Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth science. The major historic disciplines use physics, geology, mathematics, chemistry, and biology to build a quantitative understanding of the principal areas or spheres of the Earth system.
- Geology describes the rocky parts of the Earth's crust (or lithosphere) and its historic development. Major subdisciplines are mineralogy and petrology, geochemistry, geomorphology, paleontology, stratigraphy, engineering geology and sedimentology.
- Geodesy and Geophysics (joined together in the IUGG) investigate the figure of the Earth, its reaction to forces and its potential fields (magnetic and gravity field). Geophysicists explore also the Earth's core and mantle and the natural deposits, while geodesists study the movement of stars and satellites.
- Soil science covers the outermost layer of the Earth's crust that is subject to soil formation processes (or pedosphere). Major subdisciplines include edaphology and pedology.
- Oceanography and Hydrology (incl. Limnology) describe the marine and freshwater domains of the watery parts of the Earth (or hydrosphere). Major subdisciplines include hydrogeology and physical, chemical, and biological oceanography. Within the scientific union IUGG the disciplines are joined with Geophysics, except the chemical ones.
- Atmospheric sciences cover the gaseous parts of the Earth (or atmosphere) between the surface and the exosphere (~1000 km). Major subdisciplines are Meteorology, Climatology and Aeronomy.
Due to the numerous interactions between the spheres, many modern fields take an interdisciplinary approach and thus do not sit comfortably in this scheme. Even the above specialisms do not operate in isolation. For example, to understand the circulation of the oceans, the interactions between ocean, atmosphere and Earth rotation must be considered.
Other types of research are even more interpast states of the ocean, atmosphere or climate.
- Meteorology describes, explains and predicts the weather based on the interaction of principally the ocean and atmosphere.
- Climatology describes and explains the climate in terms of the interaction of the litho-, pedo-, hydro-, atmo-, cryo-, and bio- spheres.
- Atmospheric chemistry describes, explains and predicts the chemical composition of the atmosphere in principally terms of the interactions of the ocean, atmosphere, biosphere and human influence.
- Hydrology considers the flow of water through the Earth, from the transition of water in the form of precipitation in the atmosphere, to rivers, and groundwater in aquifers.
Earth system science
Many scientists are now starting to use an approach known as Earth system science which treats the entire Earth as a system in its own right, which evolves as a result of positive and negative feedback between constituent systems. The systems approach, enabled by the combined use of computer models as hypotheses tested by global satellite and ship-board data, is increasingly giving scientists the ability to explain the past and possible future behaviour of the Earth system.
Complex computer models which seek to model several different parts of the Earth system and the interactions between them are known as Earth system models. Many are based on Global climate models and include sub models for the ocean, atmosphere, biosphere and other parts of the earth system. These interactions are of particular importance when trying to understand changes over decade to centuries and longer periods.
Gaia theories explain the behaviour of the Earth system in terms of the influence of the biosphere.
Like all other scientists, earth scientists apply the scientific method: formulate hypotheses after observation of and gathering data about natural phenomena and then test those hypotheses. In earth science, data usually plays a critical role in testing and formulating hypotheses.
Partial list of the major Earth Science topics
Lithosphere or geosphere
|General subfields within the earth sciences|
|Atmospheric sciences | Geodesy | Geology | Geophysics | Glaciology|
|Hydrology | Oceanography | Soil science|
|Astronomy | Biology | Chemistry | Earth science | Ecology | Physics|
|This page uses content from Wikipedia. The original article was at Earth_science. The list of authors can be seen in the page history. As with Paleontology Wiki, the text of Wikipedia is available under the GNU Free Documentation License.|