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Ocean Floor
What is Sea-Floor Spreading?
3 Types of Evidence
Subduction at Trenches
Random
100

The deepest places on Earth are located

away from the middle ocean in places called trenches

100
What was the name of the American geologist that discovered sea-floor spreading?
Harry Hess
100
Name the three types of evidence that supported sea-floor spreading.
Evidence from molten material, magnetic stripes, drilling samples
100
What is the difference between a deep-ocean trench and the M.O.R.?
Deep-ocean trenches destroy oceanic crust, and the M.O.R. creates it.
100

The author of Romeo and Juliet.

William Shakespeare

200
What is sonar?
a device that bounces sound waves off underwater objects and then records the echoes.
200

What type of rock is magnetic that is found at the bottom of the Ocean Floor?

Igneous Rock

200

The age of the rock closer to the mid-ocean ridge is ____________ than the rock closest to the deep ocean trench

Younger

200
What is subduction?
Subduction is the process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle.
200

The year the Declaration of Independence was signed in the United States.

1776

300

The large underwater mountain range where new oceanic crust is formed

Mid ocean ridge

300

 Seafloor spreading is a process that creates new ________________________ crust.

Oceanic

300
Describe what the Alvin was and what it specifically found.
The Alvin was a small submarine, built to withstand tremendous pressure. It discovered pillow-shaped and toothpaste shaped rocks along the M.O.R.
300
Describe what is happening in the Atlantic Ocean vs. the Pacific Ocean and why.
The Atlantic Ocean is expanding, while the Pacific Ocean is shrinking. This is because the Pacific Ocean has more trenches and the Atlantic Ocean has more mid-ocean ridges.
300

The formula for the area of a circle.

What is πr²

400

Where on Earth is the oldest seafloor located?

Mediterranean Sea




400

 In seafloor spreading, the further the ocean floor is away from the mid-ocean ridge, the _____________________ that floor will be.

older

400

What do scientist see coming out of the mid-ocean ridge?

Molten material

400
Describe the ages of rocks on the ocean floor in relationship to their location.
Rocks closer to the M.O.R. are younger. Rocks further from the M.O.R. are older.
400

The name of the wizarding school Harry Potter attends.

Hogwarts

500

Describe what will happen to the size of the Pacific ocean in the future and explain why.

The Pacific Ocean is shrinking. Every year, it gets about an inch smaller as the tectonic plates that the Americas sit on are pushed westward.

500

List the 3 main steps in sea-floor spreading.

1. Molten material rises along the mid-ocean ridge, forming new crust. 2. The sea-floor spreads apart along both sides of the M.O.R. 3. The ocean floor moves like a conveyor belt, carrying the continents along with it.

500

Describe the pattern seen in the seafloor ages and magnetic stripes.  How does this pattern help to explain and provide evidence for seafloor spreading?

When the Earth's magnetic field reverses, a new stripe, with the new polarity, begins.

500
Explain why the ocean floor is "renewed" every 200 million years.
It takes 200 million years for new rock formed along the M.O.R. to reach a deep ocean trench, where it is destroyed.
500

The only planet in our solar system that rotates on its side.

Uranus