Magnetic Reversals

Question 1

Scientist found ridges and mountain ridges found on the seafloor similar to those on the continents, these are called?

Answer 1

Mid-Ocean Ridges

Question 2

Who are the scientist who proposed seafloor spreading?

Answer 2

Scientists Robert Dietz and Harry Hess

Question 3

What does sea Floor spreading theory suggests?

Answer 3

It suggests that hot, less dense material from below the Earth’s crust rises towards the surface at the mid-ocean ridge.

This material flows sideways carrying the seafloor away from the ridge, and creates a crack in the crust.

The magma flows out of the crack, cools down and becomes the new seafloor.

Overtime, the new oceanic crust pushes the old oceanic crust far from the ridge.

Question 4

The process of seafloor spreading allows the creation of new what?

Answer 4

Bodies of water and seafloor

Question 5

Is the rate of formation of a new seafloor as fast the as destruction of the old seafloor at the subduction zone?

Answer 5

It is not always as fast as the destruction of the old seafloor.

Question 6

What is one of the most active sites of seafloor spreading? With more than 14 centimeters every year.

Answer 6

The East Pacific Rise

Question 7

In the place where two oceanic plates collide or where an oceanic plate and a Continental plate collide, what occurs?

Answer 7

Subduction Zone

Question 8

If subduction is faster than seafloor spreading, does the ocean shrink or expand?

Answer 8

It shrinks

Question 9

If the seafloor spreading is greater than the subduction, does the ocean shrink or expand?

Answer 9

The ocean expands

Question 10

Findings that support the seafloor spreading theory are;

Answer 10

1. Rocks are younger st the mid-ocean ridge.
2. Rocks far from the mid-ocean ridge are older.
3. Sediments are thinner at the ridge.
4. Rocks at the ocean floor are younger than those at the continents.

Question 11

What strengthened the seafloor spreading theory?

Answer 11

The magnetic reversals

Question 12

What does a magnetic compass prove?

Answer 12

Since a magnetic compass tells us directions on earth, it proves that the earth has a magnetic field.

Question 13

The needle of a magnetic compass usually points to the North Pole of the Earth which is actually what at present?

Answer 13

The south magnetic pole at present.

Question 14

Why is the magnetic north pole pointing to the southern hemisphere, and the magnetic south pole pointing to the northern hemisphere?

Answer 14

Because opposite poles attract.

Question 15

What causes or made the Earth’s magnetic field?

Answer 15

The Earth’s magnetic field is generated by the very hot molten outer core and had already existed since the birth of our planet.

Remember, the outer core is made of molten iron and nickel alloys, and hot metal moving fast makes an electromagnetic field.

Question 16

Magnetic Reversals are also known as?

Answer 16

Magnetic Flip

Question 17

Why is the magnetic reversal also known as the magnetic Flip?

Answer 17

Because the north pole sometimes transforms into a south pole and the south pole transforms into a north pole.

Question 18

What causes magnetic Flip?

Answer 18

The change of flow in the outer core.

Question 19

The occurrence of magnetic reversals can be explained through the magnetic patterns in magnetic rocks especially those found in?

Answer 19

Ocean Floor

Question 20

What are magnetic rocks?

Answer 20

Rocks that have magnetic propertise

Question 21

How does rocks in the mid-ocean ridge showcase magnetic Flip?

Answer 21

When lava solidifies, iron bearing minerals crystallizes. As these crystallize, the minerals behave like tiny compasses and align with the Earth’s magnetic field. So when magnetic reversal occurs, there is also a change in the polarity of rocks.