---
title: "Outline of Earth science"
chunk: 1/3
source: "https://en.wikipedia.org/wiki/Outline_of_Earth_science"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:28:35.173700+00:00"
instance: "kb-cron"
---

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.

== Earth's spheres ==

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. Earth's ecosphere lies it self within the heliosphere (the Sun's astrosphere). 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.
Pedosphere – The outermost layer of the Earth that is composed of soil and subject to soil formation processes
Outer layers
By composition
Crust (geology) – The outermost solid shell of a rocky planet, dwarf planet, or natural satellite.
Moho Discontinuity– The line between the crust and the Earth's mantle.
Earth's mantle – The part of the interior of the planet Earth between the crust and the core.
By diffusion of seismic waves
Lithosphere – The rigid, outermost shell of a terrestrial-type planet or natural satellite that is defined by its rigid mechanical properties.
Asthenosphere – The highly viscous, mechanically weak and ductile region of the Earth's upper mantle
Mesozone – The part of the Earth's mantle below the lithosphere and the asthenosphere, but above the outer core.
Gutenberg discontinuity– The line between the mantle and the Earth's core.
Earth's core – The inner part of the planet, formed by differential buoyancy of the component materials causing the denser materials to accumulate nearer to the centre.
Outer core – A fluid layer composed of mostly iron and nickel between Earth's solid inner core and its mantle.
Lehmann Discontinuity – The line between the inner core and the outer core.
Inner core – The innermost part of the Earth, a solid ball of iron-nickel alloy.

== Branches of Earth science ==

=== Atmospheric science ===
Atmospheric sciences – The study of the atmosphere, its processes, and interactions with other systems

Climatology – The scientific study of climate, defined as weather conditions averaged over a period of time
Meteorology – Interdisciplinary scientific study of the atmosphere focusing on weather forecasting.
Paleoclimatology – The study of changes in climate taken on the scale of the entire history of Earth
Atmospheric chemistry – The branch of atmospheric science in which the chemistry of the atmosphere is studied
Atmospheric physics – The application of physics to the study of the atmosphere
Paleotempestology – The study of past tropical cyclone activity using geological proxies and historical documents