Chapter 2

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? 1. Kauai 2. Maui 3. Hawaii 4. Oahu 5. Loihi

1

Evidence shows that periodic reversals of Earth's magnetic field have resulted in __________. 1. a symmetrical pattern of normal and reverse magnetization in ocean crustal rocks along ridges and rises. 2. mass extinction of life-forms 3. seafloor spreading 4. interruption of Earth's gravitational field 5. apparent polar wandering

1

Of the following statements about the age of the ocean crust, which one is true? Select only one answer. 1. The oldest ocean crust is about 200 million years old and is located near an ocean trench. 2. The oldest ocean crust is about 200 million years old and is located near the mid-ocean ridge. 3. The oldest ocean crust is about 2 million years old and is located near an ocean trench. 4. The oldest ocean crust is about 2 million years old and is located near the mid-ocean ridge. 5. The oldest ocean crust is about 4.5 billion years old and is located near the edge of a continent.

1

What part of the continent(s) create the best fit when trying to piece them back together like a puzzle into the supercontinent Pangaea? 1. Continental margin 2. Continental rise 3. Continental slope 4. Shoreline 5. Continental shelf

1

Which stage of the Wilson cycle is the Atlantic Ocean currently in? Select one answer. 1. Mature stage 2. Declining stage 3. Terminal stage 4. Embryonic stage 5. Juvenile stage

1

Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents? Choose all that apply. 1. The distribution of fossils of various species 2. The way the shapes of the continents fit together like pieces of a jigsaw puzzle 3. Evidence of glaciers in areas that are now tropical 4. The pattern of geologically similar mountain belts on different continents 5. The composition of meteors from outer space

1, 2, 3, 4

Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge? Choose all that apply. 1. The ocean floor is spreading apart and new sea floor is forming at the ridge. 2. The polarity of Earth's magnetic field experiences periodic reversals. 3. Polar reversals cause existing ocean crust to remagnetize. 4. The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools. 5. Marine organisms that live on the sea floor have created this pattern.

1, 2, 4

Of the following statements about ocean crust, which is/are true? Choose all that apply. 1. Ocean crust is destroyed at deep sea trenches. 2. Ocean crust is destroyed at transform faults. 3. Ocean crust is destroyed at the mid-ocean ridge. 4. Ocean crust is created at deep sea trenches. 5. Ocean crust is created at the mid-ocean ridge.

1, 5

Which of the following is the main reason that Earth has a magnetic field? Select only one answer. 1. The solid inner core spins rapidly in the opposite direction as Earth rotates. 2. Convection in the liquid iron-nickel outer core generates a magnetic field. 3. The Sun has such a powerful magnetic field that it creates a magnetic field on Earth. 4. Convection of the silicate materials in the asthenosphere generates a magnetic field. 5. The solid iron-nickel inner core spins in the same direction as Earth, but much faster.

2

Of the following statements about nemataths and volcanic arcs, which is/are true? Choose all that apply. 1. The age of the volcanoes progressively decreases as you move from one end of a volcanic arc to the other. 2. Nemataths and volcanic arcs are both the result of volcanic activity. 3. In a volcanic arc, any of the volcanoes can be active at any time. 4. Volcanic arcs are created at hotspots. 5. Volcanic arcs are associated with convergent plate boundaries.

2, 3, 5

Iceland is located on what type of plate boundary? 1. Transform 2. Continental/continental convergent 3. Divergent 4. Oceanic/continental convergent 5. Oceanic/oceanic convergent

3

Numerous small, shallow earthquakes tend to occur at __________. 1. oceanic/continental convergent plate boundaries 2. oceanic/oceanic convergent plate boundaries 3. divergent plate boundaries 4. continental/continental convergent plate boundaries 5. transform plate boundaries

3

The flat top of a guyot or tablemount in deep water is evidence that __________. 1. burrowing organisms have destroyed the peak of the seamount 2. the seamount is an extinct volcano with the crater filled by a solidified lava lake 3. a seamount was once at the surface of the ocean, but is now submerged due to plate movement and erosion 4. the seamount has been submerged by rising sea level that resulted from global climate change 5. the seamount is an erosional remnant of a flat abyssal plain

3

What do all plate boundaries have in common? Select only one answer. 1. They are all associated with an abundance of volcanic activity. 2. They are all located along the edges of continents. 3. They are all associated with zones of earthquakes. 4. They occur only on the ocean floor. 5. They occur entirely within the middle of continents.

3

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. 1. It would be classified as an oceanic rise. 2. It would have few, widely spaced volcanoes associated with it. 3. It would be classified as an oceanic ridge. 4. It would create a broad, swollen region symmetrical to the axis of the ridge. 5. It would have a prominent and deep rift valley.

3, 5

If the rate and direction of plate movement remain the same for the next 50 million years, what would then be an accurate prediction? 1. Subsidence of the Himalayan Mountains 2. Formation of a land bridge between Australia and Antarctica 3. Rifting of the Eurasian plate to form a juvenile ocean 4. Accretion of the California Terrane onto Alaska 5. Suturing of the Atlantic Ocean

4

A trench and a chain of volcanoes known generally as a volcanic arc are always present where there is __________. 1. a convergent plate boundary 2. a transform plate boundary 3. a hotspot 4. a divergent plate boundary 5. subduction

5

Compared to the rest of the planet, an unusually high concentration of hotspots and rifting is located on the continent of Africa. A likely explanation for this is that __________. 1. a large portion of Africa is located near the equator 2. Africa is just very large 3. the thick continental crust acts as a "heat blanket" and a large portion of Africa is located near the equator 4. mantle plumes do not occur at divergent plate boundaries, and Africa has no divergent plate boundaries 5. the African Plate is essentially stationary with respect to Earth's interior and the thick continental crust acts as a "heat blanket"

5

Of the following statements about sea-floor magnetic anomalies, which is true? Select only one answer. 1. They are oriented parallel to all mountain ranges. 2. They are oriented perpendicular to all mountain ranges. 3. They are oriented perpendicular to a mid-ocean ridge. 4. They are oriented perpendicular to deep sea trenches. 5. They are oriented parallel to a mid-ocean ridge.

5

Which of the following is an example of a nematath? 1. Great Barrier Reef 2. Aleutian Islands 3. Mariana Islands 4. Iceland 5. Hawaiian Islands-Emperor Seamount Chain

5