Eyafjallajökull Case Study

Question 1

What does the Eyafjallajökull ice cap cover and how tall is it?

Answer 1

It covers a caldera and is 1666m in height

Question 2

When did the Eyafjallajökull eruption begin?

Answer 2

March 2010

Question 3

Initially in the Eyafjallajökull eruption a fissure opened up, how big was this?

Answer 3

150m

Question 4

In the first stage of the Eyafjallajökull eruption 10-12 lava craters opened up, how hot was the lava they eruption and how high did it erupt them?

Answer 4

It was 1000 degrees and was ejected 150m into the air

Question 5

What was the lava type in the Eyafjallajökull eruption and what characteristics did it have?

Answer 5

It was basalt and relatively viscous so the lava stream was slow

Question 6

How far did the molten eventually flow?

Answer 6

4000m northeast of the fissure

Question 7

How far was ash sent into the air in the primary phase of the Eyafjallajökull eruption?

Answer 7

4km

Question 8

On 14th April 2010 what phase did the Eyafjallajökull eruption enter and what did it eject in this phase?

Answer 8

An explosive phase, it ejected fine glass rich ash over 8km into the atmosphere

Question 9

What VEI measurement did the second phase of the Eyafjallajökull eruption enter?

Answer 9

4 which is large but not the biggest

Question 10

What minor local impacts were there caused by the Eyafjallajökull eruption?

Answer 10

1. A thick layer of ash fell on farm pastures at Raufarell. This became wet and compact, making farming difficult
2. Locally, river levels rose as part of the ice cap melted
3. Some local gravel roads were blocked by falling ash

Question 11

What four factors combined to make the Eyafjallajökull ash cloud dangerous to air travel?

Answer 11

1. The volcano’s location is directly under the polar jet stream
2. The direction the jet stream was heading was unusually stable at the time of the eruption’s second phase. It maintained a NW to SE direction
3. The second eruption phase took place under 200m of glacial ice. The resulting meltwater flowed back into the erupting volcano which created two specific phenomena
   - the rapidly vaporising water significantly increased the volcano’s explosive power
   - the erupting lava cooled very rapidly, which created a cloud of highly abrasive, glass-rich ash which could damage jet engine
4. The volcano’s explosive power was sufficient to inject ash directly in to the jet stream over NW Europe

Question 12

What were the responses to the Eyafjallajökull eruption?

Answer 12

1. 500 local farmers were evacuated overnight
2. Some roads were closed because of fear of flash floods
3. 14-21 April airspace if many NW European countries were stopped. There was then sporadic disruption to flights for several days depending on the variety intensity of ash cloud and weather patterns. The six-day shutdown is estimated to have cost the airlines £1.2 billion
4. A Royal Navy warship collected soldiers returning from Afghanistan and stranded holidaymakers from the Spanish port of Santander