Earths Materials and Processes Part 1 The Earths

Earth’s Materials and Processes. Part 1 The Earth’s Spheres

What is the Earth System? • A system is a group of related objects or parts that work together to form a whole. • The Earth System is all of the matter, energy, and processes within Earth’s boundary. • Earth is a complex system made of living and non-living things, and matter and energy continuously cycle through the smaller systems.

The Geosphere • The Geosphere is the mostly solid, rocky part of earth. It extends from the center of the Earth to the surface of Earth. • The thin, outermost layer of the geosphere is called the crust. It is made mostly of silicate materials. • Oceanic crust is 5 to 10 km thick. Continental crust is 35 to 40 km thick. • The mantle is the layer that lies below the crust and is about 2, 900 km thick. ’ • The mantle is made of very slow-flowing, solid rock, consisting of silicate minerals that are denser than the silicates in the crust. • Earth’s central part, called the core, has a radius of about 3, 500 km. It is made of iron and nickel, and is very thick.

The Geosphere

The Hydrosphere: Got Water • The hydrosphere is the part of Earth that is liquid water. • Oceans, lakes, rivers, marshes, groundwater, rain, and the water droplets in clouds are part of the hydrosphere. • Water on Earth is constantly moving. It even moves into and out of living things. (Cycles!)

The Hydrosphere

The Cryosphere • The cryosphere is made up of all of the frozen water on Earth. • Snow, ice, sea ice, glaciers, ice shelves, icebergs, and permafrost are all part of the cryosphere. • Changes in the cryosphere can play an important role in Earth’s climate and species survival.

The Atmosphere • The atmosphere is a mixture of mostly invisible gases that surround Earth. • It extends outward about 500 to 600 km from Earth’s surface, but most of the gases lie within 8 to 50 km of Earth’s surface. • The atmosphere consists of about 78 percent nitrogen, 21 percent oxygen, and 1 percent many other gases. • Minor gases in the atmosphere include argon, carbon dioxide, and water vapor. • The atmosphere also contains the air we breathe.

The Atmosphere • It also traps some energy from the sun, which helps keep Earth warm enough for living things to survive and multiply. • Some gases of the atmosphere absorb and reflect harmful ultraviolet (UV) rays from the sun, protecting Earth and its living things. • The atmosphere also causes space debris to burn up before reaching Earth’s surface and causing harm.

The Atmosphere

The Biosphere • The biosphere is made up of living things and the areas of Earth where they are found. • Organisms usually need oxygen or carbon dioxide to carry out life processes (such as Cellular Respiration). • Liquid water, moderate temperatures, and a stable source of energy are also important for most living things.

The Biosphere

Interaction of Earth’s Spheres • All of the five spheres of Earth interact as matter and energy change and cycle through the system. • A result of these interactions is that they make life on Earth possible. • Earth’s spheres interact as matter moves between them. In some processes, matter moves through several spheres. • Earth’s spheres also interact as energy moves from one sphere to another, and back and forth between spheres.

Earth’s Energy Budget • Almost all of Earth’s energy comes from the sun. • A tiny fraction of Earth’s energy comes from ocean tides and geothermal sources such as lava and magma. • Energy is transferred between Earth’s spheres, but it is not created or destroyed. (Law of Conservation of Energy) • Any addition of energy to one sphere must be balanced by an equal subtraction of energy from another sphere. • The movement of energy through Earth’s system forms an energy budget.

Earth’s Energy Budget

Earth’s Energy Budget • When Earth’s energy flow is balanced, global temperatures stay relatively stable over long periods of time. • Sometimes, changes in the system cause Earth’s energy budget to become unbalanced. • An increase in greenhouse gases traps more energy in the atmosphere and decreases the amount of energy radiated out to space. • Polar ice and glaciers reflect sunlight. When the ice melts, the exposed water and land absorb and then radiate more energy than the ice did. • In each case, Earth’s atmosphere becomes warmer, which may lead to climate changes.