1.2B - Chile (The Andes) Flashcards
Landslide stresses
Angle of slope Rainwater / saturation Vibration e.g. Cars Earthquakes Sea, cliff erosion
Landslide strengths
Lubricant layers
Trees / vegetation roots
Consolidation of material
Porosity of soil (water draining through)
What is meant by a Benioff Zone?
Inclined zone where deep earthquakes occur, beneath a destructive plate boundary
Crustal rocks melt with various chemical reactions
What are the types of waves?
P waves - primary waves
S waves - secondary waves
L waves - love waves
Where do love waves travel?
Through the surface of the crust, the fastest of the surface waves moves from side to side (horizontal) as it moves forward
What is a destructive plate boundary?
When oceanic and continental plates move together
Fold mountains or island arcs
What is a constructive plate boundary?
Occurs when plates move apart
Mid ocean ridges
What is a collision plate boundary?
When two continental plates collide, the plates are not forced under each other so they are forced upwards
(Form fold mountains)
What is a transform plate boundary?
When plates slide sideways past each other
Conservative or major fault
Which case study is an example of an earthquake occurring due to plate boundary stress?
The earthquake in Chile, 1960
Which types of waves arrive first and why?
Primary waves, because they have a short wavelength and a velocity of 4km/s
What factors can increase landslide rates?
Increasing convection currents More weight on the top of the slope Increasing the size of the plate Stronger slab pull Higher density rock Lightning strikes on fold mountains
Why is it difficult for buildings to remain intact during an earthquake event?
Each type of wave moves through the ground differently
Everything attached to the ground also moves
Buildings can’t stay intact
