Earth’s Internal Structure
Name the 5 layers we drew to scale in the correct order starting at the surface going to the center.
Crust, upper mantle, lower mantle, outer core, inner core
What are the 2 types of crust?
Oceanic crust and continental crust.
Does the pattern of plate boundaries most resemble a cracked egg or a traditional puzzle?
A cracked egg - the pieces vary in size and placement in a less organized way than a traditional puzzle that has similar sized pieces spaced equally apart.
What are key features of the crust?
-like shell of hard-boiled egg (extremely thin, cold, brittle)
-made of relatively light elements (silica, aluminum, and oxygen)
-broken up into gigantic pieces (tectonic plates) that move very slowly
Name the 2 layers we added to explain the make-up and movement of tectonic plates.
Lithosphere and asthenosphere.
What type of plate motion do we think most likely explains the formation of the Atlantic ocean between South/North America and Africa?
Pull apart
Which layers of the Earth do tectonic plates contain?
The crust and the upper mantle.
What are key features of the outer core?
same material as inner core but LIQUID!
heated largely by radioactive decay of uranium and thorium
liquid churns in huge currents → makes electrical current → generates a magnetic field around the entire planet
How do oceanic crust and continental crust differ?
Oceanic crust is thinner, more dense, and made of basalt.
Continental crust is thicker, less dense, and made of granite.
What is the cause of continental drift?
Plate Tectonic Theory- the Earth's tectonic plates move a little bit every year through convection currents inside the mantle.
Choose the correct term in the sentence:
Plates cover Earth’s entire surface ( with / without) significant gaps.
Plates cover Earth’s entire surface WITH significant gaps.
What are key features of the inner core?
solid metal ball
high density iron (Fe) and nickel (Ni)
spins bit faster than rest of planet (1 rotation/day),
5400oC (close to Sun’s surface temp),
pressure 3 million x’s > surface
How does the asthenosphere aid in the movement of tectonic plates?
It is soft plastic-like rock (like silly putty) forming a slippery surface for tectonic plates to slide upon.
What are 3 main ways tectonic plates can move that might cause volcanic activity?
- Pull apart
- Converge
- Slide by each other
Choose the correct term in the sentence:
Plates are huge, flat, rigid slabs of ( iron and nickel / rock / rock and water).
Plates are huge, flat, rigid slabs of ROCK.
What 2 properties increase as you go deeper below the surface of the Earth and how does each trend affect matter?
Pressure and temperature increase.
The layers become more dense and solid.
How does the lithosphere aid in the movement of the tectonic plates?
The lithosphere- made up of the crust and upper mantle—is broken into large rocky plates that form tectonic plates that lie on top of the asthenosphere.
What are the 6 lines of evidence (discovered prior to 1920) that best support the theory of continental drift?
1. Animal fossils
2. Fit of continents
3. Plant fossils
4. Glacial evidence
5. Antarctic climate change
6. Corresponding rock sequences
Choose the correct term in each sentence:
Plates are ( the same / different) shapes and sizes.
Plates are ( mobile / not mobile).
Plates are DIFFERENT shapes and sizes.
Plates are MOBILE.