Module 1 Week 1

Question 1

How old is the Earth?

Answer 1

The Earth is about 4.56 billion years old.

Question 2

What is/are the source of information regarding Earth’s History?

Answer 2

Information regarding the Earth’s history is recorded in rocks through the fossils they contain.

Question 3

The Earth is not the center of the solar system and the solar system is not even at the center of the Milky Way Galaxy. Which part of the Milky Way does the solar system reside?

Answer 3

The solar system resides in one of the arms of the spirals in the milky way galaxy. The arm is called the “Orion.”

Question 4

The inner terrestrial planets Mercury, Venus, Earth, and Mars and beyond the asteroid belt are the gaseous planets (Jupiter, Saturn, Uranus, and Neptune). What is the meaning of terrestrial?

Answer 4

In the context of the solar system, terrestrial means planets that have similar characteristics with the Earth and are made up of rocks or metals with a hard surface.

Question 5

The Earth is the “third rock” from the Sun but is also referred to as the Blue Planet. What does the Earth has an abundance of that other planets lack?

Answer 5

WATER

Question 6

What is the true shape of Earth?

Answer 6

Oblate Spheroid

Question 7

Explain the assumptions and method used by Eratosthenes to calculate the circumference of the Earth.

Answer 7

Eratosthenes estimated the Earth’s size in 276-195 BC. He observed that in Syene, which is a city to the south in Alexandria, Egypt, the sun’s rays shine directly at the well at noon during summer solstice. Thus, no vertical shadows were casted, and the sun was directly overhead. While on the northern part of Alexandria, a vertical shadow was casted on the well. So, if the sun’s rays are coming in at the same angle at the same time, it must mean that the Earth’s surface was curved. He then measured the angle of the rays of the sun and the vertical of the well. This aided him in computing for the Earth’s circumference.
Eratosthenes assumed that the sun is so distant that the sun’s rays travelling to the Earth are travelling a long parallel line. He also assumed that the Earth is spherical and not flat.

Question 7

Why is the Earth bulging at the equator?

Answer 7

The Earth is bulging at the equator because of the Earth’s rotation and centrifugal forces.

Question 8

How much of the Earth is Land and how much of it is covered by water?

Answer 8

Ocean covers 71% of the Earth’s surface while land covers only 29%.

Question 9

Why are the oceans at an average deeper than the continents are tall?

Answer 9

This is due to the difference in the density between the rocks forming the continents and the rocks forming the ocean basins. The denser the rocks are, the more they tend to sink.

Question 10

What is a hypsographic curve? What information can we get from the hypsographic curve?

Answer 10

A hypsographic curve is used to portray the average topography of the Earth. It aids in giving the measurement of land below and above sea level.

Question 11

12. How do you calculate for the mass of the Earth?

Answer 11

We can calculate the mass of the Earth using Newton’s Gravitational Theory.

Question 12

13. If the average density of the Earth is 5.517 g/cm3 and the rocks on the surface is from 1-2.9 g/cm3, what conclusions can you make regarding the density of rocks in the Earth’s Interior? What are the implications?

Answer 12

• Using this information, we can infer that the density of the Earth’s interior below the crust must be greater than at least 2.9 g/cm^3 or 5.517 g/cm^3. This means that the interior of the Earth is composed of much denser material compared to the crust. This implies, then, that the Earth must be heterogeneous. The crust is different from what is within the Earth.

Question 13

14. What is the current composition of the Atmosphere? Has the composition of the Earth’s evolved through time?

Answer 13

• The Earth’s atmosphere is currently composed of 79% Nitrogen, 21% Oxygen, and trace amounts of carbon dioxide, water vapor, ozone, helium, hydrogen, argon, and others. The atmosphere now is different compared to when the Earth began.

Question 14

15. How does the Earth’s atmosphere change with increasing altitude? What is the basis for separating the atmosphere into vertical layers?

Answer 14

• The temperature of the Earth’s atmosphere changes according to its altitude. It depends on the specific layers whether the temperature will increase or decrease. This is why the atmosphere is separated into vertical layers.

Question 15

16. Why does the atmosphere circulate? What is meant by insolation?

Answer 15

• Insolation is the amount of heat being received from the sun. Due to an imbalance in the temperature at the surface, heat is redistributed on the Earth’s surface through atmospheric circulation.

Question 16

17. Identify the different continental land masses.

Answer 16

Asia, Africa, North and South America, Europe, Australia, Antarctica, Zealandia

Question 17

18. What are the large-scale features of the ocean floor?

Answer 17

• Oceanic ridges, abyssal plains, intraplate volcanoes, transform fault, and trench.

Question 18

19. What is the Biosphere?

Answer 18

• Part of the Earth where life exists.

Question 19

20. What are the main factors that control the distribution of life on Earth?

Answer 19

• The main factors that control the distribution of life on Earth are pressure, temperature, and chemistry.

Question 20

21. What makes the Earth unique among the other planets in the Solar System?

Answer 20

• The Earth is in a “goldilocks” condition, it’s just the right condition; not too hot, not too cold, and liquid water exists.

Question 21

1. Explain the systems approach to the study of the Earth?

Answer 21

• The systems approach is the study of the Earth wherein we analyze and understand the interrelationship of the several components that make up the Earth and how they interact with each other, all powered by the energy from the sun.

Question 22

2. What are the components of the Earth System?

Answer 22

• Lithosphere, Atmosphere, Biosphere, Hydrosphere, and Solar Energy

Question 23

3. What are the two types of systems? Differentiate between the two.

Answer 23

• Closed systems are systems that exchange only energy, and no matter, with its surroundings. These only exchange heat with space and the environment. While open systems are systems that exchange both heat and matter with surroundings.

Question 24

4. What is the natural tendency of systems when there is disequilibrium? Does it loose or gain energy to its environment?

Answer 24

• If there is disequilibrium, the natural tendency of that system is always to proceed towards attaining equilibrium. The total energy of a system must decrease because the most stable state is the one with the lowest energy.

Question 25

5. What is the Gaia Hypothesis?

Answer 25

• The Gaia Hypothesis proposes that the biosphere is a self-regulating system that controls its physical and chemical environment.

Question 26

6. Explain the Daisy World Model as it relates to the Gaia Hypothesis.

Answer 26

• In the Daisy World Model, a planet is pictured as a place inhabited by black and white daisies. In the beginning, the atmosphere in daisy world was cooler and the black daisies thrive in this environment. Given that they’re black, they absorb more heat, and no earth albedo is created. The planet warms enough for the black daisies to die and for the white ones to thrive instead. Since they’re white, earth albedo is created which then cools the planet and the cycle goes on. In connection with the Gaia hypothesis, this model demonstrates self-regulation in a way that temperature regulation can be performed by organisms interacting with their environment.

Question 27

7. Differentiate between positive and negative feedback mechanisms. Give example of each.

Answer 27

• A negative feedback mechanism implies a response that opposes the disturbance in order to achieve equilibrium. An example would be the formation of clouds. A warmer temperature in the atmosphere means that it can hold more water vapor. More clouds are expected to form due to the increasing water vapor, and the increased clouds will then tend to limit the warming that initiated it.
• A positive feedback mechanism creates a response that intensifies the change and enhances the impact of the process. An example would be water vapor release. Release of greenhouse gases due to burning of fossil fuels increase temperature as heat is trapped in the atmosphere. A warmer atmosphere results in more evaporation which turns into water vapor. This water vapor, then, causes even more warming of the atmosphere.