what is the imaginary line running north and south
Meridian (geography) A (geographical) meridian (or line of longitude) is the half of an imaginary great circle on the Earth's surface, terminated by the North Pole and the South Pole, connecting points of equal longitude. The position of a point along the meridian is given by its latitude indicating how many degrees north or south of the Equator the point is. Each meridian is perpendicular to all circles of latitude. Each is also the same length, being half of a great circle on the Earth's surface and therefore measuring 20,003.93Â km (12,429.9 miles).
38th parallel north The 38th parallel north is a circle of latitude that is 38 degrees north of the Earth's equatorial plane. It crosses Europe, the Mediterranean Sea, Asia, the Pacific Ocean, North America, and the Atlantic Ocean. The 38th parallel north formed the border between North and South Korea prior to the Korean War.