Question

Q. Consider the following statements.

Assertion (A): Volcanoes are not likely to be found in the regions of earthquakes.
Reason (R): Earthquakes are induced by seismic activity; volcanoes do not require seismic activity.

In the context of the above, which of these is correct?

• A.
  A is correct, and R is an appropriate explanation of A.
• B.
  A is correct, but R is not an appropriate explanation of A.
• C.
  A is incorrect, but R is correct.
• D.
  Both A and R are incorrect.

Answer 1

The correct option is D

Both A and R are incorrect.
Explanation:

The world's distribution of earthquakes coincides very closely with that of volcanoes. Regions of great seismicity such as the circum pacific ring of fire are also regions of major volcanic eruptions.

Many processes in and around volcanoes can generate earthquakes. Most of the time, these processes are faulting and fracturing that does not lead to an eruption. However, volcanic earthquakes do occur as magma and volcanic gases rise to the surface from depth, which involves significant stress changes in the crust as the material migrates upward.

Also, earthquake activity beneath a volcano almost always increases before an eruption because magma and volcanic gas must first force their way up through shallow underground fractures and passageways. When magma and volcanic gases or fluids move, they will either cause rocks to break or cracks to vibrate.
So, both statements are incorrect.