Question 1

The rates of plate movement are comparable to those of human fingernail growth.

Accepted Answer

The plates of the Earth’s crust move at a rate of a few centimeters per year, which is comparable to the rate of growth of human fingernails (which is about 3-4 millimeters per month).

Question 2

The ages of former volcanoes decrease with their distance from their parent hot spot.

Accepted Answer

The ages of former volcanoes increase with their distance from their parent hot spot, as the tectonic plate moves over the stationary hot spot, creating new volcanoes that are younger closer to the hot spot.

Question 3

The gigantic pieces of lithospheric plates diverging,sliding past,or colliding with each other are directly responsible for the vast majority of the earthquakes,volcanic eruptions,and mountains on Earth.

Accepted Answer

The movement and interaction of lithospheric plates, such as through diverging, sliding past, or colliding with each other, is a primary cause of earthquakes, volcanic eruptions, and the creation of mountains on Earth.

Question 4

The greatest earthquakes in the world occur _____________.
A)where plates collide with each other
B)where plates separate from one another
C)where plates slide past each other
D)in the interiors of individual plates

Accepted Answer

The greatest earthquakes in the world occur where plates collide with each other, such as the boundary between the Pacific Plate and the North American Plate along the west coast of North America. These are known as subduction zones and can produce earthquakes with magnitudes greater than 8.0 on the Richter scale.

Question 5

The grand recycling of the upper few hundred kilometers of the Earth is called the tectonic cycle.

Accepted Answer

The tectonic cycle refers to the process by which the Earth's crust is constantly being formed, destroyed, and reformed through the movement of tectonic plates. This involves the recycling of materials from the upper few hundred kilometers of the Earth's surface.

Question 6

Above the oceanic ridges,the ocean water depths are relatively deep in comparison to depths away from the ridges.

Accepted Answer

Oceanic ridges are underwater mountain ranges, where the ocean floor is elevated, making the water depths shallower compared to areas away from the ridges.

Question 7

Subducted slabs completely melt in the mantle and mix with the surrounding mantle.

Accepted Answer

Subducted slabs do not completely melt in the mantle; instead, they partially melt and can trigger magma generation, but significant portions remain solid and can descend deep into the mantle, contributing to mantle convection and geochemical heterogeneity.

Question 8

The floor of the Atlantic Ocean is striped by parallel bands of magnetized rock that show alternating polarities in a pattern that is symmetrical and parallel to the mid-ocean spreading center.

Accepted Answer

This statement is true.

Question 9

The greatest mountain ranges on Earth lie on the ocean bottoms and extend more than 40,000 miles.

Accepted Answer

The Mid-Ocean Ridge system is the longest mountain range on Earth, extending more than 40,000 miles through the Atlantic, Indian, and Pacific Oceans, mostly underwater.

Question 10

In 1620,Francis Bacon of England noted the parallelism of the Atlantic coastlines of South America and Africa and suggested that these continents had once been joined.

Accepted Answer

This statement is true. Francis Bacon did note the parallelism of the Atlantic coastlines of South America and Africa and suggested that these continents had once been joined. This observation was one of the early pieces of evidence that helped support the modern theory of continental drift.

Question 11

When data from the Earth's magnetic field locked inside seafloor rocks became widely understood,skeptics around the world were convinced that seafloor spreading occurs and that the concept of plate tectonics is valid.

Accepted Answer

The discovery of data from the Earth's magnetic field locked inside seafloor rocks was a major piece of evidence that supported the concept of plate tectonics. Many skeptics became convinced of the validity of plate tectonics after this discovery.

Question 12

Gravitational pull on a dense,down-going plate at a subduction zone (slab pull)is one of the forces that keeps the lithospheric plates moving.

Accepted Answer

Gravitational pull on a dense, down-going plate at a subduction zone (slab pull) is one of the forces that contribute to the motion of lithospheric plates.

Question 13

The processes that reverse the polarity of the magnetic field are likely related to changes in the flow of the iron-rich liquid in the outer core.

Accepted Answer

This is true. Scientists believe that the changes in the flow of the liquid iron in the outer core are related to the reversal of the Earth's magnetic field. This theory is supported by observations of changes in the magnetic field that suggest the movement and behavior of the liquid iron are critical factors in causing the polarity reversal.

Question 14

The active triple junction in _________ Africa is geologically young,having begun about 25 million years ago.
A)southwestern
B)southeastern
C)northeastern
D)western
E)southern

Accepted Answer

The active triple junction in northeastern Africa is the Afar Triangle, where the Arabian, African, and Somali plates meet. This geological feature began forming around 25 million years ago.

Question 15

Recent work has suggested that the solid inner core may be spinning in the same direction as the surrounding Earth,only slower.

Accepted Answer

Recent work has suggested that the solid inner core may actually be spinning at a different rate than the surrounding Earth, and it can even rotate faster or in a different direction, not necessarily slower.

Question 16

Hot spots have active volcanoes above them on the Earth's surface and moving plates carry the volcanoes away from their hot-spot source.

Accepted Answer

Hot spots are areas of intense volcanic activity caused by a plume of hot mantle material rising to the Earth's surface. The moving tectonic plates carry the volcanoes away from their hot-spot source, resulting in a volcanic chain such as the Hawaiian Islands.

Quiz 2: Internal Energy and Plate Tectonics