Theme 3 - Living in an Active Zone Flashcards
What is a Tsunami?
A tsunami is a powerful wave that is triggered by an earthquake.
What is a plate margin?
Where two tectonic plates meet.
How do plates move at a destructive plate margin?
Towards each other (one oceanic and one continental).
Name 3 landforms at a destructive plate margin
Cone volcano, Ocean Trench, Fold Mountains.
How do plates move at a constructive plate margin?
Apart (two continental or two oceanic).
Name 3 landforms found at a constructive plate margin.
Mid Atlantic Ridge, Shield Volcano, Rift Valley.
Why do people continue to live in areas which are at risk of powerful earthquakes?
Earthquakes are rare, people can’t afford to move, cities were built before earthquake science was understood, buildings can be made life safe.
Why do people continue to live in areas which are affected by volcanoes?
Tourism, ash/lava adds nutrients to the soil allowing making fertile land, geothermal energy can be produced, eruptions are rare.
How are volcanoes formed at destructive plate margins?
As the oceanic plate subducts under the continental plate friction causes the plate to melt filling the magma chamber. Pressure forces the magma to rise, creating an eruption.
How are rift valleys formed at constructive plate margins?
As two continental plates move apart the crust fractures as sections of it move apart. Areas of crust drop down between parallel faults to form rift valleys.
What does epicentre mean?
The centre of an earthquake on the surface of the ground
What does focus mean?
The centre of an earthquake beneath the surface of the ground
