Earth's Spheres

Introduction to EARTH'S SPHERES

Everything on Earth can be placed into one of four overlapping subsystems called spheres. These spheres are interconnected and interact with one another. These four spheres contain all of the Earth's land masses, water sources, living organisms, and gases.

• Geosphere - all rock on Earth
• Hydrosphere - all water on Earth
• Atmosphere - all gases on Earth
• Biosphere - all living things on Earth

Three of these spheres are abiotic and one sphere is biotic. Abiotic describes substances that are made up of non-living materials. Biotic describes living things. Which sphere is biotic?

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EARTH'S SPHERES

Atmosphere

HYDROSPHERE

Click the image to learn more about the atmosphere. "Atmos" comes from the Greek word for air.

Click the image to learn more about the hydrosphere. "Hydro" comes from the Greek word for water.

BIOSPHERE

GEOSPHERE

Click the image to learn more about the geosphere. "Geo" comes from the Greek word for Earth.

Click the image to learn more about the biosphere. "Bio" comes from the Greek word for life.

Learn about Sphere Interactions

SPHERE INTERACTIONS PRACTICE

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THE GEOSPHERE

The geosphere encompasses the entire solid Earth, including the crust, mantle and the core. It includes all the rocky, solid components of the planet, both on the surface and below.

• Continents
• Ocean Basins
• Mountains
• Volcanoes
• Rock Formations
• Tectonic Plates
• Magma and Lava
• Soils

Geosphere Video

THE ATMOSPHERE

The atmosphere is the layer of gases that surrounds Earth. It is composed primarily of nitrogen (about 78%), oxygen (about 21%), and trace amounts of other gases.

• Responsible for weather patterns, climate, and protects life on Earth by absorbing harmful solar radiation

• Contains five main layers that are defined by variations in temperature, pressure, and composition

Atmosphere Video

THE Hydrosphere

The hydrosphere contains all of Earth's water, including oceans, lakes, rivers, groundwater, glaciers, ice caps, and even the water vapor in the atmosphere. It plays a crucial role in regulating the planet's climate, shaping landscapes through erosion and deposition, and supporting life.

• Water in the hydrosphere can be found in solid, liquid, and gaseous states

• Solid water (ice) on Earth is often called the cryosphere

Hydrosphere Video

THE BIOSPHERE

The biosphere encompasses all living organisms on Earth and their interactions with the other spheres. Life in the biosphere is categorized into 5 kingdoms: animals, plants, fungi, protists, bacteria, and archaea. Life in the biosphere depends on the resources provided by the geosphere, hydrosphere, and atmosphere.Biodiversity: The biosphere is incredibly biodiverse, meaning it contains a vast variety of species. Biodiversity is essential for the resilience and stability of ecosystems. High biodiversity can enhance ecosystem productivity and the ability to adapt to environmental changes.

Biosphere Video

Interactions BEtween Spheres

Interactions between Earth's spheres are critical for maintaining the planet's stability, habitability, and overall functioning. These interactions are known as Earth system processes and are essential for understanding environmental processes, climate dynamics, and the interconnectedness of Earth's various components.

Atmosphere

Biosphere

GEOSPHERE

HydroSphere

Interactions WITH the atmosphere

Gas emitted from volcanic eruptions have warming and cooling effects on the atmosphere. Weathering of rocks in the geosphere changes the composition of the atmosphere by removing carbon dioxide.

Geosphere

Water from the hydrosphere evaporates into the atmosphere and forms clouds through condensation. This process is vital to the water cycle, which regulates Earth's freshwater resources and influences weather patterns.

Hydrosphere

Plants in the biosphere photosynthesize, taking in carbon dioxide from the atmosphere and releasing oxygen. All organisms respire, consuming oxygen and producing carbon dioxide. These interactions maintain a balance of gases in the atmosphere and stabilize climate.

Biosphere

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Interactions WITH the HYDROSPHERE

Movements along faults, or cracks in the Earth's surface, create depressions that fill with water to form lakes and other waterways. Tectonic activity between lithospheric plates also forms mountains and higher elevations that are sources for rivers.

Geosphere

Water and energy are transferred between the hydrosphere and atmosphere through the water cycle. Water from the hydrosphere evaporates into the atmosphere and forms clouds through condensation. This process is vital for the water cycle, which regulates Earth's freshwater resources and influences weather patterns.

ATMOSPHERE

The hydrosphere sustains aquatic ecosystems, providing habitats for a wide range of species. It supplies freshwater to terrestrial ecosystems, which is essential for plant growth and biodiversity. Plants remove water from Earth's surface and move it throughout their vascular system, eventually releasing water vapor into the atmosphere via transpiration.

Biosphere

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Interactions WITH the GEOSPHERE

Atmospheric processes, such as rain, wind, and temperature fluctuations, contribute to the physical and chemical weathering of rocks in the geosphere. This leads to the breakdown of minerals and the creation of sediment, which is transported by rivers and wind, shaping landscapes over time.

ATMOSPHERE

Water causes chemical and mechanical erosion, and moves sediments into the ocean. Sedimentation in the ocean carries organic matter and nutrients from land into the marine environment. These nutrients support the growth of phytoplankton and other primary producers, forming the basis of marine food webs.

HYDROSPHERE

Soil forms as a result of physical and chemical weathering of rocks and minerals in the geosphere. Living organisms, particularly plants and microorganisms, play a crucial role in soil formation and nutrient cycling. Soils provide a medium for plant growth, supply essential nutrients, and support a diverse range of terrestrial ecosystems.

Biosphere

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Interactions WITH the Biosphere

Plants in the biosphere carry out photosynthesis, a process in which they absorb carbon dioxide (CO2) from the atmosphere and release oxygen (O2) into it. This exchange is essential for maintaining the balance of atmospheric gases and providing oxygen for terrestrial and aquatic organisms, including humans.

ATMOSPHERE

Aquatic organisms form the basis of food webs, providing sustenance for both aquatic and terrestrial organisms, including humans. Fish, for example, are a primary protein source for billions of people worldwide.

HYDROSPHERE

The continuous movement of Earth's tectonic plates changes the distribution of habitats for life in the biosphere on a long timescale. For example, volcanic islands and seamounts provide important habitats for coral reefs and sea birds and undersea hydrothermal vents provide a habitat for microorganisms.

Geosphere

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INTERACTIONS PRACTICE

Below are images of Earth's spheres interacting. Observe each image and answer the questions on your answer sheet.

Image 1

Image 2

Image 3

Image 4

IMAGE 1 - Interactions Practice

What interactions are occuring between Earth's spheres in this image?

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IMAGE 2 - Interactions Practice

What interactions are occuring between Earth's spheres in this image?

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IMAGE 3 - Interactions Practice

What interactions are occuring between Earth's spheres in this image?

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IMAGE 4 - Interactions Practice

What interactions are occuring between Earth's spheres in this image?

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The Exosphere

The exosphere is the outermost layer of Earth's atmosphere and transitions into outer space. It is a region of extremely low density, with very few gas molecules. The exosphere has no clear boundary with space and gradually merges into the vacuum of outer space. Artificial satellites, such as communication and weather satellites, orbit within the exosphere.

Mesosphere

The mesosphere begins at the top of the stratosphere and extends to an altitude of about 85 kilometers (53 miles). It is relatively cold and thin, and temperatures decrease with altitude.

Meteors burn up in the mesophere due to friction and produce streams of lights called shooting stars

Mantle

The mantle is the layer of the between the crust and the outer core where convection of molten rock takes place. It is between 100 and 2,900 km in depth. The mantle is made from slowly convecting molten rock with a plastic-like consistency. The mantle is mainly composed of silicon (Si), magnesium (Mg), and iron (Fe).

Biotic Factors

Biotic factors are all the living things on Earth.

Examples:

• Plants
• Animals
• Protists
• Fungi
• Bacteria
• Archaea

Earth's Crust

The crust is the outermost, solid, rigid, and least dense compositional layer of the Earth. It is composed mainly from the elements oxygen (O) and silicon (Si). It is about 0-100 kilometers thick. There are two main type of crust – thick and less dense continental crust and thin and dense oceanic crust.

Tectonic Plates

Tectonic plates are large, rigid pieces of the Earth's lithosphere (the solid outer layer of the Earth) that fit together like a jigsaw puzzle and cover the entire surface of the planet. These plates are constantly slowly moving and play a fundamental role in shaping the Earth's surface and geological features.

Abiotic Factors

Abiotic factors are things that are non-living and made up of non-living substances.

Examples:

• Rainfall
• Sunlight
• Soil and Rock
• Gases in the Atmosphere

Stratosphere

Temperature in the stratosphere generally increases with altitude due to the presence of the ozone layer.

• The ozone layer helps protect us from ultraviolet radiation (UV) from the sun. In fact, the ozone layer absorbs most of the UV radiation the sun sends to us. Life as we know it wouldn't be possible without this layer of protection.

• Oxygen is essential for the respiration of most living organisms and plays a crucial role in combustion and various chemical reactions.

• Carbon dioxide is a greenhouse gas and plays a significant role in regulating Earth's temperature and climate. It is also essential for photosynthesis in plants.

Earth's Core

The Earth's core is approximately between 2,900 and 6,371 km in depth and contains a solid inner core and a liquid outer core. It is composed of iron (Fe) and nickel (Ni). The core is located in the center of the Earth, is under immense pressure, and is the hottest and densest layer.

Thermosphere

• Temperature increases with altitude in the thermosphere due to absorption of high-energy solar radiation.
• Contains the ionosphere, which plays a role in radio wave propagation and hosts auroras.
• Home to the International Space Station (ISS).

The Cryosphere

The cryosphere refers to the portion of Earth's surface where water is found in its frozen state, primarily as ice. It encompasses a variety of ice forms and features and plays a crucial role in Earth's climate, hydrology, and ecosystems.

• Glaciers
• Sea Ice
• Icebergs
• Snow Cover
• Ice Caps
• Permafrost

The biosphere is biotic because it is the sphere that is made up of living things.

Troposphere

The troposphere is the lowest layer of the atmosphere and is the layer of the atmosphere where where you can find living things. The troposphere is where weather occurs and it contains the majority of Earth's clouds, precipitation, and weather-related phenomena. Temperature generally decreases with altitude in this layer.

Clouds and jet planes can be found in the troposphere.