Earth Science LESSON 2

What is a closed system?

A system where energy can enter or exit but matter cannot — Earth is a closed system for matter and open for energy.

Why is Earth considered a closed system?

Because matter (like air and water) rarely enters or leaves Earth, but energy (sunlight, heat) flows in and out.

What are the four subsystems of Earth?

Geosphere, Hydrosphere, Atmosphere, Biosphere

What is the geosphere?

The solid part of Earth — including rocks, crust, mantle, and soil.

What is the hydrosphere?

All water on Earth — oceans, lakes, rivers, glaciers, vapor, and groundwater.

What is the atmosphere?

The layer of gases surrounding Earth — includes oxygen, nitrogen, CO₂, and the ozone layer.

What is the biosphere?

All living organisms on Earth — including plants, animals, and microorganisms.

How do Earth's subsystems interact?

A change in one system (like a volcano) can affect others (like air quality, water systems, and living organisms).

Give an example of subsystem interaction.

In a volcanic eruption: geosphere erupts, atmosphere fills with ash, hydrosphere is polluted, biosphere is harmed.

What flows between Earth’s subsystems?

Matter (like water and nutrients) and energy (like sunlight and heat) flow across all four spheres.

Why is the interaction between subsystems important?

It keeps Earth’s systems balanced and supports life by moving nutrients, recycling gases, and transferring energy.