Here you’ll find 84 Earth science words that start with C, organized from “Cambrian” to “cyclone”. They cover geologic periods, rocks, landforms, and atmospheric or ocean processes used in study and teaching.

Earth science words that start with C are terms used across geology, meteorology, oceanography, and related fields. For example, “Cambrian” names a major geologic period famous for a rapid increase in animal diversity.

Below you’ll find the table with Term, Definition, Category, Example, and Links.

Term: The word itself, so you can quickly scan or search for familiar and new vocabulary entries.

Definition: A concise 1–2 sentence explanation that gives you the essential meaning and everyday context.

Category: Shows the field or topic (for example, “geology” or “meteorology”) to help you group related terms.

Example: A brief real-world instance you can relate to, helping you understand how the term appears in practice.

Links: Direction to further reading or authoritative articles if you want deeper explanation or classroom resources.

Earth science words that start with C

Term Type Typical units / scale Example occurrence / typical value Description
caldera landform km to tens of km 10 km diameter volcanic caldera Large volcanic collapse depression formed after a magma chamber empties; calderas can host lakes and supereruptions (USGS).
canyon landform meters to km deep 1,000 m Grand Canyon depth Deep valley with steep sides carved mainly by river erosion over long timescales; great for reading Earth history (USGS).
cirque landform hundreds of m scale 500 m glacial cirque Bowl-shaped head of an alpine glacier carved by ice and freeze-thaw; common in glaciated mountain ranges (NOAA).
cuesta landform km-scale ridge gently dipping sandstone ridge Asymmetric ridge formed where tilted resistant layers create steep and gentle slopes; shows layered rock geology (USGS).
cliff landform meters to hundreds of m 500 m sea cliff Steep rock face formed by erosion or faulting, often at coasts or mountain ranges; hazards for coastal erosion (NOAA).
calcrete rock cm to m thick horizons desert calcrete crust Hardened calcium carbonate layer in soils of arid regions; indicates past dry climates and groundwater chemistry (USGS).
cinder cone landform tens to hundreds of m high 300 m Strombolian cone Small steep volcanic cone built from ejected lava fragments; often short-lived but common (USGS).
continental shelf ocean 0–200 m water depth North Sea shelf, ~50 m depth Shallow submerged margin of continents important for fisheries and sediment accumulation (NOAA).
continental slope ocean 200–3,000 m depth slope from shelf to abyssal plain Steep transition from continental shelf to deep ocean, often site of submarine canyons (NOAA).
continental rise ocean 1,000–4,000 m depth sediment apron at slope base Gently sloping sediment accumulation at base of continental slope, formed by turbidity currents (NOAA).
continental crust structure tens of km thick ~35 km average thickness Thick, buoyant outer layer that makes up continents and carries continental rocks (USGS).
crust structure ~5–70 km thick oceanic crust ~7 km thick Earth’s outermost solid layer, divided into continental and oceanic types; where we live and build (USGS).
core structure thousands of km radius outer core ~2,200 km thick Central metallic Earth layers (liquid outer, solid inner) that generate the magnetic field (USGS).
convection process local to planetary scale mantle convection cells, hundreds km Heat-driven fluid or solid-rock movement; drives plate tectonics and atmospheric circulation (AGU/USGS).
conduction process small, local distances heat flow through rock, W/m² Heat transfer through materials by contact, important near Earth’s surface and in rocks (USGS).
Coriolis effect process global scale influence deflects winds to right in N. Hemisphere Apparent deflection of moving fluids due to Earth’s rotation, crucial for wind and ocean current patterns (NOAA).
chemical weathering process local to regional limestone dissolution, acid rain effects Breakdown of rocks by chemical reactions (e.g., carbonic acid dissolving calcite); shapes landscapes and soils (USGS).
clay mineral micrometer particles clay-rich soil, <2 μm particles Very fine-grained minerals formed by weathering that control soil water and chemistry (USGS).
calcite mineral hardness 3, common mineral marine shells, limestone Calcium carbonate mineral prominent in sedimentary rocks and biological shells; reacts with acid (USGS).
carbonate rock/mineral widespread sediments limestone beds, coral reefs Minerals or rocks rich in carbonate ions, key to carbon cycle and marine chemistry (NOAA).
chert rock mm to m nodules silica nodules in limestone Hard microcrystalline silica rock formed from cryptic shells or chemical precipitation (USGS).
conglomerate rock clast sizes >2 mm river-rounded gravel cemented rock Coarse sedimentary rock of rounded clasts indicating high-energy transport (USGS).
cross-bedding structure cm to m scale layers dune foresets, 1–3 m thick Angled internal layers in sediments showing ancient flow or wind directions (USGS).
cleavage property mineral-scale mica shows perfect cleavage planes Tendency of minerals to break along flat planes, useful for identification (USGS).
cap rock rock/feature m to tens of m thick salt dome cap rock Impermeable layer that traps fluids like oil, gas, or groundwater; important in petroleum geology (USGS).
cryosphere system local to global polar ice sheets, sea ice All frozen water on Earth — glaciers, sea ice, permafrost — critical for climate and sea level (IPCC).
cryoconite sediment cm-scale holes on ice dark windblown dust on glaciers Dust and soot that accelerates ice melt by lowering albedo, forming holes on glacier surfaces (NASA).
climate atmosphere global to local averages regional mean temp ~15°C Long-term average of weather; primary driver of ecosystems and human planning (IPCC).
climate change process decades to centuries global warming ~1.2°C since 1850 Long-term changes in average climate patterns, largely driven by greenhouse gases (IPCC).
cyclone atmosphere hundreds to 2,000 km tropical cyclone in Pacific Large rotating storm system with low pressure; includes hurricanes and typhoons (NOAA).
capillary fringe hydrology cm to m above water table 10–50 cm above groundwater Zone where water moves upward from the water table by capillary action, important for roots (USGS).
catchment landform km² scale drainage area small watershed, 10 km² Area draining to a single outlet, used to manage water and floods (USGS).
channel landform meters to km wide river channel 50 m wide Constrained path that conveys flowing water, shapes landscapes and sediment transport (USGS).
continental drift process geologic time scale continents moving ~cm/yr Early idea of moving continents that led to plate tectonics; continents continually shift (USGS).
convergent boundary tectonics regional to global Andes subduction zone Plate margin where plates collide, causing mountains, earthquakes, and volcanism (USGS).
crustal deformation process local to regional folded mountain belts Bending, breaking or flowing of Earth’s crust during tectonic forces (USGS).
carbonate compensation depth ocean m depth scale CCD ~4,000–5,000 m in modern oceans Depth where carbonate dissolves faster than it accumulates, shaping deep-sea sediments (NOAA).
carbon cycle process global fluxes, Pg C/yr atmosphere-ocean exchange, ~100 Pg C/yr Movement of carbon among atmosphere, biosphere, oceans, and rocks; central to climate (IPCC).
carbon sequestration process tonnes to Gt CO₂ CO₂ stored in soils or reservoirs Long-term storage of carbon in land, ocean, or engineered sites to reduce atmospheric CO₂ (IPCC).
Carboniferous period geologic time, Ma 359–299 Ma, coal-forming era Geologic period known for extensive coal-forming forests and diverse marine life (USGS).
Cambrian period geologic time, Ma 541–485 Ma, Cambrian explosion Early Paleozoic period when many animal groups first appear in the fossil record (USGS).
Cretaceous period geologic time, Ma 145–66 Ma, last dinosaurs era Period ended with mass extinction; famous for chalk deposits and dinosaurs (USGS).
Cenozoic era geologic time, Ma 66 Ma to present, age of mammals Most recent era marked by mountain building, climate changes, and human evolution (USGS).
contour line measurement meters elevation intervals 100 m contour on topographic map Line joining equal elevation points on maps, essential for reading terrain (USGS).
compass instrument degrees azimuth field compass for strike/dip Simple instrument for direction finding used in mapping and navigation (USGS).
clinometer instrument degrees or percent slope measures 30° slope Handheld tool to measure slope angles and structural orientations in the field (USGS).
conductivity measurement S/m or μS/cm seawater ~53,000 μS/cm Measure of water’s ability to carry electric current, indicates salinity and pollutants (NOAA).
concentration measurement mg/L, ppm, percentage nitrate 10 mg/L in groundwater Amount of a substance in water, air, or soil; vital for pollution and chemistry (EPA).
coral reef landform/ecosystem m to km scale Great Barrier Reef, Australia Diverse marine ecosystem built by corals that supports fisheries and protects coasts (NOAA).
cryoturbation process decimeters scale soil mixing patterned ground in permafrost areas Soil mixing caused by freeze-thaw cycles in cold regions, creates patterned soils (USGS).
capillary action process mm to cm scale water rise in soil pores, cm Movement of water through small pores against gravity, important for soil moisture (USDA/USGS).
collision zone tectonics regional mountain belts Himalaya continental collision Region where continental plates collide and crumple to form high mountains (USGS).
calving process m to km iceberg sizes iceberg calving from Antarctic glacier Breaking off of ice from glacier termini into the ocean, a major ice mass loss process (NASA).
coastal erosion process meters to km coastline cliff retreat rates vary, ~0.1–1 m/yr Wearing away of shoreline by waves and storms, affecting communities and habitats (NOAA).
coastal plain landform tens to hundreds of km wide Atlantic coastal plain Low-lying flat area adjacent to a shore, often with sediments and wetlands (USGS).
cold front atmosphere 10s to 1,000 km leading edge of cold air mass Boundary where colder air replaces warmer air, commonly producing storms and temperature drops (NOAA).
cumulonimbus atmosphere vertical up to 10–20 km thunderstorm cloud, heavy rain Towering thunderclouds producing lightning, hail, and severe weather (WMO/NOAA).
cumulus atmosphere 1–2 km vertical scale fair-weather puffy clouds Fluffy, cotton-like clouds formed by rising warm air, common on sunny days (NOAA).
cirrus atmosphere high-altitude clouds wispy 6–12 km ice clouds Thin, feathery high clouds made of ice crystals that signal upper-level winds (NOAA).
cirrostratus atmosphere high-altitude veil clouds thin halo-producing cloud Wide, thin ice-crystal cloud layer that can create halos around sun or moon (WMO).
cirrocumulus atmosphere high-altitude small patches small rippled cloudlets High, small cloud patches often indicating atmospheric instability (WMO).
Celsius measurement °C temperature scale 0°C freezing, 100°C boiling Temperature scale commonly used worldwide in weather, science, and daily life (WMO).
chemical sediment rock type local to global deposits evaporites, salt flats Sediments formed by chemical precipitation, like salts from evaporating water (USGS).
compaction process porosity percent change burial compaction reduces porosity Squeezing of sediments under weight, reducing pore space and expelling water (USGS).
concretion sedimentary feature cm to m size ironstone nodule in shale Hard, rounded bodies formed by mineral precipitation within sediment, often fossil hosts (USGS).
contact metamorphism process m to km scale baked rock around an intrusion Mineral and texture changes in rocks caused by heat from nearby magma (USGS).
continental glacier landform tens to thousands km Greenland ice sheet, ~1,700 km wide Massive ice sheet covering continental areas and shaping landscapes through ice flow (IPCC/USGS).
cation exchange capacity measurement meq/100 g soil fertile soils ~10–30 meq/100 g Soil property indicating ability to hold and exchange nutrient ions for plants (USDA).
contamination process local to regional groundwater plume from spill Introduction of harmful substances to soil, water, or air, affecting health and ecosystems (EPA).
color property visual field note red oxidized iron sandstone Visible hue of rocks and soils used for identification and environmental clues (USGS).
crystal mineral term nm to cm crystals quartz crystal, centimeters Solid material with repeating atomic structure; crystal shape helps identify minerals (USGS).
chlorite mineral phyllosilicate group green sheet silicate in metamorphics Common metamorphic mineral that indicates low-grade metamorphism (USGS).
chalcedony mineral microcrystalline silica agate banding in volcanic rock Smooth, microcrystalline quartz variety forming nodules and ornamental stones (USGS).
cone of depression hydrology m to km radius well pumping drawdown area Lowered water table around a pumped well that affects nearby groundwater levels (USGS).
chemosynthesis process local ecosystems deep-sea vent bacteria produce organic C Biological production of organic matter using chemical energy instead of sunlight (NOAA).
cohesion soil property kPa or qualitative clay cohesion holds slope materials Interparticle attraction that helps soils and rocks stick together, affecting slope stability (USGS).
convection cell process km-scale in mantle/atmosphere Hadley cell spanning tropics Closed-loop circulation driven by heating, key in weather and mantle dynamics (NOAA/AGU).
colluvium sediment m to tens of m thick slope deposit of mixed sediment Loose material moved downslope by gravity, common at foot of slopes (USGS).
core sample instrument/product cm to m cores 1 m sediment core from lake Cylindrical sample of rock, ice, or sediment used to study past environments (USGS).
coal rock m-thick seams bituminous coal seam, meters Sedimentary rock from plant remains, important fossil fuel and climate consideration (USGS).
carbonic acid chemical aqueous species, pH effect CO₂ + H₂O ⇌ H₂CO₃ in rainwater Weak acid formed from CO₂ and water, key agent in dissolving limestone (USGS).
chlorofluorocarbon chemical ppt to ppb atmospheric historical ozone-depleting gases Synthetic compounds that damaged stratospheric ozone; regulated by Montreal Protocol (WMO/UNEP).
critical zone system tens to hundreds m depth soil to bedrock life-and-water zone Earth’s near-surface layer where rock, soil, water, air and living organisms interact (NSF/USGS).
coalescence process cloud microphysics scale droplets merge to form raindrops Process where small droplets collide and combine to make larger precipitation particles (WMO).

Descriptions

caldera
canyon
cirque
cuesta
cliff
calcrete
cinder cone
continental shelf
continental slope
continental rise
continental crust
crust
core
convection
conduction
Coriolis effect
chemical weathering
clay
calcite
carbonate
chert
conglomerate
cross-bedding
cleavage
cap rock
cryosphere
cryoconite
climate
climate change
cyclone
capillary fringe
catchment
channel
continental drift
convergent boundary
crustal deformation
carbonate compensation depth
carbon cycle
carbon sequestration
Carboniferous
Cambrian
Cretaceous
Cenozoic
contour line
compass
clinometer
conductivity
concentration
coral reef
cryoturbation
capillary action
collision zone
calving
coastal erosion
coastal plain
cold front
cumulonimbus
cumulus
cirrus
cirrostratus
cirrocumulus
Celsius
chemical sediment
compaction
concretion
contact metamorphism
continental glacier
cation exchange capacity
contamination
color
crystal
chlorite
chalcedony
cone of depression
chemosynthesis
cohesion
convection cell
colluvium
core sample
coal
carbonic acid
chlorofluorocarbon
critical zone
coalescence
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