Outline of Earth sciences

Index of Earth science articles The following outline is provided as an overview of and topical guide to Earth science: Earth science – all-embracing term for the sciences related to the planet Earth. It is also known as geoscience, the geosciences or the Earthquake sciences, and is arguably a special case in planetary science, the Earth being the only known life-bearing planet. Earth science is a branch of the physical sciences which is a part of the natural sciences. It in turn has many branches. Ecosphere – there are many subsystems that make up the natural environment (the planetary ecosystem or "ecosphere") of the Earth. Many of the subsystems are characterized as "spheres", coinciding with the shape of the planet. The four spheres (for which most of the other spheres are a subtype of) are the atmosphere, the biosphere, the hydrosphere and the geosphere. Listed roughly from outermost to innermost the named spheres of the Earth are: Magnetosphere – The region around an astronomical object in which charged particles are affected by its magnetic field Atmosphere, the gases that surround the Earth (its air) By altitude Exosphere – The outermost layer of an atmosphere Exobase – The lower boundary of the exosphere Thermopause – The upper boundary of the thermosphere Thermosphere – The layer of the atmosphere above the mesosphere and below the exosphere Mesopause – The temperature minimum at the boundary between the mesosphere and the thermosphere Mesosphere – The layer of the atmosphere directly above the stratosphere and below the thermosphere Stratopause – The upper boundary of the stratosphere Stratosphere – The layer of the atmosphere above the troposphere Ozone layer – The region of Earth's stratosphere that absorbs most of the Sun's UV radiation Tropopause – The boundary of the atmosphere between the troposphere and stratosphere Troposphere – The lowest layer of the atmosphere Planetary boundary layer – The lowest part of the atmosphere, directly influenced by contact with the planetary surface By air turbulence Heterosphere – Upper parts of the atmosphere in which the component gases are not well mixed Turbopause – The altitude in the Earth's atmosphere below which turbulent mixing dominates Homosphere – Lower parts of the atmosphere in which the component gases are well mixed Other Ionosphere – The ionized part of Earth's upper atmosphere Biosphere – The global sum of all ecosystems on Earth Anthroposphere – The part of the environment that is made or modified by humans for use in human activities and human habitat Noosphere (rare) – The sphere of human thought Hydrosphere – The combined mass of water found on, under, and above the surface of a planet, minor planet or natural satellite Cryosphere – Those portions of Earth's surface where water is in solid form Geosphere/Solid Earth – (Also sometimes a collective name for the lithosphere, the hydrosphere, the cryosphere, and the atmosphere) The union of all solid parts of Earth and the Inner of Earth.