Linking the Learning - The questions below are examples that may appear on future AS and A2 examination papers.
- Explain the formation of the hazards produced by a volcanic eruption you have studied.
- Evaluate how successful the responses to a volcanic eruption you have studied where.
The Organiser - The cover page below is from a PowerPoint that can be used to help 'build a report on a specific volcanic eruption. Click here on the Google Drive link at the top of the page to download this PowerPoint.
Volcanic Activity in Iceland - Iceland lies on a constructive plate margin between the North American and the Eurasian plate. Iceland has many active and inactive volcanoes (about 130 all together!) due to it being situated on the Mid-Atlantic Ridge and has 30 active volcanic systems running through the island - see map below.
In theory Icelandic volcanic eruptions should be effusive. In general eruptions in Iceland result due to a distinct set of sequential events. Radioactive decay in the core releases heat which causes the North American and Eurasian plates to diverge - see map below. This plate movement (at about 2 cm a year) causes a build up of tensional stress within the crust. When the tensional stress exceeds the strain threshold of the rock the crust will fracture leading to the formation of vertical faults. Magma from deep inside the mantle then starts to rises along these faults and collects within magma chamber.
Baroarbunga - The 2014–2015 eruption of Bárðarbunga was an eruption in the Bárðarbunga volcanic system in Iceland, that began on August 29, 2014 and ended on February 27, 2015. The eruption emitted large volumes of sulphur dioxide and impacted air quality in Iceland. There was no effect on flights outside of the immediate vicinity due to a lack of a significant emission of volcanic ash. The eruption took place in the lava field of Holuhraun northeast of the Bárðarbunga caldera proper.
Eyjafjallajökull- Most people are familiar with Eyjafjallajökull after its eruption in 2010 caused a massive disruption in European flights. That eruption may have been a nuisance for many air travellers but in comparison to Iceland’s biggest eruptions in the past it was just (literally) the tip of the iceberg (or well, glacier). Eyjafjallajökull is right next to one of Iceland's most dangerous volcano, Katla, in the south of Iceland - see map below. The video below shows how not to pronounce the name of the volcanoes and how it should be pronounced! Have a go yourself!
Sequence of Events - The table below illustrates sequence of events before, during and after the eruption. The table also includes some of the impacts and responses of the eruption.
Before March 2010 - Seismographs recorded swarms of shallow earthquakes which suggested that magma was rising to the surface.
March 20 to April 13th - Between these dates there were minor effusive eruptions, but these were on the volcanoes flank to the South East in an area that was ice free. In places rifts opened up to produce lines of erupting lava.
April 14th to 21 April - On the 14 April an eruption started that was 250m beneath the ice of the glacier. The melted ice created a meltwater surge of jokulhlaup. Water entering the caldera mixed with the lava causing ask to be ejected high into the atmosphere. The plume of ash reached almost 10km high.
Late April to 3 May - Outpourings of lava was now the dominant feature - as by April 18 most of the ice had melted and so the ash plume dropped in height.
May 4 to May 19 - The Ash was again was a problem.
May 20 Onwards - Steam was still been emitted, but no gas and little ash.
September 2010 - By September the volcano had stopped erupting and returned to a dormant state.
Impact and responses - This section looks at how the impacts can be have a local, regional and global effect. farmers tried to seal their homes and moved their livestock inside to escape the ash and stop them grazing on fluoride coated grass as it would cause internal hemorrhaging in cattle and sheep.
On April 15th about 800 local residents and tourists staying south of the volcano were evacuated to local shelters in case glacial melt water flooded the river valleys and to reduce the threat of respiratory complication caused by breathing in falling ash. Whilst the ash was falling rescue workers wore masks to prevent these breathing problems.
To keep people safe the government set up a temporary exclusion zone to stop tourists and local residents from entering the area affected by glacial melt water and heavy ash fall.
One of the most damaging secondary effects was flooding. The embankment that carried the main southern coastal highway had to be breached by the government to let the surplus glacial melt water flow safely to the sea rather than allowing the rush of water to destroy an important bridge. This temporally disrupted road transport between the southeast and southwest of Iceland as the highway was destroyed.
Bulldozers quickly repaired the embankments and after a few weeks the highway was reconstructed. The quick action of the emergency services saved the government money and time, as it was cheaper and quicker to repair the breach in the road than to have repaired the bridge. However, the overall economic was high as the government still had to spend large amounts on repairing water and electricity supplies.
Another immediate impact was loss of income for local firms and residents. The grounding of cargo planes flying out of Iceland meant that the export of fresh fish, were badly affected resulting in reduced profits for fish processing companies and a loss of income for local fisherman. There was also a significant drop in the number of international tourists visiting Iceland in the summer of 2010 – this affect the Icelandic economy and the reduced the income of people with jobs directly and in-directly connected to the tourist industry.
The London Volcanic Ash Advisory Centre (VAAC) was responsible for providing information about the ash plume to the relevant civil aviation authorities in the form of Volcanic Ash Advisories (VAA). On the basis of this, the authorities made decisions about when and where airspace should be closed due to the safety issues. Their decisions resulted in the cancellations of flights at airports across the world, not only in those countries where airspace was restricted. Between the 4th and 12th some 100,000 flights were cancelled and 10 million passengers were affected. As the eruption occurred at the end of the Easter break many people were stuck abroad. Teachers could not return to teach, government offices were often missing key personnel – overall 400,000 Britons were stranded worldwide. The maps below show the extent of the ash cloud and the operating status of airports across Europe.
Airlines were losing millions of pound a day in lost business and that was before people began claiming compensation or cover for their extra hotel costs. Therefore, shares in the airline companies and travel businesses fell. Some small travel companies that have since gone bust have blamed the eruption in part for their demise.
The car industry was very badly affected – for example BMW hand to stop production of X5 and X6 sports activity vehicles in its North Carolina (USA) factory. This was because transmissions and other component parts could not be transported from German due to the weeklong grounding of Trans Atlantic flights. There was even a breakdown in the flow of I-phones to Europe from manufacturing bases around Shenzhen in Southern China.
Some positive impacts were that in the UK there was a huge reduction in aircraft noise especially around major airports which improved the quality of life of local residents, albeit temporarily. The Channel Tunnel and the cross Channel ferries did a lot of extra business whilst this ash eruption lasted.
The Prime Minister of Norway had to run his country from New York as there were no trans Atlantic flights to northern Europe for several days. He was seen on TV running his country from an Ipad!
The Kenyan horticultural industry lost an estimated $3 million pounds a day because the ash cloud stopped planes carrying cut flowers such as roses from flying out of Kenya, Therefore, thousands of casual workers – most of whom make only a few dollars a day of vital support for their families – were laid off.