Tectonics Flashcards
Eyjafjallajökull Volcanic Eruption (2010)
Location: Southern Iceland
Date of eruption: April 2010
The mountain lies within the country’s East Volcanic Zone.
Its name originates from an Icelandic phrase meaning “the island’s mountain glacier,” and the
volcano itself lies beneath Eyjafjallajökull (Eyjafjalla Glacier).
Its highest point rises to 5,466 feet (1,666 metres) above sea level.
Causes of the eruption Eyjafjallajökull Volcanic Eruption (2010)
Iceland has formed at a divergent plate boundary due to the North American and Eurasian plates moving apart. In addition, Iceland also lies over a hotspot or mantle plume – an upsurge of abnormally hot rock in the Earth ́s mantle.
As the plates moved apart, excessive eruptions of lava constructed volcanoes and filled rift valleys.
This has created the Mid Atlantic Ridge, a ridge of mountains and volcanoes that are mostly below sea level.
However, there are also volcanic islands along the ridge, with Iceland being the largest because of
the additional volcanism caused by the hotspot under the country.
The plates are moving apart at a rate of 1cm to 5 cm per year.
This has created a chain of volcanoes along the SE Rift zone of Iceland, which runs from NE to SW across Iceland, even passing underneath some of the countries ice caps.
Effects of the eruption Eyjafjallajökull Volcanic Eruption (2010)
800 people had to be evacuated due to glacial outburst floods.
Travel was severely disrupted as many flights were cancelled between 14 and 21 April 2010
The eruption produced 0.3 cubic kilometres of ash, which resulted in the disruption of 95,000
flights across Europe and economic losses of 5 billion euros.
Businesses lost trade.
Air operators lost millions of pounds each day.
Perishable foods were wasted as they could not be transported.
People were not able to get to work because they were stranded.
The timing of the disruption was during the Easter holidays when levels of tourism are high.
Management (Prediction) Eyjafjallajökull Volcanic Eruption (2010)
The Iceland Volcanic Observatory employs a range of methods to monitor volcanic activity so that
accurate predictions can be made. For example:
* Gas sampling: changes in gas composition indicate the activity levels of magma underground.
* GPS technology: used to monitor any significant changes on the volcano so that the risk of
activity e.g. pyroclastic flows can be assessed.
* Seismic monitoring: any minor earthquake activity is detected using seismographs and is recorded. Rising blobs of magma can cause earthquake activity and so this may be a sign of an eruption.
Management (Prevention) Eyjafjallajökull Volcanic Eruption (2010)
- Glacial outburst floods, caused when heat from the volcano melts glacial ice, are a real
risk in Iceland. 800 people were evacuated when the volcano flooded as they were in a
flood risk zone. - Aircraft were prevented from flying into/out of northern Europe for 6 days as there were
concerns that the ash cloud could cause safety risks.
Why do people live in Iceland, despite the risk?
Volcanic activity can create opportunities for people:
- Icelandic people feel relatively safe from the risk of volcanic eruptions as volcanoes in Iceland are closely monitored. Since volcanic eruptions tend to be very predictable people feel that they will be safe if an eruption occurs. Volcanic activity is monitored on a daily basis, for example GPS technology is used to monitor any significant changes on the volcano so that the risk of activity can be assessed.
- Today, there are a growing number of opportunities for jobs in the tourism industry in
Iceland. Interest in Iceland’s volcanoes peaked after the 2010 eruption and this has led to a huge growth of tourism. For example, tourists enjoy visiting the geothermally heated blue lagoon, as well as the Lava Interactive Centre is a museum about Iceland’s volcanoes. It is also possible to take tours in lava tunnels and hike on glacier-covered volcanoes. - Geothermal energy: Iceland produces 66% of its electricity from geothermal sources. Helishedi is Iceland’s largest geothermal power station. Geothermal energy uses steam to produce electricity. The steam comes from reservoirs of hot water found a few miles or more below the earth’s surface.
- Another benefit of volcanoes is that the ash from previous eruptions creates fertile farmland. Iceland also use their geothermal energy to heat greenhouses, meaning they are able to grow enough fruits and vegetables to meet 60% of consumption.
Cause of the earthquake: Turkey-Syria 2023
Location: SE Turkey, close to the border with Syria
Date: 6th Feb 2023
* Transform/conservative plate boundary - Anatolian plate is sliding past the Arabian plate.
* Tension had been building up for a long time on the East Anatolian fault.
* Pressure was released and the plates slipped along a strike slip fault.
* Shockwaves were sent out causing severe shaking of the crust.
* The earthquake measured 7.8Mv.
* As is the case with many earthquake events the mainshock was followed by many aftershocks, including three above magnitude 6.0.
* Aftershocks represent minor re-adjustments along the portion of the fault that slipped at the time of the mainshock.
Impacts: Turkey-Syria 2023
- 47,000+ deaths across SE Turkey and NW Syria.
- 6500 buildings in Turkey collapsed across 10 cities, including a 2000-year-old castle in the city of Gaziantep.
- Hundreds of thousands left homeless across SE Turkey and NW Syria.
- People were left to fend for themselves with many camped out in makeshift shelters in supermarket car parks, mosques, roadsides or amid the ruins, often desperate for food, water and heat.
Why were the effects so bad for Turkey-Syria 2023
- It was a major earthquake, measuring 7.8MV which resulted in intense shaking of the ground.
- Many strong aftershocks (including one of 7.5) toppled even more buildings after the mainshock.
- The earthquake struck close to large urban settlements, such as the city of Gaziantep. This
area also has large numbers of Syrian refugees making the area more densely populated. - Cold winter weather hampered relief efforts and the cold meant that people trapped
under rubble had less chance at survival. - There had not been an earthquake of above magnitude 7.0 in the region since the 1800s and the area lacked proper preparation.
- Turkey has seismic building codes but many buildings pre-date the codes and buildings had not been retrofitted.
- In some cases, it also seemed that proper building codes had not been followed due to corruption - this was seen in the many new apartment buildings that collapsed.
- Despite residents paying an earthquake tax for years, the emergency response to the earthquake was found to be poor - people complained of a lack of equipment, expertise and support to rescue those trapped under rubble.
- Relief to Syria was complicated by the ongoing civil war in the country.
Prediction: of Turkey-Syria 2023 earthquake
- Seismologists use GPS technology to analyse stress built up on faults. It had noted that there was a lot of stress on the East Anatolian fault and this could give way at any time, including a large earthquake above magnitude 7.0.
Prevention: of Turkey-Syria 2023 earthquake
- Turkey introduced a seismic building code after a large earthquake in 1999. However, many buildings pre-date the codes and some recent buildings have also not been built to code due to corruption (developers paid money to officials and got a certificate saying the building was safe)
- People in SE Turkey paid an earthquake tax - this is meant to help with relief efforts; however, the efforts were found to be poor with people complaining of a lack of equipment, expertise and support to rescue those trapped under rubble.
- Countries, such as the USA, deployed search and rescue personnel to Turkey (the US sent 150 specialists).
- UN aid convoys were not permitted access to Syria to provide assistance until 3 days after the earthquake.
- The international community pledged aid to Turkey and Syria.
Why do people live in tectonic zones? Earthquake
The main reasons why people continue to live in earthquake zones are:
* Large earthquakes do not occur that frequently and so people are not aware of the risk or they do not believe it will happen to them.
* People feel protected against earthquakes due to disaster preparedness measures e.g. earthquake resistant buildings, earthquake drills, disaster preparedness education and advice.
* The benefits of living in earthquake zones may outweigh the risks e.g. due to employment opportunities or it being a pleasant place to live.
