science Flashcards
Earthquakes are caused by masses of _____ shifting below Earth’s surface.
rock
When the motion of the plates is blocked, stress builds up. Eventually, the stress is released as ___________ which travels as ____ waves
energy, seismic
What is the tectonic plate movement and type of stress for divergent boundary?
Plates move apart and the stress is tension.
What is the tectonic plate movement and type of stress for convergent boundary?
Plates are coming together, stress is compression.
What is the tectonic plate movement and type of stress for transform boundary?
Plates are sliding past each other, stress is shearing.
Define and explain Subduction
Convergent boundary, makes earthquakes. It is when two plates collide and the dense plate slips beneath the plate that is less dense.
Define and give examples of where convection happens
Happens in the mantle, convection current
Define and give examples of where conduction happens
Two substances touching, heat move from the warmer to the colder
Define and explain what causes mid-ocean ridges
a ridge in the middle of the ocean, mountain underwater middle of ocean floor
Define and explain what causes mountain ranges
plates push together
Define and explain what causes rift valleys
Mountain rips apart, makes a valley in the middle
Define plate tectonics
Lithosphere/crust, plates in constant motion driven by convection currents in mantle
Explain the Ring of Fire and identify where it is located
The Ring of Fire is a big ring of active volcanoes and earthquakes and it is wrapped around the Pacific
Define the following and identify where earthquakes are typically found
sudden violent shaking of ground due to seismic waves(plates move)
Define the following and identify where volcanoes are typically found
Magma goes through the crust, found at(boundaries)edges of plates
Explain what determines if a volcanic eruption is quiet or explosive
the content of the magma and the amount of gas
what is seafloor spreading?
Seafloor spreading is a geological process when large slabs of Earth’s lithosphere splits apart from each other.
what causes seafloor spreading?
Heat from the mantle’s convection currents make the crust more plastic and less dense as tectonic plates slowly move away from each other, and this crust rises which usually forms a mountain or an elevated area of the seafloor.
Where does seafloor spreading occur?
At divergent plate boundaries.
Describe how magma becomes the new seafloor.
The crust cracks eventually and hot magma spills onto the crust.
What type of rock makes up the seafloor?
Igneous rock.
How do the plates move during seafloor spreading?
They are diverging
Where is the newest oceanic crust found?
Near the center of mid-ocean ridges.
What happens to the age, density, and thickness of the ocean floor as you move away from the mid-ocean ridge?
It becomes cooler, more dense and more thick
What is an ocean trench?
long, narrow depressions on the seafloor
Where are the deepest trenches in the world found?
In the hadalpelagic zone
What other hazards occur at that location?
The intense pressure, lack of sunlight, and frigid temperatures of the hadalpelagic zone make ocean trenches some of the most unique habitats on Earth.
What type of plate boundary do ocean trenches form at?
The denser plate
how an ocean trench forms.
Some ocean trenches are formed by the plate carrying continental crust and a plate carrying oceanic crust sliding downwards sideways
What happens to the former seafloor in a subduction zone?
Rises through volcanoes located near the trench
What force in the earth causes the plate movement for seafloor spreading and subduction zones?
Tension is what causes the plate movement for seafloor spreading as well as subduction zones.
Is crust being created or destroyed at the mid-ocean ridge?
The crust is being destroyed at the mid-ocean ridge because the crust is splitting.
Is crust being created or destroyed at subduction zones?
The crust is being created at the subduction zones.
If an ocean has more subduction zones than mid-ocean ridges, is the ocean getting larger or smaller?
I think that the ocean will be getting smaller because the plates are coming together and therefore there is less space between two separate plates.
The Atlantic Ocean has a very large mid-ocean ridge and only a few small subduction zones. What would you predict about the size of the Atlantic Ocean in the future?
I think the Atlantic Ocean will become larger or stay the same size since there might also be a chance that the mid-ocean ridge separates farther apart.
The Pacific Ocean’s ring of fire is all subduction zones and it has a much smaller mid-ocean ridge. What would you predict about the size of the Pacific Ocean in the future?
The Pacific Ocean will be smaller in the future than it is now because the plates are coming together therefore causing the pacific ocean to become smaller.
