1.
The theory that the plates of the crust are always moving is called
Correct Answer
A. Plate tectonics
Explanation
Plate tectonics is the correct answer because it refers to the scientific theory that explains how the Earth's lithosphere is divided into several large and small plates that are constantly moving and interacting with each other. These plates are located on top of the semi-fluid asthenosphere and their movement is responsible for various geological phenomena such as earthquakes, volcanic activity, and the formation of mountain ranges. Plate tectonics has provided a comprehensive understanding of the Earth's dynamic nature and has been crucial in explaining the distribution of continents, the formation of ocean basins, and the occurrence of natural hazards.
2.
The point inside Earth's crust where an earthquake begins is the
Correct Answer
A. Focus
Explanation
The point inside Earth's crust where an earthquake begins is called the focus. This is the exact location within the Earth where the seismic energy is released and the initial rupture occurs. It is usually located beneath the Earth's surface and can vary in depth. The focus is responsible for generating the seismic waves that propagate outward and cause the shaking and damage associated with earthquakes.
3.
The removal and transport of weathered material is
Correct Answer
A. Erosion
Explanation
Erosion refers to the process of removing and transporting weathered materials such as soil, rocks, and sediments. It is caused by various factors like wind, water, and ice, which wear away the Earth's surface and carry the eroded materials to other locations. Erosion plays a significant role in shaping the Earth's landscape, forming valleys, canyons, and coastlines. Therefore, erosion is the correct answer as it accurately describes the process of removing and transporting weathered material.
4.
The deep valley along the mid-ocean ridge is a
Correct Answer
A. Rift
Explanation
The correct answer is "rift." The deep valley along the mid-ocean ridge is known as a rift. A rift is a long, narrow depression in the Earth's crust where tectonic plates are moving apart. As the plates separate, magma rises to fill the gap, creating new crust. This process is responsible for the formation of new oceanic crust and the continuous spreading of the seafloor. The mid-ocean ridge is a prime example of a rift, where new crust is constantly being generated.
5.
The process by which eroded material drops or settles is
Correct Answer
A. Deposition
Explanation
Deposition refers to the process in which eroded material, such as sediment or soil particles, is dropped or settles down. This can occur when the transporting agent, such as water or wind, loses its energy and is no longer able to carry the material. Deposition plays a crucial role in shaping the Earth's surface, as it leads to the formation of landforms like deltas, beaches, and alluvial plains.
6.
A break in Earth's crust where rocks can slide past each other is a
Correct Answer
A. Fault
Explanation
A fault is a break in Earth's crust where rocks can slide past each other. This can occur due to tectonic forces, causing the rocks to fracture and create a fault line. Faults are responsible for earthquakes and can be classified into different types based on the movement that occurs along the fault plane, such as normal faults, reverse faults, and strike-slip faults.
7.
Earth's center is called its
Correct Answer
A. Core
Explanation
The correct answer is core. The Earth's core refers to its central region, composed primarily of iron and nickel. It is divided into two parts: the inner core, which is solid due to high pressure, and the outer core, which is in a liquid state. The core plays a crucial role in generating the Earth's magnetic field and is responsible for the movement of tectonic plates.
8.
The point on Earth's surface directly above an earthquake's focus is the
Correct Answer
A. Epicenter
Explanation
The point on Earth's surface directly above an earthquake's focus is known as the epicenter. This is because when an earthquake occurs, the seismic waves radiate outwards from the focus, which is the point within the Earth where the earthquake originates. The epicenter is the location on the surface that corresponds to this point of origin. It is typically where the strongest shaking and damage occur during an earthquake.
9.
Earth's outer layer is the
Correct Answer
A. Crust
Explanation
The correct answer is crust. The Earth's outer layer is called the crust. It is the thinnest layer of the Earth, ranging from about 5 to 70 kilometers in thickness. The crust is composed of solid rocks and is divided into two types: continental crust, which makes up the continents, and oceanic crust, which forms the ocean basins. The crust is the layer where we live and where most geological activity, such as earthquakes and volcanic eruptions, occurs.
10.
Which layer is responsible for Earth's magnetic field?
Correct Answer
C. Outer core
Explanation
The outer core is responsible for Earth's magnetic field. It is a layer of molten iron and nickel that surrounds the solid inner core. The Earth's rotation causes the liquid metal in the outer core to move, creating electric currents. These electric currents generate a magnetic field, known as the geomagnetic field, which extends into space and protects the Earth from harmful solar radiation.
11.
Which process is responsible for forming a sea cave?
Correct Answer
C. Weathering
Explanation
Weathering is the process responsible for forming a sea cave. Weathering refers to the breakdown and alteration of rocks and minerals at or near the Earth's surface. In the case of a sea cave, weathering occurs when the constant action of waves and tides erode and wear away the rock along the coast, creating a hollowed-out cave. Over time, the repeated pounding of the waves against the rock causes it to weaken and eventually form a sea cave.
12.
What are Earth's plates composed of?
Correct Answer
C. The crust and the upper part of the mantle (lithospHere)
Explanation
The Earth's plates are composed of the crust and the upper part of the mantle, also known as the lithosphere. The lithosphere is a rigid layer that includes both the crust and a portion of the upper mantle. This layer is broken into several large and small plates that float on the semi-fluid asthenosphere beneath them. These plates move and interact with each other, leading to various geological phenomena such as earthquakes, volcanic activity, and the formation of mountains.
13.
How do the positions of the continents today compare with their positions 220 million years ago?
Correct Answer
B. The continents are now farther apart.
Explanation
The answer is based on the theory of plate tectonics, which suggests that the Earth's continents were once joined together in a supercontinent called Pangaea around 220 million years ago. Over time, the continents have drifted apart due to the movement of tectonic plates. This process, known as continental drift, has resulted in the continents being farther apart from each other than they were in the past. Therefore, the statement "The continents are now farther apart" is the correct answer.
14.
An earthquake occurs. Which type of waves will be detected first?
Correct Answer
A. P waves
Explanation
P waves, also known as primary waves, are the fastest seismic waves and therefore will be detected first during an earthquake. These waves are compressional waves that travel through solids, liquids, and gases, causing particles to move back and forth in the same direction as the wave's propagation. They can travel through the Earth's interior, reaching seismic stations before other types of waves. S waves, or secondary waves, are slower and arrive after P waves, while surface waves are the slowest and arrive last, causing the most damage during an earthquake.
15.
What caused the Hawaiian Islands to form?
Correct Answer
C. A hot spot
Explanation
The Hawaiian Islands formed due to a hot spot. A hot spot is an area of intense volcanic activity that remains stationary while the tectonic plates move above it. As the Pacific Plate moved over the hot spot, magma from the mantle rose to the surface, creating a chain of volcanic islands. The oldest islands are located to the northwest, while the youngest island, Hawaii, is at the southeastern end of the chain. This formation process is known as "hot spot volcanism."
16.
What type of volcano is large and wide and has "safe" flowing lava?
Correct Answer
C. A shield volcano
Explanation
A shield volcano is a type of volcano that is large and wide, with gently sloping sides. It is characterized by its "safe" flowing lava, which is relatively low in viscosity and can travel long distances before solidifying. This type of volcano typically erupts effusively, meaning that the lava flows out slowly and steadily rather than exploding violently. Shield volcanoes are commonly found in hotspots and are associated with non-explosive eruptions, making them less hazardous compared to other types of volcanoes.
17.
What would happen to an active composite volcano if its vent becomes plugged by hardened lava?
Correct Answer
B. The pressure from the magma chamber would build up and the volcano might explode.
Explanation
If the vent of an active composite volcano becomes plugged by hardened lava, the pressure from the magma chamber would continue to build up. As the pressure increases, it can eventually lead to an explosive eruption. This is because the trapped gases and magma would have no way to escape, causing a buildup of pressure within the volcano. Eventually, this pressure can become too great and result in an explosive eruption, causing the volcano to potentially explode.
18.
The thin outer skin of Earth
Correct Answer
B. Crust
Explanation
The correct answer is "crust." The explanation for this is that the Earth is composed of different layers, and the crust is the outermost layer. It is the thinnest layer, ranging from about 5 to 70 kilometers in thickness, and it is made up of solid rock. The crust is where all the landforms, such as mountains, valleys, and continents, are located. It is also where we find the Earth's surface, where we live and where most geological processes, like erosion, take place.
19.
The layer of Earth that extends from the bottom of the mantle to Earth's center
Correct Answer
A. Core
Explanation
The correct answer is core. The core is the layer of Earth that extends from the bottom of the mantle to Earth's center. It is composed of two parts: the inner core, which is solid, and the outer core, which is liquid. The core is primarily made up of iron and nickel, and it plays a crucial role in generating Earth's magnetic field.
20.
The removal and transportation of weathered material
Correct Answer
C. Erosion
Explanation
Erosion refers to the process of removing and transporting weathered material. It involves the wearing away of rocks and soil by natural forces such as wind, water, and ice. These forces break down the material and carry it away, shaping the Earth's surface over time. Erosion is responsible for the formation of various landforms like valleys, canyons, and deltas.
21.
A huge sheet of ice that stays frozen all year
Correct Answer
A. Glacier
Explanation
A glacier is a massive sheet of ice that remains frozen throughout the year. It is formed by the accumulation of snow over many years, which then compacts and turns into ice. Glaciers are found in areas where the temperature is consistently cold, such as high mountain ranges or polar regions. They slowly move downhill due to their own weight, causing erosion and shaping the landscape over time.
22.
A deep valley in mid-ocean formed where two plates move apart
Correct Answer
A. Rift
Explanation
A rift is a correct answer because it refers to a deep valley that forms in the mid-ocean where two tectonic plates move apart. This process is known as seafloor spreading, where molten material rises up from the mantle and creates new crust, causing the plates to separate. As the plates move apart, a rift valley is formed, which can eventually fill with water and become a new ocean basin. This geological phenomenon is an important part of plate tectonics and the formation of new crust on Earth's surface.
23.
A break in Earth's crust where rocks slide past each other
Correct Answer
C. Fault
Explanation
A fault is a break in Earth's crust where rocks slide past each other. It is a fracture in the Earth's lithosphere, where there is movement along the fault plane. This movement can be horizontal, vertical, or a combination of both. Faults are usually associated with tectonic plate boundaries, where the Earth's crust is under stress and experiencing deformation. The movement along faults can result in earthquakes, as the stress is released in the form of seismic energy.
24.
The point inside Earth where an earthquake begins
Correct Answer
C. Focus
Explanation
The focus is the correct answer because it refers to the point inside the Earth where an earthquake begins. The focus is also known as the hypocenter and it is the exact location where the seismic energy is released. This is different from the epicenter, which is the point on the Earth's surface directly above the focus. The focus is typically located within the Earth's crust or upper mantle, where the tectonic plates interact and generate seismic activity.
25.
The layer of Earth under the crust
Correct Answer
A. Mantle
Explanation
The mantle is the layer of Earth that lies beneath the crust. It is located between the crust and the core. The mantle is composed of hot, solid rock that is capable of flowing slowly over long periods of time. It is the thickest layer of Earth, making up about 84% of its volume. The mantle plays a crucial role in the movement of tectonic plates and the convection currents that drive plate tectonics. It is also responsible for generating volcanic activity and earthquakes.
26.
Which of these is the result of energy being released as rocks in a fault slide past each other?
Correct Answer
A. Earthquake
Explanation
When rocks in a fault slide past each other, it causes a release of energy. This energy is transferred to the surrounding rock layers, causing them to vibrate. These vibrations, known as seismic waves, travel through the Earth's crust, resulting in an earthquake. Therefore, an earthquake is the result of energy being released as rocks in a fault slide past each other.
27.
Which part of Earth consists of the crust and the uppermost part of the mantle?
Correct Answer
C. LithospHere
Explanation
The lithosphere is the correct answer because it consists of the crust and the uppermost part of the mantle. The crust is the outermost layer of the Earth, while the uppermost part of the mantle is the solid, rigid layer beneath the crust. Together, they form the lithosphere, which is divided into tectonic plates that float on the semi-fluid asthenosphere beneath it. The inner core, on the other hand, is a solid sphere of iron and nickel at the center of the Earth, completely separate from the lithosphere.
28.
During an earthquake, why do S and P waves arrive at a seismometer at different times?
Correct Answer
B. They travel at different speeds.
Explanation
During an earthquake, S and P waves are generated at the focus of the earthquake, which is the point where the seismic energy is released. The P waves, also known as primary waves, are the fastest seismic waves and travel through solids, liquids, and gases. On the other hand, S waves, also known as secondary waves, are slower and can only travel through solids. As a result, the P waves reach the seismometer first, followed by the S waves. This time difference between the arrival of the two waves at the seismometer is due to their different speeds of travel.
29.
Which are formed by violent volcanic eruptions?
Correct Answer
A. Cinder cone and composite volcanoes
Explanation
Cinder cone and composite volcanoes are formed by violent volcanic eruptions. Cinder cone volcanoes are formed when explosive eruptions eject volcanic materials such as ash, cinders, and bombs, which accumulate around the vent and form a cone-shaped structure. Composite volcanoes, also known as stratovolcanoes, are formed by alternating layers of lava flows and pyroclastic materials. These volcanoes are characterized by explosive eruptions that result in the formation of steep-sided cones. Shield volcanoes, on the other hand, are formed by non-explosive eruptions and have a broad, gently sloping shape.
30.
Which of the following lists Earth's layers from outer layer to inner layer?
Correct Answer
C. Crust, mantle, outer core, inner core
Explanation
The correct answer is crust, mantle, outer core, inner core. This is the correct order of Earth's layers from outermost to innermost. The crust is the outermost layer, followed by the mantle, then the outer core, and finally the inner core.
31.
Where does sea-floor spreading occur?
Correct Answer
C. Along the mid-ocean ridge
Explanation
Sea-floor spreading occurs along the mid-ocean ridge. This is where two tectonic plates diverge or move apart from each other. As the plates separate, magma rises from the mantle and fills the gap, creating new oceanic crust. This process results in the formation of underwater mountain ranges and the continuous spreading of the sea floor.
32.
Which instrument is used to detect an earthquake?
Correct Answer
C. Seismometer
Explanation
A seismometer is used to detect an earthquake. It is an instrument that measures the vibrations caused by seismic waves, which are generated by earthquakes. Seismometers can record the intensity, duration, and frequency of these vibrations, providing valuable data for studying earthquakes and understanding their characteristics. By detecting and measuring the ground motion caused by seismic waves, seismometers play a crucial role in monitoring and studying earthquakes, helping scientists and researchers to analyze and predict seismic activity.