3. Structure of the Earth (Student's Copy)

Geosphere

The solid part of the Earth, including the crust and upper mantle.

Biosphere

The global sum of all ecosystems; the zone of life on Earth.

Hydrosphere

All the water on Earth, including oceans, lakes, rivers, and glaciers.

Atmosphere

The layer of gases surrounding the planet Earth.

Axial Tilt

The angle between the Earth's rotational axis and its orbital axis, approximately 23.5 degrees.

Revolution

The movement of the Earth around the Sun, taking approximately 365 days.

Rotation

The spinning of the Earth on its axis, which takes about 24 hours.

Tropical Year

The time taken for the Earth to complete one revolution around the Sun, correlated with the seasons, approximately 365.24 days.

Precession

The gradual shift in the orientation of Earth's axis of rotation, affecting the timing of seasons.

Convergent Boundary

A tectonic plate boundary where two plates move towards each other, often resulting in one plate being forced beneath the other.