1. Summary

This video describes the process of the snowball earth effect in which the entire surface of the planet froze although the reasoning behind this phenomenon is still debated today. It mentions the length of time in which multiple glaciations occurred. Finally, this video discusses how life seemed unsustainable, yet complex life forms still exists today. Although this video is over the 7 minutes length of time, the focus will only be on the first 7 minutes.

 2. Why Watch This Video?

  1. Have you ever wondered if there was a moment in history in which the entire planet earth froze over? This video explains the snowball Earth effect in which glaciers and ice formed throughout the entire surface of the earth. This phenomenon occurred more than once through the history of the earth.
  2. Would you like to know how life forms survived through the snowball Earth period? This video offers the theory of the “survival of the fittest” which is coined in the video as adapt or die.
  3. Have you ever been confused by how ice on the surface of the earth is able to form rapidly? This video explains how light is reflected off of the ice and sent into space which then further cools the surface of the earth, resulting in more ice being formed.

3. Key Terms

Snowball Earth: a time which the entire surface of the earth was covered in ice.

Glaciation: the process where the earth was faced with colder temperatures which resulted in the Earth being covered by ice and glaciers.

Rodinia: is the oldest supercontinent that existed during the Precambrian time that was a assembled landmasses and later on broke apart.

4. Loose Ends

Loose end #1: What survived the global freeze?

It is believed that single-cell bacteria existed on Earth before the Cambrian explosion. Single-cell bacteria was said to be the only life form on earth and the most dominant were cyanobacteria which adapted and survived the harsh climate.

Loose end #2: Was there a time when Earth froze over completely?

It is believed that the Cryogenian period, which was marked by multiple glaciations due to a relative proximity to the moon which made the tides stronger and more rapid than it is now. The beginning of the Cryogenian was marked by the Sturtian glaciation that consisted of various melting and freezing intervals.

Loose end #3: What role did sea ice play in the ice age?

Sea ice is one of the most reflective surfaces on the earth, the sun’s warmth hitting the earth gets reflected off the ice back into space, the more ice there is the more gets reflected back to space which in turn created more ice formed on earth.

5. Self-Test Questions

Question 1: During which era did the snowball earth effect occur?

Answer a: Mesozoic Era

Answer b: Neoproterozoic Era

Answer c: Cenozoic Era

Answer d: Paleoproterozoic Era


Question 2: What does the “snowball earth” hypothesis refer to?

Answer a: the time(s) when it only snowed for a long time

Answer b: the time(s) when all of the earth glaciers turned into a “snowball”

Answer c: the time(s) when the entire surface of the earth froze over

Answer d: the time(s) when parts of the earth’s surface froze over


Question 3: What was the name of the supercontinent related to the snowball earth event?

Answer a: Gondwana

Answer b: Congo

Answer c: Rodinia

Answer d: Euramerica


Question 4: Which era is marked with the beginning of an interglacial period?

Answer a: Mesozoic Era

Answer b: Paleocene Era

Answer c: Late Paleozoic Era

Answer d: Holocene Era


Question 5: What was the reason why some life forms survived the snowball earth event?

Answer a: oxygenation

Answer b: Adapt or die

Answer c: C02 balance

Answer d: fossilization

6. Answers to Self-Test Questions

1. B) Neoproterozoic Era, this is the only era in which glaciers tillites deposits and icebergs released dropstones throughout the world even near the equator.

2. C) The time(s) when the entire surface of the earth froze over. The Earth’s oceans and land surfaces were completely covered by ice and cold temperatures were present.

3. C) Rodinia. The theory is that when the supercontinent Rodinia broke apart it disturbed the carbon cycle on earth. Carbon dioxide was being removed from rocks into the atmosphere which in turn was gathered in the ocean floors which then caused a snowball earth.

4. D) The Holocene is the current geological epoch that is marked by the Holocene deglaciation. We are currently in an interglacial period where ice sheets are still present. We are within an ice age that began 3.2 millions years ago.

5. B) Adapt or die, otherwise known as “survival of the fittest” that refers to the process of natural selection, in which the organism better adapted to their environment tend to survive and produce more offspring. In this instance some life forms adapted to the earth’s freezing climate allowing them then to survive.

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Item Credit: JG Science

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