U5 unit test Flashcards
what is plate tectonics?
a scientific theory that explains how major landforms are created as a result of Earth’s subterranean movements
What is convection?
when heat is carried or transferred from hotter areas to cooler areas by the movement of fluids or gas
What is ridge push?
The pushing force created as new lithosphere constantly fills the gap between two diverging plates; this force helps push each plate away from its source
What is slab pull?
The tugging force created by gravity as the leading edge of the plate subducts; this force helps drag the entire plate away from its source and into the subduction zone
What is subduction?
When old, cold, and dense oceanic lithosphere converges with another plate and slides under it
What is a divergent boundary?
The place where two plates move away from each other
What is a convergent boundary?
The place where two plates slowly smash into each other
What is a transform boundary?
The place where two plates slide horizontally past one another
What is a hotspot?
A localized source of high heat energy within the mantle from which hot plumes of molten material rise upwards to form volcanoes
How did the theory of tectonic plates start?
Alfred wegener started the idea of tectonic plates with his theory of continental drift in 1915
What is the pressure of the earths core?
3.6 Million atm
What is the pressure of the Earths surface?
1 atm
What is the radius of the Earth in miles?
3,963.1 miles
What temperture is the surface of the Earth?
around 60ºF
What temperature is the Earths core?
Around 10,000º F
What is the density of the Earths core?
12.9g
What is the density of the Earths surface?
2.5g
What are Earths five mechanical layers? (from the inside out)
Inner core (Solid)
Outer core (Liquid)
Mesosphere (Stiff plastic)
Asthenosphere (Soft plastic)
Lithosphere (Brittle plastic)
Why does convection happen?
when a fluid (like air or water) is heated, the warmer parts become less dense and rise, while the cooler, denser parts sink, creating a circular movement called a convection current
In which of earths mechanical layers does convection happen?
The outer core, The mesosphere, and the Asthenosphere
What forces move lithospheric plates?
Ridge push, Slab pull, and Convection
How many major lithospheric plates are there?
Seven
What landforms are associated with divergent boundaries?
- a mid-ocean ridge (aka - an underwater mountain chain)
- a rift valley with sets of parallel ridges and valleys to either side.
What landforms are associated with convergent boundaries?
- a deep ocean trench + an arc of volcanic islands
- a deep ocean trench + an arc of continental volcanoes
- a continental mountain range + a high plateau
What landforms are associated with transform boundaries?
Visible cracks and faults in the crust
