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58-504: This type of cave was first formally described by Englishman Edwin Swift Balch in 1900, who suggested the French term glacieres should be used for them, even though the term ice cave was then, as now, commonly used to refer to caves simply containing year-round ice. Among speleologists , ice cave is the proper English term. A cavity formed within ice (as in a glacier) is properly called

116-867: A glacier cave . Ice caves occur as static ice caves, such as Peña Castil Ice Cave, and dynamic or cyclical ice caves, such as Eisriesenwelt . In most of the world, bedrock caves are thermally insulated from the surface and so commonly assume a near-constant temperature approximating the annual average temperature at the surface. In some cold environments, such as that surrounding Mount Erebus , average surface (and thus cave) temperatures are below freezing, and with surface water available in summer, ice caves are possible and are sometimes overlain by fumarolic ice towers . However, many ice caves exist in temperate climates, due to mechanisms that result in cave temperatures being colder than average surface temperatures where they formed. Cold traps : Certain cave configurations allow seasonal convection to import cold air from

174-420: A phase change directly from water vapor (a gas ) to ice (a solid). As more water molecules are added to the seeds, crystal growth occurs, forming ice crystals . Crystals may vary in size and shape, from an even layer of numerous microscopic-seeds to fewer but much larger crystals, ranging from long dendritic crystals (tree-like) growing across a surface, acicular crystals (needle-like) growing outward from

232-467: A "hard frost" below −2 °C (28 °F). Plants likely to be damaged even by a light frost include vines—such as beans, grapes, squashes, melons—along with nightshades such as tomatoes, eggplants, and peppers. Plants that may tolerate (or even benefit from) frosts include: Even those plants that tolerate frost may be damaged once temperatures drop even lower (below −4 °C or 25 °F). Hardy perennials, such as Hosta , become dormant after

290-400: A cave. Cave maps, called surveys , can be used to compare caves to each other by length, depth and volume, may reveal clues on speleogenesis , provide a spatial reference for further scientific study, and assist visitors with route-finding. Caves provide a home for many unique biota. Cave ecologies are very diverse, and not sharply distinct from surface habitats. Generally however, the deeper

348-438: A glass pane is exposed to very cold air on the outside and warmer, moderately moist air on the inside. If the pane is a bad insulator (for example, if it is a single-pane window), water vapour condenses on the glass, forming frost patterns. With very low temperatures outside, frost can appear on the bottom of the window even with double-pane energy-efficient windows because the air convection between two panes of glass ensures that

406-475: A heavy coating of hoar frost with big, interlocking crystals, usually needle-shaped. Rime is a type of ice deposition that occurs quickly, often under heavily humid and windy conditions. Technically speaking, it is not a type of frost, since usually supercooled water drops are involved, in contrast to the formation of hoar frost, in which water vapour desublimates slowly and directly. Ships travelling through Arctic seas may accumulate large quantities of rime on

464-421: A moisture-saturated cave may have an additional cooling effect due to the latent heat of evaporation . This may create a zone within the cave that is cooler than the rest of the cave. Because many caves have seasonally-reversing draughts, the corresponding warming of the cave through condensation in summer may occur at a different location within the cave, but in any event a moisture-saturated cave environment

522-600: A plant becomes tolerant to low temperatures. See also Cryobiology . Certain bacteria , notably Pseudomonas syringae , are particularly effective at triggering frost formation, raising the nucleation temperature to about −2 °C (28 °F). Bacteria lacking ice nucleation-active proteins ( ice-minus bacteria ) result in greatly reduced frost damage. Typical measures to prevent frost or reduce its severity include one or more of: Such measures need to be applied with discretion, because they may do more harm than good; for example, spraying crops with water can cause damage if

580-479: A process similar to the formation of dust bunnies and similar structures. Hoar frost and white frost also occur in man-made environments such as in freezers or industrial cold-storage facilities. If such cold spaces or the pipes serving them are not well insulated and are exposed to ambient humidity, the moisture will freeze instantly depending on the freezer temperature. The frost may coat pipes thickly, partly insulating them, but such inefficient insulation still

638-402: A sinkhole, frogs swept into a cave by a flash flood, etc. The two factors that limit cave ecologies are generally energy and nutrients. To some degree moisture is always available in actively forming Karst caves. Cut off from the sunlight and steady deposition of plant detritus, caves are poor habitats in comparison with wet areas on the surface. Most of the energy in cave environments comes from

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696-416: A specific temperature, its relative humidity rises above 100% becoming supersaturated , and the excess water vapor is forced to deposit onto any nearby surface, forming seed crystals . The temperature at which frost will form is called the dew point , and depends on the humidity of the air. When the temperature of the air drops below its dew point, excess water vapor is forced out of solution, resulting in

754-520: Is a consequence of the nucleation process being constrained to unfold in two dimensions, unlike a snowflake, which is shaped by a similar process, but forms in three dimensions and has a fractal dimension greater than two. If the indoor air is very humid, rather than moderately so, water first condenses in small droplets, and then freezes into clear ice . Similar patterns of freezing may occur on other smooth vertical surfaces, but they seldom are as obvious or spectacular as on clear glass. White frost

812-431: Is a solid deposition of ice that forms directly from water vapour contained in air. White frost forms when relative humidity is above 90% and the temperature below −8 °C (18 °F), and it grows against the wind direction, since air arriving from windward has a higher humidity than leeward air, but the wind must not be strong, else it damages the delicate icy structures as they begin to form. White frost resembles

870-413: Is a source of heat loss. Advection frost (also called wind frost ) refers to tiny ice spikes that form when very cold wind is blowing over tree branches, poles, and other surfaces. It looks like rimming on the edges of flowers and leaves, and usually forms against the direction of the wind . It can occur at any hour, day or night. Window frost (also called fern frost or ice flowers ) forms when

928-406: Is called "killing frost" because white frost tends to be less cold, partly because the latent heat of freezing of the water reduces the temperature drop. Many plants can be damaged or killed by freezing temperatures or frost. This varies with the type of plant, the tissue exposed, and how low temperatures get; a "light frost" of −2 to 0 °C (28 to 32 °F) damages fewer types of plants than

986-524: Is cooler than the cave air. Some cold traps may ensnare surface snow and shade it from the summer sun ’s rays , which may further contribute to the colder cave temperature. Permafrost : Even temperate environments can include pockets of bedrock that are below freezing year round, a condition called permafrost . For example, winter wind and an absence of snow cover may allow freezing deep enough to be protected from summer thaw, particularly in light-colored rock that does not readily absorb heat. Although

1044-633: Is due partly to differences of elevation, the lower areas becoming colder on calm nights. Where static air settles above an area of ground in the absence of wind, the absorptivity and specific heat of the ground strongly influence the temperature that the trapped air attains. Hoar frost , also hoarfrost , radiation frost , or pruina , refers to white ice crystals deposited on the ground or loosely attached to exposed objects, such as wires or leaves. They form on cold, clear nights when conditions are such that heat radiates into outer space faster than it can be replaced from nearby warm objects or brought in by

1102-426: Is highly favorable for the growth of microbes . Microbial assemblages in caves include archaea , bacteria , fungi and other micro- eukaryotes , these highly adapted microbial communities represent the living-backbone of cave ecosystems and play a key role in shaping structures and sustaining trophic networks. The creation of an accurate, detailed map is one of the most common technical activities undertaken within

1160-551: Is likely to experience much more evaporative cooling than condensative warming. Different freezing mechanisms result in visually and structurally distinct types of perennial cave ice. Ponded water : Surface water that collects and ponds in a cave before freezing will form a clear ice mass, and can be tens of metres thick and of great age. Large ice masses are plastic and can slowly flow in response to gravity or pressure from further accumulations. Sculpting from air flow and sublimation may reveal ancient accumulation bands within

1218-411: Is not necessarily damaged when leaf temperatures drop below the freezing point of their cell contents. In the absence of a site nucleating the formation of ice crystals, the leaves remain in a supercooled liquid state, safely reaching temperatures of −4 to −12 °C (25 to 10 °F). However, once frost forms, the leaf cells may be damaged by sharp ice crystals. Hardening is the process by which

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1276-543: Is personified in Russian culture as Ded Moroz . Indigenous peoples of Russia such as the Mordvins have their own traditions of frost deities. English folklore tradition holds that Jack Frost , an elfish creature, is responsible for feathery patterns of frost found on windows on cold mornings. In 2024, two European Space Agency spacecraft, Exomars TGO and Mars Express , discovered a thin but very wide layer of water frost on

1334-521: Is the scientific study of caves and other karst features, as well as their composition , structure, physical properties , history, ecology , and the processes by which they form ( speleogenesis ) and change over time (speleomorphology). The term speleology is also sometimes applied to the recreational activity of exploring caves, but this is more properly known as caving , potholing (British English), or spelunking (United States and Canadian English). Speleology and caving are often connected, as

1392-527: The contiguous United States , southern Florida around Miami Beach and the Florida Keys are the only reliably frost-free areas, as well as the Channel Islands off the coast of California . The hardiness zones in these regions are 11a and 11b. Permafrost is a layer of frozen earth underground which never heats above freezing even during summer months, remaining frozen year round. Although not frost in

1450-418: The liquid phase . The air must be humid, but not sufficiently humid to permit the condensation of liquid water, or icing will result instead of desublimation. The size of the crystals depends largely on the temperature, the amount of water vapor available, and how long they have been growing undisturbed. As a rule, except in conditions where supercooled droplets are present in the air, frost will form only if

1508-533: The Earth to reach deep enough to thaw the permafrost layer. The permafrost may begin from the surface of the ground or many meters beneath it, and may extend from just a meter to over a thousand meters in thickness. Permafrost contains a significant portion of the Earth's water and carbon, and prevents surface water from penetrating very deep into the ground, making it responsible in part for the typical taiga and spruce bog environments common in northern latitudes. Frost

1566-426: The air contains more water vapor than it can normally hold at a specific temperature. The process is similar to the formation of dew , except it occurs below the freezing point of water typically without crossing through a liquid state. Air always contains a certain amount of water vapor, depending on temperature. Warmer air can hold more than colder air. When the atmosphere contains more water than it can hold at

1624-424: The air is very cold, calm, and heavily saturated, such as during an ice fog . Frost may occur when warm, moist air comes into contact with a cold surface, cooling it below its dew point, such as warm breath on a freezing window. In the atmosphere, it more often occurs when both the air and the surface are below freezing, when the air experiences a drop in temperature bringing it below its dew point, for example, when

1682-462: The air temperature a few feet above ground is well above freezing. The word "hoar" comes from an Old English adjective that means "showing signs of old age". In this context, it refers to the frost that makes trees and bushes look like white hair. Hoar frost may have different names depending on where it forms: When surface hoar covers sloping snowbanks, the layer of frost crystals may create an avalanche risk; when heavy layers of new snow cover

1740-461: The atmospheric sense, it consists of dirt, soil, sand, rocks, clay, or organic matter (peat) bound firmly together by ice crystals, making the material very hard and difficult to penetrate. Permafrost exists in the colder climates of the Arctic and Antarctic, such as Russia, Canada, Alaska, Norway, Greenland, or Antarctica, where the warmer conditions of summer are insufficient to penetrate the insulation of

1798-399: The bottom part of the glazing unit is colder than the top part. On unheated motor vehicles, the frost usually forms on the outside surface of the glass first. The glass surface influences the shape of crystals, so imperfections, scratches, or dust can modify the way ice nucleates . The patterns in window frost form a fractal with a fractal dimension greater than one, but less than two. This

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1856-418: The cave becomes, the more rarefied the ecology. Cave environments fall into three general categories: Cave organisms fall into three basic classes: There are also so-called accidental trogloxenes which are surface organisms that enter caves for no survival reason. Some may even be troglophobes (“cave haters”), which cannot survive in caves for any extended period. Examples include deer which fell through

1914-616: The cave walls and ceiling. Needle ice : Infiltrating water that freezes within the bedrock can sometimes be forced into the cave passage. Intrusions : The weight of a surface glacier perched atop a cave entrance can force glacial ice a short distance into the cave. The only known examples of this phenomenon are the several 'ice plugs' at the back of Castleguard Cave in Alberta . Speleologist Speleology (from Ancient Greek σπήλαιον ( spḗlaion )  'cave' and -λογία ( -logía )  'study of')

1972-564: The concept of speleology as a distinct area of study. In 1895 Martel founded the Société de Spéléologie , the first organization devoted to cave science in the world. Other early speleologists include Herbert E. Balch . An international speleological congress was proposed at a meeting in Valence-sur-Rhone , France in 1949 and first held in 1953 in Paris . The International Union of Speleology (UIS)

2030-652: The decomposition of the materials can happen as well. A speleothem is a geological formation by mineral deposits that accumulate over time in natural caves . Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending on their depositional history and environment. Their chemical composition, gradual growth, and preservation in caves make them useful paleoclimatic proxies. Caves have an absence of stable temperature , high relative humidity , low rates of evaporation and limited supply of organic material , which help in creating an environment which

2088-452: The deposition surface is colder than the surrounding air. For instance, frost may be observed around cracks in cold wooden sidewalks when humid air escapes from the warmer ground beneath. Other objects on which frost commonly forms are those with low specific heat or high thermal emissivity , such as blackened metals, hence the accumulation of frost on the heads of rusty nails. The apparently erratic occurrence of frost in adjacent localities

2146-526: The disasters that can devastate or destroy underground biological communities. Speleologists also work with archaeologists in studying underground ruins, tunnels, sewers and aqueducts, such as the various inlets and outlets of the Cloaca Maxima in Rome . Frost Frost is a thin layer of ice on a solid surface, which forms from water vapor that deposits onto a freezing surface. Frost forms when

2204-407: The first frosts and regrow when spring arrives. The entire visible plant may turn completely brown until the spring warmth, or may drop all of its leaves and flowers, leaving the stem and stalk only. Evergreen plants, such as pine trees, withstand frost although all or most growth stops. Frost crack is a bark defect caused by a combination of low temperatures and heat from the winter sun. Vegetation

2262-414: The frosty surface, furry crystals standing out from the old snow hold off the falling flakes, forming a layer of voids that prevents the new snow layers from bonding strongly to the old snow beneath. Ideal conditions for hoarfrost to form on snow are cold, clear nights, with very light, cold air currents conveying humidity at the right rate for growth of frost crystals. Wind that is too strong or warm destroys

2320-405: The furry crystals, and thereby may permit a stronger bond between the old and new snow layers. However, if the winds are strong enough and cold enough to lay the crystals flat and dry, carpeting the snow with cold, loose crystals without removing or destroying them or letting them warm up and become sticky, then the frost interface between the snow layers may still present an avalanche danger, because

2378-506: The ice. Accumulated snow : Compressed under the weight of ongoing accumulations, snow sliding or falling into a cave entrance may eventually form ice that is coarsely crystalline, akin to glacier ice. True underground glaciers are rare. Ice formations : Water that freezes before ponding may form icicles , ice- stalagmites , ice columns or frozen waterfalls . Airborne moisture (water vapor) : Freezing vapor can form frost crystals, frost feathers and two-dimensional ice plates on

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2436-523: The lowland tropics, where they cover almost all land except at altitudes above about 3,000 metres or 9,800 feet near the equator and around 2,000 metres or 6,600 feet in the semiarid areas in tropical regions. Some areas on the oceanic margins of the subtropics are also frost-free, as are highly oceanic areas near windward coasts. The most poleward frost-free areas are the lower altitudes of the Azores , Île Amsterdam , Île Saint-Paul , and Tristan da Cunha . In

2494-416: The physical skills required for in situ study are the same. Speleology is a cross-disciplinary field that combines the knowledge of chemistry , biology , geology , physics , meteorology , and cartography to develop portraits of caves as complex, evolving systems. Before modern speleology developed, John Beaumont wrote detailed descriptions of some Mendip caves in the 1680s. The term speleology

2552-466: The plants become overburdened with ice. An effective, low cost method for small crop farms and plant nurseries, exploits the latent heat of freezing . A pulsed irrigation timer delivers water through existing overhead sprinklers at a low volumes to combat frosts down to −5 °C (23 °F). If the water freezes, it gives off its latent heat, preventing the temperature of the foliage from falling much below zero. Frost-free areas are found mainly in

2610-440: The portion of a cave within this permafrost zone will be below freezing, permafrost generally does not allow water percolation , so ice formations are often limited to crystals from vapor , and deeper cave passages may be arid and completely ice-free. Ice caves in permafrost need not be cold-traps (although some are), provided they do not draught significantly in summer. Evaporative cooling : In winter, dry surface air entering

2668-811: The result of fractal process development. The depth of frost crystals varies depending on the amount of time they have been accumulating, and the concentration of the water vapor ( humidity ). Frost crystals may be invisible (black), clear ( translucent ), or, if a mass of frost crystals scatters light in all directions, the coating of frost appears white. Types of frost include crystalline frost ( hoar frost or radiation frost) from deposition of water vapor from air of low humidity, white frost in humid conditions, window frost on glass surfaces, advection frost from cold wind over cold surfaces, black frost without visible ice at low temperatures and very low humidity, and rime under supercooled wet conditions. Plants that have evolved in warmer climates suffer damage when

2726-411: The rigging. Unlike hoar frost, which has a feathery appearance, rime generally has an icy, solid appearance. Black frost (or "killing frost") is not strictly speaking frost at all, because it is the condition seen in crops when the humidity is too low for frost to form, but the temperature falls so low that plant tissues freeze and die, becoming blackened, hence the term "black frost". Black frost often

2784-432: The solid surface on which they grow. The main difference between the ice coatings and frost spicules arises because the crystalline spicules grow directly from desublimation of water vapour from air, and desublimation is not a factor in icing of freezing surfaces. For desublimation to proceed, the surface must be below the frost point of the air, meaning that it is sufficiently cold for ice to form without passing through

2842-403: The surface in winter, but not warm air in summer. A typical example is an underground chamber located below a single entrance. In winter, cold dense air settles into the cave, displacing any warmer air which rises and exits the cave. In summer, the cold cave air remains in place as the relatively warm surface air is lighter and cannot enter. The cave will only exchange air when the surface air

2900-407: The surface itself is colder than freezing, ice will form on it. If the water deposits as a liquid that then freezes, it forms a coating that may look glassy, opaque, or crystalline, depending on its type. Depending on context, that process may also be called atmospheric icing . The ice it produces differs in some ways from crystalline frost, which consists of spicules of ice that typically project from

2958-432: The surface, snowflake-shaped crystals, or even large, knifelike blades of ice covering an object, which depends on many factors such as temperature, air pressure, air motion and turbulence, surface roughness and wettability , and the level of supersaturation. For example, water vapor adsorbs to glass very well, so automobile windows will often frost before the paint, and large hoar-frost crystals can grow very rapidly when

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3016-419: The surplus of the ecosystems outside. One major source of energy and nutrients in caves is dung from trogloxenes, most of which is deposited by bats. Other sources are mentioned above. Cave ecosystems are very fragile. Because of their rarity and position in the ecosystem they are threatened by a large number of human activities. Dam construction, limestone quarrying, water pollution and logging are just some of

3074-523: The temperature falls after the Sun sets. In temperate climates , it most commonly appears on surfaces near the ground as fragile white crystals ; in cold climates, it occurs in a greater variety of forms. The propagation of crystal formation occurs by the process of nucleation , in specific, water nucleation , which is the same phenomenon responsible for the formation of clouds, fog, snow, rain and other meteorological phenomena. The ice crystals of frost form as

3132-421: The temperature falls low enough to freeze the water in the cells that make up the plant tissue . The tissue damage resulting from this process is known as "frost damage". Farmers in those regions where frost damage has been known to affect their crops often invest in substantial means to protect their crops from such damage. If a solid surface is chilled below the dew point of the surrounding humid air, and

3190-489: The texture of the frost crystals differs from the snow texture, and the dry crystals will not stick to fresh snow. Such conditions still prevent a strong bond between the snow layers. In very low temperatures where fluffy surface hoar crystals form without subsequently being covered with snow, strong winds may break them off, forming a dust of ice particles and blowing them over the surface. The ice dust then may form yukimarimo , as has been observed in parts of Antarctica, in

3248-428: The wind. Under suitable circumstances, objects cool to below the frost point of the surrounding air, well below the freezing point of water. Such freezing may be promoted by effects such as flood frost or frost pocket . These occur when ground-level radiation cools air until it flows downhill and accumulates in pockets of very cold air in valleys and hollows. Hoar frost may freeze in such low-lying cold air even when

3306-559: Was coined by Émile Rivière in 1890. Prior to the mid-nineteenth century the scientific value of caves was considered only in its contribution to other branches of science, and cave studies were considered part of the larger disciplines of geography , geology or archaeology . Very little cave-specific study was undertaken prior to the work of Édouard-Alfred Martel (1859–1938), the 'father of modern speleology', who through his extensive and well-publicised cave explorations introduced in France

3364-608: Was founded in 1965. The growth of speleology is directly linked with that of the sport of caving , both because of the stimulation of public interest and awareness, and the fact that most speleological field-work has been conducted by sport cavers . Karst is a landscape that has limestone underneath which has been eroded. Caves are usually formed through chemical corrosion via a process of dissolution . Corrosion has several ways of doing this, it can be on carbonate rocks through chemical reactions, in gypsum and rock salt it can happen physically, and in silicate rocks and warm climate

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