GEOL 1550 Ch. 2

Of the following statements about ocean crust, which is/are true? Choose all that apply.

-Ocean crust is created at the mid-ocean ridge. -Ocean crust is destroyed at deep sea trenches.

Evidence shows that periodic reversals of Earth's magnetic field have resulted in __________.

-a symmetrical pattern of normal and reverse magnetization in ocean crustal rocks

The youngest rocks under the ocean are found

A Close to the Mid Ocean Ridge

If the rate and direction of plate movement remain the same for the next 50 million years, an accurate prediction would then be:

Accretion of the California Terrane onto Alaska

Paleomagnetism

B. Later, when the mag field recorded in a volcano's rock layers is measured, differences in mag field between the layers can be attributed to changes in the position of the NP relative to the land. how the pole has moved how the volcano has moved.

A transform boundary is where plates

C slide past each other

Which of the following is the main reason that Earth has a magnetic field? Select only one answer

Convection in the liquid iron-nickel outer core generates a magnetic field.

Consider the geologic fate of the following seamounts and islands in the Hawaiian Island-Emperor Seamount chain. Assuming conditions remain favorable for coral growth, which would most likely be the next to form an atoll?

Kauai

What is the name of the last supercontinent?

Pangaea

What do all plate boundaries have in common? Select only one answer.

They are all associated with zones of earthquakes.

Stage 3 of a coral reef, when the volcano is gone, is called a(n)

atoll

Iceland is located on what type of plate boundary?

divergent

The potential for energy release in an earthquake is proportional to the area of rock in contact at the walls of the fault.

divergent plate boundaries

Magnetic fields form as a result of __

moving charged particles

A trench and a chain of volcanoes known generally as a volcanic arc are always present where there is

subduction

The flat top of a guyot or tablemount in deep water is evidence that __________.

the seamount was once at the surface of the ocean, but is now submerged due to plate movement and erosion when it was near sea level

Which of the following statements accurately describes a segment of the mid-ocean ridge spreading at a rate of 3 centimeters per year? Choose all that apply.

-It would be classified as an oceanic ridge. -It would have a prominent and deep rift valley.

Of the following statements about nemataths and volcanic arcs, which is/are true? Choose all that apply.

-Nemataths and volcanic arcs are both the result of volcanic activity. -In a volcanic arc, any of the volcanoes can be active at any time. -Volcanic arcs are associated with convergent plate boundaries

Of the following statements about Earth's magnetic field, which is/are true? Choose all that apply.

-The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic north pole. -The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic south pole. -The lines of the magnetic force are parallel with Earth's surface at the equator.

Consider how rocks form on a mid-ocean ridge and the characteristics of Earth's magnetic field.

-The ocean floor is spreading apart and new sea floor is forming. -The polarity of Earth's magnetic field experiences reversals. -The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools

Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents? Choose all that apply

-evidence of glaciers in areas that are now tropical -the pattern of similar mountain belts on different continents -the way the shapes of the continents fit together like pieces of a jigsaw puzzle -the distribution of species of fossils

Which of the following is an example of a nematath?

Hawaiian Islands-Emperor Seamount Chain

Of the following statements about the age of the ocean crust, which one is true? Select only one answer.

The oldest ocean crust is about 200 million years old and is located near an ocean trench.

Of the following statements about sea floor magnetic anomalies, which is true? Select only one answer.

They are oriented parallel to the mid-ocean ridge.

Earthquakes result from the brittle fracture or sudden movement of rock faces in contact with each other when stress exceeds their breaking strength.

lithosphere

Compared to the rest of the planet, an unusually high concentration of hot spots and rifting is located on the continent of Africa. A likely explanation for this is that __________.

the African Plate is essentially stationary with respect to Earth's interior and the thick continental crust acts as a "heat blanket"