POLENET Science explained...

What is the polar Earth?

The polar Earth means the parts of the Earth which are close to the poles. These regions are often called the Arctic (which surrounds the north pole) and the Antarctic (which surrounds the south pole). The north pole is beneath the ocean of the Arctic, although this is often frozen over. The south pole is beneath the land of the continent of Antarctica.

Both the Arctic and Antarctic have inhospitable climates. For much of the year it is below freezing. Because so few people go to the polar regions, they are relatively unexplored and poorly understood. Scientists now realise that the polar regions are very important in the Earth's climate system. They interact with the oceans and the atmosphere.

POLENET scientists want to understand the polar Earth. The more we know about the Earth, the better our decisions about the future will be. Scientists can improve their understanding by making new observations of different aspects of the rock, ice and weather.

What is an observing network?

Observations of the Earth can tell us much more if we put them all together to make one picture. In an observing network, many similar measurements are made in many different places at the same time.

A network can also mean a group of people who coordinate their actions. This is important for POLENET because scientists working on different things can compare their results and get a better understanding of whole systems.

What do geophysicists do?

The word 'geo' comes from the Greek word meaning 'Earth'. So geophysicists are just people who use techniques from physics to investigate the Earth.

Geologists can study the rocks on the Earth's surface by looking at them directly. It isn't possible to see deep into the Earth (it's nearly 6,400 km to the centre and the deepest drill holes only go down to about 10 km depth).

For example, seismologists (a kind of geophysicist) can find out about deep structure by analysing seismic waves from earthquakes. Earthquake waves show different 'wiggles' when they pass through unusual structures in the Earth.

How is GPS used in POLENET research?

You might already be familiar with GPS (Global Positioning Systems). Signals from many satellites are received by a small unit, for example on a car or a ship. This enables a position (a latitude and longitude) to be determined. Ship and car navigation systems can be accurate to the nearest few meters.

The same technology, with better receivers and careful processing of the signals recorded from the satellites, can be made to give positions accurate to less than a centimetre. The vertical position of the receiver (height about a reference level) can also be measured very accurately.

Many people are worried about global warming. It seems as if the polar ice caps are melting, but we don't know how fast. We do know that when the ice caps melt, the land beneath bounces up because the continents are effectively floating on the Earth's mantle beneath.

We can measure how fast the continents are bouncing up (called glacial-isostatic adjustment) using accurate GPS. The position of a fixed point is measured, and then re-measured about 5 years later. The difference in position shows the rate of uplift. The scientists who do collect and analyse this kind of data are called geodesists.

Making a measurement in exactly the same point requires a survey marker to be fixed very securely to the rock. This is called a 'monument'. The photo on the left shows a monument near Law Base (summer only) in East Antarctica. Repeated positions will be determined for this marker during the International Polar Year of 2007-2008.

What other kinds of data are collected?

The picture on the left shows three scientists setting an earthquake recording station in Antarctica. Scientists who collect and analyse earthquake data are called seismologists.

POLENET scientists will also study the ice, these are glaciologists. Other, general geophysicists will collect data on the Earth's magnetic field, the atmosphere and the oceans.

How do I work as a geophysicist in polar regions?

To work as a scientist in polar regions, you need to be a good all-round physicist.

Maths is helpful, because you'll need to analyse numerical data. Are you naturally curious about what you see around you? You need to be brave and innovative, no-one has done this research before!

If you like maths and physics, you could study geophysics, or a program including geophysics, at university. There are many cool applications of physics and you might prefer to use your talents in a range of applications.

It helps to be practical and pretty fit too - good luck with whatever you choose!