Plate Movement & Heat Transfer Lecture

Question-and-answer flashcards covering heat transfer mechanisms, mantle convection, plate tectonics forces (ridge push & slab pull), and key Earth layers from the lecture notes.

What are the three main modes of heat transfer?

Conduction, convection, and radiation.

Define conduction in the context of heat transfer.

The transfer of energy from one molecule to another through direct contact, occurring most readily in solids and liquids.

How does radiation transfer heat?

By electromagnetic waves that can be absorbed, reflected, or transmitted through a cooler body.

Explain convection as a heat-transfer process.

The movement of heat within a fluid (liquid or gas) where warmer, less-dense material rises and cooler, denser material sinks, creating a current.

What is a convection current?

A cycle of rising hotter, less-dense material and sinking cooler, denser material that transfers heat within a fluid.

Where do convection currents occur inside the Earth?

Within the mantle, beneath the lithosphere.

What is the primary heat source driving mantle convection?

Heat from the Earth's core generated by the decay of radioactive elements and residual heat from Earth’s formation.

Describe the lithosphere.

The rigid outer layer of Earth composed of the crust and uppermost mantle, broken into tectonic plates.

What is the asthenosphere?

A soft, weak, plastic-like upper mantle layer on which lithospheric plates float and move.

Why does hot mantle material rise while cooler mantle material sinks?

Because temperature differences create density differences: hot material becomes less dense and rises, while cool material becomes denser and sinks.

How do convection currents contribute to plate movement?

The flowing mantle drags lithospheric plates, causing them to move slowly across the asthenosphere.

What is ridge push?

A force created when magma intrudes at an oceanic ridge, elevating and pushing plates apart.

What is slab pull?

The force exerted by a cold, dense oceanic plate that sinks into a subduction zone, pulling the trailing plate along.

State the learning competency addressed in this lesson.

Describe the possible causes of plate movement (S10ES-IA-J-36.5).

List the three specific lesson objectives mentioned.

(A) Define convection current; (B) Describe possible causes of plate movement; (C) Sketch the process of mantle convection.

How thick is Earth’s crust on average?

Approximately 0–100 km thick.

Which two Earth layers together form the lithosphere?

The crust and the uppermost mantle.

What property of matter does density describe?

How closely packed the particles of an object are, or the amount of mass in a given space.

Which layers of Earth are liquid and solid in the core region?

The outer core is liquid, while the inner core is solid.

Why does conduction occur more readily in solids than in gases?

Because particles are closer together in solids, facilitating energy transfer by collisions.

Give an everyday example of radiation heat transfer.

The Sun warming Earth via electromagnetic waves.

What happens to rising mantle material as it cools near the lithosphere?

It becomes denser, sinks back toward the lower mantle, completing the convection cycle.

What is the overall result of mantle convection on Earth’s surface?

Slow, continuous movement of tectonic plates leading to phenomena such as continental drift, earthquakes, and volcanism.