Final answer:
The difference between pressure at Earth's surface and below Earth's surface is primarily due to the weight of the fluid or medium above that particular point. Atmospheric pressure at the surface is the weight of air above, while below the surface, in cases like diving underwater, the pressure increases due to the weight of both the water and the atmosphere.
Step-by-step explanation:
The difference between pressure at Earth's surface and below Earth's surface is primarily due to the weight of the fluid or medium above that particular point. At the Earth's surface, the pressure exerted on you is a result of the weight of air above you, which is called atmospheric pressure. As you go below the Earth's surface, such as diving underwater, the pressure increases due to the weight of both the water and the atmosphere above you.
For example, if you dive a meter below the surface of a pool, you can feel a pressure increase even though it's a short distance. This is because water is much denser than air, about 775 times as dense.