Exam 2: Plate Tectonics

Transform faults are never found at mid-ocean ridges.

Major plates move on average about the rate at which fingernails grow.

Which location is associated with a divergent plate boundary?

Tiny particles of iron-bearing magnetic minerals, such as , act as a compass needle at mid-ocean ridges when magma erupts and cools recording Earth's magnetic field.

From the time accurate charts became available in the late 1700s, observers noticed the remarkable coincidence of the shape of the Atlantic coasts of Africa and South America. What additional evidence strengthened the idea of continental drift with regards to geographic fit?

Plate tectonics (continental drift) is driven by convection currents of slow-moving material within Earth's inner core.

If there was once one supercontinent over 200 million years ago, then there was a single ocean called .

The rigid outer layer of Earth that comprises the continental crust, oceanic crust, and the uppermost mantle is called the .

One piece of evidence that suggests the existence of Pangaea is the apparent fit of continents across North and South Atlantic.

Which statement about hot spots is true?

Loihi is an excellent example of a(n) .

Describe the mechanism that controls the formation of the Hawai'ian Islands. Is this island chain still actively forming?

How has the history of plate movement been captured in residual magnetic fields?

If two oceanic plates collide and one is older and cooler (and therefore, denser) than the other, what will happen?

The Hawai'ian Islands formed as they pass over a hot spot in the middle of the .

About how many kilometers (miles) is it from the center of Earth to the outer edge of the outer core?

Earlier than 200 million years ago, the continents were joined into one supercontinent called .

Ocean basins have opened and closed over great spans of time during Earth's history.  This process of opening and closing is called a .

Roughly how fast do most lithospheric plates move?

Density is a measure of relative heaviness and is defined as mass per unit volume.