This list includes 75 Earth science words that start with D, from “Dacite” to “Dynamic topography”. They cover rocks, landforms, processes, and climate or ocean phenomena used in education, research, and resource management.
Earth science words that start with D are terms used to name rocks, processes, features, and measurements across Earth sciences. For example, “dacite” reflects a place-name origin, showing how geography and history shape scientific vocabulary.
Below you’ll find the table with Word, Definition, Category, Example, and Further reading.
Word: The term itself, listed alphabetically so you can quickly scan and locate specific D-words in the list.
Definition: A concise one-to-two sentence explanation that tells you what the term means and why it matters in Earth science.
Category: Brief label indicating whether the term relates to geology, meteorology, oceanography, geomorphology, or another subfield for context.
Example: A short real-world or classroom example showing how the term appears in nature or scientific work, helping you visualize use.
Further reading: Links to articles or glossary entries where you can read more and follow up on topics you want to explore in depth.
Earth science words that start with D
| Term | Category | Typical units | Related concepts | Description |
|---|---|---|---|---|
| Dacite | Rock | N/A | Andesite, rhyolite, volcanic rock | A silica-rich volcanic rock intermediate between andesite and rhyolite, common in explosive volcanoes and lava domes. |
| Dale | Landform | N/A | Valley, drainage, stream | A small valley or low area between hills, often carved by streams; a regional term for a type of valley. |
| Dendritic drainage | Process/Pattern | N/A | River network, watershed, tributary | A tree-like river network pattern formed where the underlying rock is relatively uniform, producing many branching tributaries. |
| Dendrochronology | Discipline/Method | years | Tree rings, climate reconstruction, dating | The study of tree rings to date events and reconstruct past climates, fire history, and environmental changes year by year. |
| Dendroclimatology | Discipline | years | Dendrochronology, climate proxies | A branch of dendrochronology that interprets tree-ring patterns to infer past climate variations such as temperature and precipitation. |
| Denudation | Process | mm/yr | Erosion, weathering, uplift | The long-term wearing down of Earth’s surface by weathering, erosion, and mass movement that lowers and levels the landscape. |
| Deformation | Process | N/A | Stress, strain, faulting | Change in rock shape or volume due to tectonic forces, producing folds, faults, and fractures at many scales. |
| Deflation | Process | N/A | Wind erosion, abrasion, desert pavement | Wind-driven removal of loose particles from the ground surface, often leaving coarser materials behind. |
| Deflation hollow | Landform | m | Blowout, dune, wind erosion | A shallow depression in sandy or loess landscapes formed when wind removes fine sediment from a spot. |
| Deformation front | Tectonic feature | N/A | Fold-and-thrust belt, accretionary wedge | The leading edge of active deformation in a convergent margin where sediment and rock begin to be folded and faulted. |
| Deglaciation | Process | years | Glacier retreat, sea-level rise, interglacial | The period when glaciers shrink and ice sheets retreat, raising sea level and reshaping landscapes after glacial maxima. |
| Delta | Landform | N/A | Sediment deposition, distributary, estuary | A deposit of sediment at a river mouth where flow slows, forming branches and often fertile, flat land. |
| Deltaic deposit | Sedimentary feature | m | Delta, prodelta, distributary channel | Layers of sediment laid down in a delta environment, ranging from coarse channel fills to fine prodelta muds. |
| Density | Measurement | g/cm3; kg/m3 | Buoyancy, porosity, specific gravity | Mass per unit volume of a material; controls whether rocks, water masses, or air parcels rise or sink. |
| Density current | Ocean/Fluvial process | m/s | Turbidity current, thermohaline circulation | A gravity-driven flow in water or air caused by a mass of higher-density fluid moving beneath lighter fluid. |
| Density stratification | Phenomenon | N/A | Thermocline, pycnocline, stability | Layering of a fluid like the ocean or atmosphere into layers of different density, which limits vertical mixing. |
| Decompression melting | Process | N/A | Mantle melting, mid-ocean ridge, magma | Melting that occurs when solid mantle rises and pressure falls, producing magma without added heat. |
| Deformation band | Structural feature | N/A | Faults, fractures, shear zone | A narrow zone of localized deformation in porous rocks that alters porosity and fluid flow. |
| Debris flow | Mass movement | m3/s; m | Landslide, mudflow, hyperconcentrated flow | A fast-moving mixture of water, soil, and rock that flows downslope and can bury terrain and infrastructure. |
| Debris avalanche | Mass movement | m3 | Volcanic collapse, landslide, pyroclastic flow | Rapid, catastrophic collapse of volcanic or slope material that spreads as a fragmented, high-speed mass. |
| Debris-covered glacier | Glacier type | m/year | Glacier, moraine, supraglacial debris | A glacier whose surface is mantled by rock debris, which alters melt rates and flow behavior. |
| Deposit | Sedimentary feature | m | Sedimentation, bed, layering | Accumulation of sediment laid down by wind, water, ice, or gravity to form beds and layers. |
| Deposition | Process | N/A | Erosion, sediment transport, settling | The settling and laying down of sediment when the transporting medium loses energy. |
| Depression (atmospheric) | Weather phenomenon | hPa | Low pressure, cyclone, frontal system | A region of low atmospheric pressure associated with cloudiness, wind, and often precipitation. |
| Depression (topographic) | Landform | m | Basin, sink, closed drainage | A low area in the landscape that may collect water; can be glacial, karstic, or tectonic in origin. |
| Detailed mapping | Instrument/Method | N/A | Field survey, GIS, remote sensing | High-resolution mapping of geology, landforms, or habitats used for planning and research. |
| Diatom | Biological sediment component | N/A | Phytoplankton, siliceous ooze, paleoecology | Microscopic algae with silica shells that form important marine and freshwater sediments and climate proxies. |
| Diatreme | Volcanic feature | m | Maar, volcanic pipe, breccia | A vertical pipe filled with fragmented rock formed by explosive volcanic eruptions, often associated with kimberlites. |
| Diabase | Rock | N/A | Dolerite, gabbro, basalt | A medium-grained mafic intrusive rock equivalent to basalt, commonly forming dikes and sills. |
| Dolerite | Rock | N/A | Diabase, intrusive, dike | A regional name for diabase; medium-grained mafic rock forming sills and dikes. |
| Diorite | Rock | N/A | Granite, andesite, pluton | A coarse-grained intrusive igneous rock of intermediate composition between mafic and felsic types. |
| Dissolution | Chemical process | N/A | Weathering, karst, solute transport | The chemical removal of rock or mineral material by water, commonly forming caves and karst landscapes. |
| Dissolved oxygen | Measurement | mg/L; % saturation | Aquatic health, hypoxia, dead zone | Amount of oxygen dissolved in water; a key indicator of water quality and aquatic life support. |
| Dissolved solids | Measurement | mg/L | Salinity, conductivity, TDS | The amount of inorganic salts and small organic matter dissolved in water, often reported as total dissolved solids. |
| Discharge | Hydrology/Measurement | m3/s | Streamflow, runoff, gauge | The volume of water flowing past a point per unit time in a river or stream. |
| Discontinuity (seismic) | Structural feature | km; depth | Moho, reflector, seismic layering | A boundary in Earth’s interior where seismic velocity changes abruptly, indicating changes in rock type or state. |
| Disconformity | Stratigraphic feature | N/A | Unconformity, erosion surface, strata | A gap in the rock record where parallel strata are separated by an erosional or non-depositional interval. |
| Distal deposit | Sedimentary term | N/A | Prodelta, turbidity, basin floor | Sediments laid down far from the source, typically finer grained and deposited in deeper water or low-energy settings. |
| Divide | Hydrologic feature | N/A | Watershed, drainage basin, ridge | A topographic crest separating adjacent drainage basins where water flows in different directions. |
| Diapir | Tectonic/Structural feature | N/A | Salt dome, intrusion, buoyant rise | Upward movement of less dense material (e.g., salt) into overlying strata, forming domes or intrusions. |
| Dip | Structural measurement | degrees | Strike, bedding, fold, orientation | The angle at which a geological plane inclines from the horizontal, measured in degrees. |
| Dip-slip fault | Tectonic feature | m | Normal fault, reverse fault, vertical movement | A fault where movement is mainly vertical along the dip of the fault plane. |
| Dome | Tectonic/Volcanic feature | m | Lava dome, uplift, anticline | A rounded uplift or volcanic feature formed by magma pushing up rock or by intrusive doming. |
| Dormant volcano | Volcanic status | N/A | Active volcano, extinct volcano, eruption cycle | A volcano that is not currently erupting but may erupt again in the future. |
| Downburst | Meteorological phenomenon | m/s | Microburst, wind shear, thunderstorm | A strong downdraft from a thunderstorm that strikes the ground and spreads outward, causing damaging winds. |
| Downcutting | Erosional process | m/yr | River incision, base level, knickpoint | Vertical erosion by a river lowering its channel and widening valleys, often after uplift or sea-level change. |
| Downwelling | Oceanographic process | m/day | Upwelling, thermohaline, circulation | The sinking of surface water into deeper layers, affecting nutrient and oxygen distribution. |
| Doppler radar | Instrument | m/s; km | Weather radar, wind speed, precipitation | A radar system that measures motion (wind speed) and precipitation using Doppler shift of returned signals. |
| Drainage basin | Hydrologic feature | km2 | Watershed, river system, catchment | The land area draining to a common outlet such as a river, lake, or ocean. |
| Drainage density | Measurement | km/km2 | Stream network, runoff, basin shape | Total length of streams divided by basin area; indicates landscape dissection and runoff potential. |
| Drift | Glacial deposit | N/A | Till, outwash, glacial erratic | Sediments transported and deposited directly by glacial ice or meltwater, collectively called glacial drift. |
| Drill core | Sample | m | Borehole, stratigraphy, paleoenvironment | A cylindrical rock or sediment sample recovered from drilling used to study subsurface layers and history. |
| Dredging | Human activity | m3 | Navigation, sediment removal, coastal engineering | Removing sediment from water bottoms to maintain channels, construct ports, or restore habitats. |
| Dripstone | Speleothem | m | Stalactite, stalagmite, cave | Mineral deposits in caves (calcite) formed by dripping water that leaves behind layered mineral growths. |
| Dropstone | Sedimentary feature | N/A | Ice-rafted debris, glacial, turbidite | A large clast dropped into fine sediment from melting ice, producing a lone pebble in fine matrix. |
| Drumlin | Glacial landform | m | Mound, till, glacial flow | An elongated, streamlined hill of glacial till formed beneath moving ice, indicating flow direction. |
| Dry adiabatic lapse rate | Atmospheric measure | °C/km | Stability, parcel theory, convective lifting | Rate at which unsaturated air cools with altitude, about 9.8 °C per km, used in weather prediction. |
| Dry deposition | Atmospheric process | µg/m2/s | Wet deposition, aerosols, air pollution | Direct transfer of airborne particles and gases to surfaces without precipitation, affecting ecosystems and materials. |
| Dryland | Biome/Climate type | N/A | Arid, semi-arid, desertification | Regions where precipitation is low enough to limit vegetation, including deserts and steppes. |
| Dust devil | Atmospheric phenomenon | m/s | Vortex, convection, thermal | A small, short-lived rotating column of air formed by surface heating and rising air, often in deserts. |
| Dust storm | Atmospheric phenomenon | km/h; µg/m3 | Haboob, aeolian transport, visibility | Large-scale event lifting vast quantities of dust into the air, reducing visibility and transporting nutrients and pollutants. |
| Drowned valley | Coastal landform | N/A | Ria, sea-level rise, estuary | A former river valley flooded by sea-level rise, forming a long, narrow inlet or estuary. |
| Drowned coral reef | Ecosystem change | N/A | Sea-level rise, bleaching, reef death | A coral reef submerged or killed due to rapid sea-level rise or environmental stress, leaving a drowned structure. |
| Dead zone | Ocean phenomenon | km2; mg/L | Hypoxia, eutrophication, nutrient runoff | An area in coastal waters with extremely low oxygen where most marine life cannot survive, often due to nutrient pollution. |
| Dew point | Meteorology | °C; °F | Humidity, condensation, saturation | Temperature at which air becomes saturated and water vapor condenses; controls fog and dew formation. |
| Dewatering | Engineering/process | m3/day | Groundwater pumping, consolidation, mining | Removal of water from soil or rock to lower the water table for construction, mining, or stabilization. |
| Diagenesis | Geological process | N/A | Lithification, compaction, cementation | Chemical and physical changes that turn sediments into sedimentary rock after burial and during compaction. |
| Diurnal cycle | Phenomenon | hours | Day-night, temperature, radiation | Daily pattern of change caused by Earth’s rotation, affecting temperature, winds, and biological activity. |
| Diurnal temperature range | Climate metric | °C | Tmin, Tmax, climate variability | Difference between daily maximum and minimum temperature; useful for understanding local climate variability. |
| Diurnal tide | Oceanographic phenomenon | m | Semidiurnal, tidal constituent, lunar cycle | A tidal pattern with one high and one low tide per day, produced by specific tidal constituents. |
| Direct runoff | Hydrology | mm; m3/s | Infiltration, baseflow, stormflow | Portion of precipitation that flows directly into streams and rivers shortly after rainfall, contributing to flood peaks. |
| Dust deposition | Process | g/m2 | Aerosol transport, nutrient input, soil formation | Settling of atmospheric dust onto land or sea surfaces, supplying minerals and affecting ecosystems and climate. |
| Dynamic topography | Tectonics/Geodynamics | m | Mantle flow, uplift, isostasy | Surface elevation changes driven by mantle flow and lithospheric forces rather than crustal thickness, affecting long-term sea level. |
| Downscaling | Climate method | N/A | GCM, regional model, climate projections | Techniques to derive regional or local climate information from coarser global climate model output. |
| Dense water formation | Oceanographic process | kg/m3 | Thermohaline circulation, convection, deep water | Creation of high-density surface water by cooling or increased salinity, which sinks and drives deep ocean circulation. |
Descriptions
Dacite
Dale
Dendritic drainage
Dendrochronology
Dendroclimatology
Denudation
Deformation
Deflation
Deflation hollow
Deformation front
Deglaciation
Delta
Deltaic deposit
Density
Density current
Density stratification
Decompression melting
Deformation band
Debris flow
Debris avalanche
Debris-covered glacier
Deposit
Deposition
Depression (atmospheric)
Depression (topographic)
Detailed mapping
Diatom
Diatreme
Diabase
Dolerite
Diorite
Dissolution
Dissolved oxygen
Dissolved solids
Discharge
Discontinuity (seismic)
Disconformity
Distal deposit
Divide
Diapir
Dip
Dip-slip fault
Dome
Dormant volcano
Downburst
Downcutting
Downwelling
Doppler radar
Drainage basin
Drainage density
Drift
Drill core
Dredging
Dripstone
Dropstone
Drumlin
Dry adiabatic lapse rate
Dry deposition
Dryland
Dust devil
Dust storm
Drowned valley
Drowned coral reef
Dead zone
Dew point
Dewatering
Diagenesis
Diurnal cycle
Diurnal temperature range
Diurnal tide
Direct runoff
Dust deposition
Dynamic topography
Downscaling
Dense water formation