What is the line of longitude used as the origin in a system of coordinates called?

Prime meridian

Explanation:

The meridian is an imaginary longitudinal line that defines the zero degrees, and passes through the Greenwich is called as the international dateline. Thus the line is used to find the coordinated on the map, being equidistant is shape and areas, has positive and negative longitudes ranging from 0 to 180 degrees.

Earths place in space 

Answer volcanic eruptionsseismic waves from earthquakes;