The Earth System Terrarium The Earth System n

The Earth System

Terrarium

The Earth System n “Earth is a complex system of interacting physical, chemical and biological processes, and provides a natural laboratory whose experiments have been running since the beginning of time. ” NASA http: //serc. carleton. edu/introgeo/earthsystem/nutshell/

Earth As A Closed System Closed system: exchange of energy but negligible exchange of mass with surroundings

Earth System Science n n Earth is a dynamic body with many separate, but highly interacting parts or spheres. Earth system science studies Earth as a system composed of numerous parts, or subsystems.

The Earth System M. Ruzek, 1999

The Earth’s Four Spheres

Earth’s Four Spheres The Earth is a system consisting of four major interacting components: Geosphere: comprises the solid Earth and includes both Earth’s surface and the various layers of the Earth's interior. Atmosphere: gaseous envelope that surrounds the Earth and constitutes the transition between its and the vacuum of space Hydrosphere: includes all water on Earth (including surface water and groundwater) Biosphere: the life zone of the Earth and includes all living organisms, and all organic matter that has not yet decomposed.

Overlapping Cycles in the Earth System http: //www. uwgb. edu/dutchs/GRAPHIC 0/Astronomy/Earth. Systems. gif

The Atmosphere The Earth is surrounded by a blanket of air, which we call the atmosphere. • The atmosphere consists of four unique layers (the troposphere, the stratosphere, the mesosphere, and thermosphere). • The atmosphere reaches over 560 kilometers (348 miles) up from the surface of the Earth. • The atmosphere is primarily composed of nitrogen (about 78%) and oxygen (about 21%). Other components exist in small quantities. http: //liftoff. msfc. nasa. gov/academy/space/atmosphere. html

Atmosphere • consists of a mixture of gases composed primarily of nitrogen, oxygen, carbon dioxide, and water vapour • The mesosphere, thermosphere, and exosphere are zones of diffuse atmospheric components in the far reaches of the atmosphere. • The troposphere (0 -10 km) constitutes the climate system that maintains the conditions suitable for life on the planet's surface. The stratosphere (10 to 50 km), contains ozone that protects life on the planet by filtering harmful ultraviolet radiation from the Sun.

Atmosphere: Interactions with other Earth System components Hydrosphere: The gases of the atmosphere readily exchange with those dissolved in water bodies (e. g. oceans, lakes, etc. ) Biosphere: The atmosphere supplies oxygen and carbon dioxide that form the basis of life processes (photosynthesis and respiration). Geosphere: Gases in the atmosphere react with water to produce weak acids that aid in the breakdown of rock.

System Interactions Hurricanes (atmosphere) sweep across the ocean (hydrosphere) and onto the land (geosphere), damaging the dwellings of people (biosphere) who live along the coast. Hydrosphere Atmosphere Geosphere http: //www. itvs. org/risingwaters/ Biosphere

The Biosphere The biosphere is the “life zone” of the Earth, and includes all living organisms (including humans), and all organic matter that has not yet decomposed. • The biosphere is structured into a hierarchy known as the food chain (all life is dependant on the first tier – mainly the primary producers that are capable of photosynthesis). • Energy and mass is transferred from one level of the food chain to the next. http: //www. geology. ufl. edu/Biosphere. html

Biosphere: Interactions with other Earth System components Atmosphere: Life processes involve a many chemical reactions which either extract or emit gases to and from the atmosphere (e. g. photosynthesis consumes carbon dioxide and releases oxygen, whereas respiration does the opposite). Hydrosphere: Evaporation of water from leaf surfaces (transpiration) transfers water to the atmosphere. Geosphere: The biosphere is connected to the geosphere through soils (mixtures of air, mineral matter, organic matter, and water). Plant activity (e. g. root growth and organic acid production) are also for the mechanical and chemical breakdown of the rocks.

Hydrosphere The hydrosphere contains all the water found on our planet. • Water found on the surface of our planet includes the ocean as well as water from lakes and rivers, streams, and creeks. • Water found under the surface of our planet includes water trapped in the soil and groundwater. • Water found in our atmosphere includes water vapor. • Frozen water on our planet includes ice caps and glaciers. • Only about 3% of the water on Earth is “fresh” water, and about 70% of the fresh water is frozen in the form of glacial ice. http: //water. tamu. edu/watercycle. html

Subcomponents of hydrosphere are connected via the hydrologic cycle

Hydrosphere: Interactions with other Earth System components Atmosphere: Water is transferred between the hydrosphere and biosphere by evaporation and precipitation. Energy is also exchanged in this process. Biosphere: Water is necessary for the transport of nutrients and waste products in organisms. Geosphere: Water is the primary agent for the chemical and mechanical breakdown of rock (weathering), to form loose rock fragments and soil, and sculpts the surface of the Earth.

Geosphere The geosphere is the solid Earth that includes the continental and ocean crust as well the various layers of Earth’s interior. • 94% of the Earth is composed of the elements oxygen, silicon, and magnesium. • The geopsphere is not static (unchanging), but its surface (crust) is in a constant state of motion. • Mineral resources are mined from the geosphere. http: //ess. geology. ufl. edu/ess/Introduction/Geosphere. html

Earth’s Layers: Composition and Mechanical Characteristics Composition crust Physical Characteristics Primarily silica plus light metallic elements mantle Primarily silica plus iron and magnesium core Primarily iron and nickel lithosphere asthenosphere brittle solid (but nearly liquid) mesosphere solid outer core liquid inner core solid Note: Lithosphere contains both crust and uppermost (brittle) layer of mantle

Geosphere: Interactions with other Earth System components Atmosphere: volcanism spews significant amounts of gases into the atmosphere. For example, volcanoes inject large amounts of sulphur dioxide to the upper atmosphere, resulting in global cooling. Hydrosphere: The formation of many minerals involve incorporation or release of water. Also, water speeds up chemical reactions that produce or destroy minerals, and aids in the melting of rock. Biosphere: Nutrients released from rocks during their breakdown are dissolved in water (to be used by aquatic plants).

System Interactions Volcanoes (geosphere) erupt, sending ash and gases into the air (atmosphere) and sending lava and ash down onto surrounding forests (biosphere) and human habitations (biosphere). Geosphere Atmosphere Biosphere http: //www. ecuadortravel. net/information. volcano. pichin cha. eruption. htm

System Interactions Earthquakes (geosphere) can damage buildings which may kill people (biosphere), as well as cause fires which release gases into the air (atmosphere). Earthquakes in the ocean may cause a tsunami (hydrosphere) which can eventually hit land kill both animals and people (biosphere). Biosphere Geosphere Atmosphere Hydrosphere

Where Do Humans Fit In ? As components of the biosphere, humans are temporary receptacles of the matter and energy that flows through the Earth System “You are what you eat, drink, and breathe” Human health is, to some degree, a function of how this flow of matter and energy flows through, and interacts with, the human body In many cases, problems of human health are fundamentally linked to the natural distribution of Earth materials

The Bottom Line Considerations on how processes within the Earth System interact are extremely important in the understanding of the real world ! Understanding physical and chemical processes in the Earth System is as important as understanding biological entities in terms of understanding biological systems (all are connected) Let’s break down some walls this term !

Homework n Give two examples of how the Earth system’s four parts can interact with each other. n n Example: Animals (biosphere) can wear paths in Earth’s surface (geosphere). Identify the parts involved in the following scenarios: n n Wind blows a sailboat across a lake. A bear digs under a log to search for good.