The sciences of the Earth gather the Science S whose object is the study of the Ground (Lithosphère, Hydrosphère and atmosphere) and of its space environment; as a Planet, the Earth can be used as paradigm with the another planet study and, since space probes make it possible to explore other objects of the Solar system, the Planétologie is also classified among sciences of the Earth. This one studies in particular the the Moon, the Planet S and their natural satellite, the Astéroïde S, the Météorite S and the Comet S.

Principal fields

Geological sciences

The Géologie is the Science which, historically, dealt of the description and the history of the external layers of the Ground. It is interested traditionally in the composition, the structure and the evolution of the surface and the surface layers of the crust which, during the geological processes, are sometimes hidden under surface, sometimes exposed to surface. Since the middle of the years 1960, with the advent of the Plate tectonics replacing the old theory of the continental drift of Alfred Wegener, the geologists found a framework more general and more adapted in which to place and interpret their observations. The result is that the geologists are now also interested in major zones of the crust and coat of the Earth, which before 1965 were primarily the prerogative of the geophysicists. It results from it an advantageous mixing of the ideas for the unit from sciences of the Earth. Nevertheless, it is advisable to note that if the geologists hold account in their geological models of the assets of the internal Géophysique, the latter calls upon sufficiently simple physical models to be put in equations and to release from the quantitative results, while the geological models are often rather complex but remain qualitative. The geological sciences, organized on a worldwide scale in the International union of geological sciences, include/understand several disciplines, among which one can note:

  • the Geology itself and the physical geology , which describes in geological terms the vision that geophysics provides of the Earth;
  • the structural Geology or Tectonique, whose during geophysics is the tectonophysic , is the science which studies the deformations of the Earth and the structures of the Earth's crust produced by orogenetic movements, possibly by the movements of the terrestrial plates;
  • the Paléontologie studies the Fossile S, i.e. the fossilized remainders of many forms of life having populated the Earth in the past and provides the bases to include/understand the evolution of the life; in all objectivity, it is advisable to consider that without paleontology and the Stratigraphie which results from this, the Géologie would probably never have been born;
  • the Sédimentologie studies the phenomena of erosion of the rocks and the deposit of the remains in the form of sediments, the transformation of the latter by Diagenèse into compact sedimentary rocks, and the succession of the various sedimentary layers in time and space;
  • the Petrology or the Pétrographie constitutes the science of the rocks; they are interested at the origin, the formation and the evolution of the rocks, like their description, their texture and their properties;
  • the Minéralogie studies nature, the composition and the crystalline structure of minerals and is attached at the same time to geology and the Cristallographie, the latter belonging to the Physique;
  • the Géomorphologie is interested at the origin and the evolution of the relief, and more particularly in the processes which interact by working the landscapes, on all the scales of time and space, on the interface between the lithosphere, the hydrosphere and the atmosphere; generally, one rather arranges the geomorphology among geographical sciences than geological, because it is one of the branches of the physical Géographie;
  • the Hydrogéologie studies the geological aspects of the Hydrologie, the latter being rather classified among sciences geophysics (sciences of the layer-limits); it has many relations with the Karstologie, science which treats karstic mediums, formation of the caves and circulation of subterranean water; the knowledge acquired in karstology and hydrogeology is mainly the fact of the Spéléologie (exploration of the underground caves), which receives in return of very invaluable information of these sciences;
  • the Limnologie is interested in the study of continental water and the organizations which live there; it relates to at the same time geological sciences and biological sciences; in the same way, the Pédologie, which constitutes the science of the grounds, is a discipline at the borders of geology (study of the deterioration of the rocks, evolution mechanical and chemical of the grounds) and biology (role of the organizations in the deterioration of the bed rock and the evolution of the ground);
  • the Volcanologie studies the physicochemical nature of the volcanos and their own dynamics; one classifies it at the same time among geological sciences and sciences geophysics, in the same way moreover as the Géochimie which studies the chemical composition of the rocks, that it is in major elements or elements traces, as well as the Géochronologie which allows, thanks to various radiometric methods, to go back a rock or one to its components.
  • the Pédologie studies the various components of the ground, their morphological, mineralogical, physicochemical characteristics.

Geodetic sciences and geophysics

The Geodesy and the Géophysique are Sciences which study the Earth by mathematical and physical methods. They are gathered officially within the framework of the geodetic Union and international geophysics, which includes/understands the seven following subdivisions, forming as many international associations: (1) geodesy; (2) geomagnetism and space aeronomy; (3) hydrological sciences; (4) meteorology and sciences of the atmosphere; (5) physical sciences of the ocean; (6) seismology and physics of the interior of the Earth; (7) volcanology and chemistry of the interior of the Earth. One often subdivides these various fields of the Géophysique in Géophysique intern, Géophysique of the layer-limits and external Géophysique as follows:

Geophysical intern :

  • the Géodésie is interested in the figure, in other words with the form and dimensions of the Earth, and proves to be useful to determine the deformations on the surface of the Earth and, since the last quarter of the 20th century, to highlight movements of tectonic plates.

  • the Gravimétrie studies the terrestrial field of gravity and constitutes an essential part of the physical Géodésie; one usually uses the gravimetric techniques for a first recognition of oil-bearing or mining fields (gravimetric prospection) or archaeological (zoning microgravimetric).
  • the Géomagnétisme studies the origin and the space and temporal variations of the magnetic field of the Earth; the internal geomagnetism, whose study raises of the internal Géophysique, and the external geomagnetism are distinguished, whose study is placed within the framework of the space aeronomy and the study of the interactions between the Sun and the Earth; the Paléomagnétisme constitutes a field with share of geomagnetism interns and provides, by means of the study of the fossil Aimantation of the rocks, of the indications on the movement of the tectonic plates during the geological times; the Archéomagnétisme, which was at the origin of the Paléomagnétisme, is a method making it possible to study the variations of the geomagnetic field during the last millenia and incidentally constitutes a method of dating of certain archeological sites;
  • the Sismologie studies the origin, the nature and the effects of the Séisme S; it is undoubtedly science having contributed more to knowledge of the interior of the Earth; in particular, theoretical seismology studies the seismic wave propagation and the free oscillations of the Earth; instrumental seismology deals with developing and building instruments used to detect and record seismic vibrations (seismographs); experimental seismology deals, among many of other things, of the analysis and the interpretation of the seismograms and the definition magnitudes and seismic moments; the Sismogenèse is interested in the phenomena of microfissuring, fracturing and rupture which are at the origin of the seisms (mechanism to the hearth); the Sismotectonique treats the relation between the earthquakes and the Tectonique; the Paléosismologie tries to discover in the geological layers of the indications on last seisms and to date those in order to collect data for the needs for a statistical forecast for the seisms;
  • the Geodynamic , and in particular mathematical geodynamics, studies the total deformations of the Earth produced in particular by the lunisolar forces of tide or periodic loads or not (swell, variable atmospheric pressure, tidal wave,…), movements of precession and nutation of the Earth in space, the currents of convection in the coat, the postglacial Rising and the information which one can draw concerning viscosity from the deep layers, etc;
  • the Geophysical mathematics, of which the principal goal is to model quantitatively the structure of the interior of the Earth by using the fundamental laws of the physics and the advanced methods of statistical data processing (inversion, tomography). the purpose of
  • the Géophysique applied is interested in the external layers of the earth's crust and is to seek reservoirs oil and ores useful; one can also include in geophysics applied certain environmental studies which call upon methods geophysics ( geophysical environmental ). Methods more important to which the geophysical prospection and environmental geophysics appeal are seismic '' reflection '' and seismic '' refraction '' (methods of prospection which visualizes in-depth structures thanks to the analysis of the seismic echoes of waves created artificially by explosions or generating apparatuses of vibrations close to the surface of the ground), gravimetric prospection, magnetic prospection, electric prospection, electromagnetic prospection and the géoradar; the seismic Genius, which in particular tries to draw up charts of seismic risk, to set antiseismic standards, to envisage seisms, etc if required, can also line up among the fields of environmental geophysics, just as the Volcanologie, the Géothermie and the study of the heat flow leaving the Earth, or the problems involved in safety in the mining zones and the improvement of the environment and safety in general (forecast of risks related on the basement and the ground, impact studies, establishment of works of art, studied in particular in Géotechnique.

Geophysical of the layer-limits :

  • the Oceanography and the physical oceanology study the movements and the various oceanic phenomena (tides, currents, waves,…) ;

  • the Hydrologie studies in particular physics, the chemistry and the circulation of water in the rivers and the lakes, and the variations of the ground water;
  • the Météorologie deals with the circulation of the masses of air and the forecast of the atmospheric phenomena, in particular of time, the storms and the hurricanes;
  • the Climatologie studies different the Climat S and explains the atmospheric with large scales and long-term movements;
  • the Glaciologie studies physical and chemical nature glacial and periglacial systems.

Geophysical external :

  • the external Géomagnétisme studies the fast variations of the geomagnetic field (pulsations, bays, magnetic storms), and lies within the general scope of

  • the space Aéronomie, which studies the upper atmosphere (Stratosphère, Ionosphère), the Magnétosphère, the Solar wind and the relations soli-terrestrial, which are at the origin of the polar lights.

Weather science

The goal of the Météorologie is to find the laws governing the Dynamique Fluide that one names the Air and to be able to predict its future behavior. The air is a compressible, formed fluid of different Gaz and being in a thin layer on the surface from a reference frame in rotation (the Ground). Meteorology being a branch of physics, the theory of the fluids, the calculation of the forces and thermodynamics are made profitable to explain the behavior of the atmosphere.

See too

External bonds

  • Mineral and Fossils of the Pyrenees
  • Objective Ground: a course of geology in line
  • French Confederation of the Actors of Sciences of the Earth

Nds-nl: Eerdwetenschoppen Simple: Earth science Zh-yue: 地球科學

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