widely in scale and intensity.
• Volcanoes are typically formed at tectonic plate boundaries.
• The Earth's lithosphere is divided into several large and small tectonic plates, and the movement and interaction of these plates create conditions conducive to volcanic activity.

Magma

• Magma refers to molten rock that is located beneath the Earth's surface.
• When magma erupts and reaches the Earth's surface, it is then referred to as lava.
• Volcanic eruptions occur when pressure builds up within a magma chamber, causing magma to rise and breach the surface.

The "Ring of Fire"

• The "Ring of Fire" is a horseshoe-shaped zone or belt that encircles the Pacific Ocean.
• This region is known for its high concentration of active volcanoes.
• It is home to about 75% of the world's active and dormant volcanoes.
• These volcanoes are often associated with the subduction of tectonic plates.

 Supervolcano

• A supervolcano is not a distinct type of volcano but rather a term used to describe a volcano with the potential to produce a supereruption.
• Supereruptions are defined based on the volume of material ejected during the eruption, typically exceeding 1,000 cubic kilometers (240 cubic miles).
• One of the most notable features of supervolcanic eruptions is their potential to affect the Earth's climate.
• The massive injection of volcanic material into the atmosphere can lead to a short-term cooling effect by blocking sunlight, which may result in a "volcanic winter."
• This can impact global temperatures and weather patterns for several years.