tombolo a sand bar connecting an island to the mainland or two islands together.
train a series of waves of the same or nearly the same size.
trough the depression or hollow between waves.
wrack any marine vegetation washed to shore; also, the wreckage of a ship cast ashore.
CAVES
angel's hair the delicate needles of gypsum found growing in some caves.
breakdown a pile of rocks in a passage resulting from the collapse of a wall or ceiling.
breathing cave a cave passage in which airstreams can be felt moving in two different directions, as in respiration.
calcite calcium carbonate mineral, frequently white and mixing with water and other minerals to form stalactites, stalagmites, and other cave encrustations.
canyon any cave passage that is at least twice as high as it is wide.
cave pearl a flowerlike mineral formation made largely of calcite; also known as a pisolith.
caver a spelunker.
ceiling pocket a small dome formation on the ceiling of a cave.
chimney a narrow, vertical shaft. Also, the term used to describe the method of climbing a vertical shaft.
claustrophobia the fear of enclosed places.
column formation created by the joining of a stalactite with a stalagmite.
conduit a subterranean passage through which water flows or has flowed in the past.
crawl speleological term for any crawl space.
crouchway any passage that can be gotten through only by crouching or stooping.
dome a large, oval opening in the ceiling of a cave passage, closed at the top.
domepit a circular shaft in the floor of a cave, usually consisting of limestone or other soluble rock that has worn away.
dripstone collective term for any stalactite, stalagmite, or other formation created by dripping water and minerals.
flowstone calcium carbonate deposit forming sheets, drapery, and coatings over rocks.
fluting vertical striations in cave walls.
gallery a large chamber or hall.
glaciere a cave in a glacier.
glaciospeleology the study of glacier caves.
gour a small basin or pool of clear water edged with calcite encrustations.
grape a calcium carbonate deposit with the appearance of a grape or tea, encrusted on a cave wall.
gypsum a white or colorless mineral deposited in caves as calcium sulfate and forming flowers, needles, cotton balls, and other shapes.
karst an area of land characterized by numerous sinkholes and caves, formed by eroded limestone.
knee crawler knee pad used by spelunkers in crawl spaces.
lava tube cave a conduit or passage through which lava once flowed.
limestone sedimentary rock consisting largely of calcium carbonate. Most caves are limestone formations carved out by water.
master cave the main or largest cave in a group.
moon milk a white, puttylike form of flowstone.
pinched out a narrowing passage that becomes impenetrable. Also known as a pinch.
pitch a vertical shaft.
ponor the point where a stream disappears under a shelf of rock.
pothole any cave system where vertical shafts predominate.
sink a rounded depression often containing water.
sinkhole a hole, depression, or basin formed on the surface of karst land through which water drains underground.
sinkhole entrance access to a cave through a sinkhole.
soda straw a tiny stalactite in the shape of a soda straw.
speleology the study of caves.
spelunker one who studies or explores caves.
stalactite a long, tapering formation hanging from the roof of caves, formed by dripping water, calcium carbonate, and other minerals.
stalagmite conical calcium carbonate formation standing on the floor of caves; the counterpart of a stalactite.
sump an underwater passage in a cave; also known as a syphon.
troglobite any animal specially adapted to live in caves.
troglodyte a caveman.
troglophile any animal who inhabits a cave but may not be specially adapted to live there, such as a bat.
CLOUDS
altocumulus elliptical globular masses, forming individually, in groups, or in bands between 6,500 and 23,000 feet; also known as sheep or woolpack clouds.
altostratus bluish or grayish white sheets covering most or all of the sky between 6,500 and 23,000 feet.
anvil the flat top of a spreading cumulonimbus cloud, which resembles an anvil.
arcus any low, horizontal cloud seen at the leading edge of a thunderstorm, but particularly a roll or shelf cloud.
banner cloud a stationary, bannerlike plume seen frequently over the lee side of a mountain.
barber pole slang for any curving cloud striation, resembling the stripes on a barber pole, caused by updrafting in a thunderstorm.
ceiling the height of the lowest clouds.
cirriform thin, wispy clouds appearing at high altitude.
cirrocumulus rippled or banded clouds, often referred to as a "mackerel sky," forming between 16,000 and 45,000 feet.
cirrostratus high, thin, white veils covering all or most of the sky between 16,000 and 45,000 feet.
cirrus detached, feather or tufted clouds forming between 16,000 and 45,000 feet; also known as mares's tails.
clinometer device used to measure the height of clouds.
cloud seeding a technique in which various chemicals, especially silver iodide and dry ice, are dispersed into clouds via aircraft or rockets in an attempt to produce precipitation.
cloud tag cloud fragment. Also known as scud, fractus.
congestus a towering, cauliflower-like cumulus cloud.
contrails vapor trails left by aircraft.
cumuliform any mound or dome-shaped cloud or one that towers.
cumulonimbus towering clouds arising from cumulus 2 to 5 miles in height, yielding rain and sometimes thunderstorms. The thunderstorm cloud itself is called a thunderhead.
cumulus individual cloud masses vertically domed with a cauliflower-like appearance; associated with fair weather.
debris cloud at the base of a tornado, a rotating cloud of dust and debris.
eye wall the cloud band immediately surrounding a hurricane, the most intense area of the storm.
fractocumulus a ragged-looking cumulus cloud.
fractus any broken-off cloud fragment. Also known as scud.
funnel cloud a funnel-shaped cloud descending from a cumulus or cumulonimbus cloud, technically becoming a tornado only when debris and dust can be seen churning below it at ground level.
halo apparent circle around the sun or moon, caused by the refraction of sunlight by ice crystals in high, thin cirrus or cirrostratus clouds.
incus the anvil-shaped top of a thunderhead.
mammatocumulus cloud with extreme billowing or boiling appearance, accompanying severe thunderstorms and tornado conditions.