Flashcards in Chapter 15 - Layers of the Earth + tectonics Deck (28)
What percent of the Earth is the Mantle?
What percent of the Earth is the Core?
The outer core is (state of mass) and the inner core is (state of mass)
Outer core - liquid
Inner core - solid
what is the core mostly made of?
iron and nickel
what are the 2 types of crust?
oceanic crust and continental crust
What is the crust mainly composed of?
Oxygen, Silicon, and aluminum
Put the 5 layers of the Earth in order
Lithosphere, Asthenosphere, Mesosphere, Outer core, inner core
What does the lithosphere include?
all of the crust and the ridged outer layer of the mantle
What layer of the Earth are tectonic plates?
What does the Mesosphere consist of?
the strong lower part of the mantle - going all the way down to the beginning of the core
What does the asthenosphere consist of?
a plastic layer of the mantle on which tectonic plates flow, and solid, slow moving rock.
How are scientists able to identify the composition and density of the mantle and core without drilling down to it?
by measuring the speed of seismic waves through each part of the Earth
What was the giant landmass 245 million years ago called?
Pangea split into 2 continents called
Laurasia and Gordwana
what are mid-ocean ridges?
chains of underwater mountains where molten rock from the mantle comes up into the crust and solidifies, creating new oceanic lithosphere. Site of sea-floor spreading
who developed the theory of the continental drift?
What percent of the Earth is the Crust?
What formations occur at Transform boundaries?
What formations occur at convergent boundaries?
Mountains, volcanic arcs, and island arcs
What formations occur at Divergent boundaries?
what are the 3 types of convergent boundaries and what do they form?
continental-continental --- Mountains
continental- oceanic ---- volcanic arcs
oceanic-oceanic --- Island arcs
What is a likely cause of lithospheric plate movement?
Convection currents in the asthenosphere
what happens during transform boundaries?
Tectonic plates slide past each other horizontally
what happens during convergent boundaries?
tectonic plates collide
what happens during Divergent boundaries?
tectonic plates move away from each other due to the molten rock rising up from mid-ocean ridges - it pushes the plates away
What causes the striped pattern of materials pointing to different magnetic poles?
magnetic reversals ----- some new material is formed from the asthenosphere, which points toward north during regular polarity. Then, new material is formed during reverse polarity, causing that material to point to south
Which type of crust is denser but thinner?