Earth science or geoscience includes all fields of natural science related to the planet Earth. It is the branch of science dealing with the physical constitution of the Earth and its atmosphere. Earth science is the study of our planet’s physical characteristics, from earthquakes to raindrops, and floods to fossils. Earth science can be considered to be a branch of planetary science, but with a much older history. Earth science encompasses four main branches of study, the lithosphere, the hydrosphere, the atmosphere, and the biosphere, each of which is further broken down into more specialized fields.
There are both reductionist and holistic approaches to earth sciences. It is also the study of Earth and its neighbors in space. Some earth scientists use their knowledge of the planet to locate and develop energy and mineral resources. Others study the impact of human activity on Earth's environment, and design methods to protect the planet. Some use their knowledge about earth processes such as volcanoes, earthquakes, and hurricanes to plan communities that will not expose people to these dangerous events.
The earth sciences can include the study of geology, the lithosphere, and the large-scale structure of the earth's interior, as well as the atmosphere, hydrosphere, and biosphere. Typically, earth scientists use tools from geography, chronology, physics, chemistry, biology, and mathematics to build a quantitative understanding of how the earth works and evolves. Earth science affects our everyday lives. For example, meteorologists study the weather and watch for dangerous storms. Hydrologists study water and warn of floods. Seismologists study earthquakes and try to predict where they will strike. Geologists study rocks and help to locate useful minerals. Earth scientists often work in the field—perhaps climbing mountains, exploring the seabed, crawling through caves, or wading in swamps. They measure and collect samples (such as rocks or river water), then they record their findings on charts and maps.
The following fields of science are generally categorized within the earth sciences:
Beneath the Earth's crust lies the mantle which is heated by the radioactive decay of heavy elements. The mantle is not quite solid and consists of magma which is in a state of semi-perpetual convection. This convection process causes the lithospheric plates to move, albeit slowly. The resulting process is known as plate tectonics.
Plate tectonics might be thought of as the process by which the Earth is resurfaced. As the result of seafloor spreading, new crust and lithosphere is created by the flow of magma from the mantle to the near surface, through fissures, where it cools and solidifies. Through subduction, oceanic crust and lithosphere returns to the convecting mantle.
Areas of the crust where new crust is created are called divergent boundaries, those where it is brought back into the earth are convergent boundaries and those where plates slide past each other, but no new lithospheric material is created or destroyed, are referred to as transform (or conservative) boundaries Earthquakes result from the movement of the lithospheric plates, and they often occur near convergent boundaries where parts of the crust are forced into the earth as part of subduction.
Volcanoes result primarily from the melting of subducted crust material. Crust material that is forced into the asthenosphere melts, and some portion of the melted material becomes light enough to rise to the surface—giving birth to volcanoes.
The troposphere, stratosphere, mesosphere, thermosphere, and exosphere are the five layers which make up Earth's atmosphere. 75% of the gases in the atmosphere are located within the troposphere, the lowest layer. In all, the atmosphere is made up of about 78.0% nitrogen, 20.9% oxygen, and 0.92% argon. In addition to the nitrogen, oxygen, and argon there are small amounts of other gases including CO2 and water vapor. Water vapor and CO2 allow the earth's atmosphere to catch and hold the Sun's energy through a phenomenon called the greenhouse effect. This allows Earth's surface to be warm enough to have liquid water and support life. In addition to storing heat, the atmosphere also protects living organisms by shielding the earth's surface from cosmic rays—which are often incorrectly thought to be deflected by the magnetic field. The magnetic field—created by the internal motions of the core—produces the magnetosphere which protects Earth's atmosphere from the solar wind. As the earth is 4.5 billion years old, it would have lost its atmosphere by now if there were no protective magnetosphere.
An electromagnet is a magnet that is created by an electric current. The earth has a solid iron inner core surrounded by a fluid outer core that convects; therefore, Earth is an electromagnet. The motion of fluid convection sustains the earth's magnetic field.
Methodologies vary depending on the nature of the subjects being studied. Studies typically fall into one of three categories: observational, experimental, or theoretical. Earth scientists often conduct sophisticated computer analysis or visit an interesting location to study earth phenomena (e.g. Antarctica or hot spot island chains).
A foundational idea in earth science is the notion of uniformitarianism, which states that "ancient geologic features are interpreted by understanding active processes that are readily observed." In other words, any geologic processes at work in the present have operated in the same ways throughout geologic time. This enables those who study Earth's history to apply knowledge of how earth processes operate in the present to gain insight into how the planet has evolved and changed throughout long history.
Earth science generally recognizes four spheres, the lithosphere, the hydrosphere, the atmosphere, and the biosphere; these correspond to rocks, water, air and life. Also included by some are the cryosphere (corresponding to ice) as a distinct portion of the hydrosphere and the pedosphere (corresponding to soil) as an active and intermixed sphere.
Agronomy (from Ancient Greek ἀγρός agrós "field" and νόμος nómos "law") is the science and technology of producing and using plants for food, fuel, fiber, and land reclamation. Agronomy has come to encompass work in the areas of plant genetics, plant physiology, meteorology, and soil science. It is the application of a combination of sciences like biology, chemistry, economics, ecology, earth science, and genetics. Agronomists of today are involved with many issues, including producing food, creating healthier food, managing the environmental impact of agriculture, and extracting energy from plants. Agronomists often specialise in areas such as crop rotation, irrigation and drainage, plant breeding, plant physiology, soil classification, soil fertility, weed control, and insect and pest control.BYU Museum of Paleontology
The Brigham Young University Museum of Paleontology was started in 1976 around the collection of James A. Jensen. For many years, it was known as the BYU Earth Science Museum, and most of the collection was in storage under the LaVell Edwards Stadium.In October 2009, the museum held a grand opening of its new facilities during BYU homecoming week. With the 5,000-square-foot (460 m2) addition, it now displays most of the collection. The change of name clarifies that the museum actually houses a large collection of dinosaur bones and other fossils.The museum is currently directed by Rodney Scheetz, who was one of Jensen's students at BYU. Its main purpose is to facilitate research, but it is open to the public.Crust (geology)
In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle).
The crusts of Earth, Moon, Mercury, Venus, Mars, Io, and other planetary bodies formed via igneous processes, and were later modified by erosion, impact cratering, volcanism, and sedimentation.
Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two types have different chemical compositions and physical properties, and were formed by different geological processes.Energy
In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object. Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton.
Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object's position in a force field (gravitational, electric or magnetic), the elastic energy stored by stretching solid objects, the chemical energy released when a fuel burns, the radiant energy carried by light, and the thermal energy due to an object's temperature.
Mass and energy are closely related. Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy. For example, after heating an object, its increase in energy could be measured as a small increase in mass, with a sensitive enough scale.
Living organisms require available energy to stay alive, such as the energy humans get from food. Human civilization requires energy to function, which it gets from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The processes of Earth's climate and ecosystem are driven by the radiant energy Earth receives from the sun and the geothermal energy contained within the earth.Environmental Performance Index
The Environmental Performance Index (EPI) is a method of quantifying and numerically marking the environmental performance of a state's policies. This index was developed from the Pilot Environmental Performance Index, first published in 2002, and designed to supplement the environmental targets set forth in the United Nations Millennium Development Goals.The EPI was preceded by the Environmental Sustainability Index (ESI), published between 1999 and 2005. Both indices were developed by Yale University (Yale Center for Environmental Law and Policy) and Columbia University (Center for International Earth Science Information Network) in collaboration with the World Economic Forum and the Joint Research Centre of the European Commission. The ESI was developed to evaluate environmental sustainability relative to the paths of other countries. Due to a shift in focus by the teams developing the ESI, the EPI uses outcome-oriented indicators, then working as a benchmark index that can be more easily used by policy makers, environmental scientists, advocates and the general public. Other leading indices like the Global Green Economy Index (GGEI) provide an integrated measure of the environmental, social and economic dynamics of national economies. The GGEI utilizes EPI data for the environmental dimension of the index while also providing a performance assessment of efficiency sectors (e.g. transport, buildings, energy), investment, green innovation and national leadership around climate change.
In January 2012 four EPI reports have been released — the Pilot 2006 Environmental Performance Index, and the 2008, 2010, and 2012 Environmental Performance Index. For the 2012 report, a new "Pilot Trend EPI" was developed to rank countries based on the environmental performance changes occurred during the last decade, allowing to establish which countries are improving and which are declining.In the 2014 EPI ranking, the top five countries were Switzerland, Luxembourg, Australia, Singapore, and the Czech Republic. The bottom five countries in 2014 were Somalia, Mali, Haiti, Lesotho, and Afghanistan. The United Kingdom was ranked in 12th place, Japan 26th place, the United States 33rd, Brazil 77th, China 118th, and India came in 155th. The top five countries based on their 2012 Pilot Trend EPI were Estonia, Kuwait, El Salvador, Namibia and Congo.Flat Earth
The flat Earth model is an archaic conception of Earth's shape as a plane or disk. Many ancient cultures subscribed to a flat Earth cosmography, including Greece until the classical period, the Bronze Age and Iron Age civilizations of the Near East until the Hellenistic period, India until the Gupta period (early centuries AD), and China until the 17th century.
The idea of a spherical Earth appeared in Greek philosophy with Pythagoras (6th century BC), although most pre-Socratics (6th–5th century BC) retained the flat Earth model. Aristotle provided evidence for the spherical shape of the Earth on empirical grounds by around 330 BC. Knowledge of the spherical Earth gradually began to spread beyond the Hellenistic world from then on.In the modern era, pseudoscientific flat Earth theories have been espoused by modern flat Earth societies and, increasingly, by unaffiliated individuals using social media.Geology (journal)
Geology is a peer-reviewed publication of the Geological Society of America (GSA). GSA claims that it is the most widely read scientific journal in the field of earth science. It is published monthly, with each issue containing 20 or more articles. In 2017, the journal's impact factor was 4.635.One of the goals of the journal is to provide a forum for shorter articles (four pages each) and less focus on purely academic research–type articles.Journal of Paleontology
The Journal of Paleontology is a peer-reviewed scientific journal covering the field of paleontology. It is published by the Paleontological Society.List of Russian earth scientists
This list of Russian Earth scientists includes the notable geographers, geologists, oceanographers, meteorologists, ecologists and other representatives of Earth sciences from the Russian Federation, the Soviet Union, the Russian Empire and other predecessor states of Russia.Monthly Weather Review
The Monthly Weather Review is a peer-reviewed scientific journal published by the American Meteorological Society. It covers research related to analysis and prediction of observed and modeled circulations of the atmosphere, including technique development, data assimilation, model validation, and relevant case studies. This includes papers on numerical techniques and data assimilation techniques that apply to the atmosphere and/or ocean environment. The editor-in-chief is David M. Schultz (University of Manchester).National Centre for Earth Science Studies
The National Centre for Earth Science Studies(NCESS) (Malayalam: ദേശിയ ഭൂമി ശാസ്ത്ര പഠന കേന്ദ്രം) is an autonomous research centre to promote scientific and technological research and development studies in the earth sciences. NCESS pursues problems related to land, sea and atmosphere. It was instituted by the government of Kerala in 1978, at Thiruvananthapuram, Kerala. CESS was the earliest institute in the country to embrace the concept of Earth System Science (ESS). CESS contributions over the years have enhanced knowledge of the geological evolution of south India, the complexity of coastal processes and natural hazards, as well as in proposing mitigatory measures to deal with natural hazards.
CESS carries out studies in river basin evaluation, ground water management, coastal erosion, and other special problems.
CESS does research in earth system, micro-level watershed planning, natural hazards management, chemical analysis, CRZ mapping, and studies of air, water, land, noise pollution, etc.
CESS also does environmental impact assessment, coastal and estuarine management, terrain analysis, natural resources management, laser applications, river sand mining, and microlevel planning. CESS conducts research courses leading to doctoral degree.
Recognizing the growth potential of CESS, resource constraints of the State Government and the role CESS can play in national development, the government of Kerala proposed the taking over of the institute by the Ministry of Earth Sciences, Government of India. An expert committee made an assessment of the scientific programs pursued by the institute and deliberated on a long term vision for the institute as a national centre. The committee recommended the taking over of CESS by the MoES and according it the status of an autonomous institute under the Earth System Science Organization (ESSO) of MoES. The proposed thrust areas of research will be crustal evolution and geodynamics, sedimentology and depositional processes, coastal dynamics and cloud microphysics.
The total estimated budget requirements of CESS will be Rs.128.67 crore for the balance period of the 12th FYP.Natural history
Natural history is a domain of inquiry involving organisms including animals, fungi and plants in their environment; leaning more towards observational than experimental methods of study. A person who studies natural history is called a naturalist or natural historian.
Natural history encompasses scientific research but is not limited to it. It involves the systematic study of any category of natural objects or organisms. So while it dates from studies in the ancient Greco-Roman world and the mediaeval Arabic world, through to European Renaissance naturalists working in near isolation, today's natural history is a cross discipline umbrella of many specialty sciences; e.g., geobiology has a strong multi-disciplinary nature.Outline of Earth sciences
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 Earth 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.Outline of physical science
Physical science is a branch of natural science that studies non-living systems, in contrast to life science. It in turn has many branches, each referred to as a "physical science", together called the "physical sciences".Permeability (earth sciences)
Permeability in fluid mechanics and the earth sciences (commonly symbolized as k) is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it.
The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness.Proceedings of the USSR Academy of Sciences
The Proceedings of the USSR Academy of Sciences (Russian: Доклады Академии Наук СССР, Doklady Akademii Nauk SSSR (DAN SSSR), French: Comptes Rendus de l'Académie des Sciences de l'URSS) was a Soviet journal that was dedicated to publishing original, academic research papers in physics, mathematics, chemistry, geology, and biology. It was first published in 1933 and ended in 1992 with volume 322, issue 3.
Today, it is continued by Doklady Akademii Nauk (Russian: Доклады Академии Наук), which began publication in 1992. The journal is also known as the Proceedings of the Russian Academy of Sciences (RAS).
Doklady has had a complicated publication and translation history. A number of translation journals exist which publish selected articles from the original by subject section; these are listed below.Timeline of Earth science satellites
The Timeline of Earth science satellites shows, in chronological order, those successful satellites with a program of Earth science. Sputnik 1, while the first satellite ever launched, did not conduct Earth science. Explorer 1 was the first satellite to make an Earth science discovery when it found the Van Allen belts.Vine–Matthews–Morley hypothesis
The Vine–Matthews–Morley hypothesis, also known as the Morley–Vine–Matthews hypothesis, was the first key scientific test of the seafloor spreading theory of continental drift and plate tectonics.