5,021 articles
Dead storage
Dead storage is the volume of reservoir water below the lowest outlet that cannot be drained by gravity, traditionally sized to hold decades of sediment.
Death of Colin Scott
The death of Colin Nathaniel Scott occurred in 2016, when the 23-year-old slipped into a boiling, acidic hot spring in Yellowstone National Park, and his body dissolved.
Debris flow
A debris flow, also called a mudslide, mudflow, or lahar, is a fast-moving landslide in which soil, rock, and water flow downslope as a slurry, often triggered by intense rainfall.
Decade Volcanoes
The Decade Volcanoes are 16 volcanoes designated by IAVCEI in the 1990s, part of the UN's disaster-reduction decade, for research and public awareness to reduce volcanic risk.
Decarbonization
Decarbonization is the reduction of the carbon intensity of an economy, or CO2 emissions per unit of GDP or energy, through electrification, renewables, efficiency, and carbon removal aimed at net zero.
Decca Navigator
The Decca Navigator System was a British hyperbolic radio-navigation system, the primary coastal positioning system for world shipping from the late 1940s until GPS displaced it in the 1990s.
Deccan Traps
The Deccan Traps is a large flood basalt province in west-central India, mainly in Maharashtra, formed by massive eruptions about 66 million years ago at the Cretaceous–Paleogene boundary.
December 1983 cold wave
The December 1983 cold wave, also called the Great Freeze of '83, was an Arctic outbreak that set record lows across the United States and killed at least 151 people.
December 2009 North American blizzard
The December 2009 North American blizzard was a nor'easter that dropped up to 30 inches of snow on the East Coast from December 18 to 20, 2009.
Décollement
Décollement, French for "ungluing," is a fault surface parallel to weak bedding that separates deformed rocks above from rocks below, typical of thrust regions like the Alps.
Deep Argo
Deep Argo is an expansion of the international Argo program in which profiling floats measure temperature and salinity from the ocean surface to the sea floor every 10 days.
Deep Basin, Alberta
The Deep Basin is a large tight gas region in western Alberta along the foothills, holding natural gas in low-permeability Cretaceous rocks over a broad continuous area.
Deep sea
Deep sea: ocean below about 200 m where light fades; also called the aphotic, twilight, midnight, abyssal, and hadal zones. Cold (~4°C), high pressure, food-poor; explored by bathysphere, Trieste, and DEEPSEA CHALLENGER; targeted for seabed mining.
Deep sea drilling
Deep sea drilling is the scientific recovery of sediment and rock cores from beneath the ocean floor by research drillships, run through international programs since Project Mohole in 1961.
Deep Sea Drilling Project
The Deep Sea Drilling Project was a US-led scientific ocean drilling program run from Scripps Institution of Oceanography that used the drillship Glomar Challenger to core the deep seafloor from 1968 to 1983.
Deep Sea Warrior (AUV)
The Deep Sea Warrior (Shenhai Yongshi) is China's second deep-sea manned submersible, a 4,500-meter-class crewed vehicle delivered in 2017 that reached 4,534 meters on its first dive test.
Deep Space Climate Observatory
The Deep Space Climate Observatory, also known as DSCOVR or Triana, is an American spacecraft at the Sun-Earth L1 point, launched in 2015 to monitor solar wind and image Earth.
Deep time
Deep time is the concept that Earth's history spans billions of years beyond human intuition. John McPhee coined the phrase in 1981; the idea traces to James Hutton.
Deep well injection
Deep well injection disposes of liquid waste by pumping it into porous rock thousands of feet below drinking water aquifers, regulated in the US as Class I wells.
Deep-ocean Assessment and Reporting of Tsunamis
Deep-ocean Assessment and Reporting of Tsunamis (DART) is a NOAA tsunami monitoring system pairing seafloor pressure recorders with moored surface buoys, expanded to 39 US stations in 2008.
Deep-submergence vehicle
A deep-submergence vehicle (DSV), also called a human-occupied vehicle when crewed, is a submersible launched from a support ship to work at great ocean depths.
Deepsea Challenger
Deepsea Challenger, also known as DCV 1, is a one-person full-ocean-depth submersible built in Sydney, Australia, and piloted by James Cameron to Challenger Deep on March 26, 2012.
Degree day
A degree day measures how cold or warm a location is, comparing daily mean temperature to a base of 65°F; heating, cooling, and growing degree days track energy use and crops.
Delafossite
Delafossite is a copper iron oxide mineral, CuFeO₂, first described in 1873 from Russia and named for Gabriel Delafosse; it typifies the layered delafossite oxide family.
Delamination tectonics
Delamination tectonics is the geodynamic process in which dense mantle lithosphere peels away from the overlying crust and sinks into the asthenosphere, introduced by Peter Bird in 1979.
Delft-FEWS
Delft-FEWS, short for Flood Early Warning System, is a platform by the Dutch institute Deltares that integrates data and models for operational flood forecasting, introduced in 2002.
Delft3D
Delft3D is a software suite simulating hydrodynamics, sediment transport, waves, and water quality in coastal, estuarine, and river waters, developed by WL | Delft Hydraulics.
Dempo
Dempo (Gunung Dempo), active stratovolcano, 3,142 m, SE Sumatra, Indonesia, Sunda arc; frequent small phreatic eruptions from a crater lake since 1817; last eruption 2025; distinct rhyolitic magma.
Denali Fault
The Denali Fault is a major right-lateral strike-slip fault system in Alaska and Yukon, about 2,100 km long, comparable in length to the San Andreas fault.
Dendrochronology
Dendrochronology, or tree-ring dating, is the science of dating annual growth rings in wood to their exact calendar year. It dates artifacts and reconstructs past climate and fire history.