Great discovery

On an Arctic expedition, the polar explorer James Clark Ross discovered the magnetic South Pole. His measuring instruments had shown him the way. The magnetic pole is located on the Canadian mainland, about 2300 kilometres from the geographic North Pole.

In May 1829, the British polar explorer John Ross and his nephew James Clark Ross set out on an expedition to the Arctic. The goal of the two explorers was the Northwest Passage. It is a sea route north of the American continent that leads through the middle of the icy Arctic Ocean. When the two explorers reached a peninsula with their sailing ships, they realised that they had reached the northernmost point of the American continent. Because of the enormous ice masses and technical problems with the ships, they were stuck there. While exploring the mainland, James Clark Ross realised that they were near the magnetic South Pole. With the help of local Inuit, he set off on sledges and reached the magnetic South Pole on 1 June 1831. The geographic North Pole was about 2300 kilometres away from them. This makes the Briton James Clark Ross the first European to stay at the magnetic South Pole.

When and how the expedition with the Ross research duo will return to Europe is not yet known due to ongoing technical problems.

The Boothia Peninsula

Boothia is the name of the peninsula that polar explorer John Ross discovered in the north of the Canadian mainland. He named it after his friend, the gin manufacturer Felix Booth. This wealthy English businessman had largely paid for the polar expedition.

The Boothia Peninsula is barren: tundra and bare frost heaps and rocky outcrops dominate the landscape. This is the home of the Inuit, an ethnic group that is also native to Greenland. They live mainly from hunting seals, whales or polar bears and from fishing. Their means of transport are kayaks and sledges pulled by dogs. It was only with the support of these indigenous people that James Clark Ross succeeded in reaching the magnetic South Pole.

Polar Regions – Arctic and Antarctic

The largest ice surfaces on earth are around the North Pole and the South Pole. Because of their special location, the polar regions receive very little sunlight and solar heat, and the summers are particularly short there. That is why it is always extremely cold there – temperatures of up to minus 70 degrees Celsius prevail throughout the year. The cold has allowed huge masses of ice to form in the polar regions.

The Arctic ice around the North Pole covers a large part of the Arctic Ocean in winter. It then covers an area of several million square kilometres. For the most part, this is a layer of ice that floats on the sea. In addition, the Arctic ice covers the northern areas of Europe, Asia and North America.

In contrast, the South Pole is located on a continent, Antarctica. Antarctica is the coldest place on earth. Its land mass is almost completely buried under a carapace of ice and snow up to 4 kilometres thick. Almost three quarters of the fresh water on earth is stored in this ice

Humans, animals and plants have adapted to life in the “eternal ice”. Polar bears or reindeer, for example, protect themselves against the cold with a layer of fat and thick fur. Only a few people inhabit the Antarctic, the Arctic is somewhat more densely populated. The best-known inhabitants of the Arctic are the Inuit in North America and Greenland, but there are also the Lapps in northern Scandinavia and indigenous peoples in northern Siberia. In the past, they lived there as nomads and moved around with dog sleds. Today they use snowmobiles and many of them live in cities.

Hardly anything grows in the ice deserts around the poles because of the great cold. The ground between the polar regions and the cold temperate zone is permanently frozen to great depths. This ground is therefore also called permafrost after the Latin word “permanere” for “to last”. It only thaws slightly a few months a year. Then particularly hardy plants such as mosses, lichens or dwarf shrubs can grow on it. This region around the polar regions is also called subpolar tundra.

Earth magnet

We don’t notice it, but the compass needle shows us clearly: the earth is a huge magnet. It has two magnetic poles, a north pole and a south pole. And like all magnets, the earth is surrounded by a magnetic field: the earth’s magnetic field.

In the area of its magnetic field, a magnet exerts force on other magnets, for example on a compass needle. The effect of a magnet can also be made visible by fine iron filings: they arrange themselves around the magnet and point in the direction of its two poles. A line-like pattern is created that indicates the magnetic forces. The lines of this magnetic field are the so-called field lines.

The earth’s magnetic field also has such field lines. They emerge from the earth near the south pole, run outside the earth to the north pole and disappear into the earth again there. They are thus arranged as if a huge bar magnet were running through the middle of the earth.

The south pole of this imaginary bar magnet points approximately to the geographical north pole, its north pole to the geographical south pole. What sounds confusing at first has a simple explanation: the north and south poles attract each other. That is why the north pole of the compass needle points to the magnetic south pole of the earth, and the south pole on the needle points to the magnetic north pole.

However, the Earth’s magnetic field is not only used for orientation on this planet. Together with the atmosphere, it also protects us from threats from space. One of these threats is a charged particle stream that the sun constantly emits in all directions. This so-called solar wind is deflected by the Earth’s magnetic field. Like a capsule, the Earth’s magnetic field deflects the charged particles so that they fly past the Earth and can no longer be dangerous to us.

Compass and orientation

Without it, Christopher Columbus would have got lost on the Atlantic, Ferdinand Magellan’s ships would never have sailed around the world. For over a thousand years, sailors have used the compass for orientation. But how could this little thing show them the long way across the oceans?

The secret of the compass was only revealed very late: In 1600, the English scientist William Gilbert was the first to give a reasonable explanation for the compass needle’s property of aligning itself in a north-south direction: The earth itself is magnetic. The compass needle simply aligns itself with the earth’s magnet. And thus helps people to orient themselves.

So with compass and map in your luggage, no one can get lost – provided you know how their interaction works. The compass consists of a magnetised steel needle that sits freely movable on a point in its centre. Similar to the hands of a watch on the dial, this point is placed on a scale with all four cardinal points. When the compass is horizontal and still, its magnetic needle aligns itself with the field lines of the earth’s magnetic field: It points in a north-south direction. If you place a map under the compass and turn it until its north direction points in the same direction as the compass needle, the map is aligned. The direction of the destination is now easy to see.

But there is one small difficulty: because the magnetic poles of the earth are constantly shifting, the magnetic pole and the geographical pole do not coincide exactly. This leads to an angular difference between the two poles. This so-called declination must be taken into account when using a compass, and it is not the same everywhere on earth. Here in Germany, the declination is relatively small and is approximately between 1° and 3° to the east.

Not only humans, but also animals orient themselves to the earth’s magnetic field. Many animal species undertake long migrations during the year, for example migratory birds. To find their way south, they orientate themselves by the landscape, the position of the sun and, at night, by the stars. In addition, they have their own sense of magnetism that gives them direction. With this “compass in their body” they can find the right way even in poor visibility.