1.
The process that continually adds new crust is:
Correct Answer
C. Sea-floor spreading
Explanation
Sea-floor spreading is the correct answer because it refers to the process where new oceanic crust is formed at mid-ocean ridges. As tectonic plates move apart, magma rises from the mantle and fills the gap, creating new crust. This process is responsible for the continuous expansion of the ocean floor and the movement of the continents. It also helps in the recycling of old crust through subduction zones.
2.
The ring of fire is a ring of volcanoes and earthquakes that occur along
Correct Answer
B. Plate boundaries
Explanation
The ring of fire refers to a geographic area where a large number of volcanoes and earthquakes are concentrated. These volcanic and seismic activities primarily occur along plate boundaries, where tectonic plates interact with each other. Plate boundaries are areas where the Earth's crust is either colliding, moving apart, or sliding past each other. This movement of the plates leads to the formation of volcanoes and earthquakes, making plate boundaries the correct answer for the ring of fire.
3.
Where two plates rub past each other in opposite directions is a
Correct Answer
B. Transform boundary
Explanation
A transform boundary occurs when two tectonic plates slide past each other horizontally in opposite directions. This movement causes intense friction and pressure, resulting in earthquakes. Unlike convergent or divergent boundaries, there is no creation or destruction of crust at a transform boundary. Instead, the plates simply grind against each other, causing significant seismic activity. Therefore, a transform boundary is the correct answer in this case.
4.
The place where two plates collide is called a
Correct Answer
D. Convergent boundary
Explanation
When two tectonic plates collide, it forms a convergent boundary. At this boundary, the plates are forced together, leading to the formation of various geological features such as mountains, trenches, and volcanic activity. The collision can result in subduction, where one plate is forced beneath the other, or in the formation of a new mountain range. This type of boundary is characterized by intense geological activity and is responsible for the creation of some of the Earth's most dramatic landscapes.
5.
The place where two plates move apart is called a
Correct Answer
A. Divergent boundary
Explanation
A divergent boundary is the correct answer because it refers to the place where two tectonic plates move apart from each other. This movement creates a gap or rift between the plates, allowing magma from the mantle to rise and form new crust. This process is responsible for the formation of mid-ocean ridges and rift valleys on land.
6.
Subduction is when
Correct Answer
C. One plate slides under another
Explanation
Subduction is the process where one tectonic plate moves beneath another plate at a convergent boundary. This occurs when two plates collide, and the denser oceanic plate sinks below the less dense continental plate. Subduction zones are known for their intense seismic activity, as the descending plate can cause earthquakes. Subduction also leads to the formation of volcanic arcs and trenches, as the sinking plate can melt and create magma that rises to the surface, forming new islands or mountain ranges.
7.
The mid-ocean ridge occurs along a
Correct Answer
C. Divergent boundary where sea-floor spreading takes place
Explanation
The mid-ocean ridge occurs along a divergent boundary where sea-floor spreading takes place. Divergent boundaries are areas where two tectonic plates are moving away from each other. As the plates separate, magma rises from the mantle and fills the gap, creating new oceanic crust. This process is known as sea-floor spreading. The mid-ocean ridge is a continuous underwater mountain range that forms as a result of this process. Therefore, the correct answer is divergent boundary where sea-floor spreading takes place.
8.
The theory that states that pieces of Earth's crust are in constant, slow motion driven by movement in the mantle is called
Correct Answer
C. The theory of plate tectonics
Explanation
The theory of plate tectonics is the correct answer. This theory explains that the Earth's crust is divided into several large and small plates that are constantly moving and interacting with each other. These plates are driven by the movement of the underlying mantle, causing processes such as earthquakes, volcanic activity, and the formation of mountain ranges. The theory of plate tectonics provides a comprehensive explanation for various geological phenomena and has been widely accepted by the scientific community.
9.
The theory that continents are slowly moving over Earth's surface is called
Correct Answer
B. The theory of continental drift
Explanation
The correct answer is the theory of continental drift. This theory suggests that the continents on Earth's surface are not fixed, but rather they slowly move over time. It was proposed by Alfred Wegener in the early 20th century and provided evidence for the existence of a supercontinent called Pangaea, which later broke apart and formed the continents we see today. The theory of continental drift was a precursor to the modern theory of plate tectonics, which explains the movement of the Earth's lithospheric plates.
10.
When two continental plates pull apart a ________________________ forms
Correct Answer
D. Rift valley
Explanation
When two continental plates pull apart, a rift valley forms. This is because the tension between the plates causes the lithosphere to stretch and thin, creating a depression in the Earth's surface. This depression is known as a rift valley and is often associated with volcanic activity and the formation of new crust.
11.
Oceanic crust is ____________________ than continental crust
Correct Answer
B. More dense
Explanation
The given correct answer is "more dense". This means that the oceanic crust is denser or heavier compared to the continental crust. This is because the oceanic crust is primarily composed of basalt, which has a higher density than the continental crust, composed mainly of granite. The higher density of the oceanic crust is due to its composition and the process of cooling and solidifying of magma at mid-ocean ridges, making it denser than the continental crust.
12.
Continental crust is ______________________ than oceanic crust
Correct Answer
C. Thicker
Explanation
Continental crust is thicker than oceanic crust because it is composed of less dense rocks, such as granite, which are lighter and less likely to sink into the mantle. In contrast, oceanic crust is made up of denser rocks, like basalt, which are heavier and more prone to subduction beneath continental crust. This results in the formation of mountains and plateaus on the continental crust, while oceanic crust forms the ocean basins.
13.
A place where an unusually hot part of the mantle rises through the crust causing volcanic activity is called a
Correct Answer
B. Hot spot
Explanation
A hot spot refers to a location where an abnormally hot portion of the Earth's mantle rises through the crust, resulting in volcanic activity. This phenomenon occurs independently of plate boundaries and can lead to the formation of volcanic islands or chains, such as the Hawaiian Islands. Hot spots are characterized by a localized source of heat that generates magma, which eventually erupts onto the surface, creating volcanoes. Unlike divergent, convergent, or transform boundaries, hot spots are not directly associated with tectonic plate movement or interactions.
14.
Volcanoes are most likely to occur along a
Correct Answer
B. Convergent boundary
Explanation
Volcanoes are most likely to occur along a convergent boundary. This is because a convergent boundary is where two tectonic plates collide, causing one plate to be forced beneath the other in a process called subduction. As the subducting plate sinks into the mantle, it begins to melt due to the increasing temperature and pressure. The molten rock, or magma, rises to the surface and erupts as a volcano. This is why convergent boundaries, such as those found at subduction zones, are known for their volcanic activity.
15.
The Himalayan mountains were formed because of a
Correct Answer
D. Convergent boundary
Explanation
The correct answer is convergent boundary. Convergent boundaries occur when two tectonic plates collide, causing one plate to be forced beneath the other in a process called subduction. In the case of the Himalayan mountains, the Indian plate is colliding with the Eurasian plate, resulting in the uplift and formation of the mountain range. This collision has been ongoing for millions of years and continues to shape the landscape of the region.
16.
What causes the tectonic plates to move?
Correct Answer
D. Convection in the mantle
Explanation
The movement of tectonic plates is primarily caused by convection in the mantle. Convection occurs when heat from the Earth's core causes the mantle material to become less dense and rise. As it rises, it cools and becomes denser, causing it to sink back down. This continuous cycle of rising and sinking creates convection currents in the mantle, which in turn, drags the tectonic plates along with them. This movement of the plates leads to various geological phenomena such as earthquakes, volcanic activity, and the formation of mountains.
17.
Pieces of Earth's crust move on top of the
Correct Answer
B. Mantle
Explanation
The mantle is the layer of the Earth that lies between the crust and the outer core. It is composed of solid rock and is responsible for the movement of tectonic plates. These plates, which make up the Earth's crust, float on top of the semi-fluid mantle. The movement of the tectonic plates is what causes earthquakes, volcanic activity, and the formation of mountains. Therefore, it is accurate to say that pieces of Earth's crust move on top of the mantle.
18.
The fact that ice floats on top of water is like the fact that
Correct Answer
C. The less dense crust sits on top of the mantle
Explanation
The fact that ice floats on top of water is similar to the fact that the less dense crust sits on top of the mantle. In both cases, the lighter material is positioned above the denser material. Just as ice, being less dense than water, rises to the surface, the less dense crust is situated above the denser mantle. This arrangement is a result of the differences in density between the two layers.
19.
A map of global earthquakes and volcanoes tells you
Correct Answer
D. Where the plate boundaries are
Explanation
A map of global earthquakes and volcanoes tells you where the plate boundaries are. This is because earthquakes and volcanoes occur along the edges of tectonic plates, where the plates interact and collide. By mapping the locations of these seismic and volcanic activities, scientists can identify the plate boundaries and gain a better understanding of the Earth's tectonic activity.
20.
Hot spots are
Correct Answer
B. Stationary, they stay in the same place
Explanation
Hot spots are stationary, meaning they stay in the same place. Unlike other geological features such as tectonic plate boundaries that are constantly moving, hot spots are fixed in location. Hot spots are areas of intense volcanic activity that occur beneath the Earth's surface. They are believed to be caused by a plume of hot mantle material rising from deep within the Earth. As the tectonic plates move over these hot spots, volcanoes are formed. Examples of hot spots include the Hawaiian Islands and Yellowstone National Park.