Well done on completing the work, tasks and videos on the Oakes Future page. This really shows your commitment to the course and we are excited to be working with you more in September. This next page will be updated with different tasks to help develop your skills further. It gives you the opportunity to delve into content from the course and get you ready to start in the new term. Feel free to contact us if you have any questions but use this page to strengthen your knowledge and interest in Geography.
Watch the film right through once.
Then watch it again, pausing at the appropriate points to attempt the following questions
00.22
1. When was the main eruption of the volcano Eyjafjallajökull?
00.45
How did the second eruption on 14 April differ from the earlier eruptions in March 2010?
01.06
Explain why the explosive eruptions caused travel chaos throughout much of Europe.
01.20
Why were local people in Iceland concerned about the threat of flooding?
Pause the video at 01.41
Imagine that the floodwaters had escaped down the valley behind the farm. Suggest the social, economic and environmental impacts of such a flood.
01.50
Draw a simple sketch to show how the long grass helped to trap the ash, preventing it from being blown around. Use a scale to show that there was 5cm of ash, roughly the same height of the grass. Add labels to explain why farmers had a good crop.
02.36
What were the first signs that Eyjafjallajökull was about to erupt?
03.08
What were the effects of the eruption on Inga and her family living on the farm?
How many people have visited the Eyjafjallajökull Visitor Centre? How has this benefitted the family?
Why is Inga not particularly worried about flooding when Katla next erupts?
How are the family preparing themselves for future eruptions?
Describe the Markarfljót River today. What did it look like when the floodwaters poured into the river after the eruption?
06.01
Describe the shape and composition of the embankments alongside the river
Evaluate the success of the embankments in preventing widespread flooding.
06.20
How did the action of quick thinking road engineers help to save the metal bridge carrying the main road across the Markarfljót River? Use a simple diagram to show what happened.
07.40
How did the presence of water and the chemical composition of the magma affect the eruption of Eyjafjallajökull?
09.04
Watch the clip about volcano monitoring and complete the table below.
12.15
Describe how the eruption of Eyjafjallajökull has boosted tourism in Iceland.
Katla: Iceland’s sleeping giant
The volcano Katla last erupted in 1918 and many people believe that its next eruption is overdue. Katla is one of a line of volcanoes that mark the constructive (divergent) plate boundary that stretches through central Iceland (Figure 1).
Look at Figure 2. Notice that Katla lies beneath the Mýrdalsjökull ice cap. This means that in some respects an eruption will be similar to that of Eyjafjallajökull in 2010, which also erupted beneath ice. Notice too that Katla is marked by the presence of a caldera, a vast collapsed crater formed when the sides of a volcanic crater collapse in on itself after an eruption has occurred.
Activities
Study Figure 1. Describe the location of the volcano Katla in Iceland.
Study Figure 2.
(a) What is the name of the nearest town? (b) Describe the pattern of drainage in the area. (c) Given the pattern of drainage, what are the implications of an eruption for people and human activity to the south?
Internet Investigation: Find out more about volcanic calderas and how they are formed. Include a diagram and a labelled photo.
Katla eruption 1918
Katla last erupted on 12 October 1918 (Figure 3). The explosive eruption sent a column of steam and ash high into the atmosphere. Measuring 4 on the VEI scale, it was slightly more explosive that the eruption of Eyjafjallajökull in 2010. Whilst the ash created little more than an inconvenience, the major impact was the glacial flood resulting from the melting of the ice above the caldera. Water poured across the flat outwash plains to the south, carrying vast amounts of sediment and extending the coastline by 5km!
Internet Investigation
Find out more about the eruption of Katla in 1918. Were there any warning signs and what were the impacts on people? Include photos and maps to support your investigation.
Katla – the next eruption
Scientists believe that its next eruption is long overdue and the volcano is being monitored very carefully for signs of a fresh eruption. Monitoring includes the use of seismometers to measure earthquakes and hydrological studies in local rivers to detect the release of geothermal chemicals such as hydrogen sulphide.
Whilst there have been some indications of activity in recent years – particularly in the form of earthquakes – it has been short-lived. The main concerns are of flooding, with settlements, farms and roads at risk of serious damage. A repeat of the flooding in 1918 would create major problems in this part of Iceland and many people would need to be evacuated to safety.
Draw a graph to represent the information in Figure 4. Represent time along the horizontal axis and the VEI (Volcanic Explosivity Index) along the vertical axis. At the date for each eruption draw a vertical bar to show the VEI.
(a) Describe the pattern of your graph. Do eruptions occur at regular intervals?
(b) Calculate the average frequency of volcanic eruptions.
(c) Assess the evidence that Katla is overdue to erupt.
