Some of the heat that affects geologic processes comes from the Sun and some comes from inside the Earth What does each of these heat sources play in Earth processes?

(a) If you take off your shoes on a beach or any sandy environment and walk on it on a hot, sunny day is the sand hot or cold? Why?

Now, dig down in the sand just a few inches.

What do you feel now, and why? What does this sugsest about the depth to which heat from the Sun can penetrate the Eartha

Base th Based on this condlusion is the Sun's energy or Earth's intemal heat the cause of melting rock within the Earth? Explain

(b) The deeper down one goes into mines or drill holes, the hotter it gets. This temperature increase is geothermal gradient. Does this phenomenon support or contradict your conclusion in (a) ? Explain

(a) On a beach or in any sandy environment, on a sunny day, the sand would be hot.

This is caused by conduction. This is the heat transfer from the sun to the sand. However, sand is a poor conductor of heat. Only the parts exposed receives this heat energy from the sun. It restricts the flow of this energy to parts that are hidden from the exposure.

That is why the surface is hot, but when you dig down the sand a few inches, it becomes cool.

Based on this conclusion, it is evident that the Earth's internal heat is the cause of melting rock within the earth (except the earth doesn't have layers of soil but has layers of aluminum instead). Like I explained above, the energy from the sun cannot penetrate to that depth and start melting rocks (it have not even melted surface rocks).

The Earth's internal heat is caused by either radioactive decay, friction forces from the movement of denser core materials and the initial heat when the planet was formed. It is very intense and concentrated at this depth.

(b) It does not contradict my conclusion in (a)

Let us look at it from this angle. Earth's structure. The outer part is the crust. When you start digging or descending from the crust, you get to the mantle which is next to the core. The core is the hottest part in earth with temperatures reaching 5000 degrees Celsius. Now the temperature in this core is even affecting the mantle. This mantle is the liquid outer core. So definitely, the deeper you dig or descend, the hotter it gets. This is caused by the structure of the earth.