Geology and Earth Structure

The East African Rift Valley is a classic example of a divergent boundary, where tectonic plates are pulling apart from each other. This stretching and thinning of the crust creates deep valleys and volcanic activity. Transform boundaries involve plates sliding past each other, while convergent boundaries involve plates colliding.

Primary (P) waves, Secondary (S) waves, and Love (L) waves are all recognized types of seismic waves that travel through the Earth during an earthquake. T waves are acoustic waves in the ocean and are not classified as standard seismic waves in geology curricula. Therefore, T wave is the correct choice.

While most volcanic activity occurs along plate boundaries, volcanoes can also form over mantle plumes, which are known as hotspots. The Hawaiian Islands are a prominent example of hotspot volcanism, where magma rises through the crust far from any plate boundary.

The Richter scale is a logarithmic scale used to measure the magnitude, or energy released, by earthquakes. Other scales are used for pH (acidity), light intensity (lux or lumens), and velocity (meters per second).

The Deccan Plateau is located in southern India, far from the Himalayan plate boundary, so tectonic activity in the north does not affect it. In contrast, the collision of the Indian and Eurasian plates causes Mount Everest to rise and triggers frequent earthquakes and landslides in the Himalayan region.

A subcontinent is a large landmass that is smaller than a continent but is geographically separated from the rest of the continent by physical barriers like mountains. The Indian subcontinent is a prime example, separated from the rest of Asia by the Himalayas.

Subterranean is derived from 'sub' (under) and 'terra' (earth), meaning underground. The other words do not share this definition.

A caldera is a large volcanic crater formed by a major eruption leading to the collapse of the mouth of the volcano. It is distinct from other geological features like faults or hot spots.

An aftershock is a smaller earthquake that follows the main shock of a larger earthquake. They occur in the same region as the primary event.

Geothermal activity refers to the heating of underground water by magma. This process is responsible for features like geysers and hot springs.

A hot spot is an area in the mantle from which heat rises as a thermal plume from deep in the Earth. This heat can melt the crust to form volcanoes even away from plate boundaries.

The Ring of Fire is a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur. It is characterized by a horseshoe shape.

A seismogram is the visual record produced by a seismograph. It displays the amplitude and duration of seismic waves.

A tsunami is a series of large ocean waves caused by an underwater earthquake, landslide, or volcanic eruption. They can travel vast distances across the ocean.

The epicenter is the point on the Earth's surface directly above the focus, which is where the earthquake originates.