Earthquakes Flashcards
How are earthquakes developed?
The breakage of rocks along a fault
Can we predict earthquakes?
No
Where do most earthquakes develop?
Concentrated along plate boundaries.
The edge of oceanic and continental plates
Where are they at depth?
Subduction zone
What kind of volcanoes do the Japanese Islands have?
Strato-volcanoes with felsic and intermediate lava
What does the blue circles mean on a map illustrating earthquakes?
Shallow; does the most damage and will feel
What does the green circles mean on a map illustrating earthquakes?
Intermediate
What does the red circles mean on a map illustrating earthquakes?
deep
When an earthquake occurs what is being released?
energy waves
What’s the focus/ hypocenter?
The location where rocks actually break
What’s the epicenter?
The point on the ground above the focus
What does the prefix epi- mean?
on top of
Where does the energy come from in moving plate tectonics?
the core
What are P (primary)- wave?
Waves that travel through solids and liquids.
What are S (shake/ secondary) waves?
Waves that travel only through solids.
How do P- waves move?
Left to Right
How do S-waves move?
Up and Down
What are surface waves?
Waves that travel on the surface
Which waves arrive first?
P waves
What are also P-waves?
Sound waves
Which wave does most of the damage?
Surface waves
What are surface waves compose of?
P and S -waves
How do P - waves travel?
Parallel to the direction of propogation. (Compressed)
How do S - waves travel?
Perpendicular to the direction of propogation. (Traversed)
Where are P - waves slowed?
Less dense fluids
What we feel an earthquake, what are we actually feeling?
Surface waves
What are tsunamis?
Giant sea waves
How are tsunamis developed?
Through reverse faults (an underwater earthquake)
Where do tsunamis develop?
Underwater, oceanic plates, above an undersea earthquake
How can earthquakes be used to understand the interior of the Earth?
Due to seismic waves
What is Thailand near?
A deep thrust fault
What’s a seismogam?
A record produced by a seismograph
What’s a seismograph?
An instrument that measures and records details of earthquakes, such as force and duration
How are S-waves used to study the Earth’s inner structure?
The waves refract on the crust
How are P-waves used to study the Earth’s inner structure?
The waves are reflected from the mantle and core and declines in density as it moves though liquid
Why do earthquakes occur along the edges of plate boundaries?
Because pressure is built up and needs to be released
When we feel an earthquake, what are we actually feeling?
Surface waves
