Topic 1 : Hazardous Earth Flashcards
Name the parts of the Earth
Crust
Mantle
Outer core
Inner core
Name the two parts of the upper mantle
Lithosphere and asthenosphere
What is the outer core made of?
Iron and nickel
Name the plate boundaries
Divergent
Convergent
Conservative
Collision
What happens in divergent plate boundaries?
Plates move apart
What happens in convergent plate boundaries?
Plate moves under the other
What happens in a conservative boundary?
Plates slide past each other
What happens in a collision boundary?
Plates move towards each other
What are tectonic plates?
The earth’s surface broken into large pieces
What is radioactive decay?
Atoms of radioactive elements release particles from nuclei and give off heat
Describe oceanic crust
Very thin
Made of basalt
Thin but more dense
Describe continental crust
Low density
Made of thick granite
Thick but less dense
How do earthquakes happen?
Tectonic plates move
This is concentrated along fractures
Friction builds up against plate boundary until energy is released
This energy is sent out as seismic waves
What is the epicentre?
The point on the Earth’s surface above the focus
What are seismic waves?
Earth’s energy being released
What is the focus?
Point inside the crust where pressure is released
What are hotspot volcanoes?
Warm areas in the mantle where heat moves up and forms in the middle of a plate
What causes a tsunami?
Destructive/convergent wave plate movement causes earthquake
Sea above is forced upwards
This movement causes tsunami
Seismic waves spread and waves crash onto shore
What is climate?
Average weather over 30 years
What are ocean currents?
a continuous, directed movement of sea water generated by a number of forces acting upon the wate
What is a Hadley cell?
The largest cell
Warns air rises out the equator and travels around 30 degrees north where it cools and sinks
What is a Ferrel cell?
Smaller cell
Found between Hadley and Polar
Powered by other two cells
What is a Polar cell?
Smallest cell
Cold air sinks at North Pole and warms
What are differences in climate caused by?
Gulf Stream
How can we learn about past climate?
Historical sources
Ice cores
Tree rings
What is the Greenhouse effect?
Warming of Earth’s surface and the air above it. It is caused by gases in the air that trap energy from the Sun
Describe the pressure over land
Land heats the air above which expands and becomes tighter and rises
Forms are of low pressure in the summer
and in the winter high pressure