Earth science
Articles about geology, climate, oceans and the planet.
Clastic rock
Clastic rock: sedimentary rocks made of broken fragments (clasts)
Clay
Clay: composition, properties, origins, uses and engineering impacts
Cleveland-Lloyd Dinosaur Quarry
Cliff
Cliff: steep natural rock faces, formation, types and notable examples
Climate
Climate: long-term patterns of weather, types, causes and relevance
Climate is the long-term pattern of weather in a region — averages and ranges of temperature, precipitation, wind and related conditions — shaped by geography, oceans and atmospher
Climate change
Climate of California
Climate of California: regional types, causes, and impacts
Climate sensitivity
Climatology
Cloud
Coal
Coal: composition, formation, uses, and environmental impacts
Coal is a combustible sedimentary rock formed from ancient plant matter; used for energy and industry, it shaped the Industrial Revolution and now raises health and climate concern
Coal ball
Coal ball (permineralized peat fossils)
Coal mining
Cobble (geology)
Coccolith
Coccoliths: microscopic calcium‑carbonate plates produced by coccolithophores
Cocos plate
Cold seep
Cold seep (cold vent)
Conglomerate (geology)
Continental crust
Continental drift
Continental margin
Convergent boundary
Convergent boundary (plate tectonics)
Coprolite
Coprolite — fossilized feces and what it reveals
Coprolites are fossilized animal droppings (trace fossils) that preserve dietary remains and ecological information; used by paleontologists to reconstruct ancient diets and enviro
Corundum
Corundum — the aluminium oxide mineral behind ruby and sapphire
Cotacachi Volcano
Cotacachi Volcano: Dormant Andean Peak in Imbabura, Ecuador
Cotopaxi
Cotopaxi: Ecuador's high active stratovolcano
Crater
Craton
Cretaceous
Cretaceous Period: geology, climate, life, and the end‑Cretaceous event
Cryogenian
Cryosphere
Cryovolcano
Cyclone
Cyclone Kyarr
Cyclone Kyarr (October 2019)
Cyclone Yasi
Cyclone Yasi (2011) — Major Queensland tropical cyclone
Daikakuji Seamount
Daikakuji Seamount — extinct guyot in the Hawaiian–Emperor chain
Dark adaptor goggles
Dark adaptor goggles: purpose, design, and uses
Denudation
Denudation (geology): processes that lower and reshape Earth's surface
Deposition (geology)
Desert climate
Desert climate (arid climate): characteristics, distribution and significance
Devonian
Devonian Period (about 419–359 million years ago)
Dew
Diabase
Diabase (dolerite, microgabbro): composition, formation, and uses
Dinosaur Ridge
Dinosaur Ridge — Morrison Formation fossils and Dakota tracksite near Denver
Diorite
Diorite: Composition, Formation, Characteristics, and Uses
Dip slope
Dip slope (geology)
Dirt
Dirt: definition, composition, uses, and environmental concerns
Discharge (hydrology)
Discharge (hydrology): volumetric flow of water in rivers, lakes and streams