7.1 - Layers of the Earth
density
the physical property that determines the layers of the Earth
properties of crust
thinnest layer, least dense layer
fossil evidence
used by Wegener to defend his theory of continental drift
seismic waves
vibrations formed by earthquakes - used to learn about Earth's interior
continental drift
what is the theory that continents were once joined and drifted to their current locations
________________ million years ago, the dinosaurs became extinct, Laurasia and Gondwana had split into smaller pieces.
65 million years ago.
What are the two types of crust that a tectonic plate may contain?
Continental and oceanic.
What are the two types of crust?
Continental and oceanic.
Which type of boundary produces the most earthquakes?
Convergent boundaries.
What is the thinnest layer - made of silicon, aluminum and magnesium?
Crust
The Earth is made up of 3 layers based on the composition of each layer. What are the 3 layers?
Crust, mantle and core.
Who has the best Mom in the world?
Ella McAlvanah
Will a seismic wave traveling through a solid go faster or slower than seismic wave traveling through liquid?
Faster through solid.
Why do less dense compounds make up the crust and more dense make up the core?
Heavier, dense compounds are pulled to the center of the earth by gravity
What has to happen before rock from the earth's mantle becomes a new piece of crust?
It has to cool.
The Earth is made up of 5 layers based on the physical properties of it's layers. What are the 5 layers?
LAMOI - lithosphere, athenosphere, mesosphere, outer core and inner core.
The mantle is made up of more ______________ than the crust.
Magnesium
Where would you be most likely to find a boundary between a continental and an oceanic plate?
Off the West Coast of North America (near California).
Large pieces of lithosphere that move around the asthenosphere are called?
Tectonic plates.
What makes up 1/3 or 33% of the Earth's mass? (p. 191)
The core
Which layer of the earth is made up of solid iron?
The inner core.
Which layer makes up the greatest percentage of the Earth's mass? (p. 191)
The mantle (2/3 or 67% of the Earth's mass).
If the earth were an apple, which part would be the crust?
The skin
Who has the best daughter in the world?
Tracy McAlvanah
What type of boundary produces strike-slip faults?
Transform boundary
True or False? Oceanic crust is thinner and denser than continental crust.
True.
When rock is heated, it become less dense and tends to: a. rise b. sink c. move sideways d. erupt
a. rise
The mantle has less ________ and _________ than the crust does.
aluminum and silicon
Which term best describes the movement of continents? a. rapid b. gradual c. nonexistent d. fleeting
b. gradual
When rock cools, it becomes more dense and tends to: a. rise to the surface b. sink below the surface c. move sideways d. push against the surface
b. sink below the surface
magnetic field
caused by the liquid outer core
1/3 or 33% of the Earth's mass, iron and nickel. Up to 7,000 degrees Celcius!
core
outermost layer of earth. Made of oxygen, silicon and aluminum. Less than 1% of Earth's mass.
crust
Most geologist rejected Alfred Wagener's idea of continental drift because a. they were afraid of new ideas b. Wegener was interested in what the Earth was like millions of years ago c. Wegener used several different types of evidence to support his hypothesis d. Wegener did not have evidence that the crust could move this way
d. Wegener didn't have evidence. Evidence was discovered years later after Wegener had died.
What physical property determined how the layers of the Earth formed? a. Temperature b. Pressure c. Distance from the sun d. density
d. density
properties of inner core
densest and hottest
the temperature and pressure _________________ as you go deeper into the Earth
increases
Oceanic crust is denser because it has more of what 3 elements?
iron, calcium and magnesium
outer core
liquid layer of iron and nickel
Mesosaurus
lizard-like reptile fossils used as evidence of continental drift
makes up the greatest percentage (67%) of the Earth's mass
mantle
This liquid layer crates the Earth's magnetic field.
outer core
Ridge Push
plate motion due to gravity
Convection
plate motion due to heating and cooling
Slab Pull
plate motion due to higher densities
property of asthenosphere
putty or plastic like, flows
asthenosphere
soft layer of the mantle - the tectonic plates move on top of this layer. It's a layer of slowly flowing rock.
lithosphere
solid outer layer - crust and rigid upper part of the mantle
inner core
solid, dense center of our planet
mesosphere
strong, lower part of the mantle
