Limnology

Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.

continuous movement of water on, above and below the surface of the Earth

thumb|250px|A bog in Lauhanvuori National Park, [[Isojoki, Finland]] thumb|250px|Peat bog and peat to dry, L'Isle-aux-Coudres#Geography|L'Isle-aux-Coudres, [[Quebec, Canada, 1976]] thumb|Bog in Antwerp Province, Belgium thumb|Bog in the Seliger Lake area, Tver Oblast, Russia thumb|Peat extraction in East Frisia, Germany thumb|Drone video of Kakerdaja bog in Estonia (September 2021) thumb|A raised bog in [[Ķemeri National Park, Jūrmala, Latvia, formed approximately 10,000 years ago in the postglacial period and now a tourist attraction.]] A bog or bogland is a wetland that accumulates peat as

upright=1.2|thumb|A stream bed following a tilted valley. The maximum gradient is along the down-valley axis represented by a hypothetical straight coast channel. Meanders develop, which lengthen the course of the stream, decreasing the gradient. thumb|Meanders of the Cauto River|Rio Cauto at [[Guamo Embarcadero, Cuba]] thumb|The Jordan River, near the [[Dead Sea, 1937]]

thumb|upright=1.3|Lake Hāwea, New Zealand

thumb|Reflection (physics)|Reflections in a forest puddle

thumb|Rapids of Kern River, [[California, USA.]] Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence. Flow, gradient, constriction, and obstacles are four factors that are needed for a rapid to be created.

part of a sea, lake or river that is close to the shore

channel bottom of a stream, river, or creek

thumb|Graph showing a tropical ocean thermocline (depth vs. temperature). Note the rapid change between 100 and 1000 meters. The temperature is nearly constant after 1500 meters depth.

A seiche ( ) is a standing wave in an enclosed or partially enclosed body of water. Seiches and seiche-related phenomena have been observed on lakes, reservoirs, swimming pools, bays, harbors, caves, and seas. The key requirement for formation of a seiche is that the body of water be at least partially bounded, allowing the formation of the standing wave.

thumb|right|300px| Cyanobacterial Microbial mat|mat dominated by [[Anabaena sp. (heterocystous) in the Mayotte lagoon at 14 m depth. These cyanobacteria fix nitrogen and influence redox conditions, contributing to biogeochemical cycling in marine environments.]]

overview about physical and chemical properties of pure water

thumb|upright=1.3|Avaste Nature Reserve|Avaste Fen, Estonia. Sedges dominate the landscape. Woody shrubs and trees are sparse. thumb|upright=1.3|Wicken Fen, England. Grasses in the foreground are typical of a fen.

fish that live all or much of their lives in freshwater

measure of the amount of oxygen that can be consumed by reactions in a solution

in geography, area between high and low tide marks of water bodies (both still and moving), or a raised landform on the side of a water body

pattern formed by the streams, rivers, and lakes in a particular drainage basin

thumb|Lakes are stratified into three separate sections: I. The Epilimnion II. The Thermocline|Metalimnion III. The [[Hypolimnion The scales are used to associate each section of the stratification to their corresponding depths and temperatures. The arrow is used to show the movement of wind over the surface of the water which initiates the turnover in the epilimnion and the hypolimnion.]]

alt=Walrus |thumb|upright=1.5 |Sediment on the left tusk of a walrus. Walrus bioturbations in Arctic benthic sediments have large-scale ecosystem effects.

300px|thumb|Lakes are stratified into three separate sections: I. The Epilimnion II. The Metalimnion III. The Hypolimnion The scales are used to associate each section of the stratification to their corresponding depths and temperatures. The arrow is used to show the movement of wind over the surface of the water which initiates the turnover in the epilimnion and the hypolimnion.

Baseflow (also called drought flow, groundwater recession flow, low flow, low-water flow, low-water discharge and sustained or fair-weather runoff) is the portion of the streamflow that is sustained between precipitation events, fed to streams by delayed pathways. It should not be confused with groundwater flow. Fair weather flow is also called base flow.

low environmental oxygen levels

separation of water in a lake into distinct layers

subset of Earth's aquatic ecosystems

lake that contains high amounts of humic substances and organic acids

surface slope along a stream

Paleolimnology (from Greek: παλαιός, palaios, "ancient", λίμνη, limne, "lake", and λόγος, logos, "study") is a scientific sub-discipline closely related to both limnology and paleoecology. Paleolimnological studies focus on reconstructing the past environments of inland waters (e.g., lakes and streams) using the geologic record, especially with regard to events such as climatic change, eutrophication, acidification, and internal ontogenic processes.

lake that has consistently carried water for more than 1 million years

An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates of metabolism, and generally low population density. Oligotrophic environments are those that offer little to sustain life. These environments include deep oceanic sediments, caves, glacial and polar ice, deep subsurface soil, aquifers, ocean waters, and leached soils.

Seston (from ) refers to the particles suspended in bodies of water, such as oceans, lakes, and rivers. Small particles of seston may be formed by the breaking down of larger particles amidst the crashing of waves, mixing of water currents, or slow disintegration. The organic constituents of seston include plankton and detritus from decomposing organisms; the inorganic components of seston are of mineral origin, essentially particles of mud suspended in the water column.

A chemocline is a type of cline, a layer of fluid with different properties, characterized by a strong, vertical chemistry gradient within a body of water. In bodies of water where chemoclines occur, the cline separates the upper and lower layers, resulting in different properties for those layers. The lower layer shows a change in the concentration of dissolved gases and solids compared to the upper layer.

type of aquatic ecosystem with flowing freshwater

thumb|Carbon dioxide molecule. '''pCO2, pCO2', or P_\ce{CO2} is the partial pressure of carbon dioxide (CO2), often used in reference to blood but also used in meteorology, climate science, oceanography, and limnology to describe the fractional pressure of CO2 as a function of its concentration in gas or dissolved phases. The units of p''CO2 are mmHg, atm, torr, Pa, or any other standard unit of atmospheric pressure.

depositional feature of alluvium that accumulates on the inside bend of streams and rivers below the slip-off slope

oceanography instrument used to measure the conductivity, temperature, and pressure of seawater

thumb|upright=1.2|right|Asphalt and sandbag revetment with a geotextile filter

lakes that are above 5,000 feet altitude

gastropod mollusks which live in fresh water

thumb|upright=1.5|

outside bank of a water channel, which is continually undergoing erosion

thumb|upright=1.2|Cyanobacteria|Filamentous cyanobacteria growing on an underwater surface

device used to assess water quality

dead or dying tree that is still standing

trophy index based on the amount of biological productivity

Graph of concentrations of different species of a polyprotic acid, as a function of pH, when the solution is at equilibrium

landform in a river

upright=1.2|thumb|Mute swan (Cygnus olor) in a hydrosere community at sunrise. A hydrosere is a plant succession which occurs in an area of fresh water such as in oxbow lakes and kettle lakes. In time, an area of open freshwater will naturally dry out, ultimately becoming woodland. During this change, a range of different landtypes such as swamp and marsh will succeed each other.

river that runs through mountains, in a narrow, deep valley with steep banks, rocky stream bed, and accumulated rock debris

microbial process

mix of river discharge and seawater

American scientific society

scientific society

Number quantifying branching in rivers