The position on the surface directly above the earthquake source is called the epicenter.

Here's a breakdown:

* Focus (Hypocenter): This is the actual point underground where the earthquake originates. It's the location of the initial rupture along the fault.

* Epicenter: This is the point on the Earth's surface directly above the focus. It's where the earthquake's effects are typically the strongest.

Think of it like this: imagine a light bulb underground. The bulb is the focus, and the shadow it casts on the ground above is the epicenter.