Earth science

Earth science refers to those sciences that deal with the study of the earth and its components or parts. A common synonym for earth science is geoscience. Earth science includes those fields that study the firmament (the lithosphere or ground that makes up the land and the ocean floor), the waters (the hydrosphere which includes the oceans, the seas, rivers, lakes and so forth), and the atmosphere itself, the air around us.

Each aspect of these domains may be divided even further into separate but interrelated disciplines of study. Geology which encompasses the lithosphere includes vulcanology (the study of volcanoes), hydrology (the study of water through the atmosphere, surface, subsurface and oceans) mineralogy (the study of the composition of the geosphere, specifically the mineral composition of the geosphere), and geomorphology (the study of the forces that shape the geosphere and their different forms).

"Spheres" of study

There are commonly three ‘spheres’ in the earth sciences. Atmosphere (from the Greek root atmos meaning ‘vapor’ and sphaira, meaning ‘sphere’), lithosphere (Greek - lithos rock or ‘stone) and hydrosphere (Greek – hydros, meaning ‘water’) corresponding, respectively, to the gas, the solid ground and the water of the earth. There are other ‘spheres’ as well. The pedosphere (Greek pedon or ‘soil’) refers to the outerlayer of the lithosphere. It interacts directly with the atmosphere and the hydrosphere. The study of the glaciology, involves the glacial layer or cryosphere (Greek root kryos, frost or ice)

Disciplines and Sub-disciplines

There are a large number of subdisciplines and related disciplines that involve overlapping fields of study. A perusal of university majors and journal topics demonstrates the fundamental characteristic of earth science, although the geosciences are basically about the non-living aspects of the earth, its interaction with living organisms, past and present, is also a very large area of study.

Geology

Astrogeology

The study of the geology of other planets and extraterrestrial materials it is concerned with the geology (the surface as well as interior processes) of all solid bodies in the solar system, including the major planets and their satellites, asteroids, comets, and meteorites. Astrogeology is synonymous with ‘exogeology’ and ‘planetary geology.’ Astrogeology utilises geological studies on Earth and incorporates remote sensing of planetary bodies (e.g. telescopy) to study such geological process as volcanism, floods, cratering, tectonics, and sand movement.

Crystallography and Mineralogy

The study of crystals and minerals.

Economic geology

the study of ore deposits.

Engineering geology

the study of the geological characteristics of sites where engineering operations are going to be carried out.

Environmental geology/geosciences

the study of how geological processes affect the environment.

Exploration geology

the search for new mineral deposits.

Geochemistry

the study of the chemistry of the Earth.

Geochronology

the study of dating geological events.

Gemmology

the study of gemstones.

Geological Heritage

The study of conservation of geologically important sites.

Geomorphology

The study of landforms. Fluvial geomorphology, for example, studies how human use impacts natural settings in a watershed and determines the shape of river channels. Fluvial geomorphology attempts to predict what physical changes will occur to a water channel in response to alterations in watershed conditions; and how changes will impact human infrastructure and fish habitat.

Geophysics

the study of the physical properties of the Earth.

Glaciology

The study of glaciers, their formation, movement and environmental impact

Hydrogeology

the study of the movement of water through the Earth.

Mining geology

the study of the geology of a mine site.

Petroleum geology and Coal geology

the study of ancient organic deposits (fossil fuels).

Paleogeography and Paleogeology

Paleogeography is the study of the earth’s surface in the distant past. “The study of paleogeography has two principle goals. The first goal is to map the past positions of the continents. The second goal is to illustrate the changing distribution of mountains, lowlands, shallow seas, and deep ocean basins through time.”

Paleogeology is the study of geologic conditions in the past which are manifest in the features of subterranean layers. Both employ analyses long cylinders of bored rock or cores drilled from the earth which are charted and subjected to analytic comparisons.

Paleomagnetism

Paleomagnetism studies magnetic fields of the Earth in the past. Paleomagnetism measures the remnant magnetic field often preserved in iron-bearing rock formations. Paleomagnetic analysis can determine whether a rock was magnetized near the Pole or near the Equator and provides direct evidence of a continent's N-S (latitudinal) position, but not the E-W (longitudinal) position.

Petrology

the study of rocks (igneous, metamorphic and sedimentary)

Sedimentary geology

Sedimentary geology encompasses the subdisciplines of sedimentology & stratigraphy. The field addresses all aspects of research into sediments and sedimentation processes at all spatial and temporal scales, sedimentary systems and basin analysis, subsurface analysis of sedimentary sequences, diagenesis (processes involving biological, physical and chemical changes in sediment which may then culminate in lithification), chemical sedimentology and numerical modelling (analysis of stratification facies).

Sedimentology is the study of the production, composition, transport, and deposition of sediment.

Stratigraphy is the study of existing layers or rocks and minerals and the process of layering (stratification). The primary focuses are the process of sedimentation encompassing such dynamics as changes in sea level, tectonic activity, and climatic effects on the production of sediment (e.g. particulates carried in water runoff due to flooding) and material sequentially layered through volcanic activity.

There are other subfields as well. Lithostratigraphy is the study of strata to determine the history of geological processes and events through lithology, using well logs, mineral composition and quantity, grain size, texture and color. Chronostratigraphy is the study of the ages of strata through comparison, and correlation of separated strata to elucidate their relative and absolute ages. The interdisciplinary biologic stratigraphy (or biostratigraphy), employs the analysis of plant and animal fossils using principles of paleontology and stratigraphy to date and correlate strata using evidence as may be presented by such organisms as pollen and spores, marine microfossils (e.g. diatoms, foraminifera, and nannofossils) to determine the absolute and relative age and the environment that existed during deposition of a particular formation).

Seismology

the study of how waves move through the Earth, including earthquakes.

Structural geology

the study of geological structures.

Tectonics/Structural geology

the study of the major structural features of the Earth or the broad structure of a region.

Vulcanology

the study of volcanoes.

Oceanography

The study of the earth’s oceans.

Hydrology

The interdisciplinary study of the movement, characteristics and distribution of water, surface-water (fresh water and salt water), groundwater, and water-quality Subdisciplines include:

• Chemical hydrology: the study of the chemical characteristics of water. Also called hydrochemistry, chemical hydrology deals with the chemical characteristics of the surface water (freshwater and marine) and subterranean water. Water is a chemical solvent and, interacting chemically with materials with which it comes into contact, can dissolve many elements.
• Drainage basin management hydrology.
• Ecohydrology (the study of interactions between organisms and the hydrologic cycle.
• Engineering Hydrology
• Global hydrology
• Groundwater Hydrology
• Hydrobiology
• Hydrogeology is the study of the presence and movement of water in aquifers.
• Hydroinformatics is the adaptation of information technology to hydrology and water resources applications.
• Hydrometeorology is the study of the transfer of water and energy between land and water body surfaces and the lower atmosphere.
• Isotope hydrology is the study of the isotopic signatures of water.
• Operational Hydrology
• Qualitative Hydrology
• Sedimentology
• Surface hydrology is the study of hydrologic processes that operate at or near the Earth's surface.
• Water resources development and management

Atmospheric sciences

Paleoclimatology

Paleoclimatology is the study of ancient climates. Different types of rock and minerals form under specific climatic conditions: wet and dry, warm and cool. This is also true of ancient life forms whose presence may be determined from the fossil record. As the earth’s surface changes climatically and continents move tectonically, the amount of sunlight will vary and effect conditions on the surface, leading to changes which then become buried in the strata. Coal deposits develop under wet conditions, bauxite deposits are evident where it was warm and wet, evaporites and calcretes occur under warm and dry conditions, and tillites where it was wet and cool. The ancient distribution of different rock types provide evidence of how the global climate has changed through time and how the continents have travelled across climatic belts.

Interdisciplinary divisions

Geomicrobiology

Studies microbes and their interactions in geologic systems

Paleobiogeography

Paleobiogeography studies microbial fossils and their interactions in geologic systems. The distribution of plants and animals in the ancient past helps reveal the latitudinal and relative position of the continents. Ancient plant organisms reflect temperature and rainfall in the distant past. The similarity or dissimilarity of life on different continents can be used to estimate their geographic proximity and may reveal when these continents were connected or isolated from each other.

Paleobotany

the study of ancient plant life. Paleontology may be divided further into vertebrate, invertebrate and micropaleontology

Paleoecology

the study of ancient environments.

Paleontology

the study of ancient life forms.

Palynology

the study of ancient spores and pollens.

Resources

• Australian Museum of Geosciences [1]
• Geoscience Information Society [2]
• American Geological Institute [3]
• Geological Society of New Zealand [4]
• University of Missouri-Kansas City, Geoscience Department [5]
• Kansas University Geology Department [6]
• Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian [7]
• United States Geological Services (USGS) Gazetteer of Planetary Nomenclature [8]
• Minerology Database [9] contains 4,442 individual mineral species descriptions with links and a comprehensive image library.
• Minerology Database [10] localities, photos and data
• Links for Minerologists Introduction to Crystallography Institute of Mineralogy, University of Würzburg,
• University of Texas, Austin Paleomap Project