"easily than does the upper mantle (chemical changes within the mantle may also be important). The viscosity of the mantle ranges between 10 and 10 Pa·s, depending on depth. In comparison, the viscosity of water is approximately 10 Pa·s and that of pitch is 10 Pa·s. The source of heat that drives plate tectonics is the primordial heat left over from the planet’s formation as well as the radioactive decay of uranium, thorium, and potassium in Earth’s crust and mantle. The average density of Earth is . Because the average density of surface material is only around , we must"
"Neotectonics Neotectonics, a subdiscipline of tectonics, is the study of the motions and deformations of Earth's crust (geological and geomorphological processes) that are current or recent in geologic time. The term may also refer to the motions/deformations in question themselves. Geologists refer to the corresponding time-frame as the neotectonic period, and to the preceding time as the palaeotectonic period. Vladimir Obruchev coined the term ""neotectonics"" in his 1948 article, defining the field as ""recent tectonic movements occurred in the upper part of Tertiary (Neogene) and in the Quaternary, which played an essential role in the origin of the contemporary topography""."
"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: Plate tectonics, mountain ranges, volcanoes, and earthquakes are geological phenomena that can be explained in terms of physical and chemical processes in the Earth's crust. 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"
"planets and their moons. Tectonics Tectonics (; ) is the process that controls the structure and properties of the Earth's crust and its evolution through time. In particular, it describes the processes of mountain building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute the Earth's outer shell interact with each other. Tectonics also provides a framework for understanding the earthquake and volcanic belts that directly affect much of the global population. Tectonic studies are important as guides for economic geologists searching for fossil"
"Tectonics Tectonics (; ) is the process that controls the structure and properties of the Earth's crust and its evolution through time. In particular, it describes the processes of mountain building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute the Earth's outer shell interact with each other. Tectonics also provides a framework for understanding the earthquake and volcanic belts that directly affect much of the global population. Tectonic studies are important as guides for economic geologists searching for fossil fuels and ore deposits"
"British author Arthur C. Clarke once noted that ""Earth"" would have been better named ""Ocean"". The scientific study of water and Earth's water cycle is hydrology; hydrodynamics studies the physics of water in motion. The more recent study of the sea in particular is oceanography. This began as the study of the shape of the ocean's currents but has since expanded into a large and multidisciplinary field: it examines the properties of seawater; studies waves, tides, and currents; charts coastlines and maps the seabeds; and studies marine life. The subfield dealing with the sea's motion, its forces, and the forces"
"cryosphere (corresponding to ice) as a distinct portion of the hydrosphere, as well as the pedosphere (corresponding to soil) as an active and intermixed sphere. Earth science (also known as geoscience, the geographical sciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. There are four major disciplines in earth sciences, namely geography, geology, geophysics and geodesy. These major disciplines use physics, chemistry, biology, chronology and mathematics to build a qualitative and quantitative understanding of the principal areas or ""spheres"" of Earth. The Earth's crust, or lithosphere, is the outermost solid surface of"
"Geodesy Geodesy (), is the earth science of accurately measuring and understanding the Earth's geometric shape, orientation in space, and gravitational field. The field also incorporates studies of how these properties change over time and equivalent measurements for other planets (known as planetary geodesy). Geodynamical phenomena include crustal motion, tides, and polar motion, which can be studied by designing global and national control networks, applying space and terrestrial techniques, and relying on datums and coordinate systems. The word ""geodesy"" comes from the Ancient Greek word ""geodaisia"" (literally, ""division of the Earth""). It is primarily concerned with positioning within the temporally"
"the presence of significant thicknesses of rock salt within a sequence of rocks. This is due both to the low density of salt, which does not increase with burial, and its low strength. Neotectonics is the study of the motions and deformations of the Earth's crust (geological and geomorphological processes) that are current or recent in geological time. The term may also refer to the motions and deformations themselves. The corresponding time frame is referred to as the ""neotectonic period"". Accordingly, the preceding time is referred to as ""palaeotectonic period"". Tectonophysics is the study of the physical processes associated with"
"Earth's crustal evolution Earth's crustal evolution involves the formation, destruction and renewal of the rocky outer shell at that planet's surface. The variation in composition within the Earth's crust is much greater than that of other terrestrial planets. Mars, Venus, Mercury and other planetary bodies have relatively quasi-uniform crusts unlike that of the Earth which contains both oceanic and continental plates. This unique property reflects the complex series of crustal processes that have taken place throughout the planet's history, including the ongoing process of plate tectonics. The proposed mechanisms regarding Earth's crustal evolution take a theory-orientated approach. Fragmentary geologic evidence"
"Geodynamics Geodynamics is a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, mountain building, volcanoes, earthquakes, faulting and so on. It also attempts to probe the internal activity by measuring magnetic fields, gravity, and seismic waves, as well as the mineralogy of rocks and their isotopic composition. Methods of geodynamics are also applied to exploration of other planets. Geodynamics is generally concerned with processes that move materials throughout the Earth. In the Earth’s interior, movement"
"interactions involving the atmosphere, ocean circulation, planetary volcanism, the cryosphere, the biosphere and external forces such as variability of solar radiation and even the occasional asteroid impact. Scientists are also increasingly interested in understanding the nature of past and present changes to Earth’s climate—whether abrupt or gradual, regional or global—and the potential for human activities to influence the natural system. The researchers in the Seismology, Geology and Tectonophysics Division (SGT) study theoretical and observational seismology, solid Earth dynamics, rock mechanics, structural geology and tectonics, and sedimentary geology. They also contribute to understanding of earthquakes; the structure of Earth’s crust, mantle,"
"He later created the Laboratory of Tectonophysics at the Institute of Physics of the Earth, Academy of Sciences of the USSR, Moscow. Tectonophysics Tectonophysics, a branch of geophysics, is the study of the physical processes that underlie tectonic deformation. The field encompasses the spatial patterns of stress, strain, and differing rheologies in the lithosphere and asthenosphere of the Earth; and the relationships between these patterns and the observed patterns of deformation due to plate tectonics. Tectonophysics is concerned with movements in the Earth's crust and deformations over scales from meters to thousands of kilometers. Examples of such processes include mountain"
"Polar motion Polar motion of the Earth is the motion of the Earth's rotational axis relative to its crust. This is measured with respect to a reference frame in which the solid Earth is fixed (a so-called ""Earth-centered, Earth-fixed"" or ECEF reference frame). This variation is only a few meters. Polar motion is defined relative to a conventionally defined reference axis, the CIO (Conventional International Origin), being the pole's average location over the year 1900. It consists of three major components: a free oscillation called Chandler wobble with a period of about 435 days, an annual oscillation, and an irregular"
"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"
"they do, to understand landform history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphology is practiced within physical geography, geology, geodesy, engineering geology, archaeology and geotechnical engineering. This broad base of interests contributes to many research styles and interests within the field. The surface of Earth is modified by a combination of surface processes that sculpt landscapes, and geologic processes that cause tectonic uplift and subsidence, and shape the coastal geography. Surface processes comprise the action of water, wind, ice, fire, and living things on the surface of the Earth,"
"Crustal magnetism Crustal magnetism is the magnetic field of the crust of a planetary body. The crustal magnetism of Earth has been studied, in particular various magnetic crustal anomalies have been studied. Two examples of crustal magnetic anomalies on Earth that been studied the Americas are the Brunswick magnetic anomaly (BMA) and East Coast magnetic anomaly (ECMA). Also there can be a correlation between physical geological features and certain readings from crustal magnetism on Earth. Below the surface of the Earth the temperature increases and so the crustal magnetism is lost because it rises above the curie temperate of the"
"diastrophic movement was caused by gravitational contraction. In the United States, it was not until the late 1960s that thermal convection replaced the shrinking Earth theories. Diastrophism Diastrophism refers to deformation of the Earth's crust, and more especially to folding and faulting. Diastrophism can be considered part of geotectonics. ""Diastrophism"" comes from the Greek word meaning ""a twisting"". All processes that move, elevate or build up portions of the earth’s crust come under diastrophism. They include: (i) orogenic processes involving mountain building through severe folding and affecting long and narrow belts of the earth’s crust; (ii) epeirogenic processes involving uplift"
"solar wind, indicate that the dissipation of the magnetic field of Mars caused a near total loss of its atmosphere. The study of past magnetic field of the Earth is known as paleomagnetism. The polarity of the Earth's magnetic field is recorded in igneous rocks, and reversals of the field are thus detectable as ""stripes"" centered on mid-ocean ridges where the sea floor is spreading, while the stability of the geomagnetic poles between reversals has allowed paleomagnetists to track the past motion of continents. Reversals also provide the basis for magnetostratigraphy, a way of dating rocks and sediments. The field"
"Tectonophysics Tectonophysics, a branch of geophysics, is the study of the physical processes that underlie tectonic deformation. The field encompasses the spatial patterns of stress, strain, and differing rheologies in the lithosphere and asthenosphere of the Earth; and the relationships between these patterns and the observed patterns of deformation due to plate tectonics. Tectonophysics is concerned with movements in the Earth's crust and deformations over scales from meters to thousands of kilometers. Examples of such processes include mountain building, the formation of sedimentary basins, postglacial rebound of regions such as Fennoscandia, plate tectonics, volcanoes and earthquakes. This involves the measurement"
"bases (the international nautical mile is defined as exactly 1,852 m, corresponding to a rounding of 1,000/0.54 m to four digits). In geodesy, temporal change can be studied by a variety of techniques. Points on the Earth's surface change their location due to a variety of mechanisms: The science of studying deformations and motions of the Earth's crust and the solid Earth as a whole is called geodynamics. Often, study of the Earth's irregular rotation is also included in its definition. Techniques for studying geodynamic phenomena on the global scale include: Geodesy Geodesy (), is the earth science of accurately"
"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 go to many of the world's most exotic locations to study Earth phenomena (e.g. Antarctica or hot spot island chains). A foundational idea within the study Earth science is the notion of uniformitarianism. Uniformitarianism dictates 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 Earth history. Paleoclimatology Paleoclimatology (in British spelling, palaeoclimatology) is the study of changes in climate taken on the scale of the entire history of Earth. It uses a variety of proxy methods from the Earth and life sciences to obtain data previously preserved within things such as rocks, sediments, ice sheets, tree rings, corals, shells, and microfossils. It then uses the records to determine the past states of the Earth's various climate regions and its atmospheric system. Studies of past changes in the environment and biodiversity often reflect on the current situation, specifically the impact of climate on mass"
"Plate tectonics Plate tectonics (from the Late Latin ""tectonicus"", from the ""pertaining to building"") is a scientific theory describing the large-scale motion of seven large plates and the movements of a larger number of smaller plates of the Earth's lithosphere, since tectonic processes began on Earth between 3 and 3.5 billion years ago. The model builds on the concept of continental drift, an idea developed during the first decades of the 20th century. The geoscientific community accepted plate-tectonic theory after seafloor spreading was validated in the late 1950s and early 1960s. The lithosphere, which is the rigid outermost shell of"
"Peter Molnar (geophysicist) Peter Molnar is a professor in geological sciences at the University of Colorado. His research focuses on aspects of how mountain ranges form and continental lithosphere deforms. He is a winner of the Crafoord Prize and a fellow of the American Geophysical Union. He won the Crafoord Prize in 2014 for discovering ""the driving forces behind plate motions and the place of continents in the plate tectonic model of Earth's evolution. Innovatively combining geological and geophysical methods of inquiry with satellite measurements and modelling, the Laureate has also paved the way to a new understanding of the"
"Climatic geomorphology Climatic geomorphology is the study of the role of climate in shaping landforms and the earth-surface processes. An approach used in climatic geomorphology is to study relict landforms to infer ancient climates. Being often concerned about past climates climatic geomorphology considered sometimes to be an aspect of historical geology. Since landscape features in one region might have evolved under climates different than today, studying climatically disparate regions might help understand present-day landscapes. For example, Julius Büdel studied both cold-climate processes in Svalbard and weathering processes in tropical India to understand the origin of the relief of Central Europe,"
"been examined on Earth and on Mars. However, these are the only bodies that have by the early 21st century they have been studied even though it is predicted other bodies will have this geological feature. Crustal magnetism Crustal magnetism is the magnetic field of the crust of a planetary body. The crustal magnetism of Earth has been studied, in particular various magnetic crustal anomalies have been studied. Two examples of crustal magnetic anomalies on Earth that been studied the Americas are the Brunswick magnetic anomaly (BMA) and East Coast magnetic anomaly (ECMA). Also there can be a correlation between"
"percent of Earth's crust is unobservable using solely electromagnetic energy-based geodetic techniques. Seafloor geodesy can now expand geodetic positioning to off-shore environments. Researchers can see the effects of changes in Earth's crust far beyond what we can measure with instruments placed solely on dry land. Space geodesy utilizes electromagnetic signals propagating through the atmosphere of Earth, providing information on tropospheric temperature and water vapor and on ionospheric electron density. Thus, in the early twenty-first century, the goal of geodesy has evolved to include study of the kinematics and dynamics of both Earth’s atmosphere and the solid Earth. Geodetic research associated"
"Thermal history of the Earth The thermal history of the Earth is the study of the cooling history of Earth's interior. It is a sub-field of geophysics. Thermal histories are also computed for the internal cooling of other planetary and stellar bodies. The study of the thermal evolution of Earth's interior is uncertain and controversial in all aspects, from the interpretation of petrologic observations used to infer the temperature of the interior, to the fluid dynamics responsible for heat loss, to material properties that determine the efficiency of heat transport. Observations that can be used to infer the temperature of"
"glacial motion and the landforms that result requires tools from many different disciplines: physical geography, climatology, and geology are among the areas sometime grouped together and called earth science. During the Pleistocene (the last ice age), huge sheets of ice called continental glaciers advanced over much of the earth. The movement of these continental glaciers created many now-familiar glacial landforms. As the glaciers were expanded, due to their accumulating weight of snow and ice, they crushed and redistributed surface rocks, creating erosional landforms such as s, cirques, and hanging valleys. Later, when the glaciers retreated leaving behind their freight of"
"Some movements are aperiodic, others regular, as the Earth tides caused by the lunar and solar gravitational field. The pendulums measure a distance of 95 m between the upper and lower mountings, which contributes to the fact that the instruments detect tectonic movements with high precision and are relatively immune to some of the noise which affects smaller instruments. The Earth's crust is the outer brittle layer of our planet, on average thick in continental areas. This moves up and down by ten centimeters during the time of 12 and 24 hours due to the attraction of Moon and Sun,"
"glaciation"", unrestricted accumulations which once covered much of the northern continents. Movement of the glacier is very slow. Its velocity varies from a few centimeters per day to a few meters per day. The rate of movement depends upon the numbers of factors which are listed below : Glaciology Glaciology (from Latin: ""glacies"", ""frost, ice"", and Ancient Greek: λόγος, ""logos"", ""subject matter""; literally ""study of ice"") is the scientific study of glaciers, or more generally ice and natural phenomena that involve ice. Glaciology is an interdisciplinary Earth science that integrates geophysics, geology, physical geography, geomorphology, climatology, meteorology, hydrology, biology, and"
"formation of mountain ranges and their role in global tectonics."" Peter Molnar (geophysicist) Peter Molnar is a professor in geological sciences at the University of Colorado. His research focuses on aspects of how mountain ranges form and continental lithosphere deforms. He is a winner of the Crafoord Prize and a fellow of the American Geophysical Union. He won the Crafoord Prize in 2014 for discovering ""the driving forces behind plate motions and the place of continents in the plate tectonic model of Earth's evolution. Innovatively combining geological and geophysical methods of inquiry with satellite measurements and modelling, the Laureate has"