Iceland Unit Four Case Study

Iceland

Q1 Tectonics

Volcanic islands formed on a constructive plate margin.

Iceland is one of the most volcanically active countries in the world with 39 eruptions occurring in or around Iceland in the 20^th century. Around one third of all basaltic eruptions in recorded history were found in Iceland.

Iceland is situated along the mid-Atlantic ridge where the Eurasian and North American plates are moving apart.
Examples:

·         A fissure in Katla in 984 erupted to make the largest basaltic eruption ever seen.

·         Laki in 1783 which was only second in size to Katla.

There have also been several eruptions beneath glaciers which have led to glacier bursts. The most recent was E15 in 2010.

E15 ß is a mountain glacier where the glacier (over 100km²) covers the caldera of the volcano. Explosions can also have secondary effects on outlet glaciers (connected glaciers) and mountains as the power of the eruptions often lead to landslides, in 1967 there was a massive landslide on the Steinholtsjökull glacial tongue. ß Earthquakes are likely due to pressure of ice, violent eruptions even though they are basaltic. Massive ash clouds and water jets are the most common result of eruption due to the glacier above the vent of E15.

Q2 Landscape

An island country, the main island is just south of the Arctic Circle and the country itself is on the boundary between the North Atlantic and Arctic oceans.

E15 ß The summit is elevated 1,666ms above sea level and the Caldera is filled by a glacier which is over 100km² in size. The ash cloud created by E15 that covered Europe in 2010 was the largest disruption to air travel since the Second World War. The eruption in April ejected around 250million cubic metres.
The Mid-Atlantic Ridge is part of the longest mountain range in the world as it is a part of every ocean stretching over 65,00kms. The ridge is a spreading centre (which means the sea floor expands with lava rising to the surface) and grows at a rate of around 2.5cms per year. The ridge was also central in the initial breakup of Pangaea.
Mountainous hilly landscapes with long slow slopes and peaks like waves, land may be suppressed by weight of glaciers. Land is rich in minerals and is therefore a biodiversity hotspot; basaltic lava is easily eroded away by glaciers. Fissures are common (e.g. Laki not a volcanic eruption but fissures either side) create wide flat plains with a stair like structure.

Q3 People

500 people had to be evacuated as a result of the 2010 eruption but the population is so low that even being a tectonic hotspot, there is little chance of disaster. Laki’s eruption killed 50% of all livestock and 25% of the human population.

However, globally Iceland has been known to have a bigger impact. The 2010 eruption caused the largest disruption in air travel since the Second World War.

Laki’s eruption also may have resulted in a global temperature drop due to sulphur emissions. There was also estimated to be 6million deaths as a result worldwide. There were also crop failures in Europe and droughts in India as a result of the air pollution.

Q4 Management

There is little that can be done to manage the eruptions but seismic activity is recorded in order to predict any future eruptions. There are also evacuation measures in place. Usually the European political systems are responsible for this as being closer to mainland Europe than mainland North America they are often associated together.

 

http://en.wikipedia.org/wiki/Iceland_hotspot

http://www.platetectonics.com/oceanfloors/iceland.asp

http://www.ouramazingplanet.com/3074-iceland-tectonic-plates-meet.html