Seafloor Spreading
If the Earth's crust is created at the mid-ocean ridges, then where is the crust being "recycled"?
At subduction zones, which form deep ocean trenches
What does molten mean?
liquified (rock)
A volcano that has not erupted in 200 years is called what?
Dormant
What type of boundary happens when two plates slide past each other?
Transform boundary
The core of the Earth is solid. True or False?
True
The Earth only has 8 tectonic plates. True or False?
False, 8 major plates, but there are several small plates, such as the Nazca plate.
Who first proposed the theory of Continental Drift (Plate Tectonics)?
Alfred Wegener
To what can we compare to how fast the continents are moving away from each other at divergent boundaries?
The same rate as our fingernails grow.
What are the circular movements through the mantle called?
Convection Currents
Name two main types of natural disasters that often occur at plate boundaries?
Earthquakes and volcanoes
The _________________ is the center of the earthquake.
epicenter
What are the three main layers of the Earth?
Crust, Mantle and Core
What is the lithosphere? Tell us about the two layers of Earth that it involves.
The lithosphere is made up of Earth's crust and the uppermost part of the mantle.
What did Wegener call the supercontinent that existed on Earth 250 million years ago?
Pangaea
These are an underwater mountain systems formed by plate tectonics; the largest single volcanic feature on Earth.
Mid-Ocean Ridges
The theory that the outer layer of Earth is divided and moves across Earth's surface
Plate Tectonics
What is the name of the volcano that erupted in the pacific northwest of the United States in 1980?
Mt. Saint Helens
What happens in the subduction area of convergent plates?
The denser oceanic plate is pushed beneath the less dense continental plate. A trench is formed and sometimes volcano(s) can form.
What are the two types of crust?
Oceanic and Continental
What do we call the area where 75% of the Earth's volcanoes are located?
The Ring of Fire
What is the phenomenon called that proved Wegener was correct about his Theory of Plate Tectonics? And, who was one of the scientists to discover this.
Seafloor Spreading and Harry Hess
Can sea floor spreading occur outside of the ocean? Why or Why not?
Yes, because not all oceanic crust is located in the ocean basin
This describes the movements of tectonic plates over long periods of time.
Continental Drift
Faults can store ______________ like a coiled spring.
energy
What type of plate boundaries create mountain ranges like the Himalayas? What is the name of the process happening at that mountain range?
Convergent boundary and it is called uplift.
Movement caused by warmer fluids rising and cooler fluids sinking is called
Convection
What is the Asthenosphere?
- tectonic plates float on the asthenosphere
- not liquid, yet has plasticity
- in the upper mantle
- cooler than the lower part of the mantle
Name the 3 main pieces of evidence that Wegener pointed to prove continental drift.
1. Coastlines on different continents that looked as if they could be puzzle pieces, 2. The same age and type of fossils on different continents, 3. Similar rock layers on the coastlines of the matching continents.
There are patterns in the ages of rock on the seafloor; the youngest rocks are at the ___________ and the oldest rocks are located at the _______________.
Ridges, trenches
Define the ocean basin
A depression in the Earth where the ocean lies.
Volcanoes usually occur where two plates converge; yet, Hawaii was (and still is forming) on a ________ ___________
Magma plume
The _______________ Scale is a way to compare the size of one earthquake with the size of another.
Richter
What does "Pangaea" mean?
"All the Earth"
Name 4 of Earth's 8 major tectonic plates.
1. African, 2. Antarctic, 3. Eurasian, 4. Indian Plate, 5. Australian Plate, 6. North American Plate, 7. South American Plate and 8.Pacific Plate
Scientists measure movement of Earth's surface with __________________
Seismograph
How do scientists estimate the age of the crust coming from ridges on the ocean floor?
Iron granules in the rock record the orientation of the Earth's magnetic field.
This is melted, molten rock material beneath Earth's surface; it cools slowly to form rocks with larger crystals.
Magma
Name three main types of Volcanoes
Shield, Cinder Cone, and Strata Cone
Part 1. What is the name of the large fault line that splits through California?
Part 2. What are the two plates that this fault runs through?
1. The San Andreas fault
2. The North American and Pacific Plates
How many years do scientists believe that the Earth's magnetic poles "flip"?
200,000 years
Can you name one of Earth's small tectonic plates?
Scotia, Caribbean, Juan de Fuca, Cocos, Philipine, Bismark, Mariana, Easter, or Juan Fernandez
What were Marie Tharp and Bruce Heezen famous for?
They made the first scientific map of the ocean floor and discovered the Mid-Atlantic Ridge.