Where is the location of an earthquake's epicenter?

An earthquake epicenter is the point on the Earth's surface directly above the earthquake focus.

Explanation:

An earthquake epicenter is the point on the Earth's surface directly above the earthquake focus. The epicenter is the geographical location of the earthquake reported on television stations and written reports about earthquakes. The point where the rocks actually break is the earthquake focus.

An earthquake epicenter can be located from records made of earthquake waves on devices called seismographs

Explanation:..

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me