1.
Who first explained mechanism for earthquakes?
Correct Answer
A. H. Reid
Explanation
H. Reid is the correct answer because he was the first to explain the mechanism for earthquakes. He proposed the elastic rebound theory, which states that earthquakes are caused by the sudden release of energy in the Earth's crust due to the movement and rupture of rocks along a fault line. This theory revolutionized our understanding of earthquakes and is still widely accepted today.
2.
Earthquakes are
Correct Answer
B. Movements along faults
Explanation
Earthquakes occur due to movements along faults, which are fractures in the Earth's crust where rocks on either side have moved past each other. These movements can cause the Earth's surface to shake, resulting in an earthquake. Faults are commonly found in areas where tectonic plates meet and interact, such as along plate boundaries. As the plates move, stress builds up along the fault line until it is released in the form of an earthquake. Therefore, movements along faults are responsible for causing earthquakes.
3.
Earthquakes are produced by
Correct Answer
C. Rapid release of energy
Explanation
Earthquakes are produced by a rapid release of energy. This release of energy occurs when there is a sudden movement or rupture along a fault line in the Earth's crust. The stress that builds up along the fault line is released in the form of seismic waves, causing the ground to shake. This rapid release of energy can be triggered by various factors such as tectonic plate movements, volcanic activity, or even human-induced activities like mining or reservoir-induced seismicity.
4.
Movement along faults are explained by
Correct Answer
D. Plate tectonics theory
Explanation
Plate tectonics theory is the correct answer because it explains the movement along faults by stating that the Earth's lithosphere is divided into several large plates that float and move on the semi-fluid asthenosphere beneath them. These plates interact with each other at their boundaries, which are known as faults. The movement along these faults is a result of the interaction between the plates, such as convergent, divergent, or transform boundaries. This theory provides a comprehensive explanation for various geological phenomena, including earthquakes, volcanic activity, and the formation of mountains.
5.
Seismology is
Correct Answer
A. The study of earthquake waves
Explanation
Seismology is the study of earthquake waves. This field of study focuses on understanding the behavior and characteristics of seismic waves that are generated by earthquakes. Seismologists analyze these waves to determine the location, magnitude, and source of earthquakes, as well as to study the Earth's interior structure. By studying earthquake waves, seismologists can also gain insights into the processes and mechanisms that cause earthquakes, helping to improve our understanding of seismic activity and develop better methods for earthquake prediction and hazard assessment.
6.
A general feature of an earthquake is
Correct Answer
C. A & B
Explanation
An earthquake is generally characterized by two main features: movements along faults and the vibration of the Earth caused by the rapid release of energy. These two features are closely associated with earthquakes and are commonly observed during seismic events. Therefore, the correct answer is A & B, as both options accurately describe general features of an earthquake.
7.
Rocks spring back is a phenomena called
Correct Answer
A. Elastic Rebound
Explanation
Elastic Rebound is the correct answer because it refers to the phenomenon where rocks spring back to their original shape after being subjected to stress and then released. This is commonly observed during earthquakes, where accumulated stress in the Earth's crust is suddenly released, causing the rocks to "rebound" and generate seismic waves. Plate Tectonics and Seismology are not directly related to the specific behavior of rocks springing back, hence they are not the correct answers.
8.
A general feature of an earthquake is
Correct Answer
D. All of the above
Explanation
The correct answer is "All of the above". This is because all the given options are true for a general feature of an earthquake. An earthquake is characterized by the vibration of the Earth, which is caused by the rapid release of energy. It is also typically preceded by foreshocks and followed by aftershocks. Additionally, earthquakes occur due to movements along faults, making this option the correct answer.
9.
Which is an earthquake recording instrument?
Correct Answer
C. SeismograpH
Explanation
A seismograph is an earthquake recording instrument that is used to measure and record the vibrations caused by seismic waves. It consists of a base that remains stationary during an earthquake, and a pendulum or mass suspended from it. When an earthquake occurs, the base shakes while the suspended mass remains relatively still due to inertia. This movement is recorded by a pen attached to the mass, which traces the seismic waves on a rotating drum or paper. The data collected by seismographs is crucial for studying and understanding earthquakes, as well as for monitoring seismic activity around the world.
10.
Which instrument records the movement of Earth?
Correct Answer
A. SeismograpH
Explanation
A seismograph is an instrument that records the movement of the Earth. It detects and measures seismic waves caused by earthquakes, volcanic eruptions, or other seismic events. The seismograph consists of a suspended mass that remains stationary while the Earth moves beneath it. As the Earth shakes, the mass remains relatively still, and a pen attached to it records the motion on a rotating drum or a digital display. This allows scientists to analyze and study the characteristics of the seismic waves, providing valuable information about the Earth's interior and the occurrence of earthquakes.
11.
A seismogram is ...
Correct Answer
A. A record of the Earth's movement
Explanation
A seismogram is a graphical representation or record of the Earth's movement. It is created by a seismograph, which is an instrument designed to detect and measure seismic waves caused by earthquakes or other sources of ground motion. The seismogram provides valuable information about the timing, duration, and intensity of the Earth's movement, allowing scientists to study and analyze seismic activity.
12.
A seismogram records ...
Correct Answer
C. Wave amplitude vs. time
Explanation
A seismogram records wave amplitude vs. time. A seismogram is a graph that represents the ground motion caused by seismic waves during an earthquake. It shows the amplitude or size of the waves on the y-axis and the time on the x-axis. By analyzing the seismogram, scientists can determine various characteristics of the earthquake, such as its magnitude, duration, and the types of waves that were generated. Therefore, the correct answer is wave amplitude vs. time.
13.
What are the main types of earthquake waves?
Correct Answer
A. Body waves, surface waves
Explanation
Earthquake waves can be classified into two main types: body waves and surface waves. Body waves are seismic waves that travel through the Earth's interior, while surface waves travel along the Earth's surface. Primary waves (P-waves) and secondary waves (S-waves) are specific types of body waves. P-waves are the fastest seismic waves and can travel through solids, liquids, and gases, while S-waves are slower and can only travel through solids. Short waves and long waves, as well as slow waves and fast waves, are not accurate descriptions of earthquake waves.
14.
Surface waves are ...
Correct Answer
D. Complex in motion and the slowest velocity of all waves
Explanation
Surface waves are complex in motion and have the slowest velocity among all waves. Unlike other types of waves, such as transverse and longitudinal waves, surface waves involve both vertical and horizontal motion. This complex motion is due to the interaction between the medium and the wave. Surface waves, like ocean waves or seismic waves, travel relatively slowly compared to other types of waves. This is because they are influenced by factors such as friction and the properties of the medium they are traveling through. Therefore, the correct answer is that surface waves are complex in motion and have the slowest velocity of all waves.
15.
Which is true about a surface wave?
Correct Answer
A. Has complex motion
Explanation
A surface wave is a type of wave that travels along the boundary between two different mediums, such as air and water or solid ground. It has complex motion because it combines both transverse and longitudinal motion. This means that the particles of the medium move both up and down as well as back and forth. Surface waves are known to cause the most damage during earthquakes and can travel through solids, liquids, and gases. Therefore, the statement "has complex motion" is true about a surface wave.
16.
Which waves are made up of primary and secondary waves?
Correct Answer
B. Body waves
Explanation
Body waves are the waves that travel through the Earth's interior. They are made up of primary (P) waves and secondary (S) waves. P waves are the fastest seismic waves and can travel through solids, liquids, and gases. S waves are slower than P waves and can only travel through solids. Therefore, body waves are the waves that are made up of primary and secondary waves.
17.
Which is true about primary waves?
Correct Answer
D. None of the above
Explanation
Primary waves, also known as P-waves, are a type of seismic wave that travel through the Earth's interior. Unlike the "shake" motion described in the options, primary waves actually cause particles in the ground to compress and expand in the same direction that the wave is traveling. Additionally, primary waves can travel through both solids and liquids, unlike the option that states they only travel through solids. Lastly, primary waves have a faster velocity than secondary waves, contrary to the option that suggests they have a slower velocity. Therefore, none of the given options are true about primary waves.
18.
Which is true about primary waves?
Correct Answer
A. Travel through solids, liquids and gases
Explanation
Primary waves, also known as P-waves, are seismic waves that can travel through solids, liquids, and gases. They are the fastest seismic waves and have a push-pull or compressional motion, which causes particles to vibrate in the same direction as the wave is traveling. This allows P-waves to travel through different mediums, including solid rock, liquid magma, and even the Earth's atmosphere. Therefore, the statement "travel through solids, liquids, and gases" is true for primary waves.
19.
Which is true about primary waves?
Correct Answer
A. Push-pull (compressional) motion
Explanation
Primary waves, also known as P-waves, are a type of seismic waves that exhibit push-pull or compressional motion. This means that the particles in the medium through which the waves travel are alternately compressed and expanded in the same direction as the wave propagation. P-waves can travel through solids, liquids, and gases, unlike other seismic waves. Additionally, P-waves have the fastest velocity among all seismic waves, not the slowest. Therefore, the correct answer is "Push-pull (compressional) motion."
20.
Primary and secondary waves are ....
Correct Answer
A. Body waves
Explanation
Body waves refer to seismic waves that travel through the Earth's interior, as opposed to surface waves that only travel along the Earth's surface. Primary waves (P-waves) and secondary waves (S-waves) are both types of body waves. P-waves are compressional waves that travel faster and can move through solids, liquids, and gases, while S-waves are shear waves that travel slower and can only move through solids. Therefore, the correct answer is "Body waves" because primary and secondary waves are types of seismic waves that propagate through the Earth's interior.
21.
Which is true about secondary waves?
Correct Answer
C. Slower velocity than primary waves
Explanation
Secondary waves, also known as S-waves, exhibit a push-pull or compression motion. They can travel through solids, but not through liquids or gases. Additionally, secondary waves have a slower velocity than primary waves. Therefore, the correct answer is that secondary waves have a slower velocity than primary waves.
22.
Which is true about primary waves?
Correct Answer
A. Greatest velocity of all earthquake waves
Explanation
Primary waves, also known as P-waves, are a type of seismic wave that travel through the Earth's interior during an earthquake. They are the fastest seismic waves and have the greatest velocity compared to other earthquake waves. P-waves are longitudinal waves that can travel through solid, liquid, and gas, causing particles to move in the same direction as the wave propagation. This characteristic allows P-waves to arrive at seismic stations first, providing valuable information about the location and magnitude of an earthquake.
23.
Which is true about secondary waves?
Correct Answer
D. All of the above
Explanation
Secondary waves, also known as S-waves, exhibit a "shake" motion perpendicular to their direction of travel. They can only travel through solids, as they require a medium with shear strength to propagate. Additionally, S-waves have a slower velocity compared to primary (P) waves. Therefore, the correct answer is that all of the given statements about secondary waves are true.
24.
The place within the Earth where the earthquake originates is the ...
Correct Answer
A. Focus
Explanation
The focus refers to the exact point within the Earth where an earthquake originates. It is the location where the seismic energy is released, causing the ground to shake. The focus is usually located deep within the Earth's crust or upper mantle. The seismic waves radiate outwards from the focus, causing the surface to vibrate and resulting in an earthquake. The focus is different from the epicenter, which is the point on the Earth's surface directly above the focus. The diameter and magnitude are not directly related to the location of the earthquake's origin.
25.
The epicenter is the ...
Correct Answer
C. Point on the surface directly above the focus
Explanation
The epicenter refers to the point on the Earth's surface directly above the focus of an earthquake. The focus is the location within the Earth where the earthquake originates. Therefore, the epicenter represents the point on the surface that is directly above the focus.
26.
How is the epicenter located?
Correct Answer
D. By using the difference in arrival times between the primary and secondary wave recordings
Explanation
The epicenter is located by using the difference in arrival times between the primary and secondary wave recordings. This is because primary waves (P-waves) travel faster than secondary waves (S-waves) and arrive at the recording station first. By measuring the time difference between the arrival of P-waves and S-waves, scientists can calculate the distance between the recording station and the epicenter. This method is based on the fact that seismic waves travel at different speeds through different materials, allowing for the determination of the epicenter location.
27.
P and S waves are a short name for ...
Correct Answer
A. Primary and secondary waves
Explanation
The correct answer is Primary and secondary waves. P and S waves are commonly used abbreviations for primary and secondary waves, respectively. These waves are seismic waves that are generated by earthquakes and travel through the Earth's interior. P waves are the fastest and can travel through both solids and liquids, while S waves are slower and can only travel through solids. The use of these abbreviations is common in the field of seismology to differentiate between different types of seismic waves.
28.
Which is true about a secondary wave?
Correct Answer
C. A & B
Explanation
A secondary wave is a type of body wave that travels through the Earth's interior. It is also known as an S-wave and is characterized by its slower velocity compared to a primary wave. Therefore, both statements A and B are true about a secondary wave.
29.
A time-travel graph is used to find ...
Correct Answer
B. The distance to the epicenter
Explanation
A time-travel graph is used to find the distance to the epicenter. This graph plots the arrival times of seismic waves at different distances from the earthquake source. By analyzing the graph, it is possible to determine the time it takes for the waves to reach different locations, which can then be used to calculate the distance between those locations and the epicenter.
30.
What is the minimum number of station recordings needed to locate an epicenter?
Correct Answer
C. 3
Explanation
To locate an epicenter, at least three station recordings are needed. This is because each station records the arrival time of the seismic waves from the earthquake at its location. By comparing the arrival times of the seismic waves at different stations, the distance from each station to the epicenter can be determined. With the distances from at least three stations, the epicenter can be triangulated. Therefore, three station recordings are the minimum requirement to locate an epicenter.
31.
How is the epicenter located?
Correct Answer
A. A circle equal to the epicenter distance is drawn around each station and the point where the circles intersect is the epicenter
Explanation
In order to locate the epicenter of an earthquake, circles with a radius equal to the epicenter distance are drawn around each station. The point where these circles intersect is the epicenter. This method is based on the fact that seismic waves radiate outwards from the epicenter and are recorded at different distances by different stations. By analyzing the arrival times of these waves at different stations, the epicenter can be determined by finding the point of intersection of the circles.
32.
What type of graph is used to find the distance to the epicenter?
Correct Answer
D. A time-travel grapH
Explanation
A time-travel graph is used to find the distance to the epicenter. This type of graph plots the time it takes for seismic waves to travel to different locations from the epicenter. By measuring the time it takes for the waves to reach different locations, scientists can calculate the distance to the epicenter. This is done by comparing the arrival times of different waves at different locations and using the known speeds of the waves. Therefore, a time-travel graph is essential in determining the distance to the epicenter of an earthquake.
33.
How is the epicenter located?
Correct Answer
A. Using three or more seismograpHs
Explanation
The epicenter is located using three or more seismographs. Seismographs are instruments that record the vibrations caused by earthquakes. By analyzing the time it takes for the seismic waves to reach different seismographs, scientists can triangulate the epicenter. The greater the distance between the seismographs, the more accurate the determination of the epicenter. Therefore, using three or more seismographs allows for a more precise location of the epicenter.
34.
What terms involve the location of an earthquake?
Correct Answer
A. Focus, Epicenter
Explanation
The terms "Focus" and "Epicenter" both involve the location of an earthquake. The focus refers to the point within the Earth where the earthquake originates, while the epicenter is the point on the Earth's surface directly above the focus. These terms are commonly used in seismology to describe the location and intensity of an earthquake.
35.
What is the measure of the degree of earthquake shaking at a given locale based on the amount of damage?
Correct Answer
A. Intensity
Explanation
Intensity is the measure of the degree of earthquake shaking at a given locale based on the amount of damage. It quantifies the effects of an earthquake at a specific location, taking into account factors such as structural damage, ground shaking, and human perception. Magnitude, on the other hand, measures the total amount of energy released by an earthquake, while focus refers to the location underground where the earthquake originates. Liquefaction is a phenomenon where saturated soil temporarily loses strength and behaves like a liquid during an earthquake.
36.
Intensity is often measured by ...
Correct Answer
B. Modified Mercalli Intensity Scale
Explanation
The Modified Mercalli Intensity Scale is often used to measure intensity. Unlike the Richter Scale or Moment Magnitude Scale, which measure the magnitude of an earthquake, the Modified Mercalli Intensity Scale measures the effects and damage caused by an earthquake at specific locations. It takes into account factors such as human perception, structural damage, and geological effects. The H. Reid Intensity Scale is not a commonly used scale for measuring earthquake intensity.
37.
Magnitude is often measured by ...
Correct Answer
A. Richter scale
Explanation
The Richter scale is commonly used to measure the magnitude of earthquakes. It quantifies the energy released by an earthquake by measuring the amplitude of seismic waves. Developed by Charles F. Richter in 1935, it is a logarithmic scale that assigns a numerical value to the earthquake based on the amplitude of seismic waves recorded by seismographs. The Richter scale is widely recognized and used by scientists and the general public to understand and compare the intensity of earthquakes.
38.
Which of the following is true?
Correct Answer
C. Both A & B
Explanation
Both A and B are true. Magnitude is often measured by the Richter Scale, which is a logarithmic scale that measures the amount of energy released during an earthquake. Intensity, on the other hand, is measured by the Modified Mercalli Scale, which assesses the effects of an earthquake on humans, structures, and the environment. While magnitude quantifies the energy of an earthquake, intensity describes its impact on the ground. Therefore, both scales play important roles in understanding and studying earthquakes.
39.
Which scale measures the magnitude of an earthquake?
Correct Answer
C. Both A & B
Explanation
Both the Richter scale and the Moment magnitude scale measure the magnitude of an earthquake. The Richter scale, developed by Charles F. Richter in 1935, measures the amplitude of seismic waves produced by an earthquake. On the other hand, the Moment magnitude scale, also known as the Mw scale, measures the total energy released by an earthquake. Both scales are commonly used to quantify the strength and size of earthquakes, with the Moment magnitude scale being more accurate for larger and more distant earthquakes.
40.
The concept of magnitude was introduced by ...
Correct Answer
B. Charles Richter
Explanation
Charles Richter introduced the concept of magnitude. He developed the Richter scale, which is used to measure the strength of earthquakes. The scale assigns a numerical value to the seismic energy released by an earthquake. This allows scientists to compare the intensity of different earthquakes and assess their potential impact. Richter's work revolutionized the field of seismology and provided a standardized way to quantify earthquake magnitude.
41.
What is true about the Richter scale?
Correct Answer
A. It does not estimate the size of very large earthquakes adequately
Explanation
The Richter scale is a logarithmic scale used to measure the magnitude of earthquakes. It measures the amplitude of seismic waves produced by an earthquake. However, the Richter scale is not suitable for estimating the size of very large earthquakes accurately. This is because it was originally developed to measure smaller earthquakes and becomes less reliable as the magnitude increases. Therefore, it does not estimate the size of very large earthquakes adequately.
42.
Which is true concerning the Richter scale?
Correct Answer
B. Based on amplitude of largest seismic wave
Explanation
The Richter scale is a logarithmic scale that measures the amplitude of the largest seismic wave produced by an earthquake. It is used to quantify the magnitude or size of an earthquake. The scale is based on the principle that each whole number increase on the Richter scale represents a tenfold increase in the amplitude of the seismic waves and roughly a 32-fold increase in the energy released. Therefore, the statement "Based on amplitude of largest seismic wave" is true as it accurately describes the basis of the Richter scale.
43.
Which is true about the Richter scale?
Correct Answer
A. Each unit of Richter magnitude equates to roughly a 32 fold energy increase
Explanation
The Richter scale measures the magnitude of an earthquake, which is a measure of the energy released by the earthquake. Each unit on the Richter scale represents a tenfold increase in the amplitude of seismic waves recorded by seismographs. Since the energy released by an earthquake is proportional to the amplitude of the seismic waves, each unit increase on the Richter scale corresponds to roughly a 32 fold increase in energy. Therefore, the statement that each unit of Richter magnitude equates to roughly a 32 fold energy increase is true.
44.
Which of the following statements are true?
Correct Answer
C. Both A & B
Explanation
Both statement A and B are true. The Richter scale is not suitable for accurately measuring the size of very large earthquakes. It was originally developed for smaller earthquakes and becomes less accurate as the magnitude increases. On the other hand, the moment magnitude scale is specifically designed to measure the size of very large earthquakes. It takes into account various factors such as the area of the fault that slipped and the amount of slip, providing a more accurate measurement for larger earthquakes. Therefore, both A and B are correct statements.
45.
The moment magnitude scale is ...
Correct Answer
B. Derived from the amount of displacement that occurs along a fault zone
Explanation
The moment magnitude scale is derived from the amount of displacement that occurs along a fault zone. This scale is used to measure the size of earthquakes based on the total energy released during the earthquake. It takes into account the area of the fault that slips, the average amount of slip, and the rigidity of the rocks involved. This allows for a more accurate measurement of the earthquake's magnitude compared to other scales that rely solely on the amplitude of seismic waves or the degree of earth shaking at a given locale.
46.
What factors determine structural damage?
Correct Answer
D. All of the above
Explanation
The factors that determine structural damage include the intensity of the earthquake, the duration of the vibrations, and the nature of the material upon which the structure rests. The intensity of the earthquake refers to the amount of energy released during the seismic event, which can directly impact the level of damage. The duration of the vibrations also plays a role, as prolonged shaking can cause more stress and strain on the structure. Additionally, the nature of the material beneath the structure can affect its stability and susceptibility to damage. Therefore, all of these factors contribute to determining the extent of structural damage.
47.
The design of the structure is a factor in determining ...
Correct Answer
C. Structural damage
Explanation
The design of a structure plays a crucial role in determining the extent of structural damage. A well-designed structure is more likely to withstand external forces and maintain its integrity, resulting in less damage. On the other hand, a poorly designed structure may be more susceptible to damage, especially during events such as earthquakes or strong winds. Therefore, the design of a structure directly influences the level of structural damage it may experience.
48.
A tsumani is
Correct Answer
B. A seismic sea wave
Explanation
A tsunami is a seismic sea wave caused by an underwater earthquake, volcanic eruption, or landslide. It is not a hurricane, landslide, or liquefaction of the ground. Tsunamis can travel across the ocean at high speeds and can cause significant damage and loss of life when they reach the coast.
49.
Which of the following occurs during liquefaction of the ground?
Correct Answer
D. Saturated material turns to fluid
Explanation
During liquefaction of the ground, the saturated material in the ground loses its strength and stiffness, causing it to behave like a fluid instead of a solid. This occurs due to the increase in pore water pressure caused by the shaking of the ground during an earthquake. As a result, the ground loses its ability to support structures and can lead to the sinking or tilting of buildings and other infrastructure.
50.
Which of the following statements are true?
Correct Answer
C. Both A and B
Explanation
During liquefaction of the ground, saturated material turns to fluid. This is because liquefaction occurs when the ground loses its strength due to the saturation of soil particles with water, causing the soil to behave like a liquid.
During liquefaction of the ground, underground objects may float to the surface. This is because the loss of soil strength can cause the upward movement of objects or structures that were previously buried underground, as they become buoyant in the liquefied soil.