Question 1

Evaluate the following statement. "Simplified models such as Glatzmaier and Roberts' computer simulation cannot falsify a hypothesis."

Accepted Answer

Simplified models such as Glatzmaier and Roberts' computer simulation can provide evidence for a hypothesis but cannot definitively prove or falsify it. The failure of a correlation between the model and the hypothesis could be due to an error in the model rather than the hypothesis, so it does not necessarily mean that the hypothesis is false. Therefore, option A is the correct choice.

Question 2

How many years were required for a magnetic reversal to occur according to Glatzmaier and Roberts' computer simulation?

Accepted Answer

Glatzmaier and Roberts' computer simulation suggested that a magnetic reversal could take approximately 200,000 years to occur.

Question 3

Approximately how long has it been since the last magnetic reversal?

Accepted Answer

The last magnetic reversal is estimated to have occurred about 780,000 years ago.

Question 4

Judge the following sentence according to the criteria given below. Ice cubes rise to the top of a glass of water because ice is less dense than water.

Accepted Answer

The assertion that ice cubes rise to the top of a glass of water because ice is less dense than water is correct, and the reason is valid. This is due to a principle in physics known as buoyancy, which states that an object will float in a fluid if it is less dense than the fluid. Since ice is less dense than water, it floats to the top of the glass.

Question 5

What substitution did Glatzmaier and Roberts make in their model?

Accepted Answer

Glatzmaier and Roberts substituted thermal convection for compositional convection in their model. This means they based their model on the circulation of heat within the outer core rather than the circulation of different composition materials.

Question 6

Which factor is not included in Glatzmaier and Roberts' model?

Accepted Answer

Glatzmaier and Roberts' model, which simulates the geodynamo—the process that generates Earth's magnetic field—includes factors such as Earth's rotation, convective motion, and the principles of electricity and magnetism. However, it does not specifically account for compositional convection, which involves variations in the composition of the fluid in the outer core affecting its motion.

Question 7

What hypothesis has been presented for the close parallel relationship of the magnetic field and the rotation axis?

Accepted Answer

The hypothesis for the close parallel relationship between the Earth's magnetic field and its rotation axis suggests that rotation causes spiraling convection currents in the Earth's outer core. These currents, composed of molten iron and nickel, generate the planet's magnetic field through the dynamo effect.

Question 8

Judge the following sentences according to the criteria given below. Ice cubes are dropped in a glass of warm water and float to the top. The ice cubes rose to the top of the glass of warm water because the frozen ice is colder than the warm water.

Accepted Answer

The assertion is correct because ice cubes do float in warm water, but the reason provided is invalid. Ice floats not because it is colder but because it is less dense than liquid water.

Question 9

Liquid metal at the base of the outer core moves upward due to ________ convection.

Accepted Answer

The answer of Liquid metal at the base of the...

Question 10

What happened to the initial magnetic field introduced into the computer simulation by Glatzmaier and Roberts?

Accepted Answer

The initial magnetic field introduced into the computer simulation by Glatzmaier and Roberts became self-sustaining, demonstrating how the Earth's dynamo could operate.

Question 11

What is a possible effect of a magnetic reversal on Earth's organisms?

Accepted Answer

During a magnetic reversal, the Earth's magnetic field weakens, which can lead to increased exposure to cosmic radiation.

Question 12

What occurred to magnetic field strength in Glatzmaier and Roberts' model during polarity reversals?

Accepted Answer

According to Glatzmaier and Roberts' model, during polarity reversals, the magnetic field strength decreased. This was shown in their simulation where the magnetic field strength weakened and became more disordered before reversing polarity.

Question 13

The property of matter that describes its resistance to flow is called

Accepted Answer

Viscosity is the property of a fluid that describes its resistance to flow.

Question 14

Which of the following is a hypothesis regarding the initial formation of Earth's magnetic field?

Accepted Answer

The answer of Which of the following is a hypothesis...

Question 15

How long did the supercomputer require to run Glatzmaier and Roberts' original simulation of 45,000 years?

Accepted Answer

The supercomputer required a year to run Glatzmaier and Roberts' original simulation of 45,000 years.

Question 16

What did Glatzmaier and Roberts' model suggest as a reason for magnetic reversal?

Accepted Answer

Glatzmaier and Roberts' model suggested that magnetic reversals are caused by interactions between the magnetic fields in the Earth's inner and outer cores.

Question 17

The shape of Earth's magnetic field resembles

Accepted Answer

Earth's magnetic field is similar to that of a bar magnet, with a north magnetic pole and a south magnetic pole.

Question 18

Judge the following sentences according to the criteria given below. On average, heat flow through oceanic crust is greater than heat flow through continental crust because mantle heat is transferred towards the surface by convection.

Accepted Answer

This sentence is a factual statement that is supported by scientific research. The reason given is also valid and accurately describes the process by which mantle heat is transferred to the surface through convection. Therefore, both the assertion and reason are correct and the reason is valid.

Question 19

What is a dynamo?

Accepted Answer

A dynamo is a device that converts motion energy into electrical energy through electromagnetic induction. It typically consists of a rotating coil of wire and a stationary magnet. As the coil rotates in the magnetic field, the magnetic field induces a voltage in the wire, producing electricity. Option A describes a fluid dynamo, option B describes a permanent magnet motor, and option D is not an accurate description of a dynamo.

Question 20

Conduction dominates everywhere within the lithosphere.

Accepted Answer

Conduction is the primary heat transfer mechanism in the lithosphere, but in the asthenosphere and deeper parts of the Earth, convection becomes more significant.

Quiz 10: Motion Inside Earth