east longitude

基本解释

The epicenter of the quake was located 31.0 degrees north latitude and 103.4 degrees east longitude, the bureau said.
该局还说，震中位于北纬三十一度，东经一百零三点四度。
Center point coordinates are located at 17 degrees, 5 minutes east longitude and 5 degrees, 0 minutes north latitude.
中心点素坐标位于东经17度5分，北纬5度0分。
The epicenter was monitored at 22.5 degrees north latitude and 113.9 degrees east longitude, with a depth of about 23 kilometers, said the station.
地震局称，据监测，震源位于北纬22.5度，东经113.9度，深度达23公里。

So each hour's time difference between the ship and the starting point marks a ship's progress of fifteen degrees of longitude to the east or west.