Textbook: Chapter 1 - An Evolving Earth 1 Flashcards
What event marks the beginning of the universe?
The Big Bang, which occurred about 13 billion years ago.
How old is Earth, and how did it form?
Earth formed about 4.6 billion years ago from condensed gases and debris in our solar system.
What was the initial atmosphere of Earth composed of?
Mostly hydrogen and helium.
What is the “Snowball Earth” theory?
A hypothesis that suggests Earth was completely covered in ice during certain periods due to reduced solar radiation and increased glaciation.
How did Earth’s oceans initially form?
Ice comets and “cosmic rain” cooled the planet, creating Earth’s first oceans.
Match the atmospheric gas with its role in Earth’s early climate:
a. Water vapour
b. Carbon dioxide
c. Oxygen
d. Nitrogen
- Main greenhouse gas trapping solar radiation
- Produced by photosynthetic bacteria, allowed complex life to evolve
- Increased in the atmosphere during volcanic eruptions and trapped heat
- Makes up about 78% of today’s atmosphere, mostly inert
Answers:
a - 1
b - 3
c - 2
d - 4
What major event marks the transition from the Precambrian to the Cambrian period, noted for a burst in biodiversity?
A. The Ice Age
B. The Cambrian Explosion
C. The formation of Pangaea
D. The development of agriculture
B
Which theory proposes that Earth’s magnetic field was formed by the sinking of iron cores?
A. Snowball Earth Theory
B. Plate Tectonics Theory
C. Geodynamo Theory
D. Greenhouse Gas Theory
C
The Holocene Epoch is significant because it:
A. Was a period when the Earth was completely covered in ice
B. Marks the beginning of human civilization
C. Saw the creation of Earth’s first oceans
D. Was when Pangaea first formed
B
Which of these gases was NOT a major part of Earth’s original atmosphere?
A. Hydrogen
B. Helium
C. Ammonia
D. Oxygen
D
