Lesson 2: Earth's Heat Internal Sources (reporter and summary)

Tho core of the Earth is about as hot as the surface of the Sun - around 5,000-6,000°C

In Iceland, people use geothermal energy (from Earth'a heat) to warm homes, cook food, and even keep sidewalks from freezing.

How did Earth form 4.5 billion years ago?

From the collision of dust, rocks, and planetesimals in space.

What did the violent impacts during Earth’s formation release?

Huge amounts of energy that made Earth so hot much of it melted.

What is the term for the Earth’s interior heat?

Internal heat or geothermal energy.

What would happen to Earth without internal heat?

It would be a cold, dead planet.

What natural processes are driven by internal heat?

Volcanoes, earthquakes, and the movement of tectonic plates.

What is primordial heat?

The leftover energy from Earth’s formation about 4.6 billion years ago.

From what process does primordial heat originate?

From the repeated collisions of dust, gas, and planetesimals in the early solar system.

What force caused planetesimals to collide and form larger bodies?

Gravity.

What happened to the kinetic energy from these collisions?

It was converted into heat, melting much of the young Earth.

Gravitational Pressure

as you go deeper into earth the weight of the overlying layers pushes down slowly on the rocks below. This intense pressure causes the materials inside the earth to compress and squeeze tightly together. Which adds to earth’s internal heat.

Near the core, what is the estimated pressure?

3 to 4 million times greater than the atmospheric pressure at sea level

Heat from Radioactive Decay

inside the earth , there are naturally occurring radioactive isotopes such as potassium-40, uranium-235, uranium-238, thorium-232. These isotopes are unstable and over time their nuclei they break down in a process called radioactive decay.

DENSE CORE MATERIAL

The Earth's inner core is extremely dense because it in made mostly of iron sind nickel, withs traces of other heavy elements lika golet platinom, and tungsten, As these heavy materials sunk to the center during Earth's early formation, they generated huge amounts of heat through friction and compression and the pressure is very immense approximately 360 gigapascals (QPa), which is equivalent to about 46 million atmospheres..

The pressure and density together produce enormous thermal energy, which contributes to Earth's. Magnetic field, internal lient and the temperature that can reach up to 6000 (nearly as hot as the surface of the Sun)

Into what category are conduction, convection, and radiation classified?

They are the three modes of heat transfer.

What is conduction?

Heat transfer through direct contact of particles (e.g., a metal rod heating up from one end).

What is convection?

Heat transfer through the movement of fluids (liquids or gases) caused by differences in density.

What is radiation?

Heat transfer through electromagnetic waves, without requiring a medium (e.g., heat from the Sun).