1.
Most earthquakes happen here : _______________________
Correct Answer
B. Plate boundaries
Explanation
Earthquakes primarily occur at plate boundaries because this is where the tectonic plates that make up the Earth's crust interact. These interactions can result in the release of energy, causing the ground to shake. At plate boundaries, there are three main types of interactions: divergent boundaries where plates move apart, convergent boundaries where plates collide, and transform boundaries where plates slide past each other. These interactions create stress and strain in the Earth's crust, leading to earthquakes. In contrast, the middle of the ocean and the middle of a plate have less tectonic activity and are therefore less prone to earthquakes.
2.
Normal faults are created by this type of stress
Correct Answer
C. Tension
Explanation
Normal faults are created by tensional stress. Tensional stress occurs when forces pull apart or stretch the Earth's crust. This type of stress causes the hanging wall to move downward relative to the footwall, resulting in a normal fault. In a normal fault, the hanging wall moves down along a inclined fault plane, creating a gap or a rift in the Earth's crust.
3.
The Richter Scale measures ___________________ an earthquake.
Correct Answer
D. The magnitude of
Explanation
The Richter Scale measures the magnitude of an earthquake. The magnitude refers to the size or energy released by the earthquake at its source. It is determined by measuring the amplitude of seismic waves recorded by seismographs. The Richter Scale is logarithmic, meaning that each whole number increase on the scale represents a tenfold increase in the amplitude of the seismic waves and approximately 31.6 times more energy released. Therefore, the Richter Scale provides a quantitative measure of the strength or intensity of an earthquake.
4.
Scientists use _______________________ to measure the strength of an earthquake.
Correct Answer
B. SeismograpHs
Explanation
Seismographs are the instruments used by scientists to measure the strength of an earthquake. These devices are designed to detect and record the vibrations caused by seismic waves. By analyzing the data collected from seismographs, scientists can determine various characteristics of an earthquake, such as its magnitude and intensity. Seismographs are essential tools in earthquake monitoring and research, providing valuable information for understanding and predicting seismic activity.
5.
The Mercalli scale measures ______________________ an earthquake.
Correct Answer
D. The amount of damage done by
Explanation
The Mercalli scale measures the amount of damage done by an earthquake. This scale is used to assess the effects of an earthquake on structures, the environment, and people. It takes into account factors such as the intensity of shaking, the extent of ground rupture, and the level of damage to buildings and infrastructure. By evaluating the damage caused by an earthquake, the Mercalli scale provides valuable information for understanding its impact and helping with disaster response and recovery efforts.
6.
Scientists use _________________________ to find an earthquakes measurment on the Mercalli scale.
Correct Answer
A. People's observations
Explanation
Scientists use people's observations to find an earthquake's measurement on the Mercalli scale. This is because the Mercalli scale is a subjective measurement that assesses the intensity of an earthquake based on the effects it has on people, buildings, and the environment. By gathering information from individuals who experienced the earthquake, scientists can determine the level of shaking and damage caused, which helps in determining the earthquake's intensity on the Mercalli scale. This method complements the use of seismographs, seismograms, and GPS, which provide objective data on the earthquake's magnitude and location.
7.
How many seismograms are needed to find the epicenter of an earthquake?
Correct Answer
C. Three
Explanation
To find the epicenter of an earthquake, three seismograms are needed. Seismograms are records of the ground motion caused by an earthquake. By comparing the arrival times of the seismic waves at different seismograph stations, scientists can triangulate the epicenter. The time difference between the arrival of P-waves and S-waves at each station helps determine the distance from the epicenter. With three seismograms, the intersection of the circles representing the distances from each station will pinpoint the epicenter. Therefore, three seismograms are required for accurate determination of the earthquake's epicenter.
8.
Which type of seismic waves move the fastest?
Correct Answer
B. P Waves
Explanation
P Waves, also known as primary waves, are the fastest seismic waves. These waves are compressional waves that travel through solids, liquids, and gases. They have the ability to push and pull particles in the same direction as the wave is moving, allowing them to travel faster than other types of seismic waves. Surface waves and S Waves, on the other hand, are slower and have different modes of particle motion.
9.
Which type of seismic waves are the most destructive?
Correct Answer
C. Surface Waves
Explanation
Surface waves are the most destructive type of seismic waves. These waves travel along the Earth's surface and cause the ground to move in a rolling or swaying motion. They have a larger amplitude and longer period compared to other seismic waves, which results in greater damage to buildings and infrastructure. Surface waves are responsible for the majority of the destruction during earthquakes, causing shaking and ground displacement that can lead to landslides, building collapses, and other hazards.
10.
What does the amount of time between the arrival of the P Waves and the arrival of the S Waves tell a scientist?
Correct Answer
D. The distance the epicenter is from the seismograpH
Explanation
The amount of time between the arrival of the P Waves and the arrival of the S Waves tells a scientist the distance the epicenter is from the seismograph.