Now watch the following video and look at the images after before completing the

tableInspired by Iceland

Case study of a Volcanic Eruption

Here is what the syllabus says you need to know about volcanoes:1.Different types of volcanoes; this means shield and ?? volcanoes2.A case study of a volcanic eruption; its cause (i.e. Plate movements), primary and secondary effects, positive and negative impacts; immediate and long term responses3.Monitoring and predicting volcanic eruptions.

You will know one thing about each of the causes, effects and responses to an eruption

You will know several things about each of the causes, effects and responses to an eruption

You will know several things about each of the causes, effects and responses to an eruption and be able to link most of them together

Lesson Objectives on an eruption case studyLesson Objectives on an eruption case study

We are going to look at the eruption of Eyjafjallajökull in Iceland as our case

study

Introduction to the eruption - including Location

Eyjafjalljokull

Eyja fjalla jökullglaciermountainIslands

EYJAFJALLAJÖKULL

‘A – yar – fi – at – lah – yok – ult’

Causes of the eruption

• Iceland is situated on the mid Atlantic ridge. This is on the plate boundary between the north American plate and the Eurasian plate

Up to 19th March 2010 scientists monitoring tectonic activity detected small earthquakes caused by magma moving through fissures in the Earth’s crust. They predicted that an eruption was close.

1. Small cracks, or fissures, in the Earth’s crust allow molten magma to force its way towards the surface.

2. Magma chambers are formed close the surface. Magma collects in these.

3. As more magma is stored in the chamber, pressure builds up. Eventually, the pressure is strong enough to start an eruption.

Fimmvörðuháls

Diagram reference: Keilir - Atlantic Center of Excellence

Eyjafjallajökull

20th MarchMagma finds its way to the surface. Lava erupts through a 0.5km long volcanic fissure at Fimmvörðuháls. This is a rocky area between the Eyjafjallajökull and Mýrdalsjökull glaciers.

The eruption created spectacular lava flows. As the eruption was not below the ice, there was no danger of flooding. Many people flocked to see the eruption creating ice motorways over the ash covered glaciers.

The eruption was considered so safe that tourists, including some ladies in high heels, were helicoptered close to the eruption.

Some called the eruption a ‘volcanic Disneyland.’

By the 31st March lava and basalt covered around one square kilometre and many thought that the eruption was over.

On the 12th April a second volcanic fissure opened and scientists measured a 3.2 magnitude earthquake. The earthquake was close to the surface which suggested that magma was once again on the move. On 13th April another earthquake measuring 2.5 magnitude was recorded beneath the Eyjafjallajökull ice cap.

At 1.15am on the 14th April Eyjafjallajökull burst open. The volcanic fissure cut though 200m of ice. Huge plumes of tephra and ash were ejected into the atmosphere and the ice melted.

By the 16th April the eruption had caused glacial floods, or  jökulhlaups. Ash had reached up to 8km high in the atmosphere and lava flows reached 3km from the volcanic fissure.

What were the main events of the eruption between 19th March and 16th April 2010?

14-16th April.Over the next four days, ash was ejected up to 8 km high in the atmosphere and lava flowed up to 3 km from the main vent.

1.15am 14th April.Eyjafjallajökull burst open once more and a fissure opened through 200m of ice covering the volcano. A huge cloud of tephra and ash started to come out of the volcanic vent.

13thth AprilA series of shallow earthquakes were recorded

12th April.A second volcanic fissure opened during an earthquake measuring 3.2 magnitude beneath Eyjafjallajökull and many smaller earthquakes were recorded

31st March. New basalt (the rock created by cooling lava) covered around 1 square kilometre

This eruption produced a spectacular ‘volcanic Disneyland’ and tourists flocked to the site to see amazing lava flows.

20th March.At 11:30pm a volcanic fissure opened at Fimmvörðuháls, a rocky area between two glaciers

19th March.Scientists monitoring the area measured earthquakes caused by magma moving into fissures

Start Here

Map compiled by Páll Einarsson and Ásta Rut Hjartardóttir, The Geo-science Institute of the University of Iceland

Birth of an Island

Play video

So that is the introduction and causes done..... Remember the Lesson objectives?

You will know one thing about each of the causes, effects and responses to an eruption

You will know several things about each of the causes, effects and responses to an eruption

You will know several things about each of the causes, effects and responses to an eruption and be able to link most of them together

Lesson Objectives on an eruption case studyLesson Objectives on an eruption case study

Effects of Eyjafjallajökull

primary and secondary effects, positive and negative impacts; immediate and long term responses

Use lesson 4 local effectsUse lesson 5 global effects