All questions of Natural Hazards & Disasters for Super TET Exam

D.

Highly fluid ones are less viscous, hence are less explosive while the acidic ones arc explosive due to high viscosity.

The what? Can you please provide more context or clarify your question?

Explanation:

Laccoliths and batholiths are both forms of intrusive igneous rock formations. However, the given descriptions of these formations are not accurate. Let's discuss each one separately:

Laccoliths:
- Laccoliths are formed when magma is injected into the crust and spreads out between existing rock layers.
- The magma pushes the overlying rock layers upward, creating a dome or mushroom-like shape.
- As the magma cools and solidifies, it forms a concordant intrusive body (meaning it follows the layering of the surrounding rocks).
- Laccoliths are typically smaller in size compared to batholiths.

Batholiths:
- Batholiths are also formed by the intrusion of magma into the crust, but they are much larger in size.
- They are characterized by their level base and lack of a pipe-like conduit.
- Batholiths represent a massive body of igneous rock that extends over a large area and is typically exposed at the surface due to erosion of the overlying rocks.
- They are also concordant intrusive bodies.

Understanding the given statements:
- The given statements incorrectly describe laccoliths as "large domes that cool in the deeper depth of the crust."
- Similarly, batholiths are inaccurately described as "large dome-shaped bodies with a pipe-like conduit from below."
- These descriptions do not match the actual definitions of laccoliths and batholiths, making the given statements incorrect.

Correct Answer:
- Based on the above explanation, the correct answer is option 'D' - None of the above, as both statements are inaccurate.

Overview:
In this question, we are given two statements about earthquakes and we need to determine if they are correct or incorrect. The statements are as follows:
1. The point where the energy is released is called the epicentre.
2. The point on the surface, nearest to the epicentre, is called the hypocentre.

Explanation:
To answer this question, let's analyze each statement individually.

Statement 1: The point where the energy is released is called the epicentre.
- The epicentre is the point on the Earth's surface directly above the focus of an earthquake.
- It is the location where the seismic waves originate and is usually the area of greatest damage.
- When an earthquake occurs, the energy is released from the focus and travels in waves through the Earth's interior, reaching the surface at the epicentre.
- Therefore, statement 1 is correct.

Statement 2: The point on the surface, nearest to the epicentre, is called the hypocentre.
- The hypocentre, also known as the focus, is the exact point within the Earth where the earthquake originates.
- It is the point at which the energy is released, and seismic waves start to radiate outwards.
- The hypocentre is located beneath the Earth's surface, whereas the epicentre is on the surface directly above it.
- Therefore, statement 2 is incorrect.

Conclusion:
Based on the explanations above, we can conclude that statement 1 is correct, but statement 2 is incorrect. Therefore, the correct answer is option 'C' - Both 1 and 2.

Sources of earthquakes

• Tectonic earthquakes - sliding of plates along a fault plane.
• Volcanic earthquakes - Collapse of roofs of underground mines.

Assertion (A): Shallow-focus earthquakes occur along transform boundaries.
Reason (R): Transform faults are found where plates slide past one another.

The correct answer is option 'A' - A is correct, and R is an appropriate explanation of A.

Explanation:
- Shallow-Focus Earthquakes:
- Shallow-focus earthquakes are earthquakes that occur within the upper 70 kilometers of the Earth's surface.
- The focus refers to the location within the Earth where the seismic energy is released.
- Shallow-focus earthquakes are typically associated with tectonic plate boundaries.

- Transform Boundaries:
- Transform boundaries are areas where tectonic plates slide past one another horizontally.
- These boundaries are characterized by transform faults, which are large strike-slip faults that accommodate the horizontal movement of the plates.
- Transform boundaries are found along oceanic ridges, where they connect segments of spreading mid-ocean ridges, and on land where they form the boundaries between two plates.

- Relationship between Shallow-Focus Earthquakes and Transform Boundaries:
- Transform boundaries are associated with shallow-focus earthquakes because of the intense stress and friction generated by the sliding of the plates.
- As the plates slide past each other, they can become locked due to friction. When the stress along the fault exceeds the strength of the rocks, it is released in the form of an earthquake.
- The shallow-focus earthquakes along transform boundaries are often characterized by strong shaking and can cause significant damage in populated areas.

- Assertion and Reason:
- The assertion (A) states that shallow-focus earthquakes occur along transform boundaries, which is true.
- The reason (R) provides an appropriate explanation for this phenomenon by stating that transform faults are found where plates slide past one another.
- The sliding motion at transform boundaries generates stress and friction, leading to the occurrence of shallow-focus earthquakes.

- Conclusion:
- Based on the above explanation, it can be concluded that assertion (A) is correct, and reason (R) is an appropriate explanation of assertion (A).
- Therefore, the correct answer is option 'A'.

Occurrence of Volcanoes in Geological Locations
The presence of volcanoes is closely associated with tectonic activity, and can occur in various geological settings. Let's explore the three mentioned locations:
1. Coastal Mountain Ranges
- Coastal mountain ranges are often formed at convergent plate boundaries where tectonic plates collide.
- The subduction of one plate beneath another leads to melting and the formation of magma, which can rise to create volcanic activity.
- Examples include the Andes in South America and the Cascades in the United States.
2. Off-shore Islands
- Off-shore islands can also be volcanic in origin, often formed by the same tectonic processes that create coastal mountain ranges.
- These islands frequently arise from hotspots or the movement of tectonic plates over magma plumes.
- Notable examples include the Hawaiian Islands, which are formed by a hotspot, and the Aleutian Islands, resulting from subduction zones.
3. Midst of Deep Ocean Beds
- Deep ocean beds are home to mid-ocean ridges, where tectonic plates are diverging.
- As the plates separate, magma rises from the mantle to fill the gap, leading to volcanic activity primarily in the form of underwater volcanoes.
- The formation of new oceanic crust occurs here, exemplified by the Mid-Atlantic Ridge.
Conclusion
In summary, all three geological locations—coastal mountain ranges, off-shore islands, and deep ocean beds—are likely to host volcanic activity due to their association with tectonic processes. Thus, the correct answer is option 'D': All of the above.

There are three types of plate boundaries: spreading zones, transform faults and subduction zones.