bedrock - General term for the underlying rock layer in a region.
benthic - Benthic organism live at the bottom of a body of water such
as sea, river, lake etc. These organisms are sometimes referred to
collectively as the "benthos".
bergschrund - The crevasse formed where
a glacier meets the solid rock of a mountain slope, usually very wide and the
widest crevasse on the glacier.
beset - The situation of a ship when
closely surrounded by ice on all sides.
biota - All of the living organisms of an ecosystem or an area, plants,
animals, bacteria, fungi etc.
black ice - Newly-formed iced over sea water. It
is thin enough for the dark water to be visible through it and can be
crossed only at speed by a light sledge.
blizzard - A cold storm with winds of at least 56 kilometres per hour
(35 miles per hour) and temperatures below - 6.7°C (20°F). Usually also
characterized by poor visibility due to snow blowing around. Little snow may
actually fall during a blizzard, the high winds pick up snow from the ground
and carry it around, visibility is often greatly reduced.
brash ice - Ice rubble, loose pieces of
ice of various sizes from gravel sized to table sized. Originates from sea-ice
that is breaking up or commonly as debris from calving ice bergs or ice bergs
that break up as part of their ongoing erosion. Whenever one large piece of
ice falls off another, brash is also generated and can cover quite large
amounts of sea. There were times in Antarctica when we would gather brash ice
that had blown into the cove where our base was to melt down and use as fresh
water. The ice usually came from ice bergs that had broken up off shore, with
the wind blowing it into the cove.
breakable crust - A dreadful surface
over which to travel. A layer of snow that has hardened on top and sunk below.
Walking across such an area means that you lift your foot and place it as for
a normal step, but just a few inches higher, it takes most of your weight, but
as you lift your weight onto it, at the last second the crust breaks and
you're standing there with both feet a few inches below the surface crust. As
much effort as walking up stairs just to stay on the level, going up hill is
doubly hard.
C
calve - The formation of an iceberg from a
glacier. Once the ice flowing from a glacier reaches a body of water it begins
to float and may crack at the "hinge zone", once free of the glacier
a piece of ice becomes an iceberg and the glacier has calved.
cirrus clouds - Thin, wispy high
altitude clouds that form at heights of 6 to 12 kilometres (3.8 to 7.6 miles).
climatology - The study of weather conditions over long periods of
time.
commensal - Plants and / or animals living together and gaining benefit
from the relationship. Generally a fairly loose bond and not as intimate as a
symbiotic relationship.
congelation ice - A type of sea ice that forms
underneath frazil ice.
continental shelf - The region in the ocean around a continent between
the shoreline and the continental slope. An area of shallow water where the
depth is usually less than 200 meters (650 feet). In Antarctica however, the
continental shelf averages 500 meters in depth (1640 feet)! The continental
shelf has formed by slow deposition of sediment eroded from the continent and
has a gentle slope (around 1°).
continental slope - Narrow, steep (3° to 6° slope) transition zone
between the shallow shelf and the deep ocean floor.
Coriolis effect - moving objects appear
to deflect from their anticipated straight-line course. Coriolis effect is a
result of the rotation Earth (and an observer's position on it). Responsible
for the fact that water spirals down a plug-hole rather than going straight
and the direction is different in each hemisphere. Only at the equator does
water go straight down.
crevasse - A deep, usually vertical,
crack or split in a glacier, occurs as a result of the brittle ice flowing
over a uneven surface beneath the ice. Crevasses can easily become covered by
blown snow, even very wide ones. Great care must be taken when crossing ice
and snow fields to avoid them.
cryosphere - That portion of Earth's surface that is permanently frozen
through the year.
cyanobacteria - Very specialized acellular organisms classified as
blue-green algae. Cyanobacteria can photosynthesize, making their own food
from sunlight. They are exceptionally tough organisms, able to colonize and
survive in harsh environments.
D
desert - An area where there is little moisture due to there being
little precipitation is low and evaporation is high. Precipitation usually is
less than 25 centimetres a year (10 inches). Large deserts include the Sahara
Desert in Northern Africa or the continent of Antarctica.
diatoms - Single celled planktonic algae with external skeleton made of
silica. The skeletons, or tests, of dead diatoms sink to the sea floor and
accumulate in the sediment. If sufficient quantities of skeletal material
accumulate, a diatomaceous mud (10% diatoms) or diatomaceous ooze (>30%
diatoms) results. The chlorophyll from the diatoms may give it greenish tinge.
diversity - The variety of different
characteristics, features or organisms. The variety of species in a given
region or the number of different species in a particular place. High
diversity usually means a more stable and less easily disturbed ecosystem.
downwelling - In oceanography, the replacement of deep waters by
surface waters moving down because of a change in temperature or more rarely
salinity. Downwelling may bring waters rich in oxygen to the deeper parts of
the ocean or lake.
draft - The distance below the water
level (sea level) the bottom of an iceberg reaches. In some cases, icebergs
are blown into shallow waters by storms and the bottom ploughs into the ocean
causing the iceberg to get stuck. Draft also refers to how far below the water
line the keel of a ship reaches and so determines how close into shore the
ship can go.
E
East Wind Drift (Antarctic Coastal Current) - Westward
flowing ocean surface current that flows anti-clockwise around Antarctica,
driven by the polar easterlies.
easterlies - Winds that blow from the east (yup-really). The polar
easterlies blow close to the continent and help move the ocean surface
currents known as the east wind drift.
ecology - The study of the abundance of organisms in an ecosystem and
the relationships between the organisms and their environment.
ecosystem - A particular environment, large or small, with characteristic
physical conditions and types of organisms living there.
elevation - The height of an object or
area above a particular reference point, usually the height above sea level.
evaporation - Change in state from a liquid or a solid to a gas.
Evaporation takes place most quickly in an arid or dry environment when there
is little or no water vapour in the air. Antarctica is arid and solid ice can
"evaporate" or turn into a gas, particularly if a (relatively) warm
wind blows across a snow or ice field. The change from a solid directly to a
gas is properly called sublimation - like the "smoke" you get when
you open the freezer door.
extraordinary Katabatic wind - Katabatic wind that is particularly
long-lasting (days to even weeks) and remains fairly constant in strength
during that time.
F
fast ice - Sea ice that forms in situ along
the coastline and remains attached.
fauna - Animals. Antarctic fauna includes seals, penguins, whales,
krill, ice-fish, nematode worms, mites, and wingless midges (plus a few other
animals). Also sometimes used in the phrase "charismatic mega-fauna"
large animals with charisma - penguins, seals, whales
finnesko - Boots made entirely from fur
including the sole. Originally an Inuit item of clothing, no longer in use,
much used in the heroic age of Arctic and Antarctic exploration. Packed with
sennegrass, a dried grass for additional insulation.
firn - A transitional stage between snow and glacial ice, a type of
snow that has survived a summer melting season and has become more compact
than freshly falling snow.
fissure - A long, very deep, narrow
opening, sometimes used instead of crevasse.
fjord (fiord) - A long, narrow, steep-walled, u-shaped coastal
inlet. Fjords typically have been excavated by glaciers.
flora - Plants. Fairly limited in Antarctica,
mainly mosses.
frazil ice - Ice crystals in the water
column, usually near the water surface. Frazil ice crystals are not oriented
in an organized manner, and have the appearance of slush or separated needles, diving through
frazil ice you can see that below the main body, the crystals are quite large
and separate. The first stage in the formation of sea ice.
frost smoke - Condensed water vapour
that forms as a mist above any open sea water in very cold weather.
G
gale - A strong wind. On the Beaufort Scale
- used to gauge the speed of the wind, a gale has winds of 39 to 46 miles per
hour (62 to 74 kilometres per hour). Gales can break twigs off trees (not that
you can tell in Antarctica) and make walking very difficult. Gales are common
in Antarctica.
geology - The study of Earth, the
history of the rocks, what processes that have occurred and are occurring on
and within it (to the rocks).
geomagnetic pole - If
the Earth's molten metallic core is imagined to be a giant bar magnet, the
Geomagnetic Pole is where you would expect the magnetic field lines to
converge. But ocean currents, mountains and solar activity mess things up,
similar to how a compass can be confused if you hold it near something metal.
Because of this while the geomagnetic pole is where the needle of a compass should
point straight downwards, it is the magnetic pole where this is actually the
case. The Magnetic Pole can move many kilometres in a day, whereas the
Geomagnetic Pole moves much more slowly.
The geomagnetic poles aren't fixed and
wander about, currently the south geomagnetic pole is about 1160 kilometres
(725 miles) north (think about it) of the south geographic pole (close to the
Russian Vostok Station).
With thanks to Glenn Grant - 60South.com
geophysics - The study of the physical properties of Earth as a planet.
Geophysicists may study the interior of the Earth, the geomagnetic field of
the Earth, or the Earth's gravity field. Most of the work is done using very
high tech equipment and requires much translation to be understood by normal
people.
geothermal - Geo - earth, thermal - heat. Heat generated within the
interior of Earth. Visible indications of geothermal activity are geysers when
underground water comes into contact with a heat source, such as hot rocks
near a volcano. In Antarctica, Deception Island is geothermally active, there
are also thought to be several regions on the continent where glaciers are
melted from below by geothermal heat making them flow more quickly at those
regions.
glacial erosion - The wearing down of
the Earth's surface by glaciers. Rock debris at the bottom of a glacier
scrapes and erodes the surface over which the glacier flows like a giant
hugely heavy piece of sand paper.
glaciation - The formation, activity,
and retreat of glaciers through time. The glaciation of a region refers to the
growth of ice over that region. Large parts of the Northern Hemisphere
experienced glaciation in the past - ice ages.
glacier - A river of ice. Usually a mixture of ice, air, water, and
rock debris formed at least partially on land. They are large enough for the
ice to flow with gravity. Glaciers can be small valley glaciers, ice
streams, ice caps, and ice sheets. The term glacier also includes ice shelves
if they are fed by glaciers. Freshwater.
glaciology - The study of the physical and chemical properties of snow
and ice, not necessarily just of glaciers. Glaciologists might study the
movement of ice sheets, and how ice flows. Also the study of how snow slowly
changes to glacier ice.
glaze - A smooth, clear coat of ice.
grease ice - A thin layer of ice crystals beginning to show
organization on the water surface with a greasy appearance and like a slush
puppy in consistency.
grounding line - The point a glacier that is flowing into a sea or lake
loses contact with seafloor and begins to float as an ice shelf.
H
hanging valley - A u-shaped valley that
joins the wall of a larger valley. The smaller valley floor "hangs"
above the larger valley floor. Hanging valleys are made by valley glaciers
carving out a path, when the glacier was active the smaller valley glacier
would have flowed into the larger valley glacier.
heat reservoir - Places where heat is
absorbed and then distributed slowly to the surroundings. Oceans and other
large bodies of water act as heat reservoirs. They absorb heat and slowly pass
it to the atmosphere. This is one reason why coastal areas and islands never
get as cold as areas inland in winter. The heat doesn't have to be very great,
the sea can still seem very cold, as long as it is above the surrounding air
temperature, heat will be transferred.
highs (high pressure zones) - Places
where the the atmospheric pressure is above the surrounding region. Clear
weather often accompanies high pressure systems.
hoarfrost - A light, feathery ice coating built up from water particles
in the air crystallizing out into tiny ice sculptures (you have to look
carefully).
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