Science in the News: Arctic monitoring expedition

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					Science in the News: Arctic monitoring expedition


Title: Arctic monitoring expedition

Description:

This activity contains an article about a proposed expedition to measure the thickness of the
Arctic ice, followed by questions to test students’ comprehension of the article, and to
encourage further research and discussion.



Links to the curriculum:

This activity looks at an application of radar and communications technology, linking to:
Sc4       Physical processes – the electromagnetic spectrum
       3e           that the electromagnetic spectrum includes radio waves, microwaves,
                    infrared, visible light, ultraviolet waves, X-rays and gamma rays
       3i           that radio waves, microwaves, infrared and visible light carry information over
                    large and small distances, including global transmission via satellites.
         Breadth of study
       1b           considering ways in which science is applied in technological developments.
Science in the News: Arctic monitoring expedition




                       Arctic monitoring expedition

                                            In February 2009, explorer Pen Hadow and two colleagues
                                            went on a 2000 km trek across the Arctic to the geographic
                                            North Pole, dragging behind them a sledge with radar and
                                            other monitoring equipment. The expedition was to provide
                                            valuable data to tell scientists just how the Arctic ice is
                                            being affected by climate change.
                                      Until this expedition, scientists used satellite and submarine
                                      data to measure how the ice is changing, but there were
    An arctic landscape (iStockphoto) vast areas where they could not tell how thick the ice was,
and so could not estimate how long it would be before it melted, if current trends continued.
The ground penetrating radar equipment that Pen Hadow and his colleagues dragged
behind them sent pulses of radar down through the ice and used the reflections to measure
the ice thickness. Usually this type of equipment weighs about 100 kg, but engineers had to
design equipment that was light enough for the team to tow. The resulting ‘Sprite’ radar
weighs only 4 kg. Prior to the expedition, tests conducted in Canada to compare the results
of the Sprite radar with drilled ice cores showed that the Sprite radar is very accurate indeed.
So the expedition was able to measure the thickness of the ice every few centimetres on the
way to the North Pole.
A computer on the sledge collects data from the radar, bio-monitoring equipment, cameras
and video, and transmits it to whichever of a series of 66 communications satellites is within
range. The communications satellites then re-transmit the data on to a base-camp in the UK.



                                                    QUESTIONS

1    Until this expedition, how did scientists find out how the Arctic ice is changing?

2   What new information has this expedition enabled scientists to measure, and what has
    this enabled them to predict more accurately?

3    Describe in your own words how ground penetrating radar works.

4    Which types of electromagnetic radiation were used during this expedition, and where?

5   Suggest some reasons why it was important to test the equipment in Canada before the
    expedition began.



Challenge
You can find out more information about this expedition, the people, the science and the
technology involved, from the website www.vancoarcticsurvey.com . Choose one aspect of
the expedition that particularly interests you and find out more about it. Be prepared to share
what you find out with another group or with your whole class.
Science in the News: Arctic monitoring expedition




                   Answers and useful information

Answers to questions

1    Until this expedition, scientists used data collected by satellites and by submarines.

2   This expedition has enabled scientists to measure the thickness of the Arctic ice across
    a large area, enabling them to predict more accurately how long it will take for the Arctic
    ice to melt.

3   Ground penetrating radar sends pulses of radio waves down through the ground and
    measures the time taken for the pulse to return after it has been reflected from a
    boundary between different media (ice and rock, for example). The speed of the radio
    waves is known, so the distance can be calculated from the time.

4   Camera and video data uses visible light (or possibly infrared – if data is collected using
    thermal imaging cameras). The ground penetrating radar uses radio waves. The signals
    transmitted to the satellite and to the base station are likely to be in the form of
    microwaves.

5   The equipment had to be tested before the expedition began to ensure that it would
    continue to work in the extremely cold conditions of the Arctic (which is very tough on
    electronic components, often cracking both soldered joints and the plastics used for
    many components). The radar used was a new design so it had to be tested to ensure
    that it would give accurate results. This was done by comparing the ice thickness
    recorded by the Sprite radar to the ice thickness found by drilling cores through the ice to
    the ground beneath.



Challenge
The website www.vancoarcticsurvey.com has a wide range of information, both technical
and much less technical, enabling students working at a wide range of levels to find
appropriate and relevant information to share with others.

				
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posted:9/14/2012
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