- The removal of material from a glacier, melting, evaporation,
or calving (bits dropping off the end into the sea to form icebergs).
Opposite of accumulation.
ablation zone - That
portion of a glacier where more material is lost (by melting
or evaporation) than gained by snowfall.
- The deep ocean plain, a relatively flat part of the ocean
floor lying at depths between 3500 meters (11,480 feet / 2.2
miles down) and greater than 6000 meters (19,680 feet / 3.7
miles down). This region is dark, cold (and very gloomy) subject
to little or very slow water movements and very stable.
- The addition of material to glaciers, snow, rain, material
blown by wind, and avalanches. Opposite of ablation.
accumulation zone - The region of the glacier where mass
is only added (as snow or rain), no mass is lost. Usually this
area is near the origin of the glacier at higher altitudes.
- How reflective a surface is. High albedo means that much of
the incoming radiation is reflected (for example snow and ice);
low albedo means that much of the incoming radiation is absorbed
(for example water).
algae - A plant group that
compose the majority or all of the phytoplankton in bodies of
water, mostly unicellular though there are multicellular forms
such as kelp. Algae can form lichens in a symbiotic relationship
Antarctic Bottom Water - The coldest
and densest water mass in the global oceans. Formed in particular
places on the Antarctic continental shelf such as Weddell Sea
and Ross Sea when surface water cools and becomes more dense
and so sinks to the ocean floor. Once formed it tends to flow
northwards hugging the seafloor. It can be traced into many
ocean basins, including parts of the North Atlantic Ocean.
Trough - An atmospheric feature located between 60°S
and 65°S. A zone of low pressure that causes variable winds
moving from west to east and responsible for the "Screaming
sixties" as known to seamen.
(Polar Front) - A surface boundary where which the colder,
north flowing Antarctic Surface Waters sink beneath warmer circulating
waters. This marks a change in the oceans surface temperature
and also chemical composition. North of the convergence, the
area is known as the sub-Antarctic.
Very dry. An area with little rain or precipitation of any kind
(snow, hail, sleet etc.) usually less than 25 centimetres (10
inches) of annual rainfall, Antarctica is largely classed as
arthropod - A group of invertebrates with
hard exoskeletons and jointed limbs such as insects, spiders,
and crustaceans (shrimps, crabs, lobsters).
- The gases that surround a planet. Earth's atmosphere consists
of about 20% oxygen and 79% nitrogen with smaller amounts of
other gases. "Atmosphere" is also used as a unit for
the measurement of pressure. One atmosphere equals 14.7 pounds
per square inch being the pressure due to the mass of the gases
acting on the earth at sea level.
- Movement within the atmosphere, winds and air currents, caused
by differences in pressure from one region to another. Air moves
from a region of high pressure where it is "piled up"
to "thinner" areas of low pressure.
pressure - The amount of pressure exerted by the atmosphere
at a given point (force per unit area). Essentially the effect
of the mass of the air above a particular point being pulled
down by gravity
sciences - The study of the atmosphere, of the envelope
of gases that surround the Earth. Atmospheric science include
meteorology and climatology.
aurora - The display
of "dancing" light patterns seen in areas of high
latitudes - nearer the poles. Auroras are caused by magnetic
storms from the sun releasing huge amounts of energy. The energy
travels toward the Earth as an ionic cloud. On reaching the
earth, the cloud "blows" over the poles and interacts
with Earth's magnetic field. The ions interact with the
ionosphere energize oxygen and nitrogen molecules which causes
them to emit light.
Anything in the
northern hemisphere is referred to as "Boreal", in
the southern hemisphere as "Austral", hence Aurora
Borealis in the north and Aurora Australis in the south.
- A mass of snow and/or ice detached from where it rested and
slipping down a slope.
An imaginary line through the centre of the Earth, around which
the planet rotates.
- A group of acellular microscopic organisms, bacteria are found
everywhere. Different types may be involved in the decomposition
of organic matter, in making food by photosynthesis, in the
guts of all multicellular organisms, in the deepest ocean and
in Antarctica, even living inside rocks as protection from the
Beaufort scale - A way of measuring
the strength of the wind given as a number or "force":
Beaufort wind scale
Specifications for use on land
Specifications for use at sea
0 - 1 mph
Smoke rises vertically
Sea like a mirror
1 - 3 mph
Direction of wind shown by smoke drift, but
not by wind vanes.
Ripples with the appearance of scales are
formed, but without foam crests.
4 - 8 mph
Wind felt on face, leaves rustle, ordinary
vanes moved by wind.
Small wavelets, still short, but more pronounced.
Crests have a glassy appearance and do not break.
9 - 13 mph
Leaves and small twigs in constant motion,
wind extends light flag.
Large wavelets. Crests begin to break. Foam
of glassy appearance. Perhaps scattered white horses.
14 - 19 mph
Raises dust and loose paper, small branches
Small waves, becoming larger; fairly frequent
20 - 25 mph
Small trees in leaf begin to sway, crested
wavelets form on inland waters.
Moderate waves, taking a more pronounced
long form, many white horses are formed. Chance of some
26 - 32 mph
Large branches in motion, whistling heard
in telegraph wires, umbrellas used with difficulty.
Large waves begin to form, the white foam
crests are more extensive everywhere. Probably some spray.
33 - 41 mph
Whole trees in motion, inconvenience felt
when walking against the wind.
Sea heaps up and white foam from breaking
waves begins to be blown in streaks along the direction
of the wind.
42 - 50 mph
Breaks twigs off trees, generally impedes
Moderately high waves of greater length,
edges of crests begin to break into spindrift. The foam
is blown in well-marked streaks along the direction of the
51 - 61 mph
Slight structural damage occurs (chimney-pots
and slates removed).
High waves. Dense streaks of foam along the
direction of the wind. Crests of waves begin to topple,
tumble and roll over. Spray may affect visibility.
62 - 74 mph
Seldom experienced inland; trees uprooted,
considerable structural damage occurs.
Very high waves with long over- hanging crests.
The resulting foam, in great patches, is blown in dense
white streaks along the direction of the wind. On the whole
the surface of the sea takes on a white appearance. The 'tumbling'
of the sea becomes heavy and shock-like. Visibility affected.
75 - 91 mph
Very rarely experienced; accompanied by wide-spread
Exceptionally high waves (small and medium-size
ships might be for a time lost to view behind the waves).
The sea is completely covered with long white patches of
foam lying along the direction of the wind. Everywhere the
edges of the wave crests are blown into froth. Visibility
92 + mph
The air is filled with foam and spray. Sea
completely white with driving spray; visibility very seriously
- 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".
- The crevasse formed where a glacier meets the solid rock of
a mountain slope, usually very wide and the widest crevasse
on the glacier.
The situation of a ship when closely surrounded by ice on all
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.
- 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.
- 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.
- 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
- 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.
- Thin, wispy high altitude clouds that form at heights of 6
to 12 kilometres (3.8 to 7.6 miles).
- 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
- 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.
- 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.
- 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.
- an anchor board buried deep in snow to secure sledge or night
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.
- 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.
- 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.
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.
- A particular environment, large or small, with characteristic
physical conditions and types of organisms living there.
- The height of an object or area above a particular reference
point, usually the height above sea level.
- 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.
Katabatic wind - Katabatic wind that is particularly long-lasting
(days to even weeks) and remains fairly constant in strength
during that time.
ice - Sea ice that forms in
situ along the coastline and remains attached.
- 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,
- 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.
- A long, very deep, narrow opening, sometimes used instead
fjord (fiord) - A long, narrow,
steep-walled, u-shaped coastal inlet. Fjords typically have
been excavated by glaciers.
Plants. Fairly limited in Antarctica, mainly mosses.
- 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.
- Condensed water vapour that forms as a mist above any open
sea water in very cold weather.
- a snow vehicle withtracks, ie Muskeg
G.A. / general assistant
- a position with British Antarctic Survey, actually quite a
specific assistant as these are people with advanced mountaineering
skills and experience who accompany those without (i.e. scientists)
on extended trips of weeks or even a month or two or three in
the field to carry out field work. The G.A.'s job is to make
sure the scientist is able to do his scientific duties as un-hindered
as possible and also to protect him from Antarctica (and possibly
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
- The study of Earth, the history of the rocks, what processes
that have occurred and are occurring on and within it (to the
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.
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 -
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.
- 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.
- 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.
- 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.
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
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.
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
- 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.
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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