Download Heimaey

WJEC – Geology of the Human Environment (GL3) – Jan 2004
1.
Figure 1 is a map of Heimaey, a volcanic island to the south of Iceland. It shows the
impact of the 1973 eruption on the fishing port of Vestmannaeyjar.
Adapted from
“Volcanoes” Alwyn Scarth
Figure 1
(a)
(i)
Account for the presence of volcanic activity in this area with
reference to the island’s plate tectonic situation.
[2]
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(ii)
State the type of lava most commonly erupted from volcanoes in this
situation.
[1]
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(b)
(i)
Describe two hazards that may have been associated with the tephra
fall.
[2]
1 ……………….………………………………………………………………………………...
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2 ………………….…………………………………………………………………………...…
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(ii)
Suggest two factors responsible for the distribution and thickness of the
tephra shown on Figure 1.
[2]
1 ……………….………………………………………………………………………………...
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2 ………………….…………………………………………………………………………...…
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(c)
Explain how spraying with seawater affected the flow of lava.
[3]
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(d)
Describe three possible advantages for the local population of living in a
volcanic area.
[3]
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2………………………………………………………………………………………………..
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3………………………………………………………………………………………………...
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Total 13 marks
Notes for answers
These represent suggested answers and do not necessarily represent all the possible acceptable
alternatives of a mark scheme.
Question 1
(a)
(b)
(i)
Constructive/divergent boundary/Mid Atlantic Ridge
Rising convection currents/magma
Partial melting of mantle/ocean crust
(2 max)
[2]
(ii)
Mafic/basaltic
[1]
(i)
Burial/collapsed buildings/infrastructure/with weight
Fire from the hot tephra
Destruction/damage from direct hit with bombs
Respiratory/machinery problems from fine ash
Other relevant hazards – effect on farming/fishing/vision
Hazards by association – Gas/lahar/pyroclasic flows
Must be described.
(2 max)
[2]
Distance from the volcanic vent
Direction/strength of the prevailing wind
Effect of blast energy/direction
Particle size/weight
(2 max)
[2]
Lava cools rapidly/temperature drops
Solidifies/crystallises
Becomes more viscous
Flows slower/stops/changes course
(3 max)
[3]
New land
Fertile volcanic soil
Thermal energy source
Improved harbour
Tourism
Building materials
Other sensible – Mineral water/deposits
(3 max)
[3]
(ii)
(c)
(d)
Total 13 marks
ESTA would like to thank the WJEC for allowing this question to be published on GEOTREX. Any comments
should be directed to the Subject Officer for Geology at the WJEC. 15/04/2007