ELABORATED COMPLETE SOLUTIONS PASSED
1. Name the layers of the
Earth's structure. Crust (lithosphere), mantle (asthenosphere), outer
core, inner core
2. What are the two types of
crust and their Oceanic crust (6 km thick, made of silica and
characteristics?
magnesium) and continental crust (25-90 km thick,
made of silica and aluminium)
3. What is the thickness of the man- 3000 km
tle?
4. What is the state of the
outer core? Liquid
5. What are the main
components of the inner Iron and nickel, 3700°C thick
core?
6. Explain what drives
convection currents. Radioactive decay, naturally occurring elements
such as uranium release heat. Residual energy
which has been left behind when the Earth formed.
7. How do convergent plate bound- Towards each other
aries move?
8. How do divergent plate 11.
bound- aries move?
9. Name the two types of
conver- gent plate
boundary.
10. What are the characteristics
of the oceanic plates ?
,HAZARDOUS EARTH EXAM QUESTIONS &
ELABORATED COMPLETE SOLUTIONS PASSED
Away from each other
Collision and destructive
Oceanic crust is only 5-10 km thick. Oceanic
crust is denser, can be subducted and is
constantly being destroyed and replaced at
plate boundaries.
, HAZARDOUS EARTH EXAM QUESTIONS &
ELABORATED COMPLETE SOLUTIONS PASSED
What are the characteristics Continental crust is typically 30-50 km thick. It is older,
of continental plates ?
lighter and cannot be destroyed.
12. Name a type of divergent
plate boundary. Constructive
13. Explain why volcanoes occur
on destructive plate margin.
Destructive plate margins are when the oceanic
plate is subducted under the continental plate. This
happens be- cause convection currents cause the
plates to move to- wards each other, the oceanic
plate is denser than the continental plate. The
oceanic plate subducts into the as- thenosphere. The
14. Explain why volcanoes occur
on constructive plate margin. oceanic plate melts due to the increased heat, this
creates magma and eventually forms composite
volcanoes.
This is when plates move away from each other. As the
plate move apart the rising heat from the
asthenosphere creates magma which rises and fills
the gap. As it cools it from new oceanic lithosphere.
It forms shield volcanoes. Weak earthquakes occur
here as there is little pressure building up.
15. What type of volcanoes occur on It forms shield volcanoes, a chain of volcanoes
form creat-
constructive plate ing a mid-ocean ridge.
margin.
The parts of the convection currents that move towards the
16. Explain the formation surface are called plumes. The heat here is
of hotspots. concentrated and bring heat to the surface. If these
plumes are in the middle of tectonic plates they
create hotspots. Creating shield volcanoes far away