All articles starting with G
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Geological Survey of Canada
The Geological Survey of Canada is Canada's national geoscience organization, founded in 1842 under its first director William Logan and now part of Natural Resources Canada.
Geological Survey of India
The Geological Survey of India, founded in 1851 to find coal for the Railways, is the national earth-science agency under the Ministry of Mines, headquartered in Kolkata.
Geological Survey of Ireland
The Geological Survey of Ireland (GSI), founded in 1845, is Ireland's national earth science center, providing free maps and data on groundwater, geohazards, and the seabed.
Geologist
A geologist is a scientist who studies the solid Earth, including its composition, structure, processes, and history, and applies that knowledge to locating resources and assessing hazards.
Geology
Geology, also known as geoscience or Earth science, is the study of the Earth's composition, structure, processes, and history since its origin, read from a rock record spanning roughly 4,500 million years.
Geology of India
The geology of India spans Archean cratons over 3 billion years old, the Deccan Traps flood basalts, and the Himalaya built by India's collision with Eurasia.
Geology of Mercury
The geology of Mercury, also called Hermeology, is the study of the surface of the solar system's innermost planet, shaped by cratering and volcanic plains.
Geology of Pluto
The geology of Pluto is the study of the dwarf planet's landforms, revealed by NASA's New Horizons flyby in 2015: nitrogen glaciers, methane mountains, and tectonics.
Geology of the Grand Canyon area
The geology of the Grand Canyon area exposes nearly two billion years of Earth history in the walls of the canyon cut by the Colorado River in northwestern Arizona.
Geology of the Moon
The geology of the Moon, also known as lunar geology, is the study of the Moon's layered interior, highlands, maria, and impact craters, which preserve early solar-system history.
Geom Mojam
Geom Mojam (검모잠) was a Goguryeo leader who, after Goguryeo fell in 668, led a revival movement against Tang rule and was killed by Anseung in 670.
Geomag
Geomag is a Swiss-made magnetic construction toy of magnetic rods and steel spheres that join into three-dimensional structures, invented and patented in 1998 by Geomagworld SA.
Geomagic Control X
Geomagic Control X is a 3D inspection and metrology software package that compares 3D scan data against CAD models, introduced in 2016 by 3D Systems and now owned by Hexagon.
Geomagnetic reversal
A geomagnetic reversal, also called a magnetic pole reversal, is a change of Earth's magnetic field to the opposite polarity; the last occurred about 780,000 years ago.
Geomagnetic secular variation
Geomagnetic secular variation is the slow change in Earth's core-generated main magnetic field over years to centuries, at rates up to about 200 nanotesla per year.
Geomagnetic storm
A geomagnetic storm, or magnetic storm, is a major disturbance of Earth's magnetosphere, driven by the solar wind, that can disrupt power grids, satellites, and radio communication.
Geomagnetically induced current
A geomagnetically induced current (GIC) is an electric current driven through long conductors such as power lines by geomagnetic storms; it caused the 1989 Québec blackout.
Geomancy (علم الرمل)
Geomancy, also known as geomantic divination (علم الرمل, "science of the sand"), is a divinatory art casting sixteen figures from random marks in sand or paper.
GEOMAR Helmholtz Centre for Ocean Research Kiel
GEOMAR Helmholtz Centre for Ocean Research Kiel (GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel) is a German marine research institute in Kiel studying the ocean from seafloor to atmosphere.
Geomembrane canal lining
Geomembrane canal lining is the use of welded impermeable polymer sheets to seal irrigation canals against seepage, cutting losses that can reach 30 to 50 percent of carried water.
Geometer moth
Geometer moths (Geometridae), also called geometer moths or inchworm moths, are one of the largest moth families, with about 24,000 species in nine subfamilies worldwide, known for looping inchworm larvae and tympanal hearing organs.
Geometric abstraction in Venezuela
Geometric abstraction in Venezuela is abstract art built on pure geometric form, line, and color that became the country's dominant artistic language from the late 1940s through the 1970s.
Geometric albedo
Geometric albedo is the ratio of a celestial body's brightness at full phase to that of a perfectly reflecting, diffusely scattering disk of the same apparent size.
Geometric algebra
Geometric algebra is the geometric interpretation of Clifford algebra, which Clifford combined with Grassmann's exterior algebra in 1878. It defines vectors and volumes as elements within a unified system.
Geometric Brownian motion
Geometric Brownian motion, also known as exponential Brownian motion, is a continuous-time stochastic process, always positive, that serves as the standard model for asset prices and underlies the Black–Scholes option pricing model.
Geometric calculus (Grossman–Katz)
Geometric calculus, also known as multiplicative calculus, is a non-Newtonian calculus created by Michael Grossman and Robert Katz in which the derivative and integral are multiplicative rather than additive.
Geometric complexity theory
Geometric complexity theory is a program in computational complexity theory, founded by Ketan Mulmuley and Milind Sohoni in 2001, that uses algebraic geometry and representation theory to prove lower bounds such as P ≠ NP.
Geometric constellation shaping
Geometric constellation shaping (GCS), or geometric shaping, is a modulation technique for optical fiber that repositions equally probable QAM constellation points to improve performance, a low-complexity alternative to probabilistic shaping.
Geometric design of roads
Geometric design of roads, or road geometry, is the branch of highway engineering defining road layout and dimensions: horizontal and vertical alignment, cross section, and intersections.
Geometric dimensioning and tolerancing
Geometric dimensioning and tolerancing (GD&T), also called geometric tolerancing, is a standardized symbolic language used on engineering drawings to define allowable variation in part geometry.