Convection and Heat Transport Concepts

The lecture covers the movement of tectonic plates, focusing on mantle convection and the forces driving these movements. It explains the concept of heat transport, energy consumption, and the role of volcanic activity in heat flow. The lecture also delves into heat conduction, temperature gradients, and the global heat flow, providing insights into the geothermal gradient and the convection process within the Earth's mantle.

What is the primary focus of the lecture discussed before Christmas?

• The movement of tectonic plates

• The formation of mountains

• The history of the Earth

• The study of ocean currents

How does the Earth's mantle behave over long timescales?

• As a solid

• As a fluid

• As a gas

• As a plasma

What is the main mechanism of heat transport discussed in the lecture?

• Conduction

• Reflection

• Radiation

• Advection

What is the average global heat flow from the Earth's interior?

• 10 to the 23rd joules per year

• 10 to the 20th joules per year

• 10 to the 21st joules per year

• 10 to the 22nd joules per year

Which regions have the highest heat flow according to the lecture?

• African craton

• North American craton

• Eastern Pacific and Southern Indian Ocean

• South American craton

What is the term used to describe the line that shows temperature increase with depth in the Earth?

• Thermal gradient

• Geoterm

• Thermocline

• Isotherm

What is the state of the Earth's outer core?

• Liquid

• Plasma

• Gas

• Solid

What is the critical factor for convection to occur in a fluid layer?

• High pressure

• High temperature gradient

• Strong magnetic field

• Low density

What role does gravity play in the convection process?

• It increases the temperature gradient

• It makes the lighter material buoyant

• It causes the fluid to cool down

• It stabilizes the fluid layer

What happens to small instabilities in a fluid layer with a small temperature difference?

• They are eliminated

• They rise to the top

• They are stabilized

• They cause convection