Download Volcanology - Departments

Volcanology
LO: Review past questions
Test plate boundary knowledge
Know the types of lava and their
characteristics
Plate Boundary Test
Convection
Current
Direction
Collision
Conservative
Destructive
O/C
Destructive
O/O
Constructive
O/O
Constructive
C/C
Plate
Movement
Direction
Plates
Features
involved
Rate of
movement
Map
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Mark on examples of:
Island arcs
Trenches
Fold Mountains
Ocean Ridges
Types of lava
• Lava produced by the upward movement
of materials from the mantle is BASALTIC
and tends to be located:
• Along mid ocean ridges
• Over hot spots
• Alongside rift valleys
Types of Lava
• Lava resulting from the process of
subduction is described as ANDESITIC
and occurs as/at:
• Island arcs
• Destructive plate boundaries where
oceanic crust is being destroyed and
gases are being added
Basaltic Lava
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Low viscosity
Hot (1200 degrees celsius)
Runny
Low silica content (45-52%)
Takes a long time to cool
Retains gas which makes it mobile
Gentle sloping large features
Frequent but gentle eruptions
Lava and steam erupted
Constructive PBs
Fissures (Heimaey, Mid Atlantic Ridge, Iceland)
Hot spots (Mauna Loa, Hawaii)
Acidic Lava
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Viscous
Cooler (800 degrees celsius)
Slow flowing
Cools quickly
Loses gas quickly, becoming sticky
Steep-sided features
Less frequent but violent eruptions (gas build up)
Ash, rock, gas, steam and lava erupted
Destructive plate boundaries where oceanic crust is
destroyed
• Subduction (Mt St Helens)
• Island arcs (Mt Pelee, Martinique)
Lava Footage
• http://www.youtube.com/watch?v=xExdEX
OaA9A
• http://www.youtube.com/watch?v=U3Pyux
hzGow
• http://www.youtube.com/watch?v=CxvtV7a
NMT0&feature=fvw
• http://www.youtube.com/watch?v=p8CHS
ThR-Mo&feature=related
Volcanoes and lava type
• http://kids.discovery.com/games/pompeii/p
ompeii.html