Science

Under what conditions will magma be very thick and sticky?

When magma has a high silica content it will be very viscous and sticky.

Do Cinder Cones have explosive eruptions? Explain.

Yes, they eject pyroclastic materials and highly viscous lava through a thin, central chimney. All this results in an explosive eruption.

Where does the word 'volcano' come from?

It comes from the name of the greek god Vulcan.

What is lava?

Lava is magma that has reached and cooled on Earth's surface.

What volcano is known for its famous eruption that destroyed the city of Pompeii in Italy?

Mt. Vesuvius. The eruption occurred in 79 A.D.

What is the name of a crater like depression in volcanoes that is formed when a magma chamber is emptied?

A Caldera.

What is the difference between a dormant volcano and an active volcano?

A dormant volcano is not currently active, but may become active in the future. An active volcano is erupting or has erupted recently and is expected to erupt again in the near future.

What is a magma chamber?

A magma chamber is a large underground pool of liquid rock found beneath the Earth's surface.

What is a volcano?

A volcano is a geologic feature that produces an eruption.

What are Cinder Cones mostly made of?

Cinder Cones are mostly made of pyroclastic material.

What kind of plate boundaries cause volcanoes to form?

Convergent Plate Boundaries.

True or False: A dormant volcano will never erupt again.

False. A dormant volcano is 'sleeping' and may erupt again in the future.

True or False: Volcanoes are only found on land.

False. They can also occur on the ocean floor.

Are volcanic eruptions rare events?

No, there are over 50 volcanic eruptions every year.

Are volcanoes randomly located on Earth's surface? Explain.

No, volcanoes are the result of a subduction zone or when magma rises to the surface.

What is the name of all the debris that a volcano ejects?

Pyroclastic Materials.

What causes the region called the Ring of Fire?

The Ring of Fire is caused by subduction of the Pacific Plate under other plates.

Where are more than 75% of Earth's volcanoes located?

The border of the Pacific plate (also called the Ring of Fire).

How many types of volcanoes are there? Name them.

There are 3 types of volcanoes: Composite Cones, Cinder Cones, and Shield Volcanoes.

About how many active volcanoes are there on Earth?

There is about 1,900 active volcanoes on Earth.

True or False: A magma chamber is the subterranean cavity containing the liquid and semi-liquid magma which feeds a volcano.

True.

True or False: Composite cones are regarded as the most dangerous type of volcano.

True.

True or False: Lava is cooled extrusive magma.

True. Lava is both the molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling.

True or False: The Mid-Atlantic Ridge is the result of sea floor spreading.

True. The Mid- Atlantic ridge is the result of sea floor spreading at a constructive plate boundary located along the floor of the Atlantic ocean.