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Ekman pumping
Ekman pumping is the vertical motion induced in a rotating fluid where a frictional boundary layer meets the interior, caused by friction turning the flow across isobars.
Ekman transport
Ekman transport is the net horizontal movement of wind-driven surface water in the ocean, deflected 90 degrees to the right of the wind in the Northern Hemisphere.
El Abra mine
El Abra is an open-pit copper mine in Chile's Antofagasta Region, 75 kilometers northeast of Calama, owned by Freeport-McMoRan (51%) and Codelco, producing copper cathodes since 1996.
El Niño–Southern Oscillation
The El Niño–Southern Oscillation (ENSO) is a Pacific Ocean climate pattern alternating between the warm El Niño and cool La Niña phases, driving year-to-year climate variability.
El Rosario Formation
El Rosario Formation (Formación Rosario), Late Cretaceous Campanian-Maastrichtian marine to non-marine clastic unit on the Pacific coast of Baja California, Mexico; type section near El Rosario town; includes deep-marine turbidites and rich fossils.
El Teniente
El Teniente is an underground copper mine in the Andes of central Chile, about 50 kilometers east of Rancagua, and the largest underground copper deposit in operation.
El Victor
El Victor is a gold deposit and former open pit in the Mulatos District of Sonora, Mexico, operated by Alamos Gold and mined until mid-2021.
Elastic-rebound theory
Elastic-rebound theory explains earthquakes as the sudden release of elastic strain that builds up in rock around a locked fault, proposed by Harry Fielding Reid after the 1906 San Francisco earthquake.
Eldorado Gold
Eldorado Gold Corporation is a Canadian mid-tier gold mining company headquartered in Vancouver, producing 488,268 ounces of gold in 2025 from mines in Canada, Türkiye, and Greece.
Electrical resistivity imaging
Electrical resistivity imaging, also called electrical resistivity tomography (ERT), is a geophysical method that maps subsurface resistivity by injecting current and measuring voltage, used to find groundwater, contaminants, and geology.
Electrical resistivity method
The electrical resistivity method is a geophysical surveying technique, originating in the 1910s, that injects current into the ground to map groundwater, salinity, fractures, and contaminants.
Electrical resistivity tomography
Electrical resistivity tomography (ERT) is a geophysical imaging method that reconstructs subsurface electrical resistivity from electrode measurements, producing 2D sections and 3D volumes for hydrogeology, geotechnics, and environmental studies.
Electromagnetic tomography
Electromagnetic tomography is a geophysical method that reconstructs subsurface electrical conductivity from electromagnetic field measurements made at the surface, in boreholes, or from the air.
Electronic navigational chart
An electronic navigational chart (ENC) is a standardized vector chart database issued by a government-authorized hydrographic office for use with ECDIS, conforming to International Hydrographic Organization standards.
Éléonore
Éléonore is an underground gold mine in Eeyou Istchee Baie-James, northern Quebec, which opened in 2014 and has been operated since 2025 by Dhilmar Ltd.
Éléonore Mine
The Éléonore Mine is an underground gold mine in the James Bay region of northern Quebec, on the Roberto deposit, in production since 2015 under Goldcorp.
EM-DAT
EM-DAT, the Emergency Events Database, is a free global database of disasters and their human and economic impacts from 1900 to the present, maintained by CRED at UCLouvain in Brussels.
Emerald
Emerald is the green gem variety of the mineral beryl, colored by trace chromium or vanadium; the most prized stones come from Colombia, with Zambia, Brazil, and Zimbabwe also major sources.
Emergency Alert System
The Emergency Alert System (EAS) is the United States' national broadcast alerting system, established in 1997 to relay emergency messages from federal, state, and local authorities to the public.
Emergency Broadcast System
The Emergency Broadcast System (EBS) was the United States' national emergency alerting system for radio and television from 1963 to the 1990s, established by President Kennedy.
Emergent constraint
An emergent constraint is a relationship across an ensemble of climate models between an observable present-day climate quantity and a projected future change, letting observations narrow projections.
Emission level
An emission level is the altitude from which radiation escaping a planet's atmosphere originates, or, in air-quality modeling, the height at which a pollutant is released.
Emissions Gap Report
The Emissions Gap Report is an annual assessment by the United Nations Environment Programme, published since 2010, that measures the gap between countries' climate pledges and Paris Agreement goals.
Endmember extraction
Endmember extraction is a hyperspectral image analysis method that identifies the pure spectral signatures of materials in a scene, the first step of spectral unmixing.
Enhanced Fujita scale
The Enhanced Fujita scale (EF scale) rates tornado intensity from EF0 to EF5 based on damage; it has been used by the US National Weather Service since 2007.
Enhanced weathering
Enhanced weathering is a carbon removal method that spreads crushed silicate rock on farmland or coasts, dissolving it to convert atmospheric CO2 into ocean-stored bicarbonate.
Ensemble forecasting
Ensemble forecasting is a weather and climate prediction method that runs a numerical model many times with varied initial conditions, yielding probabilities instead of a single forecast.
Enstatite
Enstatite is a rock-forming silicate mineral of the pyroxene group with ideal formula Mg2Si2O6, occurring chiefly in ultramafic igneous rocks and dominant in the enstatite chondrite meteorites.
Entisols
Entisols are one of the 12 orders of USDA Soil Taxonomy: mineral soils with little or no horizon development, covering about 18 percent of Earth's ice-free land.
Environment America
Environment America is a federation of state-based environmental advocacy organizations in the United States, founded in 2007 out of the state PIRG network and headquartered in Denver.