How Volcanoes Froze the Earth (Twice)

What is the term used to describe the period of intense glaciation that occurred between 716 and 635 million years ago?

• Jurassic

• Permian

• Cryogenian

• Ice Age

What evidence do scientists use to support the theory of Snowball Earth?

• Fossilized plants

• Drop stones

• Volcanic ash

• Meteorite impacts

What was one initial hypothesis about how the Earth could have frozen over during the Cryogenian period?

• The Earth had less water

• The Earth was closer to the sun

• The Earth tilted on its side

• The Earth had more volcanic activity

What type of rock provides evidence for the extent of glaciation during the Cryogenian period?

• Metamorphic rock

• Carbonate rock

• Igneous rock

• Sedimentary rock

What was the main factor that disrupted Earth's carbon cycle during the Cryogenian period?

• Decrease in volcanic activity

• Formation of a new supercontinent

• Increase in solar radiation

• Breakup of Rodinia

How did the dimmer sun during the Cryogenian period affect Earth's climate?

• It made the Earth warmer

• It increased volcanic activity

• It had no effect

• It contributed to cooling

What role did sulfur dioxide play in the glaciation of Earth?

• It increased volcanic eruptions

• It had no effect

• It cooled the Earth

• It warmed the Earth

What is the feedback loop called that made the glaciation during the Cryogenian period unstoppable?

• Greenhouse effect

• Runaway icehouse effect

• Albedo effect

• Thermal expansion

What event marked the end of the Cryogenian period?

• Thawing of glaciers

• Decrease in solar radiation

• Increase in volcanic activity

• Formation of a new supercontinent

What period followed the Cryogenian, characterized by the emergence of animal life?

• Ediacaran

• Ordovician

• Cambrian

• Silurian