Geology and Earth Structure

A subcontinent is a large, distinguishable part of a continent, such as the Indian subcontinent, which is geographically and tectonically distinct from the rest of Asia.

Plate tectonics is the scientific theory describing the large-scale motion of the plates making up Earth's lithosphere.

Tectonic activity refers to the movement of the Earth's lithospheric plates, which shapes the surface through earthquakes, volcanoes, and mountain building.

The inner core is the innermost part of the Earth, composed primarily of a solid iron-nickel alloy.

The crust is the outermost solid shell of the Earth.

The mantle extends from the base of the crust to a depth of about 2900 km.

The Earth's structure consists of the crust, followed by the mantle, and then the core.

The continental crust is significantly thicker (averaging 30-35 km) than the oceanic crust (averaging 5-7 km).

The Earth is structured in layers, with the crust on the outside, the mantle in the middle, and the core at the very center. The core is further divided into inner and outer sections.

The crust is the thin, outermost solid layer of the Earth. It is where all life exists and where geological processes like plate tectonics occur.

The epicenter is the point on the Earth's surface directly above the focus, which is the actual point of origin of the earthquake within the crust.

Secondary waves (S-waves) are shear waves that travel slower than primary waves and cannot propagate through liquids, meaning they cannot pass through the Earth's liquid outer core.

Surface waves (L-waves or Love waves) travel along the Earth's surface rather than through the interior. Because they are the slowest, they have more time to build up amplitude and cause the most destruction.

The focus (or hypocenter) is the specific location within the Earth where the rock rupture begins and seismic energy is first released.

Primary waves (P-waves) are compressional waves that travel the fastest through the Earth's interior, arriving at seismic stations before any other waves.