chapter 1: plate tectonics earth’s layers continents changing position over time plates moving...
TRANSCRIPT
Chapter 1: Plate Tectonics
Earth’s Layers
Continents Changing Position
Over Time
Plates Moving Apart
Plates Coming Together
100 100 100 100
200 200 200 200
300 300 300 300
400 400 400 400
500 500 500 500
This is a solid sphere of metal found in the
center of the Earth. It is mainly made up of nickel and iron.
The Inner Core
Although the word “asthenosphere”
comes from the Greek word asthenes, meaning weak, it is
not actually weak. How can it be characterized?
layer of hotter, softer rock in the upper mantle.
Solid lithosphere rests on it. Hot tar.
Most large tectonic plates include two types of crust.
What are these types of crust?
Continental&
Oceanic
To explore the interior of the Earth, what must scientists study?
They must study the energy from earthquakes or underground explosions.
Alfred Wegener proposed this hypothesis to help
explain Earth’s continents moving over time.
Continental Drift
Theory
What three pieces of evidence did Alfred Wegener use to
support his hypothesis on the continents moving? And provide
detail to at least one. Fossils- ancient reptile Mesosaurus had been discovered in South America and
western Africa. Not found anywhere else.
Climate- Greenland had once been near the equator and slowly moved to the Arctic
circle.
Geology- best evidence came from finding a type of rock that was in Brazil matched
rock found in western Africa.
Huge underwater mountain ranges that circle the
Earth like the seams of a baseball. They are also formed from divergent
boundaries. Mid-Ocean Ridges
How does the age of the sea floor show that plates are
moving?
Rock is youngest near the ridge, and older farther away. Showing that older rock was carried away from the ridge some time ago.
This is a boundary where plates are moving apart. What is the name of this boundary and where are most of them found?
Divergent Boundary—in the ocean
True or False. Mid-ocean ridges are the longest chain of mountains on
Earth.
True—Mid-Atlantic Ridge
is the longest.
What is a hot spot?
an area where a column of hot material rises from deep within a planet’s mantle and heats up the lithosphere above it, often causing volcanic
activity at the surface.
Suppose a magnetic reversal occurred today. How would new rocks at mid-ocean ridges differ from the rocks that
formed last year?
The magnetic minerals in the new rocks would be aligned in the
opposite direction.
Name and describe the three types of plate movement.
1.Divergent—moving apart2.Convergent—pushing together/colliding
3.Transform—scraping past each other
There are 3 types of convergent boundaries. Please list all
three and describe them briefly.
Continental-continental collision: two plates carrying continental crust push
together
Oceanic-Oceanic subduction: one plate w/oceanic crust sinks
Oceanic-Continental Subduction: occurs where crust sinks under continental crust.