5,021 articles
Colusite
Colusite is a vanadium-bearing copper sulfide mineral, Cu26V2(As,Sb,Sn,Ge)6S32, whose synthetic analogs with formula Cu26T2M6S32 are earth-abundant p-type thermoelectric materials reaching ZT near 1.0 at about 700 K.
Community Collaborative Rain, Hail and Snow Network
CoCoRaHS, the Community Collaborative Rain, Hail and Snow Network, is a volunteer weather-observing network founded in 1998 in Fort Collins, Colorado, with over 28,000 active observers.
Community Earth System Model
The Community Earth System Model (CESM) is a coupled global climate model simulating Earth's past, present, and future, supported by the National Science Foundation and run by NCAR.
Comparative climate of major cities
A comparative survey of temperature, precipitation, and seasonal patterns across major world cities, based on a 2019 study projecting that 77% of 520 cities will have 2050 climates resembling another existing city's.
Compass rose
A compass rose, also called a rose of the winds, is a circular symbol on maps and nautical charts showing direction, graduated in degrees from 0° to 360°.
Complex response
Complex response is a concept in fluvial geomorphology, introduced by Stanley Schumm in 1973, in which one event triggers multiple episodes of erosion and deposition.
Comstock Lode
The Comstock Lode is a major silver and gold lode in the Virginia Range of western Nevada, discovered in 1859 and mined chiefly at Virginia City.
Concretion
A concretion, sometimes called a turtle stone, is a hard rock mass formed when mineral cement precipitates between sediment grains, often around a shell or bone nucleus.
Condensation
Condensation is the phase change in which water vapor becomes liquid water, the reverse of vaporization. It turns cooling, rising air into cloud and releases latent heat.
Condestable
Condestable is an underground iron oxide copper-gold mine in Lima Department, Peru, about 90 km south of Lima, producing copper with gold and silver credits for over 60 years.
Conduit flow
Conduit flow is groundwater movement through solution-enlarged conduits in karst aquifers such as limestone and gypsum; conduits form as acidic water dissolves fractures, then dominate the aquifer's hydraulics despite occupying little of its storage.
Cone of depression
A cone of depression is the cone-shaped lowering of the water table around a pumping well, first given a mathematical treatment by Charles V. Theis in 1935.
Cone of uncertainty (tropical cyclone)
The cone of uncertainty, officially the Tropical Cyclone Track Forecast Cone, is a National Hurricane Center graphic showing a tropical cyclone's probable track over five days.
Confined aquifer
A confined aquifer is a water-bearing layer sealed between impermeable rock, holding groundwater under pressure; a well drilled into it can flow at the surface without pumping.
Conglomerate (geology)
Conglomerate, also called Nagelfluh, is a coarse-grained clastic sedimentary rock made of rounded fragments over 2 millimeters wide set in sand or silt, the consolidated equivalent of gravel.
Coniacian
The Coniacian is a stage of the Late Cretaceous geologic timescale spanning about 89.8 to 85.7 million years ago, between the Turonian and Santonian stages.
Conodont biostratigraphy
Conodont biostratigraphy dates and correlates marine sedimentary rocks, especially limestones, from the late Cambrian to the end of the Triassic using the evolutionary succession of conodonts, extinct eel-like jawless vertebrates.
Constancia mine
The Constancia mine is a large open-pit copper mine in Chumbivilcas province, Cusco, in south-eastern Peru, owned by Hudbay Minerals and producing commercially since 2015 at about 4,100 meters in the Andes.
Contact metamorphism
Contact metamorphism is the local alteration of country rock around an igneous intrusion, driven mainly by heat rather than pressure, producing a contact aureole and typically unfoliated hornfels.
Contact nucleation
Contact nucleation, also called contact freezing, is a mode of ice nucleation in which a supercooled cloud droplet freezes when an ice-nucleating particle touches its surface.
Contact relationship analysis
Contact relationship analysis is a stratigraphic method that interprets geologic contacts, the surfaces where rocks meet, to establish which rock unit or structure is older and which is younger.
Continental climate
Continental climate (kontinentalt klima): climate of continental interiors with extreme seasonal temperature ranges, low precipitation and humidity; Köppen D types, Conrad continentality index, Siberian and Canadian examples.
Continental collision
Continental collision is the convergence of two continental plates which, because continental crust is too buoyant to subduct, crumples and thickens to form mountain belts like the Himalaya.
Continental crust
Continental crust is Earth's thick, buoyant, silica-rich outer layer, covering roughly 30 to 40 percent of the surface and averaging about 41 km in thickness.
Continental drift
Continental drift is the theory, introduced by Alfred Wegener in 1912, that continents were once joined as Pangaea and have since drifted to their present positions.
Continental rift
A continental rift is a nascent plate boundary along which extension thins the lithosphere, forming elongate zones of faulting and volcanism that may open a new ocean basin.
Continental shelf
A continental shelf is the submerged, gently sloping edge of a continent, extending from the shoreline to the shelf break at roughly 100 to 200 meters depth.
Continentality
Continentality is a climatology measure of how strongly a location is influenced by a landmass; continental interiors have hotter summers, colder winters, and larger temperature ranges.
Contourite
A contourite is a sediment deposited or substantially reworked by persistent bottom currents in the ocean or lakes, forming drifts up to 2 km thick that record past ocean circulation.
Contrail
A contrail, also called a condensation trail or vapor trail, is a line-shaped ice-crystal cloud that forms behind high-flying aircraft, from engine exhaust condensing or from pressure changes around wings.