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electromagnet. Navigating the Arctic Ocean with a compass with an unobstructed needle you ll be
able to find a location where the needle points directly downwards directly towards the centre of the Earth.
This location is called the magnetic North Pole. Because the compass needle s North always points to the
opposite pole, it is in fact the magnetic South Pole that inhabits the high north but general convention accepts
the false appraisal of this northern pole which is always on the move. Currently, the magnetic North
Pole is at 82.7°N / 114.4°W, approx. 800 km south of the geographic North Pole, and it moves northwest
wards at a rate of 40 km annually.
The magnetic North Pole and South Pole are not place symmetrically on each hemisphere. Convert these
two poles to a geocentric dipole by placing them at either end of a straight line through the centre of the
Earth and one will get two intersection points at the Earth s surface. The one on the northern hemisphere is
called the geomagnetic North Pole. Obviously, this point also moves around, and right now it is at 79.74°N /
71.78°W which is in Nares Strait north of Inglefield Land in northwesternmost Greenland.
... and à propos Poles. Why don t you visit the Poles in the beautiful northern areas of the Baltic republic
just south of Denmark.
The inconstancy of the Arctic Circle
The Arctic Circle of the northern hemisphere is defined as the latitude where the sun at summer solstice
(most often 21 June) is above the sea level horizon all 24 hours and at winter solstice below the same horizon
all 24 hours. Obviously, dates are the opposite for the Antarctic Circle in the southern hemisphere.
To attract and please many tourists, a commercial village has been erected north of Rovaniemi in northern
Finland, allegedly right on top of the Arctic Circle that is clearly marked as a fixed element in the terrain.
However, the Arctic Circle is not stationary. It moves steadily towards the pole or towards the equator. Why
is this so?
Well, Earth s rotational axis is tilted from the vertical plane. In average this tilt is 23°30 but it
rarely assumes that exact value because during a 41000-year cycle the tilt varies between 21°34 and
24°36 . Currently, the tilt is 23°27 and every year it is diminished so much that the Arctic Circle moves 14,5
meters towards the geographic North Pole. If you take 90°N and subtract the current tilt the result will be
66°33 N that is the latitudinal parallel today named The Arctic Circle . An increased tilt of the axis will give
warmer summers and colder winters. A lesser tilt will decrease the differences between seasons.
Danish Polar Center
IPY Service Manual for Kangerlussuaq 2008
version 1 June 2008
Compiled and written by Henning Thing (het@fi.dk)
Danish Polar Center Danish Agency for Science, Technology and Innovation
page 58 of 60
By the way, we should be very thankful to Saturn, Jupiter and our good old Luna. Through their gravitational
pull they have managed to stabilize the Earth so the wobble of the axis stays within the 3° that we have
learned to live with.
If one day our Moon should no longer be orbiting Earth, then our rotation axis would wobble so wildly
that the Arctic Circle could relocate to Equatorial regions, and Life as we know it would cease to exist.
Arctic :: Antarctic -- What is up and down?
Arctic and Antarctic. Pole and antipole. Presently, with climate change debate and models conceive new
consequences for the Polar regions and eventually the lower latitudes it is fundamental to keep the cool
facts clear:
The Arctic consists of an ocean surrounded by relatively low land masses. The Antarctic consists of a
mountainous land mass surrounded by ocean. The geographic North Pole is located at sea level. The geographic
South Pole is 2835 metres above sea level on top of the Antarctic Ice Sheet. The Arctic includes the
land territories of eight countries from the continents Asia, North America and Europe. The Antarctic is its
own entire continent declared a common world heritage claimed for peace and research according to the
Antarctic Treaty of 1959.
The Arctic has almost 4 million inhabitants many of whom are indigenous peoples. The Antarctic has never
had indigenous inhabitants but only seasonal employees of the research stations, in total around 4000 scientists
and technicians.
The ice of the Arctic Ocean is almost entirely frozen seawater. The ice of the Antarctic Ice Sheet is entirely
frozen freshwater, also known as glacial ice. A continued global warming is forecasted to have profound effects
in large parts of the Arctic, while climate in most of the Antarctic is forecasted to remain unchanged.
When the Arctic Ocean sea ice melts there is no increase in sea level. If the Antarctic Ice Sheet should
　
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