Eyjafjallajökull, it?s not over till it?s over
Last week we saw a picture on the Internet that showed that the Icelandic
volcano Eyjafjallajökull (pronounced ?ay-uh-fee-at-luh-yo-koot-luh/span>?)
was emitting less carbon dioxide than would have been emitted by the thousands
of planes that usually fly in Europe each day. So in the short term the
volcano?s eruption saved the skies from tonnes of carbon dioxide because so many
flights were grounded due to the volcano?s ash. Science by Email decided to
investigate.
Just how gassy is an erupting volcano? The main gas that is released from a
volcano is water vapour, followed by carbon dioxide (CO2) then sulfur
dioxide (SO2). Other gases that are emitted in smaller amounts
include hydrogen fluoride (HF) and hydrogen sulfide (H2S), amongst
many others.
These gases are trapped underneath Earth?s surface in hot magma. As this molten
material moves upwards into areas of lower pressure, these gases expand. When a
volcano is erupting, expanding gases can explode magma into the sky.
Volcanoes smell bad and it can be painful to breathe near one ? you can blame
sulphur dioxide and hydrogen sulfide. Sulphur dioxide can irritate your nose,
throat, eyes and skin. This gas can also change in the atmosphere to sulfuric
acid and cause acid rain. Hydrogen sulphide gas is colourless, flammable and can
also be irritating to the eyes and upper respiratory tract ? not to mention
being very, very stinky. It smells like rotten eggs.
Water vapour and carbon dioxide are the Earth?s main greenhouse gases. A
European volcano expert has estimated that the volcano Eyjafjallajökull is
emitting between 150 000 and 300 000 tonnes of carbon dioxide a day. Scientists
measure gas from a volcano using instruments such as spectrometers, which use
information about light to calculate which gases are present in the atmosphere.
All the flights in and out of Europe emit around 344 109 tonnes of carbon
dioxide per day. Just one flight from London to Paris can emit around 244
kilograms of carbon dioxide.
EEven though Eyjafjallajökull emitted lots of greenhouse gases, when you take
into account flights all around the world, land clearing, coal-fired power
stations, transport and agriculture; human-made emissions of carbon dioxide far
outweigh the amount of carbon dioxide emitted from volcanic eruptions.
