Heat Flow In The Earth

Question 1

What are the two major surficial driving forces of plate tectonics?

Answer 1

Ridge-push (upwelling magma)

Slab-Pull (cold sinking lithosphere)

Question 2

What are the two sources of the Earth’s internal heat?

Answer 2

1. Primordial heat trapped during planetary accretion

2. Radioactive decay

Question 3

What is the thermal power of the Sun?

Answer 3

1.22 x 10^5 TW

Question 4

What surface processes on Earth involve heat?

Answer 4

Water cycle, erosion, biosphere

Question 5

What deep processes in the earth are driven by heat?

Answer 5

Convection
Plate movements
Metamorphism
Plutonism
Volcanism

Question 6

Name the four fundmental types of heat transfer.

Answer 6

Conduction/diffusion, advection, convection, and radiation.

Question 7

What is conduction/diffusion?

Answer 7

Heat transfer between objects in physical contact.

Question 8

What is advection?

Answer 8

Heat transfer by moving an object containing heat.

Question 9

What is convection?

Answer 9

Heat transfer due to fluid motion

Question 10

What is radiation?

Answer 10

Heat transfer due to emission or absorption of electromagnetic radiation.

Question 11

Which of the modes of heat transfer does Fourier’s First Law refer to and what does it describe?

Answer 11

Conduction or diffusion
Heat flow (q) equals (-ive) product of material’s thermal conductivity (K) and temperature gradient (t/z)

Question 12

What is the unit for temperature gradient?

Answer 12

Temperature gradient is the change in temp over a given distance
Unit: 1K/m

Question 13

What is thermal conductivity, K?

Answer 13

A material’s ability to transfer heat via conduction

Question 14

What are the relevant radioactive isotopes involved in Earth’s heat production?

Answer 14

U-238, U-235, Th-232, K-40