What are the three types of stress?
Compressional, Tensional, Shear
In which direction does each pull the earth?
Comp- Force pressing in
Ten- Force pulling out
Shear- Force that twists
Difference between stress and strain?
Stress is force acting on a material, strain is deformation of material
During elastic deformation does rock go back to its original shape?
What is failure?
When a material breaks.
What causes failure?
When stress outweighs the strength of the material
What is ductile deformation?
Material is permanently deformed.
Relate fork to elastic, ductile and failure.
Bend fork a bit- Elastic
Bend fork more- Ductile
Break fork- Failure
Three types of faults?
Reverse, Normal and Strike-slip
What causes reverse?
What causes normal?
What causes strike-slip?
Three types of seismic waves?
P-Wave, S-Wave, Surface Wave
Where in the earth and in what direction do P-waves move?
Back and forth; inner earth
Where in the earth and in what direction do S-waves move?
Up and Down; inner earth
Where in the earth and in what direction do surface waves move?
Back, forth, up and down; surface
Where is focus?
What is the fault line?
Line going up through earth
Where is the epicenter?
Which of the three wave types arrives first?
What does the disappearance of S-Waves tell scientists about the outer core?
Outer Core is liquid
How long does it take for a P-wave to reach a seismic station 2000 km's away from the epicenter?
How long does it take for a S-wave to reach a seismic station 2000 km's away from the epicenter?
What is the separation time between the waves?
What is the difference in the strength of an earthquake for each magnitude level up?
A factor of 10 (10 times for one level up, 100 times for two levels up)
What is magnitude?
Energy released by the earthquake
What is intensity?
How many seismic stations do you need to calculate the location of an earthquake?
Where do we see most earthquakes occurring?
Which depth of an earthquake is the strongest if all have the same magnitude?
What is an earthquake hazard in our class?
Cabinets aren't secured to the wall
Why is this dangerous?
They could fall on students
What could be done to fix this?
Bolt the cabinets to the wall
What does removing mass from the crust cause?
Isostatic Rebound causes crust to rise
Where does the sediment come from in a basin?
Erosion from island arcs
Why are there two main elevations that dominate earth's topography?
Because there are two types of crust, with different densities and thicknesses
What is isostatic rebound?
When crust rises because mass is removed.
What type of plate boundary is associated with Orogenic Belts?
Why are convergent boundaries associated with Orogenic Belts?
The force of two crusts collides to create mountains
In a mountain peak, what is there to provide necessary buoyancy for the peak?