КомпасА и полюсА.
А отчего это Гривич между Британией и Ирландией пролегает? Что за компания владеет Аляской ? (карты кликабельные)
In 1701, Edmund Halley produced the world’s first isogonic chart, which shows how the angle between magnetic north and true north varies at different points in the Atlantic Ocean.
Magnetic declination or variation is the angle on the horizontal plane between magnetic north (the direction the north end of a compass needle points, corresponding to the direction of the Earth's magnetic field lines) and true north (the direction along a meridian towards the geographic North Pole). This angle varies depending on position on the Earth's surface, and changes over time.