751 articles
1976 Big Thompson River flood
The 1976 Big Thompson River flood was a flash flood that struck Big Thompson Canyon between Estes Park and Drake, Colorado, on July 31, 1976, killing 144 people.
2004 Gonaïves floods
The 2004 Gonaïves floods were flash floods and mudflows that struck Gonaïves, Haiti, on 18 and 19 September 2004, killing more than 3,000 people in the country.
2007 Jakarta flood
The 2007 Jakarta flood struck the Indonesian capital in early February 2007, inundating up to half the city, killing about 66 people, and displacing some 340,000 residents.
2018 Sunda Strait tsunami
The 2018 Sunda Strait tsunami struck Indonesia's Java and Sumatra coasts on 22 December 2018, killing 437 people, after the erupting Anak Krakatau volcano collapsed.
2024 Nepal floods
The 2024 Nepal floods were late-monsoon floods and landslides across Nepal on 26–28 September 2024, killing more than 240 people and displacing over 10,000 families.
2025 Uttarakhand flash flood
The 2025 Uttarakhand flash flood was a catastrophic debris flow that buried Dharali village in Uttarkashi district, Uttarakhand, India, on 5 August 2025, killing at least 61 people and destroying much of the village.
2026 Indiana floods
The 2026 Indiana floods were riverine and flash floods across Indiana in August and September 2026 that killed 7 people and set White River records.
2026 Nepal floods
2026 Nepal floods: 26 August 2026 Langtang Lirung avalanche-triggered flash flood down the Bhotekoshi–Trishuli–Narayani (1,453 dead, 5,179 missing) and the 11 October Budhi Gandaki blockage-failure flood; Rasuwa, Nuwakot, Dhading worst hit; $4.7 billion recovery estimate.
A23a
A23a, also known as Iceberg A23a, is a giant tabular iceberg that calved from Antarctica's Filchner Ice Shelf in 1986 and drifted to South Georgia.
Abyssal zone
The abyssal zone, also called the abyssopelagic zone, is the deep-ocean zone at depths of roughly 3,000 to 6,000 meters, where temperatures stay near freezing and no sunlight reaches.
Accumulation zone
The accumulation zone is the higher part of a glacier where annual accumulation from snowfall, wind drift, and avalanches exceeds ablation, separated from the ablation zone by the equilibrium line.
Acid neutralizing capacity
Acid neutralizing capacity (ANC) is a measure of the ability of water or soil to neutralize added acids, serving as the standard indicator of surface water sensitivity to acidification.
Acoustic Doppler current profiler
An acoustic Doppler current profiler (ADCP) is a sonar instrument that measures current speed and direction at many depths by analyzing the Doppler shift of sound echoes.
Acoustic Doppler velocimetry
Acoustic Doppler velocimetry is a technique that measures fluid velocity from the Doppler shift of sound echoed by particles moving with the flow, used in turbulence and current studies.
Acoustic imaging
Acoustic imaging forms images of underwater objects and environments from sound-wave echoes, and it is the dominant technique for mapping the seafloor and inspecting submerged structures.
Active flux
Active flux, also called active transport, is the downward export of carbon and nutrients from the ocean's surface layer to depth by the metabolism and movement of vertically migrating zooplankton.
Admiralty chart
An Admiralty chart is a nautical chart issued by the United Kingdom Hydrographic Office since 1800, showing depths, dangers, and aids to navigation for safe voyages.
Advection-dispersion equation
The advection-dispersion equation is the classical governing equation for solute transport in groundwater, describing how dissolved substances move by advection, which carries them with the fluid, and hydrodynamic dispersion, which spreads them.
Advection–diffusion model
The advection–diffusion model is a mathematical model describing how a quantity such as heat, salinity, or pollutant concentration is carried by fluid flow while spreading by diffusion.
Agulhas leakage
Agulhas leakage is the transport of warm, salty Indian Ocean water into the South Atlantic south of Africa, via Agulhas rings and other eddies, feeding the global overturning circulation.
Airborne snow observatory
The Airborne Snow Observatory (ASO) is a NASA airborne system pairing scanning lidar with an imaging spectrometer to map mountain snow depth and snow water equivalent, first flown in 2013.
Akademik Mstislav Keldysh (Академик Мстислав Келдыш)
Akademik Mstislav Keldysh (Академик Мстислав Келдыш) is a Russian oceanographic research vessel, built in Finland and entered in 1981, best known as support ship for the Mir submersibles.
Alfred Wegener Institute for Polar and Marine Research
The Alfred Wegener Institute for Polar and Marine Research (Alfred-Wegener-Institut, AWI) is a German institute in Bremerhaven that coordinates German polar research, founded in 1980.
Alkenone paleothermometry
Alkenone paleothermometry is a method for reconstructing past sea surface temperature from alkenone compounds produced by haptophyte algae, introduced in 1986 and applied worldwide to Quaternary and older sediments.
Alternative stable states
Alternative stable states are distinct self-maintaining ecosystem configurations possible under identical environmental conditions, an idea from the 1960s with shallow lakes as the classic example.
Anammox
Anammox, short for anaerobic ammonium oxidation, is a microbial process in which bacteria convert ammonium and nitrite into nitrogen gas, discovered in 1995 and now used to treat wastewater.
Anatoxin-a
Anatoxin-a (ATX-a) is a potent neurotoxic bicyclic amine alkaloid produced by freshwater cyanobacteria, which acts on the nicotinic acetylcholine receptor and can cause neurological disorders and death.
Annual exceedance probability
Annual exceedance probability is the probability, expressed as a percentage, that a flood or rainfall event of a given magnitude will be equaled or exceeded in any given year.
Anoxic waters
Anoxic waters, also called anoxic sea water, are bodies of water lacking dissolved oxygen, occurring naturally in basins like the Black Sea and increasingly in coastal waters receiving nutrient pollution.
Antarctic Bottom Water
Antarctic Bottom Water (AABW) is the coldest, densest water mass in the ocean, forming around Antarctica's margins and spreading north to fill much of the deep ocean.