Earthquakes- Plate Tectonics Flashcards
What is continental drift?
Where continents are always in motion
Who hypothesized continental drift?
Alfred Wegener
What was the name of the super continent?
Pangea
What are 3 evidences of continental drift?
Climate change, fossils, and land features
What is sea-floor spreading?
The process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge
What are the mountain ranges in the middle of the ocean called?
Mid-ocean ridge
The sea-floor moves like what?
Does it carry the continents along with it?
The sea-floor moves like a conveyor belt. It DOES takes the continents with it
What are 3 evidences of sea-floor spreading?
Magnetic stripes, samples, and molten material
What are plate tectonics?
Rigid slabs of rock that move with respect to each other
What type of current is behind plate tectonics?
Convection currents
What are the 3 types of plate boundaries?
Convergent- 2 plates collide
Divergent- Plates move apart
Transform- Plates slide past each other
What are 3 types of stress?
Compression, tension, and shearing
Name 2 landforms caused by compression.
Mountain ranges, ocean trenches
What is the difference between plastic and elastic strain?
Plastic strain makes a permanent change in the shape of a rock
Name the 3 types of faults.
Normal, reverse, and strike-slip
Describe each fault line.
(You can draw on the test)
I think we all wanna draw
What is the focus?
The point beneath the earth’s surface where rocks under stress breaks to cause an earthquake
What is the epicenter?
The point on the surface directly above the focus
Name 3 types of seismic waves.
Primary (P waves), Secondary (S waves), and Surface waves
Which seismic wave is seen first?
Primary waves (P waves)
Which seismic wave somes 2nd after lag?
Secondary waves (S waves)
Which seismic wave causes ground movement?
Surface waves
How do you find the epicenter of an earthquake?
Triangulating data
What device measures seismic activity?
Seismometer
What is a major belt of volcanic activity in the Pacific Ocean?
Ring of fire
What is a string of islands created by volcanoes called?
Island arc
What is a hot spot?
A large plume of hot mantle material rising from deep within the earth
The difference between quiet and explosive eruptions is the content of what mineral?
Silica
What is an extinct volcano?
Most likely never going to erupt again
What is a doormant volcano?
Most likely IS going to erupt again
How does a shield volcano form?
Lava flows out gradually building a wide, gently sloping mountain
How does a composite volcano form?
Tall, cone-shaped mountains in which layers of lava alternate with layers of ash
How does a cinder cone volcano form?
When lava has high viscosity it produces ash, cinders and bombs, which all build up around the vent in a steep, cone-shaped hill or small mountain
How does a lava plateau form?
High, level area that has been built up over time from lava seeping out of several cracks then traveling a distance before cooling and solidifying
How does a caldera form?
Huge hole left by the collapse of a volcanic mountain
What is geothermal activity?
Occurs when magma, a few kilometers, beneath earth’s surface, heats underground water, and forms hot springs and geysers
What is a hot springs?
Formed when groundwater is heated by a nearby body of magma or hot rock and eventually rises to the surface to collect in a natural pool
What is a geyser?
Fountain of water and steam that erupts from the ground when buildup of pressure is released
Name 2 landforms caused by tension.
Mid-ocean ridges, continental rifts
Name 2 landforms caused by shearing.
Transform faults, fault zones
