1.
What is another name for the Mohorovičić Discontinuity?
Correct Answer
D. Moho
Explanation
The Mohorovičić Discontinuity, often referred to as the Moho, is the boundary between the Earth’s crust and the mantle. It was named after the Croatian seismologist Andrija Mohorovičić who discovered it. The discontinuity is characterized by an abrupt increase in seismic wave velocity and marks the end of the Earth’s crust.
2.
At which boundary is the Moho typically located?
Correct Answer
B. Convergent
Explanation
The Mohorovičić Discontinuity (Moho) is typically located at convergent boundaries, where two tectonic plates are colliding or one plate is subducting beneath another. At these boundaries, the intense geological activity and interactions between plates often lead to the formation of the Moho.
3.
What does the Mohorovičić Discontinuity separate?
Correct Answer
A. Crust and Mantle
Explanation
It marks the boundary between the Earth's rigid outer layer (the crust) and the underlying, partially molten layer known as the mantle. This discontinuity is characterized by a change in the velocity of seismic waves, indicating the transition from the solid crust to the more ductile and partially molten mantle beneath.
4.
In which layer of the Earth is the Moho situated?
Correct Answer
B. Mantle
Explanation
The Moho marks the boundary between the Earth's crust and the underlying mantle. Specifically, it is located within the uppermost part of the mantle. This boundary is characterized by a change in the velocity of seismic waves, providing important insights into the different properties of the Earth's crust and mantle.
5.
What is the primary method for studying the Moho?
Correct Answer
A. Seismic TomograpHy
Explanation
Seismic tomography involves the analysis of seismic waves produced by earthquakes. By measuring the time it takes for these waves to travel through the Earth and using a network of seismometers, scientists can create detailed images of the Earth's interior, including the Moho.
6.
What is the Moho's significance in plate tectonics?
Correct Answer
C. Influences Seismic Behavior
Explanation
The Moho marks the boundary between the Earth's crust and mantle, and as seismic waves pass through this boundary, their behavior is influenced by the contrasting properties of these layers. This seismic interaction provides valuable information about the structure, composition, and thickness of the Earth's crust. Understanding the Moho is crucial for studying the dynamics of tectonic plates, as seismic waves play a key role in investigating the subsurface and the processes associated with plate movements.
7.
How deep is the Mohorovičić Discontinuity typically found below continents?
Correct Answer
C. 30-40 km
Explanation
The Mohorovičić Discontinuity, also known as the Moho, is typically found at an average depth of about 32 kilometers beneath the continents. This depth can vary, with the discontinuity being deeper beneath mountain ranges and shallower beneath plains. Thus the answer is 30-40 km.
8.
Which seismic wave is most affected by the Moho?
Correct Answer
B. S-wave
Explanation
S-waves are shear waves, and they experience a significant change in velocity and amplitude as they encounter the Moho. The Moho represents a boundary between the Earth's crust and mantle, and the differences in composition and physical properties between these layers cause a pronounced effect on the behavior of S-waves.
9.
What is the Moho's role in seismic wave behavior?
Correct Answer
B. Path Deviation
Explanation
As seismic waves pass through the Earth's interior and encounter the Moho, they undergo changes in velocity and direction. This phenomenon is known as path deviation. The Moho acts as a boundary between the Earth's rigid crust and the underlying, more ductile mantle. When seismic waves encounter this boundary, they can be refracted, reflected, or diffracted, leading to changes in their paths.
10.
In which region is the Mohorovičić Discontinuity more pronounced?
Correct Answer
B. Oceanic Crust
Explanation
The Moho is often more distinct and well-defined in oceanic crust compared to continental crust. This distinction is primarily due to differences in composition, temperature, and geological processes between oceanic and continental crust. In oceanic crust, the Moho is typically more clearly defined because the oceanic crust is generally thinner and more homogeneous compared to the continental crust.