Can Ice predict the future?
In this chapter you can find out just what an ice core is, where and how it is collected and what it can tell us about the past and future changes in our climate. Right now, scientists around the world are busy revealing the secrets hidden deep in the ice.
Rollover wordcloud to see more info.
So, what is an Ice Core?
Short section of an Ice core.
Ice cores, are normally
taken in 4 metre sections.
If you joined them end to end,
they can be up to 3000m long.
Which is the same as 30
full size Football pitches!
An ice core is a cylinder of ice removed using a hollow drill from the snow and ice that has built up over years. Air bubbles and other interesting material from previous time periods have been trapped in the ice. The air in the bubbles provides a picture of the climate at the time and also allows us to work out the temperature at that time..
In the close up picture above you can clearly see bubbles
and debris trapped in the ice.
The bubbles contain air that can be over 800,000 years old!
Click the pic for a closer look.
Ice cores are cylindrical samples of ice removed from ice sheets and glaciers.
Because ice cores are taken from regions which remain frozen year-round,
they contain detailed information about the history of the Earth's climate,
for those who know how to look. Paleoclimatologists often study ice cores
extensively to gather data about major climate events and to piece together
patterns in the Earth's meteorological history. Ice cores can be found
in storage in numerous research facilities and archives.
In order to take a core sample from ice, researchers must find an area with significant ice deposits, ideally an area where ice has been present for thousands of years. The polar ice caps are a prime location for taking ice cores, as are some permanent glaciers. The researchers drill into the ice with specialized equipment, using a liquid to maintain pressure so that the hole does not collapse, and they remove samples of ice from the hole and bag them for further study.
Why isn't the Earth frozen?
We are a just bit too far away from the sun for comfort. Going by our location we should be frozen solid. So why aren't we? Our planet's central heating system ought to be fairly simple: energy comes to us from the sun in the form of sunlight. The earth then glows with warmth, giving off infrared light. [All warm bodies give off this invisible infrared glow - including humans. Night-vision goggles work by detecting it, as do heat-seeking missiles, and TV remotes] Carbon Dioxide [CO2] and other impurities in the atmosphere stop the infrared light escaping and so keep us warm. This is now known as the greenhouse effect.
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How Can Computers Help?
Information stored in ice thousands of years old, may be used to reconstruct
climates that existed aeons ago. As snow falls on ice caps and ice sheets where
temperatures normally stay below freezing all year round, it creates a record
of the environmental conditions as layers of snow and ice form year after year.
By comparing ancient materials trapped in the ice with modern data, we can
tell if anything has changed. Using powerful computing, the collected
data can be analysed in more detail than ever before.
Some methods used include;
The mass spectrometer.
Measures the oxygen isotope ratio.
Measures the capacitance and conductance of the ice.
A process that allows the separation of ions and polar molecules based on their charge.
What is Chromatography?
Chromatography is a way of separating mixtures.
Paper chromatography is used for mixtures of dyes and happens because the different dyes move different speeds on the paper when they are ‘pulled up’ by the solvent e.g. water The dyes have different abilities to ‘hold on’ to the paper as they have different structures.
An ion is a charged particle e.g. sodium (Na+) or sulphate e.g. (SO42)-. These ions can be separated and detected by chromatography. The amounts of these ions gives us important clues.
For example. If we find lots of sulphate in the ice samples, this suggests lots of volcanoes were erupting at this time as volcanoes release sulphates.
The science of global warming
Air bubbles trapped in the ice cores provide a record of past air composition. Current levels of the gas carbon dioxide (CO2) in the air are higher than any previous level in the past 650,000 years. Scientists at the Mauna Loa observatory in Hawaii say that CO2 levels in the atmosphere now stand at 387 parts per million (ppm), up almost 40% since the industrial revolution. CO2 is the chief greenhouse gas that results from human activities and causes global warming and climate change.
The Earth's average surface temperature has increased by 1.4oF (0.8oC) since the early years of the 20th century. The 11 warmest years on record (since 1850) have all occurred in the past 13 years. The five warmest years to date are 2005, 1998, 2002, 2003, 2007.
The general scientific consensus is that global warming is largely the result of increased atmospheric concentrations of carbon dioxide and other greenhouse gas emissions. The growth in emissions is caused by human activities, primarily fossil fuel combustion and changes in land use, such as agriculture and deforestation.
How do we get an Ice Core?
Drilling an ice core is not an easy job. The drill is a highly specialized tool that must be able to operate under very harsh conditions. The drill head cuts away a ring of ice and the ice core slides into the tube. It can contain up to 4 metres of ice in one cut. Ice cores are usually about 10 cm in diameter. As they are brought to the surface a scientist will examine the core and attempt to place that section of core in time. Alternating bands of light and dark snow can been seen when light is shone through the ice core from behind. The light layers represent summer snow and the dark layers are winter snow. By keeping track of the individual layers they can be counted in much the same way as tree rings. More sophisticated techniques for dating ice cores are done later back in the laboratory by analyzing the concentration of oxygen atoms in the ice.
Drilling through 3 km of ice could take up to 1000 drillings!
Ice cores are mainly collected from Antarctica and Greenland. The oldest recovered ice reaches 800,000 years back in time and was drilled between 1999 and 2004 at Dome Concordia. Antarctica.
The data graph above shows concentrations of CO2 in our atmosphere in Parts Per Million by Volume or PPMV overlayed on to the Antartic temperature. The raised area of crowded red at the right hand end of the graph represents the last 10,000 years in our history.
The sequence of satellite images
above shows the total collapse of the
Larson B ice shelf.
The Collapse Of Larson B - Proof of global warming?
Ice shelves are layers of ice, fed by glaciers, that float on the ocean around much of Antarctica. The Larsen B shelf was about 220 meters thick. Scientists believe that it existed for at least 400 years prior to this event and likely existed since the end of the last major glaciation 12,000 years ago. The area lost in this most recent event is about the same size as Cornwall(3,500 square kilometres). This is the largest single event in a series of retreats by ice shelves along the peninsula over the last 30 years. The retreats are attributed to a strong climate warming in the region. The rate of warming is approximately 0.5 degrees Celsius per decade, and the trend has been present since at least the late 1940s. Overall in the peninsula, the extent of seven ice shelves has declined by a total of about 13,500 square kilometres since 1974.
When fiction becomes a frightening fact!
The opening scenes of the Hollywood climate disaster movie 'The Day After Tomorrow' show the hero working in Antarctica. He is camping on a massive floating shelf of ice, called Larsen B, drilling ice cores through its surface. The first sign of impending doom comes when the ice shelf cracks, right across the research site. In trying to save his precious ice cores, our hero only just survives. This scene is based, loosely, on a true story. Larsen B is a real ice shelf, or at least it was. It was more than 3,000 square kilometres in area, and 220 metres thick. In February 2002, over a period of just a few weeks, Larsen B unexpectedly shattered. By the beginning of March, 500 million tonnes of ice, covering an area the size of Cornwall, had vanished.
Research: Larson B ice shelf. The British Arctic Survey
What is a Ratio?
Written as 2:1
A ratio is a way to compare amounts of something.
For example, to make drink you may need to mix 2 parts water to 1 part juice. This means the ratio of water to juice is 2 : 1
In ice cores, the ratio of 18O to 16O molecules are
measured against the "Standard Mean Ocean Water" control, or SMOW. To work
out the Oxygen isotope ratio, we take the control from the sample and divide
the result by the control.
There are three different isotopes of oxygen. 16O, 17O and 18O. So by measuring the amount of different Oxygen Isotopes in the ice we can discover the temperature at the time of the snowfall.
Atomic Number: 8. Atomic Radius: 66 pm [pico metres]
Atomic Symbol: O. Melting Point: -218.79 oC
Relative Atomic Mass: 15.9994. Boiling Point: -182.95 oC
Celsius and Fahrenheit This equation states the relationship between temperature in Celsius (C) and temperature in Fahrenheit (F): F = 9/5C + 32 Most of us know that water freezes at 0 oC. Using the equation, we can work out that this is equal to 32 F. We also know that water boils at 100 oC, which is equal to 212 F. Research: Daniel Gabriel Fahrenheit, Anders Celsius
The Albedo effect.
Changes in the polar regions can cause more warming in the entire planet earth system through feedback effects. One such effect is the reduction of ice and snow due to warmer temperatures. When the white and gray snow and ice disappears, less sun rays are reflected out and instead the heat is absorbed by land and sea - which causes further increase in the warming.
The word Albedo is derived from Latin albedo "whiteness", in turn from albus "white", and was first used by Johann Heinrich Lambert in 1760.
Feature article: Sustainable Energy. Feature Company: Ecotricity
Ecotricity: ecofriendly electricity: electric energy produced by ecologically friendly means, for example, by solar power or wind power.
Ecotricity is the name of an electricity company with a difference, it is dedicated to changing the way electricity is made. They take the money the customers spend on electricity and invest it in clean forms of power like wind energy. What's more, they are the only green electricity company making any ground actually building these new renewable energy sources.
In the last 7 years Ecotricity has invested nearly £50million in wind energy. Building wind turbines and selling electricity across the country since 1996. They can supply people and buisnesses alike, and are proud to be recommended by the Soil Association and Oxfam.
Some people may not realise that we can now choose who supplies our electricity, and how it's made, so wherever you live in the UK you can actually choose to have your home, school or business supplied by clean energy. Switching to green electricity takes about five minutes and it's probobly the biggest single step you can take to reduce your emissions and protect the environment.
Ecotricty also sponsers 'Greenbird' a record breaking wind powered vehicle:
What is The Greenbird?
Harnessing the power of the wind is what Ecotricity is all about! And now we're taking our love of wind to a new level, with the fastest wind powered vehicle on Earth! The Greenbird will challenge all your preconceptions of wind powered travel - it's simply an amazing machine powered only by nature. And not just on land... on ice too. It's part aeroplane, part sailboat, part Formula One car...
The Greenbird is two vehicles: a land craft and an ice craft, powered only by the wind. The project's aim is to break both the land and ice world speed records. On March 26, 2009, the Ecotricity Greenbird set a new world land speed record for wind powered vehicles of 126.2 mph. The team hopes to both better that new record, and continue to work toward breaking the ice record in Winter 2010/11. The project is a partnership between Ecotricity, and engineer Richard Jenkins, founder of the Windjet Project. The team is all British, independent, visionary, passionate and utterly committed to envisioning a zero carbon transportation future.
To find out more click
Environment Under Threat
The Antarctic is an amazing place, it is incredibly important to our understanding of how the world works. It is a place of extremes. Almost 60 times the size of the United Kingdom, Antarctica is the highest,coldest and windiest continent. Less than 1% of it is free of ice or snow. The ice cap, which shrouds the peaks and valleys of the continent,contains almost 70% of the world's freshwater and 90% of the world's ice. During winter the ocean surface freezes, forming a cover of sea ice as large as the continent it surrounds. Many animal species are under threat and their numbers are declining. The loss of an Emperor penguin colony in 2009 and the terminal decline of the Albatross are just two examples. To find out what is going on Marine scientists study seals as they are a 'keystone species' and act as important signs of the health of the whole ecosystem. There are three main types of seal that are monitored in the by the British Antarctic Survey from their station on Bird Island in South Georgia, part of the Falkland Islands. [map of location here]
Tracking and Technology and Ecology
Most of a seal’s life is spent in the sea, and it would be a very cold and wet job to see what they are up to, so we have to use other methods to monitor them. Today one of the most important tools used track animals is GPS (Global Positioning Systems) and it started life as a piece of string. In 1803, the Naturalist John James Audubon wondered if migrating birds came back to the same place each year. His idea was to tie a string around the leg of a bird before it flew south. The following spring, Audubon saw the bird had come back.
This data set shows the tracking of northern elephant seals
with red and magenta lines and sooty shearwater seabirds
with green lines fromJanuary 2005, through February, 2006.
Global Positioning System (GPS) tags have been developed giving accurate information of the seals’ movements. [Almost the same at the GPS tracking in your car] Such information can tell us how seals find and catch their prey and which areas of the ocean are important to them. To study the seals for longer periods British Arctic Survey have developed small Global Location Sensing devices (GLS), which use sunset/rise times and local noon to calculate where an animal is located. Although information from these devices is less accurate than that from GPS tags, they are smaller (approximately the size of a £1 coin) and cheaper. They also last for much longer which means they can track individuals over many years and even trace the movements of weaned pups departing on their first trips.Source: BAS