volcanic hazards

Question 1

describe the location of Eyjafjalljokull

Answer 1

It is located in the eastern volcanic zone in the south of Iceland which is situated between a constructive plate boundary between the north american plate and the eurasian plate.

As these plates moved apart the magma rises in the empty chamber

Question 2

what caused the volcanic ash

Answer 2

1. a second eruption occurred in April under an ice cap
2. the interaction of magma and water caused rapid cooling which caused a plume of tephra which was over 10km high with spread east

Question 3

effects of the eyjafjallajokul eruption

Answer 3

1. tephra
2. flooding due to the melting of the ice cap
3. pyroclastic flows

Question 4

hazards of a volcanic erruption

Answer 4

1. tephra- ash ejected into the atmosphere
2. nuees ardentes- very hot flows (800 degrees) of gas and tephra
3. lava flows

Question 5

economic impacts of the eyjafjalljokull volcanic eruption

Answer 5

1. 100,000 flights were cancelled, causing delays all across the world (£130 million per day)
2. Exporters of perishable goods were particularly affected such as Kenya as the fresh stock had to go to waste
3. this is particularly damaging as the Kenyan economy is so reliant on the export of fresh goods

Question 6

Why may the delay of flights be a good thing

Answer 6

1. passengers looked for other ways to travel such a boat ride. these companies were better able to benefit
2. they used more eco friendly methods of transport
   preventing 3 million tonnes of carbon from being released

Question 7

environmental impact of the eyjafjallajokul eruption

Answer 7

1. ash from the volcano deposited iron into the North Atlantic Ocean causing a plankton boom
2. this clouds the water and prevents the sunlight from entering the water
3. preventing underwater vegetation from growing
4. phytoplankton consume their nutrient and a further phytoplankton boom occurs
5. without vegetation fish are less able to survive
6. less fishing
7. which is particularly damaging as the Icelandic economy is so reliant on fishing

Question 8

social impacts of eyjafjallajokul

Answer 8

a study found that people after the eruption suffered form intense coughing and wheezing and eye and skin iritation

Question 9

characteristics of basaltic lava

Answer 9

1. effusive eruption
2. low viscosity
3. low silica content
4. often flows greater than 10 km
5. hotter than 1000 degrees

Question 10

what type of volcanoes does basaltic lava form

Answer 10

shield volcanoes

Question 11

what type of volcanoes does Andesitic lava form

Answer 11

composite

Question 12

formation of composite volcanoes

Answer 12

1. at subduction zones at destructive plate boundaries
2. steep-sided cones formed from layers of pyroclastic flows. The thick lava cannot travel far down the slope of the volcano before it cools which makes the slopes of the volcano steeper

Question 13

formation shield volcanoes

Answer 13

1. form at constructive plate boundaries
2. gently sloping sides as produce fast flowing basic (fluid) lava that can flow for many miles.
3. Mount Kilauea is a named example of one

Question 14

why is there a difference between lavas

Answer 14

the ocean floor contains different sediment. this can alter the silica content in the lave giving it different properties

Question 15

characteristics of andesitic lava

Answer 15

1. explosive erruption
2. high viscosity
3. high silica content
4. flows less than 10km
5. around 700 degrees

Question 16

how much carbon is e15 emitting per day

Answer 16

Iceland’s Eyjafjoell volcano is emitting between 150,000 and 300,000 tonnes of carbon dioxide (CO2) per day,

Question 17

what is the current market price for carbon emissions in Europe

Answer 17

14 euros per tonne

Question 18

why was the eruption at e15 not damaging to global warming

Answer 18

1. The ash cloud has not reached the high atmosphere, where it would have the most effect
2. contains little sulphur, which forms reflective droplets of sulphuric acid

Question 19

how much carbon did the mass grounding of air planes prevent from going into the atmosphere

Answer 19

2.8 million tonnes

the carbon emitted was dwarfed by the amount of carbon that was saved

Question 20

what land forms form at destructive plate boundaries

Answer 20

composite volcanoes. eg Mount Fuji

this is because when the oceanic plate subduct it melts. making the magma beneath the crust have a high silica content and less runny as a result.

fold mountains
occur when two continental plates come together
such as the Himalayas (Indian and eurasian plate)

Question 21

why is e15 a contructive plate boundary

Answer 21

the lava has a lower silica content as